Pull vfs name lookup updates from Al Viro:
"Small namei.c patch series, mostly to simplify the rules for nameidata
state. It's actually from the previous cycle - but I didn't post it
for review in time...
Changes visible outside of fs/namei.c: file_open_root() calling
conventions change, some freed bits in LOOKUP_... space"
* 'work.namei' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
namei: make sure nd->depth is always valid
teach set_nameidata() to handle setting the root as well
take LOOKUP_{ROOT,ROOT_GRABBED,JUMPED} out of LOOKUP_... space
switch file_open_root() to struct path
The function name should be modified to register_sysctl_paths instead of
register_sysctl_table_path.
Link: https://lkml.kernel.org/r/1615807194-79646-1-git-send-email-zhouchuangao@vivo.com
Signed-off-by: zhouchuangao <zhouchuangao@vivo.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
- Evaluate $(call cc-option,...) etc. only for build targets
- Add CONFIG_VMLINUX_MAP to generate .map file when linking vmlinux
- Remove unnecessary --gcc-toolchains Clang flag because the --prefix
flag finds the toolchains
- Do not pass Clang's --prefix flag when using the integrated as
- Check the assembler version in Kconfig time
- Add new CONFIG options, AS_VERSION, AS_IS_GNU, AS_IS_LLVM to clean up
some dependencies in Kconfig
- Fix invalid Module.symvers creation when building only modules without
vmlinux
- Fix false-positive modpost warnings when CONFIG_TRIM_UNUSED_KSYMS is
set, but there is no module to build
- Refactor module installation Makefile
- Support zstd for module compression
- Convert alpha and ia64 to use generic shell scripts to generate the
syscall headers
- Add a new elfnote to indicate if the kernel was built with LTO, which
will be used by pahole
- Flatten the directory structure under include/config/ so CONFIG options
and filenames match
- Change the deb source package name from linux-$(KERNELRELEASE) to
linux-upstream
-----BEGIN PGP SIGNATURE-----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=ti9L
-----END PGP SIGNATURE-----
Merge tag 'kbuild-v5.13' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild
Pull Kbuild updates from Masahiro Yamada:
- Evaluate $(call cc-option,...) etc. only for build targets
- Add CONFIG_VMLINUX_MAP to generate .map file when linking vmlinux
- Remove unnecessary --gcc-toolchains Clang flag because the --prefix
flag finds the toolchains
- Do not pass Clang's --prefix flag when using the integrated as
- Check the assembler version in Kconfig time
- Add new CONFIG options, AS_VERSION, AS_IS_GNU, AS_IS_LLVM to clean up
some dependencies in Kconfig
- Fix invalid Module.symvers creation when building only modules
without vmlinux
- Fix false-positive modpost warnings when CONFIG_TRIM_UNUSED_KSYMS is
set, but there is no module to build
- Refactor module installation Makefile
- Support zstd for module compression
- Convert alpha and ia64 to use generic shell scripts to generate the
syscall headers
- Add a new elfnote to indicate if the kernel was built with LTO, which
will be used by pahole
- Flatten the directory structure under include/config/ so CONFIG
options and filenames match
- Change the deb source package name from linux-$(KERNELRELEASE) to
linux-upstream
* tag 'kbuild-v5.13' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild: (42 commits)
kbuild: Add $(KBUILD_HOSTLDFLAGS) to 'has_libelf' test
kbuild: deb-pkg: change the source package name to linux-upstream
tools: do not include scripts/Kbuild.include
kbuild: redo fake deps at include/config/*.h
kbuild: remove TMPO from try-run
MAINTAINERS: add pattern for dummy-tools
kbuild: add an elfnote for whether vmlinux is built with lto
ia64: syscalls: switch to generic syscallhdr.sh
ia64: syscalls: switch to generic syscalltbl.sh
alpha: syscalls: switch to generic syscallhdr.sh
alpha: syscalls: switch to generic syscalltbl.sh
sysctl: use min() helper for namecmp()
kbuild: add support for zstd compressed modules
kbuild: remove CONFIG_MODULE_COMPRESS
kbuild: merge scripts/Makefile.modsign to scripts/Makefile.modinst
kbuild: move module strip/compression code into scripts/Makefile.modinst
kbuild: refactor scripts/Makefile.modinst
kbuild: rename extmod-prefix to extmod_prefix
kbuild: check module name conflict for external modules as well
kbuild: show the target directory for depmod log
...
Networking has many sysctls that could fit in one u8.
This patch adds proc_dou8vec_minmax() for this purpose.
Note that the .extra1 and .extra2 fields are pointing
to integers, because it makes conversions easier.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Since
sysctl: pass kernel pointers to ->proc_handler
we have been pre-allocating a buffer to copy the data from the proc
handlers into, and then copying that to userspace. The problem is this
just blindly kzalloc()'s the buffer size passed in from the read, which in
the case of our 'cat' binary was 64kib. Order-4 allocations are not
awesome, and since we can potentially allocate up to our maximum order, so
use kvzalloc for these buffers.
[willy@infradead.org: changelog tweaks]
Link: https://lkml.kernel.org/r/6345270a2c1160b89dd5e6715461f388176899d1.1612972413.git.josef@toxicpanda.com
Fixes: 32927393dc ("sysctl: pass kernel pointers to ->proc_handler")
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
CC: Matthew Wilcox <willy@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
-----BEGIN PGP SIGNATURE-----
iHUEABYKAB0WIQRAhzRXHqcMeLMyaSiRxhvAZXjcogUCYCegywAKCRCRxhvAZXjc
ouJ6AQDlf+7jCQlQdeKKoN9QDFfMzG1ooemat36EpRRTONaGuAD8D9A4sUsG4+5f
4IU5Lj9oY4DEmF8HenbWK2ZHsesL2Qg=
=yPaw
-----END PGP SIGNATURE-----
Merge tag 'idmapped-mounts-v5.12' of git://git.kernel.org/pub/scm/linux/kernel/git/brauner/linux
Pull idmapped mounts from Christian Brauner:
"This introduces idmapped mounts which has been in the making for some
time. Simply put, different mounts can expose the same file or
directory with different ownership. This initial implementation comes
with ports for fat, ext4 and with Christoph's port for xfs with more
filesystems being actively worked on by independent people and
maintainers.
Idmapping mounts handle a wide range of long standing use-cases. Here
are just a few:
- Idmapped mounts make it possible to easily share files between
multiple users or multiple machines especially in complex
scenarios. For example, idmapped mounts will be used in the
implementation of portable home directories in
systemd-homed.service(8) where they allow users to move their home
directory to an external storage device and use it on multiple
computers where they are assigned different uids and gids. This
effectively makes it possible to assign random uids and gids at
login time.
- It is possible to share files from the host with unprivileged
containers without having to change ownership permanently through
chown(2).
- It is possible to idmap a container's rootfs and without having to
mangle every file. For example, Chromebooks use it to share the
user's Download folder with their unprivileged containers in their
Linux subsystem.
- It is possible to share files between containers with
non-overlapping idmappings.
- Filesystem that lack a proper concept of ownership such as fat can
use idmapped mounts to implement discretionary access (DAC)
permission checking.
- They allow users to efficiently changing ownership on a per-mount
basis without having to (recursively) chown(2) all files. In
contrast to chown (2) changing ownership of large sets of files is
instantenous with idmapped mounts. This is especially useful when
ownership of a whole root filesystem of a virtual machine or
container is changed. With idmapped mounts a single syscall
mount_setattr syscall will be sufficient to change the ownership of
all files.
