user/sven/linux.git/kernel/acct.c, branch v5.10.249

acct: perform last write from workqueue

2025-03-13T11:47:35Z

[ Upstream commit 56d5f3eba3f5de0efdd556de4ef381e109b973a9 ] In [1] it was reported that the acct(2) system call can be used to trigger NULL deref in cases where it is set to write to a file that triggers an internal lookup. This can e.g., happen when pointing acc(2) to /sys/power/resume. At the point the where the write to this file happens the calling task has already exited and called exit_fs(). A lookup will thus trigger a NULL-deref when accessing current->fs. Reorganize the code so that the the final write happens from the workqueue but with the caller's credentials. This preserves the (strange) permission model and has almost no regression risk. This api should stop to exist though. Link: https://lore.kernel.org/r/20250127091811.3183623-1-quzicheng@huawei.com [1] Link: https://lore.kernel.org/r/20250211-work-acct-v1-1-1c16aecab8b3@kernel.org Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Reported-by: Zicheng Qu Cc: stable@vger.kernel.org Signed-off-by: Christian Brauner Signed-off-by: Sasha Levin

kernel/acct.c: use dedicated helper to access rlimit values

2025-03-13T11:47:34Z

[ Upstream commit 3c91dda97eea704ac257ddb138d1154adab8db62 ] Use rlimit() helper instead of manually writing whole chain from task to rlimit value. See patch "posix-cpu-timers: Use dedicated helper to access rlimit values". Link: https://lkml.kernel.org/r/20210728030822.524789-1-yang.yang29@zte.com.cn Signed-off-by: Yang Yang Reported-by: Zeal Robot Cc: Randy Dunlap Cc: sh_def@163.com Cc: Yang Yang Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds Stable-dep-of: 56d5f3eba3f5 ("acct: perform last write from workqueue") Signed-off-by: Sasha Levin

kernel/acct.c: use #elif instead of #end and #elif

2025-03-13T11:47:34Z

[ Upstream commit 35189b8ff18ee0c6f7c04f4c674584d1149d5c55 ] Cleanup: use #elif instead of #end and #elif. Link: https://lkml.kernel.org/r/20201015150736.GA91603@rlk Signed-off-by: Hui Su Reviewed-by: Andrew Morton Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds Stable-dep-of: 56d5f3eba3f5 ("acct: perform last write from workqueue") Signed-off-by: Sasha Levin

acct: block access to kernel internal filesystems

2025-03-13T11:47:30Z

commit 890ed45bde808c422c3c27d3285fc45affa0f930 upstream. There's no point in allowing anything kernel internal nor procfs or sysfs. Link: https://lore.kernel.org/r/20250127091811.3183623-1-quzicheng@huawei.com Link: https://lore.kernel.org/r/20250211-work-acct-v1-2-1c16aecab8b3@kernel.org Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Reviewed-by: Amir Goldstein Reported-by: Zicheng Qu Cc: stable@vger.kernel.org Signed-off-by: Christian Brauner Signed-off-by: Greg Kroah-Hartman

acct: fix potential integer overflow in encode_comp_t()

2023-01-14T09:16:14Z

[ Upstream commit c5f31c655bcc01b6da53b836ac951c1556245305 ] The integer overflow is descripted with following codes: > 317 static comp_t encode_comp_t(u64 value) > 318 { > 319 int exp, rnd; ...... > 341 exp <<= MANTSIZE; > 342 exp += value; > 343 return exp; > 344 } Currently comp_t is defined as type of '__u16', but the variable 'exp' is type of 'int', so overflow would happen when variable 'exp' in line 343 is greater than 65535. Link: https://lkml.kernel.org/r/20210515140631.369106-3-zhengyejian1@huawei.com Signed-off-by: Zheng Yejian Cc: Hanjun Guo Cc: Randy Dunlap Cc: Vlastimil Babka Cc: Zhang Jinhao Signed-off-by: Andrew Morton Signed-off-by: Sasha Levin

