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Ryusuke Konishi 2c3bdba002 nilfs2: fix potential bug in end_buffer_async_write
commit 5bc09b397cbf1221f8a8aacb1152650c9195b02b upstream.

According to a syzbot report, end_buffer_async_write(), which handles the
completion of block device writes, may detect abnormal condition of the
buffer async_write flag and cause a BUG_ON failure when using nilfs2.

Nilfs2 itself does not use end_buffer_async_write().  But, the async_write
flag is now used as a marker by commit 7f42ec3941 ("nilfs2: fix issue
with race condition of competition between segments for dirty blocks") as
a means of resolving double list insertion of dirty blocks in
nilfs_lookup_dirty_data_buffers() and nilfs_lookup_node_buffers() and the
resulting crash.

This modification is safe as long as it is used for file data and b-tree
node blocks where the page caches are independent.  However, it was
irrelevant and redundant to also introduce async_write for segment summary
and super root blocks that share buffers with the backing device.  This
led to the possibility that the BUG_ON check in end_buffer_async_write
would fail as described above, if independent writebacks of the backing
device occurred in parallel.

The use of async_write for segment summary buffers has already been
removed in a previous change.

Fix this issue by removing the manipulation of the async_write flag for
the remaining super root block buffer.

Link: https://lkml.kernel.org/r/20240203161645.4992-1-konishi.ryusuke@gmail.com
Fixes: 7f42ec3941 ("nilfs2: fix issue with race condition of competition between segments for dirty blocks")
Signed-off-by: Ryusuke Konishi <konishi.ryusuke@gmail.com>
Reported-by: syzbot+5c04210f7c7f897c1e7f@syzkaller.appspotmail.com
Closes: https://lkml.kernel.org/r/00000000000019a97c05fd42f8c8@google.com
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-02-23 09:25:27 +01:00
Documentation docs: kernel_feat.py: fix build error for missing files 2024-02-23 09:25:16 +01:00
LICENSES LICENSES: Add the copyleft-next-0.3.1 license 2022-11-08 15:44:01 +01:00
arch x86/efistub: Use 1:1 file:memory mapping for PE/COFF .compat section 2024-02-23 09:25:27 +01:00
block block: fix partial zone append completion handling in req_bio_endio() 2024-02-23 09:25:18 +01:00
certs certs: Reference revocation list for all keyrings 2023-08-17 20:12:41 +00:00
crypto crypto: algif_hash - Remove bogus SGL free on zero-length error path 2024-02-23 09:25:11 +01:00
drivers of: property: Add in-ports/out-ports support to of_graph_get_port_parent() 2024-02-23 09:25:27 +01:00
fs nilfs2: fix potential bug in end_buffer_async_write 2024-02-23 09:25:27 +01:00
include eventfs: Hold eventfs_mutex when calling callback functions 2024-02-23 09:25:21 +01:00
init update workarounds for gcc "asm goto" issue 2024-02-23 09:24:47 +01:00
io_uring io_uring/net: fix multishot accept overflow handling 2024-02-23 09:25:10 +01:00
ipc Add x86 shadow stack support 2023-08-31 12:20:12 -07:00
kernel sched/membarrier: reduce the ability to hammer on sys_membarrier 2024-02-23 09:25:27 +01:00
lib Revert "kobject: Remove redundant checks for whether ktype is NULL" 2024-02-23 09:24:58 +01:00
mm blk-wbt: Fix detection of dirty-throttled tasks 2024-02-23 09:25:16 +01:00
net netfilter: ipset: Missing gc cancellations fixed 2024-02-23 09:25:18 +01:00
rust rust: upgrade to Rust 1.73.0 2024-02-16 19:10:43 +01:00
samples work around gcc bugs with 'asm goto' with outputs 2024-02-23 09:24:47 +01:00
scripts modpost: Add '.ltext' and '.ltext.*' to TEXT_SECTIONS 2024-02-23 09:25:03 +01:00
security lsm: fix the logic in security_inode_getsecctx() 2024-02-23 09:25:02 +01:00
sound ASoC: amd: yc: Add DMI quirk for Lenovo Ideapad Pro 5 16ARP8 2024-02-23 09:25:14 +01:00
tools tools/rtla: Fix Makefile compiler options for clang 2024-02-23 09:25:15 +01:00
usr initramfs: Encode dependency on KBUILD_BUILD_TIMESTAMP 2023-06-06 17:54:49 +09:00
virt ARM: 2023-09-07 13:52:20 -07:00
.clang-format iommu: Add for_each_group_device() 2023-05-23 08:15:51 +02:00
.cocciconfig
.get_maintainer.ignore get_maintainer: add Alan to .get_maintainer.ignore 2022-08-20 15:17:44 -07:00
.gitattributes .gitattributes: set diff driver for Rust source code files 2023-05-31 17:48:25 +02:00
.gitignore kbuild: rpm-pkg: rename binkernel.spec to kernel.spec 2023-07-25 00:59:33 +09:00
.mailmap 20 hotfixes. 12 are cc:stable and the remainder address post-6.5 issues 2023-10-24 09:52:16 -10:00
.rustfmt.toml rust: add `.rustfmt.toml` 2022-09-28 09:02:20 +02:00
COPYING COPYING: state that all contributions really are covered by this file 2020-02-10 13:32:20 -08:00
CREDITS USB: Remove Wireless USB and UWB documentation 2023-08-09 14:17:32 +02:00
Kbuild Kbuild updates for v6.1 2022-10-10 12:00:45 -07:00
Kconfig kbuild: ensure full rebuild when the compiler is updated 2020-05-12 13:28:33 +09:00
MAINTAINERS MAINTAINERS: add Catherine as xfs maintainer for 6.6.y 2024-02-16 19:10:43 +01:00
Makefile Linux 6.6.17 2024-02-16 19:10:57 +01:00
README Drop all 00-INDEX files from Documentation/ 2018-09-09 15:08:58 -06:00

README

Linux kernel
============

There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.

In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``.  The formatted documentation can also be read online at:

    https://www.kernel.org/doc/html/latest/

There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.

Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.