- Idmapped mounts always take the current ownership into account as
idmappings specify what a given uid or gid is supposed to be mapped
to. This contrasts with the chown(2) syscall which cannot by itself
take the current ownership of the files it changes into account. It
simply changes the ownership to the specified uid and gid. This is
especially problematic when recursively chown(2)ing a large set of
files which is commong with the aforementioned portable home
directory and container and vm scenario.
- Idmapped mounts allow to change ownership locally, restricting it
to specific mounts, and temporarily as the ownership changes only
apply as long as the mount exists.
Several userspace projects have either already put up patches and
pull-requests for this feature or will do so should you decide to pull
this:
- systemd: In a wide variety of scenarios but especially right away
in their implementation of portable home directories.
https://systemd.io/HOME_DIRECTORY/
- container runtimes: containerd, runC, LXD:To share data between
host and unprivileged containers, unprivileged and privileged
containers, etc. The pull request for idmapped mounts support in
containerd, the default Kubernetes runtime is already up for quite
a while now: https://github.com/containerd/containerd/pull/4734
- The virtio-fs developers and several users have expressed interest
in using this feature with virtual machines once virtio-fs is
ported.
- ChromeOS: Sharing host-directories with unprivileged containers.
I've tightly synced with all those projects and all of those listed
here have also expressed their need/desire for this feature on the
mailing list. For more info on how people use this there's a bunch of
talks about this too. Here's just two recent ones:
https://www.cncf.io/wp-content/uploads/2020/12/Rootless-Containers-in-Gitpod.pdfhttps://fosdem.org/2021/schedule/event/containers_idmap/
This comes with an extensive xfstests suite covering both ext4 and
xfs:
https://git.kernel.org/brauner/xfstests-dev/h/idmapped_mounts
It covers truncation, creation, opening, xattrs, vfscaps, setid
execution, setgid inheritance and more both with idmapped and
non-idmapped mounts. It already helped to discover an unrelated xfs
setgid inheritance bug which has since been fixed in mainline. It will
be sent for inclusion with the xfstests project should you decide to
merge this.
In order to support per-mount idmappings vfsmounts are marked with
user namespaces. The idmapping of the user namespace will be used to
map the ids of vfs objects when they are accessed through that mount.
By default all vfsmounts are marked with the initial user namespace.
The initial user namespace is used to indicate that a mount is not
idmapped. All operations behave as before and this is verified in the
testsuite.
Based on prior discussions we want to attach the whole user namespace
and not just a dedicated idmapping struct. This allows us to reuse all
the helpers that already exist for dealing with idmappings instead of
introducing a whole new range of helpers. In addition, if we decide in
the future that we are confident enough to enable unprivileged users
to setup idmapped mounts the permission checking can take into account
whether the caller is privileged in the user namespace the mount is
currently marked with.
The user namespace the mount will be marked with can be specified by
passing a file descriptor refering to the user namespace as an
argument to the new mount_setattr() syscall together with the new
MOUNT_ATTR_IDMAP flag. The system call follows the openat2() pattern
of extensibility.
The following conditions must be met in order to create an idmapped
mount:
- The caller must currently have the CAP_SYS_ADMIN capability in the
user namespace the underlying filesystem has been mounted in.
- The underlying filesystem must support idmapped mounts.
- The mount must not already be idmapped. This also implies that the
idmapping of a mount cannot be altered once it has been idmapped.
- The mount must be a detached/anonymous mount, i.e. it must have
been created by calling open_tree() with the OPEN_TREE_CLONE flag
and it must not already have been visible in the filesystem.
The last two points guarantee easier semantics for userspace and the
kernel and make the implementation significantly simpler.
By default vfsmounts are marked with the initial user namespace and no
behavioral or performance changes are observed.
The manpage with a detailed description can be found here:
1d7b902e28
In order to support idmapped mounts, filesystems need to be changed
and mark themselves with the FS_ALLOW_IDMAP flag in fs_flags. The
patches to convert individual filesystem are not very large or
complicated overall as can be seen from the included fat, ext4, and
xfs ports. Patches for other filesystems are actively worked on and
will be sent out separately. The xfstestsuite can be used to verify
that port has been done correctly.
The mount_setattr() syscall is motivated independent of the idmapped
mounts patches and it's been around since July 2019. One of the most
valuable features of the new mount api is the ability to perform
mounts based on file descriptors only.
Together with the lookup restrictions available in the openat2()
RESOLVE_* flag namespace which we added in v5.6 this is the first time
we are close to hardened and race-free (e.g. symlinks) mounting and
path resolution.
While userspace has started porting to the new mount api to mount
proper filesystems and create new bind-mounts it is currently not
possible to change mount options of an already existing bind mount in
the new mount api since the mount_setattr() syscall is missing.
With the addition of the mount_setattr() syscall we remove this last
restriction and userspace can now fully port to the new mount api,
covering every use-case the old mount api could. We also add the
crucial ability to recursively change mount options for a whole mount
tree, both removing and adding mount options at the same time. This
syscall has been requested multiple times by various people and
projects.
There is a simple tool available at
https://github.com/brauner/mount-idmapped
that allows to create idmapped mounts so people can play with this
patch series. I'll add support for the regular mount binary should you
decide to pull this in the following weeks:
Here's an example to a simple idmapped mount of another user's home
directory:
u1001@f2-vm:/$ sudo ./mount --idmap both:1000:1001:1 /home/ubuntu/ /mnt
u1001@f2-vm:/$ ls -al /home/ubuntu/
total 28
drwxr-xr-x 2 ubuntu ubuntu 4096 Oct 28 22:07 .
drwxr-xr-x 4 root root 4096 Oct 28 04:00 ..
-rw------- 1 ubuntu ubuntu 3154 Oct 28 22:12 .bash_history
-rw-r--r-- 1 ubuntu ubuntu 220 Feb 25 2020 .bash_logout
-rw-r--r-- 1 ubuntu ubuntu 3771 Feb 25 2020 .bashrc
-rw-r--r-- 1 ubuntu ubuntu 807 Feb 25 2020 .profile
-rw-r--r-- 1 ubuntu ubuntu 0 Oct 16 16:11 .sudo_as_admin_successful
-rw------- 1 ubuntu ubuntu 1144 Oct 28 00:43 .viminfo
u1001@f2-vm:/$ ls -al /mnt/
total 28
drwxr-xr-x 2 u1001 u1001 4096 Oct 28 22:07 .
drwxr-xr-x 29 root root 4096 Oct 28 22:01 ..
