No description
  • C 96.8%
  • Assembly 0.9%
  • Rust 0.7%
  • Shell 0.6%
  • Python 0.5%
  • Other 0.3%
Find a file
Han Guangjiang 6a0c394300 blk-throttle: fix access race during throttle policy activation
[ Upstream commit bd9fd5be6b ]

On repeated cold boots we occasionally hit a NULL pointer crash in
blk_should_throtl() when throttling is consulted before the throttle
policy is fully enabled for the queue. Checking only q->td != NULL is
insufficient during early initialization, so blkg_to_pd() for the
throttle policy can still return NULL and blkg_to_tg() becomes NULL,
which later gets dereferenced.

 Unable to handle kernel NULL pointer dereference
 at virtual address 0000000000000156
 ...
 pc : submit_bio_noacct+0x14c/0x4c8
 lr : submit_bio_noacct+0x48/0x4c8
 sp : ffff800087f0b690
 x29: ffff800087f0b690 x28: 0000000000005f90 x27: ffff00068af393c0
 x26: 0000000000080000 x25: 000000000002fbc0 x24: ffff000684ddcc70
 x23: 0000000000000000 x22: 0000000000000000 x21: 0000000000000000
 x20: 0000000000080000 x19: ffff000684ddcd08 x18: ffffffffffffffff
 x17: 0000000000000000 x16: ffff80008132a550 x15: 0000ffff98020fff
 x14: 0000000000000000 x13: 1fffe000d11d7021 x12: ffff000688eb810c
 x11: ffff00077ec4bb80 x10: ffff000688dcb720 x9 : ffff80008068ef60
 x8 : 00000a6fb8a86e85 x7 : 000000000000111e x6 : 0000000000000002
 x5 : 0000000000000246 x4 : 0000000000015cff x3 : 0000000000394500
 x2 : ffff000682e35e40 x1 : 0000000000364940 x0 : 000000000000001a
 Call trace:
  submit_bio_noacct+0x14c/0x4c8
  verity_map+0x178/0x2c8
  __map_bio+0x228/0x250
  dm_submit_bio+0x1c4/0x678
  __submit_bio+0x170/0x230
  submit_bio_noacct_nocheck+0x16c/0x388
  submit_bio_noacct+0x16c/0x4c8
  submit_bio+0xb4/0x210
  f2fs_submit_read_bio+0x4c/0xf0
  f2fs_mpage_readpages+0x3b0/0x5f0
  f2fs_readahead+0x90/0xe8

Tighten blk_throtl_activated() to also require that the throttle policy
bit is set on the queue:

  return q->td != NULL &&
         test_bit(blkcg_policy_throtl.plid, q->blkcg_pols);

This prevents blk_should_throtl() from accessing throttle group state
until policy data has been attached to blkgs.

