OpenCloudOS-Kernel/kernel
Andrei Vagin 2b5f9dad32 fs/exec: switch timens when a task gets a new mm
Changing a time namespace requires remapping a vvar page, so we don't want
to allow doing that if any other tasks can use the same mm.

Currently, we install a time namespace when a task is created with a new
vm. exec() is another case when a task gets a new mm and so it can switch
a time namespace safely, but it isn't handled now.

One more issue of the current interface is that clone() with CLONE_VM isn't
allowed if the current task has unshared a time namespace
(timens_for_children doesn't match the current timens).

Both these issues make some inconvenience for users. For example, Alexey
and Florian reported that posix_spawn() uses vfork+exec and this pattern
doesn't work with time namespaces due to the both described issues.
LXC needed to workaround the exec() issue by calling setns.

In the commit 133e2d3e81 ("fs/exec: allow to unshare a time namespace on
vfork+exec"), we tried to fix these issues with minimal impact on UAPI. But
it adds extra complexity and some undesirable side effects. Eric suggested
fixing the issues properly because here are all the reasons to suppose that
there are no users that depend on the old behavior.

Cc: Alexey Izbyshev <izbyshev@ispras.ru>
Cc: Christian Brauner <brauner@kernel.org>
Cc: Dmitry Safonov <0x7f454c46@gmail.com>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Florian Weimer <fweimer@redhat.com>
Cc: Kees Cook <keescook@chromium.org>
Suggested-by: "Eric W. Biederman" <ebiederm@xmission.com>
Origin-author: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: Andrei Vagin <avagin@gmail.com>
Signed-off-by: Kees Cook <keescook@chromium.org>
Link: https://lore.kernel.org/r/20220921003120.209637-1-avagin@google.com
2022-10-25 15:15:52 -07:00
..
bpf treewide: use get_random_u32() when possible 2022-10-11 17:42:58 -06:00
cgroup PSI updates for v6.1: 2022-10-14 13:03:00 -07:00
configs Kbuild: add Rust support 2022-09-28 09:02:20 +02:00
debug mm: remove vmacache 2022-09-26 19:46:18 -07:00
dma - Yu Zhao's Multi-Gen LRU patches are here. They've been under test in 2022-10-10 17:53:04 -07:00
entry entry: kmsan: introduce kmsan_unpoison_entry_regs() 2022-10-03 14:03:25 -07:00
events - Yu Zhao's Multi-Gen LRU patches are here. They've been under test in 2022-10-10 17:53:04 -07:00
futex freezer,sched: Rewrite core freezer logic 2022-09-07 21:53:50 +02:00
gcov
irq genirq: Provide generic_handle_domain_irq_safe(). 2022-09-19 15:08:38 +02:00
kcsan treewide: use get_random_bytes() when possible 2022-10-11 17:42:58 -06:00
livepatch Livepatching changes for 6.1 2022-10-10 11:36:19 -07:00
locking treewide: use prandom_u32_max() when possible, part 1 2022-10-11 17:42:55 -06:00
module module: tracking: Keep a record of tainted unloaded modules only 2022-10-10 12:16:19 -07:00
power Scheduler changes for v6.1: 2022-10-10 09:10:28 -07:00
printk printk: Mark __printk percpu data ready __ro_after_init 2022-09-29 15:20:52 +02:00
rcu Merge branches 'doc.2022.08.31b', 'fixes.2022.08.31b', 'kvfree.2022.08.31b', 'nocb.2022.09.01a', 'poll.2022.08.31b', 'poll-srcu.2022.08.31b' and 'tasks.2022.08.31b' into HEAD 2022-09-01 10:55:57 -07:00
sched PSI updates for v6.1: 2022-10-14 13:03:00 -07:00
time treewide: use prandom_u32_max() when possible, part 1 2022-10-11 17:42:55 -06:00
trace Tracing fixes for 6.1: 2022-10-13 10:36:57 -07:00
.gitignore
Kconfig.freezer
Kconfig.hz
Kconfig.locks
Kconfig.preempt Revert "signal, x86: Delay calling signals in atomic on RT enabled kernels" 2022-03-31 10:36:55 +02:00