-rw------- 1 u1001 u1001 3154 Oct 28 22:12 .bash_history
-rw-r--r-- 1 u1001 u1001 220 Feb 25 2020 .bash_logout
-rw-r--r-- 1 u1001 u1001 3771 Feb 25 2020 .bashrc
-rw-r--r-- 1 u1001 u1001 807 Feb 25 2020 .profile
-rw-r--r-- 1 u1001 u1001 0 Oct 16 16:11 .sudo_as_admin_successful
-rw------- 1 u1001 u1001 1144 Oct 28 00:43 .viminfo
u1001@f2-vm:/$ touch /mnt/my-file
u1001@f2-vm:/$ setfacl -m u:1001:rwx /mnt/my-file
u1001@f2-vm:/$ sudo setcap -n 1001 cap_net_raw+ep /mnt/my-file
u1001@f2-vm:/$ ls -al /mnt/my-file
-rw-rwxr--+ 1 u1001 u1001 0 Oct 28 22:14 /mnt/my-file
u1001@f2-vm:/$ ls -al /home/ubuntu/my-file
-rw-rwxr--+ 1 ubuntu ubuntu 0 Oct 28 22:14 /home/ubuntu/my-file
u1001@f2-vm:/$ getfacl /mnt/my-file
getfacl: Removing leading '/' from absolute path names
# file: mnt/my-file
# owner: u1001
# group: u1001
user::rw-
user:u1001:rwx
group::rw-
mask::rwx
other::r--
u1001@f2-vm:/$ getfacl /home/ubuntu/my-file
getfacl: Removing leading '/' from absolute path names
# file: home/ubuntu/my-file
# owner: ubuntu
# group: ubuntu
user::rw-
user:ubuntu:rwx
group::rw-
mask::rwx
other::r--"
* tag 'idmapped-mounts-v5.12' of git://git.kernel.org/pub/scm/linux/kernel/git/brauner/linux: (41 commits)
xfs: remove the possibly unused mp variable in xfs_file_compat_ioctl
xfs: support idmapped mounts
ext4: support idmapped mounts
fat: handle idmapped mounts
tests: add mount_setattr() selftests
fs: introduce MOUNT_ATTR_IDMAP
fs: add mount_setattr()
fs: add attr_flags_to_mnt_flags helper
fs: split out functions to hold writers
namespace: only take read lock in do_reconfigure_mnt()
mount: make {lock,unlock}_mount_hash() static
namespace: take lock_mount_hash() directly when changing flags
nfs: do not export idmapped mounts
overlayfs: do not mount on top of idmapped mounts
ecryptfs: do not mount on top of idmapped mounts
ima: handle idmapped mounts
apparmor: handle idmapped mounts
fs: make helpers idmap mount aware
exec: handle idmapped mounts
would_dump: handle idmapped mounts
...
The process_sysctl_arg() does not check whether val is empty before
invoking strlen(val). If the command line parameter () is incorrectly
configured and val is empty, oops is triggered.
For example:
"hung_task_panic=1" is incorrectly written as "hung_task_panic", oops is
triggered. The call stack is as follows:
Kernel command line: .... hung_task_panic
......
Call trace:
__pi_strlen+0x10/0x98
parse_args+0x278/0x344
do_sysctl_args+0x8c/0xfc
kernel_init+0x5c/0xf4
ret_from_fork+0x10/0x30
To fix it, check whether "val" is empty when "phram" is a sysctl field.
Error codes are returned in the failure branch, and error logs are
generated by parse_args().
Link: https://lkml.kernel.org/r/20210118133029.28580-1-nixiaoming@huawei.com
Fixes: 3db978d480 ("kernel/sysctl: support setting sysctl parameters from kernel command line")
Signed-off-by: Xiaoming Ni <nixiaoming@huawei.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Luis Chamberlain <mcgrof@kernel.org>
Cc: Kees Cook <keescook@chromium.org>
Cc: Iurii Zaikin <yzaikin@google.com>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Heiner Kallweit <hkallweit1@gmail.com>
Cc: Randy Dunlap <rdunlap@infradead.org>
Cc: <stable@vger.kernel.org> [5.8+]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Extend some inode methods with an additional user namespace argument. A
filesystem that is aware of idmapped mounts will receive the user
namespace the mount has been marked with. This can be used for
additional permission checking and also to enable filesystems to
translate between uids and gids if they need to. We have implemented all
relevant helpers in earlier patches.
As requested we simply extend the exisiting inode method instead of
introducing new ones. This is a little more code churn but it's mostly
mechanical and doesnt't leave us with additional inode methods.
Link: https://lore.kernel.org/r/20210121131959.646623-25-christian.brauner@ubuntu.com
Cc: Christoph Hellwig <hch@lst.de>
Cc: David Howells <dhowells@redhat.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: linux-fsdevel@vger.kernel.org
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com>
The generic_fillattr() helper fills in the basic attributes associated
with an inode. Enable it to handle idmapped mounts. If the inode is
accessed through an idmapped mount map it into the mount's user
namespace before we store the uid and gid. If the initial user namespace
is passed nothing changes so non-idmapped mounts will see identical
behavior as before.
Link: https://lore.kernel.org/r/20210121131959.646623-12-christian.brauner@ubuntu.com
Cc: Christoph Hellwig <hch@lst.de>
Cc: David Howells <dhowells@redhat.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: linux-fsdevel@vger.kernel.org
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: James Morris <jamorris@linux.microsoft.com>
Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com>
When file attributes are changed most filesystems rely on the
setattr_prepare(), setattr_copy(), and notify_change() helpers for
initialization and permission checking. Let them handle idmapped mounts.
If the inode is accessed through an idmapped mount map it into the
mount's user namespace. Afterwards the checks are identical to
non-idmapped mounts. If the initial user namespace is passed nothing
changes so non-idmapped mounts will see identical behavior as before.
Helpers that perform checks on the ia_uid and ia_gid fields in struct
iattr assume that ia_uid and ia_gid are intended values and have already
been mapped correctly at the userspace-kernelspace boundary as we
already do today. If the initial user namespace is passed nothing
changes so non-idmapped mounts will see identical behavior as before.
Link: https://lore.kernel.org/r/20210121131959.646623-8-christian.brauner@ubuntu.com
Cc: Christoph Hellwig <hch@lst.de>
Cc: David Howells <dhowells@redhat.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: linux-fsdevel@vger.kernel.org
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com>
Using the read_iter/write_iter interfaces allows for in-kernel users
to set sysctls without using set_fs(). Also, the buffer is a string,
so give it the real type of 'char *', not void *.
[AV: Christoph's fixup folded in]
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
This error path returned directly instead of calling sysctl_head_finish().
Fixes: ef9d965bc8 ("sysctl: reject gigantic reads/write to sysctl files")
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Pull sysctl fixes from Al Viro:
"Fixups to regressions in sysctl series"
* 'work.sysctl' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
sysctl: reject gigantic reads/write to sysctl files
cdrom: fix an incorrect __user annotation on cdrom_sysctl_info
trace: fix an incorrect __user annotation on stack_trace_sysctl
random: fix an incorrect __user annotation on proc_do_entropy
net/sysctl: remove leftover __user annotations on neigh_proc_dointvec*
net/sysctl: use cpumask_parse in flow_limit_cpu_sysctl
Instead of triggering a WARN_ON deep down in the page allocator just
give up early on allocations that are way larger than the usual sysctl
values.
Fixes: 32927393dc ("sysctl: pass kernel pointers to ->proc_handler")
Reported-by: Vegard Nossum <vegard.nossum@oracle.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
After a recent change introduced by Vlastimil's series [0], kernel is
able now to handle sysctl parameters on kernel command line; also, the
series introduced a simple infrastructure to convert legacy boot
parameters (that duplicate sysctls) into sysctl aliases.
This patch converts the watchdog parameters softlockup_panic and
{hard,soft}lockup_all_cpu_backtrace to use the new alias infrastructure.
It fixes the documentation too, since the alias only accepts values 0 or
1, not the full range of integers.