Fixes: a3166c5170 ("blk-throttle: delay initialization until configuration")
Co-developed-by: Liang Jie <liangjie@lixiang.com>
Signed-off-by: Liang Jie <liangjie@lixiang.com>
Signed-off-by: Han Guangjiang <hanguangjiang@lixiang.com>
Reviewed-by: Yu Kuai <yukuai3@huawei.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Sasha Levin <sashal@kernel.org>
History 2025-10-15 12:03:26 +02:00
arch ARM: dts: omap: am335x-cm-t335: Remove unused mcasp num-serializer property 2025-10-15 12:03:25 +02:00
block blk-throttle: fix access race during throttle policy activation 2025-10-15 12:03:26 +02:00
certs sign-file,extract-cert: use pkcs11 provider for OPENSSL MAJOR >= 3 2024-09-20 19:52:48 +03:00
crypto crypto: rng - Ensure set_ent is always present 2025-10-12 13:01:57 +02:00
Documentation dt-bindings: vendor-prefixes: Add undocumented vendor prefixes 2025-10-15 12:03:23 +02:00
drivers null_blk: Fix the description of the cache_size module argument 2025-10-15 12:03:26 +02:00
fs btrfs: fix symbolic link reading when bs > ps 2025-10-15 12:03:18 +02:00
include vdso: Add struct __kernel_old_timeval forward declaration to gettime.h 2025-10-15 12:03:25 +02:00
init Fix CC_HAS_ASM_GOTO_OUTPUT on non-x86 architectures 2025-10-15 12:03:13 +02:00
io_uring io_uring-6.17-20250919 2025-09-19 12:10:49 -07:00
ipc vfs-6.17-rc1.mmap_prepare 2025-07-28 13:43:25 -07:00
kernel genirq/test: Ensure CPU 1 is online for hotplug test 2025-10-15 12:03:24 +02:00
lib vdso/datastore: Gate time data behind CONFIG_GENERIC_GETTIMEOFDAY 2025-10-15 12:03:24 +02:00
LICENSES LICENSES: Replace the obsolete address of the FSF in the GFDL-1.2 2025-07-24 11:15:39 +02:00
mm mm: swap: check for stable address space before operating on the VMA 2025-10-06 11:20:05 +02:00
net net/9p: fix double req put in p9_fd_cancelled 2025-10-12 13:01:57 +02:00
rust rust: cpumask: Mark CpumaskVar as transparent 2025-10-15 12:03:19 +02:00
samples 15 hotfixes. 11 are cc:stable and the remainder address post-6.16 issues 2025-09-17 21:34:26 -07:00
scripts scripts/misc-check: update export checks for EXPORT_SYMBOL_FOR_MODULES() 2025-10-15 12:03:22 +02:00
security lsm: CONFIG_LSM can depend on CONFIG_SECURITY 2025-10-15 12:03:17 +02:00
sound ASoC: qcom: audioreach: fix potential null pointer dereference 2025-10-06 11:20:06 +02:00
tools selftests/bpf: Fix count write in testapp_xdp_metadata_copy() 2025-10-15 12:03:24 +02:00
usr usr/include: openrisc: don't HDRTEST bpf_perf_event.h 2025-05-12 15:03:17 +09:00
virt Merge tag 'kvm-x86-no_assignment-6.17' of https://github.com/kvm-x86/linux into HEAD 2025-07-29 08:36:42 -04:00
.clang-format Linux 6.15-rc5 2025-05-06 16:39:25 +10:00
.clippy.toml rust: clean Rust 1.88.0's warning about clippy::disallowed_macros configuration 2025-05-07 00:11:47 +02:00
.cocciconfig scripts: add Linux .cocciconfig for coccinelle 2016-07-22 12:13:39 +02:00
.editorconfig .editorconfig: remove trim_trailing_whitespace option 2024-06-13 16:47:52 +02:00
.get_maintainer.ignore MAINTAINERS: remove Alyssa Rosenzweig 2025-09-18 21:17:31 +02:00
.gitattributes .gitattributes: set diff driver for Rust source code files 2023-05-31 17:48:25 +02:00
.gitignore gitignore: allow .pylintrc to be tracked 2025-07-02 17:10:04 -06:00
.mailmap 7 hotfixes. 4 are cc:stable and the remainder address post-6.16 issues or 2025-09-28 09:32:00 -07:00
.pylintrc docs: add a .pylintrc file with sys path for docs scripts 2025-04-09 12:10:33 -06:00
.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 MAINTAINERS: retire Boris from TLS maintainers 2025-08-26 17:36:01 -07:00
Kbuild drm: ensure drm headers are self-contained and pass kernel-doc 2025-02-12 10:44:43 +02:00
Kconfig io_uring: Rename KConfig to Kconfig 2025-02-19 14:53:27 -07:00
MAINTAINERS i2c-for-6.17-rc8 2025-09-28 13:19:23 -07:00
Makefile Linux 6.17.2 2025-10-12 13:01:58 +02:00
README README: Fix spelling 2024-03-18 03:36:32 -06:00

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 reStructuredText 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.