On Sat, Aug 17, 2024 at 10:56 AM Yafang Shao <laoar.shao@xxxxxxxxx> wrote:
>
> Using {memcpy,strncpy,strcpy,kstrdup} to copy the task comm relies on the
> length of task comm. Changes in the task comm could result in a destination
> string that is overflow. Therefore, we should explicitly ensure the
> destination string is always NUL-terminated, regardless of the task comm.
> This approach will facilitate future extensions to the task comm.
>
> As suggested by Linus [0], we can identify all relevant code with the
> following git grep command:
>
> git grep 'memcpy.*->comm\>'
> git grep 'kstrdup.*->comm\>'
> git grep 'strncpy.*->comm\>'
> git grep 'strcpy.*->comm\>'
>
> PATCH #2~#4: memcpy
> PATCH #5~#6: kstrdup
> PATCH #7~#8: strcpy
>
> Please note that strncpy() is not included in this series as it is being
> tracked by another effort. [1]
>
> In this series, we have removed __get_task_comm() because the task_lock()
> and BUILD_BUG_ON() within it are unnecessary.
>
> Suggested-by: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx>
> Link: https://lore.kernel.org/all/CAHk-=wjAmmHUg6vho1KjzQi2=psR30+CogFd4aXrThr2gsiS4g@xxxxxxxxxxxxxx/ [0]
>
> Changes:
> v6->v7:
> - Improve the comment (Alejandro)
> - Drop strncpy as it is being tracked by another effort (Justin)
> https://github.com/KSPP/linux/issues/90 [1]
>
> v5->v6: https://lore.kernel.org/linux-mm/20240812022933.69850-1-laoar.shao@xxxxxxxxx/
> - Get rid of __get_task_comm() (Linus)
> - Use ARRAY_SIZE() in get_task_comm() (Alejandro)
>
> v4->v5: https://lore.kernel.org/all/20240804075619.20804-1-laoar.shao@xxxxxxxxx/
> - Drop changes in the mm/kmemleak.c as it was fixed by
> commit 0b84780134fb ("mm/kmemleak: replace strncpy() with strscpy()")
> - Drop changes in kernel/tsacct.c as it was fixed by
> commmit 0fe2356434e ("tsacct: replace strncpy() with strscpy()")
>
> v3->v4: https://lore.kernel.org/linux-mm/20240729023719.1933-1-laoar.shao@xxxxxxxxx/
> - Rename __kstrndup() to __kmemdup_nul() and define it inside mm/util.c
> (Matthew)
> - Remove unused local varaible (Simon)
>
> v2->v3: https://lore.kernel.org/all/20240621022959.9124-1-laoar.shao@xxxxxxxxx/
> - Deduplicate code around kstrdup (Andrew)
> - Add commit log for dropping task_lock (Catalin)
>
> v1->v2: https://lore.kernel.org/bpf/20240613023044.45873-1-laoar.shao@xxxxxxxxx/
> - Add comment for dropping task_lock() in __get_task_comm() (Alexei)
> - Drop changes in trace event (Steven)
> - Fix comment on task comm (Matus)
>
> v1: https://lore.kernel.org/all/20240602023754.25443-1-laoar.shao@xxxxxxxxx/
>
> Yafang Shao (8):
> Get rid of __get_task_comm()
> auditsc: Replace memcpy() with strscpy()
> security: Replace memcpy() with get_task_comm()
> bpftool: Ensure task comm is always NUL-terminated
> mm/util: Fix possible race condition in kstrdup()
> mm/util: Deduplicate code in {kstrdup,kstrndup,kmemdup_nul}
> net: Replace strcpy() with strscpy()
> drm: Replace strcpy() with strscpy()
>
> drivers/gpu/drm/drm_framebuffer.c | 2 +-
> drivers/gpu/drm/i915/i915_gpu_error.c | 2 +-
> fs/exec.c | 10 -----
> fs/proc/array.c | 2 +-
> include/linux/sched.h | 32 +++++++++++---
> kernel/auditsc.c | 6 +--
> kernel/kthread.c | 2 +-
> mm/util.c | 61 ++++++++++++---------------
> net/ipv6/ndisc.c | 2 +-
> security/lsm_audit.c | 4 +-
> security/selinux/selinuxfs.c | 2 +-
> tools/bpf/bpftool/pids.c | 2 +
> 12 files changed, 65 insertions(+), 62 deletions(-)
>
> --
> 2.43.5
>
Hello Andrew,
Could you please apply this series to the mm tree ?
--
Regards
Yafang