We also took the opportunity here to improve the documentation of the
previously converted hung_task_panic (see the patch series [0]) and put
the alias table in alphabetical order.
[0] http://lkml.kernel.org/r/20200427180433.7029-1-vbabka@suse.cz
Signed-off-by: Guilherme G. Piccoli <gpiccoli@canonical.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Kees Cook <keescook@chromium.org>
Cc: Iurii Zaikin <yzaikin@google.com>
Cc: Luis Chamberlain <mcgrof@kernel.org>
Link: http://lkml.kernel.org/r/20200507214624.21911-1-gpiccoli@canonical.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
We can now handle sysctl parameters on kernel command line and have
infrastructure to convert legacy command line options that duplicate
sysctl to become a sysctl alias.
This patch converts the hung_task_panic parameter. Note that the sysctl
handler is more strict and allows only 0 and 1, while the legacy
parameter allowed any non-zero value. But there is little reason anyone
would not be using 1.
Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Kees Cook <keescook@chromium.org>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Cc: Christian Brauner <christian.brauner@ubuntu.com>
Cc: David Rientjes <rientjes@google.com>
Cc: "Eric W . Biederman" <ebiederm@xmission.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: "Guilherme G . Piccoli" <gpiccoli@canonical.com>
Cc: Iurii Zaikin <yzaikin@google.com>
Cc: Ivan Teterevkov <ivan.teterevkov@nutanix.com>
Cc: Luis Chamberlain <mcgrof@kernel.org>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/20200427180433.7029-4-vbabka@suse.cz
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
We can now handle sysctl parameters on kernel command line, but
historically some parameters introduced their own command line
equivalent, which we don't want to remove for compatibility reasons.
We can, however, convert them to the generic infrastructure with a table
translating the legacy command line parameters to their sysctl names,
and removing the one-off param handlers.
This patch adds the support and makes the first conversion to
demonstrate it, on the (deprecated) numa_zonelist_order parameter.
Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Luis Chamberlain <mcgrof@kernel.org>
Acked-by: Kees Cook <keescook@chromium.org>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Cc: Christian Brauner <christian.brauner@ubuntu.com>
Cc: David Rientjes <rientjes@google.com>
Cc: "Eric W . Biederman" <ebiederm@xmission.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: "Guilherme G . Piccoli" <gpiccoli@canonical.com>
Cc: Iurii Zaikin <yzaikin@google.com>
Cc: Ivan Teterevkov <ivan.teterevkov@nutanix.com>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/20200427180433.7029-3-vbabka@suse.cz
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Patch series "support setting sysctl parameters from kernel command line", v3.
This series adds support for something that seems like many people
always wanted but nobody added it yet, so here's the ability to set
sysctl parameters via kernel command line options in the form of
sysctl.vm.something=1
The important part is Patch 1. The second, not so important part is an
attempt to clean up legacy one-off parameters that do the same thing as
a sysctl. I don't want to remove them completely for compatibility
reasons, but with generic sysctl support the idea is to remove the
one-off param handlers and treat the parameters as aliases for the
sysctl variants.
I have identified several parameters that mention sysctl counterparts in
Documentation/admin-guide/kernel-parameters.txt but there might be more.
The conversion also has varying level of success:
- numa_zonelist_order is converted in Patch 2 together with adding the
necessary infrastructure. It's easy as it doesn't really do anything
but warn on deprecated value these days.
- hung_task_panic is converted in Patch 3, but there's a downside that
now it only accepts 0 and 1, while previously it was any integer
value
- nmi_watchdog maps to two sysctls nmi_watchdog and hardlockup_panic,
so there's no straighforward conversion possible
- traceoff_on_warning is a flag without value and it would be required
to handle that somehow in the conversion infractructure, which seems
pointless for a single flag
This patch (of 5):
A recently proposed patch to add vm_swappiness command line parameter in
addition to existing sysctl [1] made me wonder why we don't have a
general support for passing sysctl parameters via command line.
Googling found only somebody else wondering the same [2], but I haven't
found any prior discussion with reasons why not to do this.
Settings the vm_swappiness issue aside (the underlying issue might be
solved in a different way), quick search of kernel-parameters.txt shows
there are already some that exist as both sysctl and kernel parameter -
hung_task_panic, nmi_watchdog, numa_zonelist_order, traceoff_on_warning.
A general mechanism would remove the need to add more of those one-offs
and might be handy in situations where configuration by e.g.
/etc/sysctl.d/ is impractical.
Hence, this patch adds a new parse_args() pass that looks for parameters
prefixed by 'sysctl.' and tries to interpret them as writes to the
corresponding sys/ files using an temporary in-kernel procfs mount.
This mechanism was suggested by Eric W. Biederman [3], as it handles
all dynamically registered sysctl tables, even though we don't handle
modular sysctls. Errors due to e.g. invalid parameter name or value
are reported in the kernel log.
The processing is hooked right before the init process is loaded, as
some handlers might be more complicated than simple setters and might
need some subsystems to be initialized. At the moment the init process
can be started and eventually execute a process writing to /proc/sys/
then it should be also fine to do that from the kernel.
Sysctls registered later on module load time are not set by this
mechanism - it's expected that in such scenarios, setting sysctl values
from userspace is practical enough.
[1] https://lore.kernel.org/r/BL0PR02MB560167492CA4094C91589930E9FC0@BL0PR02MB5601.namprd02.prod.outlook.com/
[2] https://unix.stackexchange.com/questions/558802/how-to-set-sysctl-using-kernel-command-line-parameter
[3] https://lore.kernel.org/r/87bloj2skm.fsf@x220.int.ebiederm.org/
Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Luis Chamberlain <mcgrof@kernel.org>
Reviewed-by: Masami Hiramatsu <mhiramat@kernel.org>
Acked-by: Kees Cook <keescook@chromium.org>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Iurii Zaikin <yzaikin@google.com>
Cc: Ivan Teterevkov <ivan.teterevkov@nutanix.com>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: David Rientjes <rientjes@google.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: "Eric W . Biederman" <ebiederm@xmission.com>
Cc: "Guilherme G . Piccoli" <gpiccoli@canonical.com>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Christian Brauner <christian.brauner@ubuntu.com>
Link: http://lkml.kernel.org/r/20200427180433.7029-1-vbabka@suse.cz
Link: http://lkml.kernel.org/r/20200427180433.7029-2-vbabka@suse.cz
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Instead of having all the sysctl handlers deal with user pointers, which
is rather hairy in terms of the BPF interaction, copy the input to and
from userspace in common code. This also means that the strings are
always NUL-terminated by the common code, making the API a little bit
safer.
As most handler just pass through the data to one of the common handlers
a lot of the changes are mechnical.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: Andrey Ignatov <rdna@fb.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
The function d_prune_aliases has the problem that it will only prune
aliases thare are completely unused. It will not remove aliases for
the dcache or even think of removing mounts from the dcache. For that
behavior d_invalidate is needed.
To use d_invalidate replace d_prune_aliases with d_find_alias followed
by d_invalidate and dput.
For completeness the directory and the non-directory cases are
separated because in theory (although not in currently in practice for
proc) directories can only ever have a single dentry while
non-directories can have hardlinks and thus multiple dentries.
As part of this separation use d_find_any_alias for directories
to spare d_find_alias the extra work of doing that.
Plus the differences between d_find_any_alias and d_find_alias makes
it clear why the directory and non-directory code and not share code.