kernel: acct.c: fix some kernel-doc nits

2020-10-16T18:11:19Z

Fix kernel-doc notation to use the documented Returns: syntax and place the function description for acct_process() on the first line where it should be. Signed-off-by: Randy Dunlap Signed-off-by: Andrew Morton Cc: Alexander Viro Link: https://lkml.kernel.org/r/b4c33e5d-98e8-0c47-77b6-ac1859f94d7f@infradead.org Signed-off-by: Linus Torvalds

kernel/: fix repeated words in comments

2020-10-16T18:11:19Z

Fix multiple occurrences of duplicated words in kernel/. Fix one typo/spello on the same line as a duplicate word. Change one instance of "the the" to "that the". Otherwise just drop one of the repeated words. Signed-off-by: Randy Dunlap Signed-off-by: Andrew Morton Link: https://lkml.kernel.org/r/98202fa6-8919-ef63-9efe-c0fad5ca7af1@infradead.org Signed-off-by: Linus Torvalds

mmap locking API: convert mmap_sem comments

2020-06-09T16:39:14Z

Convert comments that reference mmap_sem to reference mmap_lock instead. [akpm@linux-foundation.org: fix up linux-next leftovers] [akpm@linux-foundation.org: s/lockaphore/lock/, per Vlastimil] [akpm@linux-foundation.org: more linux-next fixups, per Michel] Signed-off-by: Michel Lespinasse Signed-off-by: Andrew Morton Reviewed-by: Vlastimil Babka Reviewed-by: Daniel Jordan Cc: Davidlohr Bueso Cc: David Rientjes Cc: Hugh Dickins Cc: Jason Gunthorpe Cc: Jerome Glisse Cc: John Hubbard Cc: Laurent Dufour Cc: Liam Howlett Cc: Matthew Wilcox Cc: Peter Zijlstra Cc: Ying Han Link: http://lkml.kernel.org/r/20200520052908.204642-13-walken@google.com Signed-off-by: Linus Torvalds

mmap locking API: use coccinelle to convert mmap_sem rwsem call sites

2020-06-09T16:39:14Z

This change converts the existing mmap_sem rwsem calls to use the new mmap locking API instead. The change is generated using coccinelle with the following rule: // spatch --sp-file mmap_lock_api.cocci --in-place --include-headers --dir . @@ expression mm; @@ ( -init_rwsem +mmap_init_lock | -down_write +mmap_write_lock | -down_write_killable +mmap_write_lock_killable | -down_write_trylock +mmap_write_trylock | -up_write +mmap_write_unlock | -downgrade_write +mmap_write_downgrade | -down_read +mmap_read_lock | -down_read_killable +mmap_read_lock_killable | -down_read_trylock +mmap_read_trylock | -up_read +mmap_read_unlock ) -(&mm->mmap_sem) +(mm) Signed-off-by: Michel Lespinasse Signed-off-by: Andrew Morton Reviewed-by: Daniel Jordan Reviewed-by: Laurent Dufour Reviewed-by: Vlastimil Babka Cc: Davidlohr Bueso Cc: David Rientjes Cc: Hugh Dickins Cc: Jason Gunthorpe Cc: Jerome Glisse Cc: John Hubbard Cc: Liam Howlett Cc: Matthew Wilcox Cc: Peter Zijlstra Cc: Ying Han Link: http://lkml.kernel.org/r/20200520052908.204642-5-walken@google.com Signed-off-by: Linus Torvalds

acct: stop using get_seconds()

2019-12-18T17:07:31Z

In 'struct acct', 'struct acct_v3', and 'struct taskstats' we have a 32-bit 'ac_btime' field containing an absolute time value, which will overflow in year 2106. There are two possible ways to deal with it: a) let it overflow and have user space code deal with reconstructing the data based on the current time, or b) truncate the times based on the range of the u32 type. Neither of them solves the actual problem. Pick the second one to best document what the issue is, and have someone fix it in a future version. Signed-off-by: Arnd Bergmann