Makefile kmsan: disable instrumentation of unsupported common kernel code 2022-10-03 14:03:20 -07:00
acct.c acct: use VMA iterator instead of linked list 2022-09-26 19:46:22 -07:00
async.c
audit.c audit: use time_after to compare time 2022-08-29 19:47:03 -04:00
audit.h audit: remove selinux_audit_rule_update() declaration 2022-09-07 11:30:15 -04:00
audit_fsnotify.c audit: fix potential double free on error path from fsnotify_add_inode_mark 2022-08-22 18:50:06 -04:00
audit_tree.c audit: use fsnotify group lock helpers 2022-04-25 14:37:28 +02:00
audit_watch.c audit_init_parent(): constify path 2022-09-01 17:39:30 -04:00
auditfilter.c
auditsc.c audit/stable-6.1 PR 20221003 2022-10-04 11:05:43 -07:00
backtracetest.c
bounds.c mm: multi-gen LRU: minimal implementation 2022-09-26 19:46:09 -07:00
capability.c
cfi.c cfi: Switch to -fsanitize=kcfi 2022-09-26 10:13:13 -07:00
compat.c
configs.c
context_tracking.c MAINTAINERS: Add Paul as context tracking maintainer 2022-07-05 13:33:00 -07:00
cpu.c Intel Trust Domain Extensions 2022-05-23 17:51:12 -07:00
cpu_pm.c context_tracking: Take IRQ eqs entrypoints over RCU 2022-07-05 13:32:59 -07:00
crash_core.c vmcoreinfo: add kallsyms_num_syms symbol 2022-08-28 14:02:44 -07:00
crash_dump.c
cred.c x86: Mark __invalid_creds() __noreturn 2022-03-15 10:32:44 +01:00
delayacct.c delayacct: support re-entrance detection of thrashing accounting 2022-09-26 19:46:07 -07:00
dma.c
exec_domain.c
exit.c - hfs and hfsplus kmap API modernization from Fabio Francesco 2022-10-12 11:00:22 -07:00
extable.c context_tracking: Take NMI eqs entrypoints over RCU 2022-07-05 13:32:59 -07:00
fail_function.c fail_function: fix wrong use of fei_attr_remove() 2022-09-11 21:55:11 -07:00
fork.c fs/exec: switch timens when a task gets a new mm 2022-10-25 15:15:52 -07:00
freezer.c freezer,sched: Rewrite core freezer logic 2022-09-07 21:53:50 +02:00
gen_kheaders.sh kbuild: build init/built-in.a just once 2022-09-29 04:40:15 +09:00
groups.c security: Add LSM hook to setgroups() syscall 2022-07-15 18:21:49 +00:00
hung_task.c sched: Fix more TASK_state comparisons 2022-09-30 16:50:39 +02:00
iomem.c
irq_work.c irq_work: use kasan_record_aux_stack_noalloc() record callstack 2022-04-15 14:49:55 -07:00
jump_label.c jump_label: make initial NOP patching the special case 2022-06-24 09:48:55 +02:00
kallsyms.c kcfi updates for v6.1-rc1 2022-10-03 17:11:07 -07:00
kallsyms_internal.h kallsyms: move declarations to internal header 2022-07-17 17:31:39 -07:00
kcmp.c
kcov.c kcov: kmsan: unpoison area->list in kcov_remote_area_put() 2022-10-03 14:03:23 -07:00
kexec.c panic, kexec: make __crash_kexec() NMI safe 2022-09-11 21:55:06 -07:00
kexec_core.c kexec: replace kmap() with kmap_local_page() 2022-09-11 21:55:08 -07:00
kexec_elf.c
kexec_file.c panic, kexec: make __crash_kexec() NMI safe 2022-09-11 21:55:06 -07:00
kexec_internal.h panic, kexec: make __crash_kexec() NMI safe 2022-09-11 21:55:06 -07:00
kheaders.c
kmod.c
kprobes.c Merge https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next 2022-10-03 13:02:49 -07:00
ksysfs.c kexec: turn all kexec_mutex acquisitions into trylocks 2022-09-11 21:55:06 -07:00
kthread.c signal: break out of wait loops on kthread_stop() 2022-10-09 16:01:59 -07:00
latencytop.c latencytop: use the last element of latency_record of system 2022-09-11 21:55:12 -07:00
module_signature.c
notifier.c notifier: Add blocking/atomic_notifier_chain_register_unique_prio() 2022-05-19 19:30:30 +02:00
nsproxy.c fs/exec: switch timens when a task gets a new mm 2022-10-25 15:15:52 -07:00
padata.c