To make it clear these routines now invalidate dentries rename
proc_prune_siblings_dache to proc_invalidate_siblings_dcache, and rename
proc_sys_prune_dcache proc_sys_invalidate_dcache.
V2: Split the directory and non-directory cases. To make this
code robust to future changes in proc.
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
This prepares the way for allowing the pid part of proc to use this
dcache pruning code as well.
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
I about to need and use the same functionality for pid based
inodes and there is no point in adding a second field when
this field is already here and serving the same purporse.
Just give the field a generic name so it is clear that
it is no longer sysctl specific.
Also for good measure initialize sibling_inodes when
proc_inode is initialized.
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
In the sysctl code the proc_dointvec_minmax() function is often used to
validate the user supplied value between an allowed range. This
function uses the extra1 and extra2 members from struct ctl_table as
minimum and maximum allowed value.
On sysctl handler declaration, in every source file there are some
readonly variables containing just an integer which address is assigned
to the extra1 and extra2 members, so the sysctl range is enforced.
The special values 0, 1 and INT_MAX are very often used as range
boundary, leading duplication of variables like zero=0, one=1,
int_max=INT_MAX in different source files:
$ git grep -E '\.extra[12].*&(zero|one|int_max)' |wc -l
248
Add a const int array containing the most commonly used values, some
macros to refer more easily to the correct array member, and use them
instead of creating a local one for every object file.
This is the bloat-o-meter output comparing the old and new binary
compiled with the default Fedora config:
# scripts/bloat-o-meter -d vmlinux.o.old vmlinux.o
add/remove: 2/2 grow/shrink: 0/2 up/down: 24/-188 (-164)
Data old new delta
sysctl_vals - 12 +12
__kstrtab_sysctl_vals - 12 +12
max 14 10 -4
int_max 16 - -16
one 68 - -68
zero 128 28 -100
Total: Before=20583249, After=20583085, chg -0.00%
[mcroce@redhat.com: tipc: remove two unused variables]
Link: http://lkml.kernel.org/r/20190530091952.4108-1-mcroce@redhat.com
[akpm@linux-foundation.org: fix net/ipv6/sysctl_net_ipv6.c]
[arnd@arndb.de: proc/sysctl: make firmware loader table conditional]
Link: http://lkml.kernel.org/r/20190617130014.1713870-1-arnd@arndb.de
[akpm@linux-foundation.org: fix fs/eventpoll.c]
Link: http://lkml.kernel.org/r/20190430180111.10688-1-mcroce@redhat.com
Signed-off-by: Matteo Croce <mcroce@redhat.com>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Kees Cook <keescook@chromium.org>
Reviewed-by: Aaron Tomlin <atomlin@redhat.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Normally, the inode's i_uid/i_gid are translated relative to s_user_ns,
but this is not a correct behavior for proc. Since sysctl permission
check in test_perm is done against GLOBAL_ROOT_[UG]ID, it makes more
sense to use these values in u_[ug]id of proc inodes. In other words:
although uid/gid in the inode is not read during test_perm, the inode
logically belongs to the root of the namespace. I have confirmed this
with Eric Biederman at LPC and in this thread:
https://lore.kernel.org/lkml/87k1kzjdff.fsf@xmission.com
Consequences
============
Since the i_[ug]id values of proc nodes are not used for permissions
checks, this change usually makes no functional difference. However, it
causes an issue in a setup where:
* a namespace container is created without root user in container -
hence the i_[ug]id of proc nodes are set to INVALID_[UG]ID
* container creator tries to configure it by writing /proc/sys files,
e.g. writing /proc/sys/kernel/shmmax to configure shared memory limit
Kernel does not allow to open an inode for writing if its i_[ug]id are
invalid, making it impossible to write shmmax and thus - configure the
container.
Using a container with no root mapping is apparently rare, but we do use
this configuration at Google. Also, we use a generic tool to configure
the container limits, and the inability to write any of them causes a
failure.
History
=======
The invalid uids/gids in inodes first appeared due to 8175435777 (fs:
Update i_[ug]id_(read|write) to translate relative to s_user_ns).
However, AFAIK, this did not immediately cause any issues. The
inability to write to these "invalid" inodes was only caused by a later
commit 0bd23d09b8 (vfs: Don't modify inodes with a uid or gid unknown
to the vfs).
Tested: Used a repro program that creates a user namespace without any
mapping and stat'ed /proc/$PID/root/proc/sys/kernel/shmmax from outside.
Before the change, it shows the overflow uid, with the change it's 0.
The overflow uid indicates that the uid in the inode is not correct and
thus it is not possible to open the file for writing.
Link: http://lkml.kernel.org/r/20190708115130.250149-1-rburny@google.com
Fixes: 0bd23d09b8 ("vfs: Don't modify inodes with a uid or gid unknown to the vfs")
Signed-off-by: Radoslaw Burny <rburny@google.com>
Acked-by: Luis Chamberlain <mcgrof@kernel.org>
Cc: Kees Cook <keescook@chromium.org>
Cc: "Eric W . Biederman" <ebiederm@xmission.com>
Cc: Seth Forshee <seth.forshee@canonical.com>
Cc: John Sperbeck <jsperbeck@google.com>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Cc: <stable@vger.kernel.org> [4.8+]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Add file_pos field to bpf_sysctl context to read and write sysctl file
position at which sysctl is being accessed (read or written).
The field can be used to e.g. override whole sysctl value on write to
sysctl even when sys_write is called by user space with file_pos > 0. Or
BPF program may reject such accesses.
Signed-off-by: Andrey Ignatov <rdna@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Add helpers to work with new value being written to sysctl by user
space.
bpf_sysctl_get_new_value() copies value being written to sysctl into
provided buffer.
bpf_sysctl_set_new_value() overrides new value being written by user
space with a one from provided buffer. Buffer should contain string
representation of the value, similar to what can be seen in /proc/sys/.
Both helpers can be used only on sysctl write.
File position matters and can be managed by an interface that will be
introduced separately. E.g. if user space calls sys_write to a file in
/proc/sys/ at file position = X, where X > 0, then the value set by
bpf_sysctl_set_new_value() will be written starting from X. If program
wants to override whole value with specified buffer, file position has
to be set to zero.
Documentation for the new helpers is provided in bpf.h UAPI.
Signed-off-by: Andrey Ignatov <rdna@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Containerized applications may run as root and it may create problems
for whole host. Specifically such applications may change a sysctl and
affect applications in other containers.
Furthermore in existing infrastructure it may not be possible to just
completely disable writing to sysctl, instead such a process should be
gradual with ability to log what sysctl are being changed by a
container, investigate, limit the set of writable sysctl to currently
used ones (so that new ones can not be changed) and eventually reduce
this set to zero.
The patch introduces new program type BPF_PROG_TYPE_CGROUP_SYSCTL and
attach type BPF_CGROUP_SYSCTL to solve these problems on cgroup basis.
New program type has access to following minimal context:
struct bpf_sysctl {
__u32 write;
};
Where @write indicates whether sysctl is being read (= 0) or written (=
1).
Helpers to access sysctl name and value will be introduced separately.
BPF_CGROUP_SYSCTL attach point is added to sysctl code right before
passing control to ctl_table->proc_handler so that BPF program can
either allow or deny access to sysctl.
Suggested-by: Roman Gushchin <guro@fb.com>
Signed-off-by: Andrey Ignatov <rdna@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
proc_sys_lookup can fail with ENOMEM instead of ENOENT when the
corresponding sysctl table is being unregistered. In our case we see
this upon opening /proc/sys/net/*/conf files while network interfaces
are being deleted, which confuses our configuration daemon.
The problem was successfully reproduced and this fix tested on v4.9.122
and v4.20-rc6.
v2: return ERR_PTRs in all cases when proc_sys_make_inode fails instead
of mixing them with NULL. Thanks Al Viro for the feedback.
Fixes: ace0c791e6 ("proc/sysctl: Don't grab i_lock under sysctl_lock.")
Cc: stable@vger.kernel.org
Signed-off-by: Ivan Delalande <colona@arista.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Patch series "ipc: Clamp *mni to the real IPCMNI limit", v3.
The sysctl parameters msgmni, shmmni and semmni have an inherent limit
of IPC_MNI (32k). However, users may not be aware of that because they
can write a value much higher than that without getting any error or
notification. Reading the parameters back will show the newly written
values which are not real.
Enforcing the limit by failing sysctl parameter write, however, can
break existing user applications. To address this delemma, a new flags
field is introduced into the ctl_table. The value CTL_FLAGS_CLAMP_RANGE
can be added to any ctl_table entries to enable a looser range clamping
without returning any error. For example,
.flags = CTL_FLAGS_CLAMP_RANGE,
This flags value are now used for the range checking of shmmni, msgmni
and semmni without breaking existing applications. If any out of range
value is written to those sysctl parameters, the following warning will
be printed instead.
Kernel parameter "shmmni" was set out of range [0, 32768], clamped to 32768.
Reading the values back will show 32768 instead of some fake values.
This patch (of 6):
Fix a typo.
Link: http://lkml.kernel.org/r/1519926220-7453-2-git-send-email-longman@redhat.com
Signed-off-by: Waiman Long <longman@redhat.com>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Acked-by: Luis R. Rodriguez <mcgrof@kernel.org>
Cc: Davidlohr Bueso <dave@stgolabs.net>
Cc: Manfred Spraul <manfred@colorfullife.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
proc_sys_link_fill_cache() does not need to check whether we're called
for a link - it's already done by scan().
Link: http://lkml.kernel.org/r/20180228013506.4915-2-danilokrummrich@dk-develop.de
Signed-off-by: Danilo Krummrich <danilokrummrich@dk-develop.de>
Acked-by: Kees Cook <keescook@chromium.org>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: "Luis R . Rodriguez" <mcgrof@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
proc_sys_link_fill_cache() does not take currently unregistering sysctl
tables into account, which might result into a page fault in
sysctl_follow_link() - add a check to fix it.
This bug has been present since v3.4.
Link: http://lkml.kernel.org/r/20180228013506.4915-1-danilokrummrich@dk-develop.de
Fixes: 0e47c99d7f ("sysctl: Replace root_list with links between sysctl_table_sets")
Signed-off-by: Danilo Krummrich <danilokrummrich@dk-develop.de>
Acked-by: Kees Cook <keescook@chromium.org>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Cc: "Luis R . Rodriguez" <mcgrof@kernel.org>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This is the mindless scripted replacement of kernel use of POLL*
variables as described by Al, done by this script:
for V in IN OUT PRI ERR RDNORM RDBAND WRNORM WRBAND HUP RDHUP NVAL MSG; do
L=`git grep -l -w POLL$V | grep -v '^t' | grep -v /um/ | grep -v '^sa' | grep -v '/poll.h$'|grep -v '^D'`
for f in $L; do sed -i "-es/^\([^\"]*\)\(\<POLL$V\>\)/\\1E\\2/" $f; done
done
with de-mangling cleanups yet to come.
NOTE! On almost all architectures, the EPOLL* constants have the same
values as the POLL* constants do. But they keyword here is "almost".
For various bad reasons they aren't the same, and epoll() doesn't
actually work quite correctly in some cases due to this on Sparc et al.
The next patch from Al will sort out the final differences, and we
should be all done.
Scripted-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Many source files in the tree are missing licensing information, which
makes it harder for compliance tools to determine the correct license.
By default all files without license information are under the default
license of the kernel, which is GPL version 2.
Update the files which contain no license information with the 'GPL-2.0'
SPDX license identifier. The SPDX identifier is a legally binding
shorthand, which can be used instead of the full boiler plate text.
This patch is based on work done by Thomas Gleixner and Kate Stewart and
Philippe Ombredanne.
How this work was done:
Patches were generated and checked against linux-4.14-rc6 for a subset of
the use cases:
- file had no licensing information it it.
- file was a */uapi/* one with no licensing information in it,
- file was a */uapi/* one with existing licensing information,
Further patches will be generated in subsequent months to fix up cases
where non-standard license headers were used, and references to license
had to be inferred by heuristics based on keywords.
The analysis to determine which SPDX License Identifier to be applied to
a file was done in a spreadsheet of side by side results from of the
output of two independent scanners (ScanCode & Windriver) producing SPDX
tag:value files created by Philippe Ombredanne. Philippe prepared the
base worksheet, and did an initial spot review of a few 1000 files.
The 4.13 kernel was the starting point of the analysis with 60,537 files
assessed. Kate Stewart did a file by file comparison of the scanner
results in the spreadsheet to determine which SPDX license identifier(s)
to be applied to the file. She confirmed any determination that was not
immediately clear with lawyers working with the Linux Foundation.
Criteria used to select files for SPDX license identifier tagging was:
- Files considered eligible had to be source code files.
- Make and config files were included as candidates if they contained >5
lines of source
- File already had some variant of a license header in it (even if <5
lines).
All documentation files were explicitly excluded.
The following heuristics were used to determine which SPDX license
identifiers to apply.
- when both scanners couldn't find any license traces, file was
considered to have no license information in it, and the top level
COPYING file license applied.
For non */uapi/* files that summary was:
SPDX license identifier # files
---------------------------------------------------|-------
GPL-2.0 11139
and resulted in the first patch in this series.
If that file was a */uapi/* path one, it was "GPL-2.0 WITH
Linux-syscall-note" otherwise it was "GPL-2.0". Results of that was:
SPDX license identifier # files
---------------------------------------------------|-------
GPL-2.0 WITH Linux-syscall-note 930
and resulted in the second patch in this series.
- if a file had some form of licensing information in it, and was one
of the */uapi/* ones, it was denoted with the Linux-syscall-note if
any GPL family license was found in the file or had no licensing in
it (per prior point). Results summary:
SPDX license identifier # files
---------------------------------------------------|------
GPL-2.0 WITH Linux-syscall-note 270
GPL-2.0+ WITH Linux-syscall-note 169
((GPL-2.0 WITH Linux-syscall-note) OR BSD-2-Clause) 21
((GPL-2.0 WITH Linux-syscall-note) OR BSD-3-Clause) 17
LGPL-2.1+ WITH Linux-syscall-note 15
GPL-1.0+ WITH Linux-syscall-note 14
((GPL-2.0+ WITH Linux-syscall-note) OR BSD-3-Clause) 5
LGPL-2.0+ WITH Linux-syscall-note 4
LGPL-2.1 WITH Linux-syscall-note 3
((GPL-2.0 WITH Linux-syscall-note) OR MIT) 3
((GPL-2.0 WITH Linux-syscall-note) AND MIT) 1
and that resulted in the third patch in this series.