panic.c kernel/panic: Drop unblank_screen call 2022-09-01 16:55:35 +02:00
params.c
pid.c gfs2: Add glockfd debugfs file 2022-06-29 13:07:16 +02:00
pid_namespace.c kernel: pid_namespace: use NULL instead of using plain integer as pointer 2022-04-29 14:38:00 -07:00
profile.c kernel/profile.c: simplify duplicated code in profile_setup() 2022-09-11 21:55:12 -07:00
ptrace.c freezer,sched: Rewrite core freezer logic 2022-09-07 21:53:50 +02:00
range.c
reboot.c kernel/reboot: Add SYS_OFF_MODE_RESTART_PREPARE mode 2022-10-04 15:59:36 +02:00
regset.c
relay.c relay: use kvcalloc to alloc page array in relay_alloc_page_array 2022-10-03 14:21:43 -07:00
resource.c resource: Introduce alloc_free_mem_region() 2022-07-21 17:19:25 -07:00
resource_kunit.c
rseq.c rseq: Kill process when unknown flags are encountered in ABI structures 2022-08-01 15:21:42 +02:00
scftorture.c scftorture: Fix distribution of short handler delays 2022-04-11 17:07:29 -07:00
scs.c kasan, vmalloc: only tag normal vmalloc allocations 2022-03-24 19:06:48 -07:00
seccomp.c seccomp: Add wait_killable semantic to seccomp user notifier 2022-05-03 14:11:58 -07:00
signal.c Scheduler changes for v6.1: 2022-10-10 09:10:28 -07:00
smp.c bitmap patches for v6.1-rc1 2022-10-10 12:49:34 -07:00
smpboot.c smpboot: use atomic_try_cmpxchg in cpu_wait_death and cpu_report_death 2022-09-11 21:55:10 -07:00
smpboot.h
softirq.c context_tracking: Take IRQ eqs entrypoints over RCU 2022-07-05 13:32:59 -07:00
stackleak.c stackleak: add on/off stack variants 2022-05-08 01:33:09 -07:00
stacktrace.c
static_call.c static_call: Don't make __static_call_return0 static 2022-04-05 09:59:38 +02:00
static_call_inline.c static_call: Don't make __static_call_return0 static 2022-04-05 09:59:38 +02:00
stop_machine.c Scheduler changes in this cycle were: 2022-05-24 11:11:13 -07:00
sys.c Random number generator updates for Linux 6.1-rc1. 2022-10-10 10:41:21 -07:00
sys_ni.c kernel/sys_ni: add compat entry for fadvise64_64 2022-08-20 15:17:45 -07:00
sysctl-test.c kernel/sysctl-test: use SYSCTL_{ZERO/ONE_HUNDRED} instead of i_{zero/one_hundred} 2022-09-08 16:56:45 -07:00
sysctl.c - Yu Zhao's Multi-Gen LRU patches are here. They've been under test in 2022-10-10 17:53:04 -07:00
task_work.c task_work: use try_cmpxchg in task_work_add, task_work_cancel_match and task_work_run 2022-09-11 21:55:10 -07:00
taskstats.c genetlink: start to validate reserved header bytes 2022-08-29 12:47:15 +01:00
torture.c
tracepoint.c tracepoint: Optimize the critical region of mutex_lock in tracepoint_module_coming() 2022-09-26 13:01:18 -04:00
tsacct.c taskstats: version 12 with thread group and exe info 2022-04-29 14:38:03 -07:00
ucount.c ucounts: Split rlimit and ucount values and max values 2022-05-18 18:24:57 -05:00
uid16.c
uid16.h
umh.c freezer,sched: Rewrite core freezer logic 2022-09-07 21:53:50 +02:00
up.c
user-return-notifier.c
user.c
user_namespace.c ucounts: Split rlimit and ucount values and max values 2022-10-09 16:24:05 -07:00
usermode_driver.c blob_to_mnt(): kern_unmount() is needed to undo kern_mount() 2022-05-19 23:25:47 -04:00
utsname.c
utsname_sysctl.c - hfs and hfsplus kmap API modernization from Fabio Francesco 2022-10-12 11:00:22 -07:00
watch_queue.c This was a moderately busy cycle for documentation, but nothing all that 2022-08-02 19:24:24 -07:00
watchdog.c powerpc updates for 6.0 2022-08-06 16:38:17 -07:00
watchdog_hld.c Revert "printk: add functions to prefer direct printing" 2022-06-23 18:41:40 +02:00
workqueue.c kcfi updates for v6.1-rc1 2022-10-03 17:11:07 -07:00
workqueue_internal.h