- when the two scanners agreed on the detected license(s), that became
the concluded license(s).
- when there was disagreement between the two scanners (one detected a
license but the other didn't, or they both detected different
licenses) a manual inspection of the file occurred.
- In most cases a manual inspection of the information in the file
resulted in a clear resolution of the license that should apply (and
which scanner probably needed to revisit its heuristics).
- When it was not immediately clear, the license identifier was
confirmed with lawyers working with the Linux Foundation.
- If there was any question as to the appropriate license identifier,
the file was flagged for further research and to be revisited later
in time.
In total, over 70 hours of logged manual review was done on the
spreadsheet to determine the SPDX license identifiers to apply to the
source files by Kate, Philippe, Thomas and, in some cases, confirmation
by lawyers working with the Linux Foundation.
Kate also obtained a third independent scan of the 4.13 code base from
FOSSology, and compared selected files where the other two scanners
disagreed against that SPDX file, to see if there was new insights. The
Windriver scanner is based on an older version of FOSSology in part, so
they are related.
Thomas did random spot checks in about 500 files from the spreadsheets
for the uapi headers and agreed with SPDX license identifier in the
files he inspected. For the non-uapi files Thomas did random spot checks
in about 15000 files.
In initial set of patches against 4.14-rc6, 3 files were found to have
copy/paste license identifier errors, and have been fixed to reflect the
correct identifier.
Additionally Philippe spent 10 hours this week doing a detailed manual
inspection and review of the 12,461 patched files from the initial patch
version early this week with:
- a full scancode scan run, collecting the matched texts, detected
license ids and scores
- reviewing anything where there was a license detected (about 500+
files) to ensure that the applied SPDX license was correct
- reviewing anything where there was no detection but the patch license
was not GPL-2.0 WITH Linux-syscall-note to ensure that the applied
SPDX license was correct
This produced a worksheet with 20 files needing minor correction. This
worksheet was then exported into 3 different .csv files for the
different types of files to be modified.
These .csv files were then reviewed by Greg. Thomas wrote a script to
parse the csv files and add the proper SPDX tag to the file, in the
format that the file expected. This script was further refined by Greg
based on the output to detect more types of files automatically and to
distinguish between header and source .c files (which need different
comment types.) Finally Greg ran the script using the .csv files to
generate the patches.
Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org>
Reviewed-by: Philippe Ombredanne <pombredanne@nexb.com>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Merge yet more updates from Andrew Morton:
- various misc things
- kexec updates
- sysctl core updates
- scripts/gdb udpates
- checkpoint-restart updates
- ipc updates
- kernel/watchdog updates
- Kees's "rough equivalent to the glibc _FORTIFY_SOURCE=1 feature"
- "stackprotector: ascii armor the stack canary"
- more MM bits
- checkpatch updates
* emailed patches from Andrew Morton <akpm@linux-foundation.org>: (96 commits)
writeback: rework wb_[dec|inc]_stat family of functions
ARM: samsung: usb-ohci: move inline before return type
video: fbdev: omap: move inline before return type
video: fbdev: intelfb: move inline before return type
USB: serial: safe_serial: move __inline__ before return type
drivers: tty: serial: move inline before return type
drivers: s390: move static and inline before return type
x86/efi: move asmlinkage before return type
sh: move inline before return type
MIPS: SMP: move asmlinkage before return type
m68k: coldfire: move inline before return type
ia64: sn: pci: move inline before type
ia64: move inline before return type
FRV: tlbflush: move asmlinkage before return type
CRIS: gpio: move inline before return type
ARM: HP Jornada 7XX: move inline before return type
ARM: KVM: move asmlinkage before type
checkpatch: improve the STORAGE_CLASS test
mm, migration: do not trigger OOM killer when migrating memory
drm/i915: use __GFP_RETRY_MAYFAIL
...
To keep parity with regular int interfaces provide the an unsigned int
proc_douintvec_minmax() which allows you to specify a range of allowed
valid numbers.
Adding proc_douintvec_minmax_sysadmin() is easy but we can wait for an
actual user for that.
Link: http://lkml.kernel.org/r/20170519033554.18592-6-mcgrof@kernel.org
Signed-off-by: Luis R. Rodriguez <mcgrof@kernel.org>
Acked-by: Kees Cook <keescook@chromium.org>
Cc: Subash Abhinov Kasiviswanathan <subashab@codeaurora.org>
Cc: Heinrich Schuchardt <xypron.glpk@gmx.de>
Cc: Kees Cook <keescook@chromium.org>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Commit e7d316a02f ("sysctl: handle error writing UINT_MAX to u32
fields") added proc_douintvec() to start help adding support for
unsigned int, this however was only half the work needed. Two fixes
have come in since then for the following issues:
o Printing the values shows a negative value, this happens since
do_proc_dointvec() and this uses proc_put_long()
This was fixed by commit 5380e5644a ("sysctl: don't print negative
flag for proc_douintvec").
o We can easily wrap around the int values: UINT_MAX is 4294967295, if
we echo in 4294967295 + 1 we end up with 0, using 4294967295 + 2 we
end up with 1.
o We echo negative values in and they are accepted
This was fixed by commit 425fffd886 ("sysctl: report EINVAL if value
is larger than UINT_MAX for proc_douintvec").
It still also failed to be added to sysctl_check_table()... instead of
adding it with the current implementation just provide a proper and
simplified unsigned int support without any array unsigned int support
with no negative support at all.
Historically sysctl proc helpers have supported arrays, due to the
complexity this adds though we've taken a step back to evaluate array
users to determine if its worth upkeeping for unsigned int. An
evaluation using Coccinelle has been done to perform a grammatical
search to ask ourselves:
o How many sysctl proc_dointvec() (int) users exist which likely
should be moved over to proc_douintvec() (unsigned int) ?
Answer: about 8
- Of these how many are array users ?
Answer: Probably only 1
o How many sysctl array users exist ?
Answer: about 12
This last question gives us an idea just how popular arrays: they are not.
Array support should probably just be kept for strings.
The identified uint ports are:
drivers/infiniband/core/ucma.c - max_backlog
drivers/infiniband/core/iwcm.c - default_backlog
net/core/sysctl_net_core.c - rps_sock_flow_sysctl()
net/netfilter/nf_conntrack_timestamp.c - nf_conntrack_timestamp -- bool
net/netfilter/nf_conntrack_acct.c nf_conntrack_acct -- bool
net/netfilter/nf_conntrack_ecache.c - nf_conntrack_events -- bool
net/netfilter/nf_conntrack_helper.c - nf_conntrack_helper -- bool
net/phonet/sysctl.c proc_local_port_range()
The only possible array users is proc_local_port_range() but it does not
seem worth it to add array support just for this given the range support
works just as well. Unsigned int support should be desirable more for
when you *need* more than INT_MAX or using int min/max support then does
not suffice for your ranges.
If you forget and by mistake happen to register an unsigned int proc
entry with an array, the driver will fail and you will get something as
follows:
sysctl table check failed: debug/test_sysctl//uint_0002 array now allowed
CPU: 2 PID: 1342 Comm: modprobe Tainted: G W E <etc>
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS <etc>
Call Trace:
dump_stack+0x63/0x81
__register_sysctl_table+0x350/0x650
? kmem_cache_alloc_trace+0x107/0x240
__register_sysctl_paths+0x1b3/0x1e0
? 0xffffffffc005f000
register_sysctl_table+0x1f/0x30
test_sysctl_init+0x10/0x1000 [test_sysctl]
do_one_initcall+0x52/0x1a0
? kmem_cache_alloc_trace+0x107/0x240
do_init_module+0x5f/0x200
load_module+0x1867/0x1bd0
? __symbol_put+0x60/0x60
SYSC_finit_module+0xdf/0x110
SyS_finit_module+0xe/0x10
entry_SYSCALL_64_fastpath+0x1e/0xad
RIP: 0033:0x7f042b22d119
<etc>
Fixes: e7d316a02f ("sysctl: handle error writing UINT_MAX to u32 fields")
Link: http://lkml.kernel.org/r/20170519033554.18592-5-mcgrof@kernel.org
Signed-off-by: Luis R. Rodriguez <mcgrof@kernel.org>
Suggested-by: Alexey Dobriyan <adobriyan@gmail.com>
Cc: Subash Abhinov Kasiviswanathan <subashab@codeaurora.org>
Cc: Liping Zhang <zlpnobody@gmail.com>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Cc: Heinrich Schuchardt <xypron.glpk@gmx.de>
Cc: Kees Cook <keescook@chromium.org>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Patch series "sysctl: few fixes", v5.
I've been working on making kmod more deterministic, and as I did that I
couldn't help but notice a few issues with sysctl. My end goal was just
to fix unsigned int support, which back then was completely broken.
Liping Zhang has sent up small atomic fixes, however it still missed yet
one more fix and Alexey Dobriyan had also suggested to just drop array
support given its complexity.
I have inspected array support using Coccinelle and indeed its not that
popular, so if in fact we can avoid it for new interfaces, I agree its
best.
I did develop a sysctl stress driver but will hold that off for another
series.
This patch (of 5):
Commit 7c60c48f58 ("sysctl: Improve the sysctl sanity checks")
improved sanity checks considerbly, however the enhancements on
sysctl_check_table() meant adding a functional change so that only the
last table entry's sanity error is propagated. It also changed the way
errors were propagated so that each new check reset the err value, this
means only last sanity check computed is used for an error. This has
been in the kernel since v3.4 days.
Fix this by carrying on errors from previous checks and iterations as we
traverse the table and ensuring we keep any error from previous checks.
We keep iterating on the table even if an error is found so we can
complain for all errors found in one shot. This works as -EINVAL is
always returned on error anyway, and the check for error is any non-zero
value.
Fixes: 7c60c48f58 ("sysctl: Improve the sysctl sanity checks")
Link: http://lkml.kernel.org/r/20170519033554.18592-2-mcgrof@kernel.org
Signed-off-by: Luis R. Rodriguez <mcgrof@kernel.org>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Cc: Kees Cook <keescook@chromium.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Andrei Vagin writes:
FYI: This bug has been reproduced on 4.11.7
> BUG: Dentry ffff895a3dd01240{i=4e7c09a,n=lo} still in use (1) [unmount of proc proc]
> ------------[ cut here ]------------
> WARNING: CPU: 1 PID: 13588 at fs/dcache.c:1445 umount_check+0x6e/0x80
> CPU: 1 PID: 13588 Comm: kworker/1:1 Not tainted 4.11.7-200.fc25.x86_64 #1
> Hardware name: CompuLab sbc-flt1/fitlet, BIOS SBCFLT_0.08.04 06/27/2015
> Workqueue: events proc_cleanup_work
> Call Trace:
> dump_stack+0x63/0x86
> __warn+0xcb/0xf0
> warn_slowpath_null+0x1d/0x20
> umount_check+0x6e/0x80
> d_walk+0xc6/0x270
> ? dentry_free+0x80/0x80
> do_one_tree+0x26/0x40
> shrink_dcache_for_umount+0x2d/0x90
> generic_shutdown_super+0x1f/0xf0
> kill_anon_super+0x12/0x20
> proc_kill_sb+0x40/0x50
> deactivate_locked_super+0x43/0x70
> deactivate_super+0x5a/0x60
> cleanup_mnt+0x3f/0x90
> mntput_no_expire+0x13b/0x190
> kern_unmount+0x3e/0x50
> pid_ns_release_proc+0x15/0x20
> proc_cleanup_work+0x15/0x20
> process_one_work+0x197/0x450
> worker_thread+0x4e/0x4a0
> kthread+0x109/0x140
> ? process_one_work+0x450/0x450
> ? kthread_park+0x90/0x90
> ret_from_fork+0x2c/0x40
> ---[ end trace e1c109611e5d0b41 ]---
> VFS: Busy inodes after unmount of proc. Self-destruct in 5 seconds. Have a nice day...
> BUG: unable to handle kernel NULL pointer dereference at (null)
> IP: _raw_spin_lock+0xc/0x30
> PGD 0
Fix this by taking a reference to the super block in proc_sys_prune_dcache.
The superblock reference is the core of the fix however the sysctl_inodes
list is converted to a hlist so that hlist_del_init_rcu may be used. This
allows proc_sys_prune_dache to remove inodes the sysctl_inodes list, while
not causing problems for proc_sys_evict_inode when if it later choses to
remove the inode from the sysctl_inodes list. Removing inodes from the
sysctl_inodes list allows proc_sys_prune_dcache to have a progress
guarantee, while still being able to drop all locks. The fact that
head->unregistering is set in start_unregistering ensures that no more
inodes will be added to the the sysctl_inodes list.
Previously the code did a dance where it delayed calling iput until the
next entry in the list was being considered to ensure the inode remained on
the sysctl_inodes list until the next entry was walked to. The structure
of the loop in this patch does not need that so is much easier to
understand and maintain.
Cc: stable@vger.kernel.org
Reported-by: Andrei Vagin <avagin@gmail.com>
Tested-by: Andrei Vagin <avagin@openvz.org>
Fixes: ace0c791e6 ("proc/sysctl: Don't grab i_lock under sysctl_lock.")
Fixes: d6cffbbe9a ("proc/sysctl: prune stale dentries during unregistering")
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
Pull namespace updates from Eric Biederman:
"This is a set of small fixes that were mostly stumbled over during
more significant development. This proc fix and the fix to
posix-timers are the most significant of the lot.
There is a lot of good development going on but unfortunately it
didn't quite make the merge window"
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace:
proc: Fix unbalanced hard link numbers
signal: Make kill_proc_info static
rlimit: Properly call security_task_setrlimit
signal: Remove unused definition of sig_user_definied
ia64: Remove unused IA64_TASK_SIGHAND_OFFSET and IA64_SIGHAND_SIGLOCK_OFFSET
ipc: Remove unused declaration of recompute_msgmni
posix-timers: Correct sanity check in posix_cpu_nsleep
sysctl: Remove dead register_sysctl_root
The function no longer does anything. The is only a single caller of
register_sysctl_root when semantically there should be two. Remove
this function so that if someone decides this functionality is needed
again it will be obvious all of the callers of setup_sysctl_set need
to be audited and modified appropriately.
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
Commit e7d316a02f ("sysctl: handle error writing UINT_MAX to u32
fields") introduced the proc_douintvec helper function, but it forgot to
add the related sanity check when doing register_sysctl_table. So add
it now.
Signed-off-by: Liping Zhang <zlpnobody@gmail.com>
Cc: Subash Abhinov Kasiviswanathan <subashab@codeaurora.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Linus Torvalds