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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~#9: strncpy PATCH #10~#11: strcpy Suggested-by: Linus Torvalds Link: https://lore.kernel.org/all/CAHk-=wjAmmHUg6vho1KjzQi2=psR30+CogFd4aXrThr2gsiS4g@mail.gmail.com/ [0] Changes: v2->v3: - 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@gmail.com/ - 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@gmail.com/ Yafang Shao (11): fs/exec: Drop task_lock() inside __get_task_comm() auditsc: Replace memcpy() with __get_task_comm() 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} mm/kmemleak: Replace strncpy() with __get_task_comm() tsacct: Replace strncpy() with __get_task_comm() tracing: Replace strncpy() with __get_task_comm() net: Replace strcpy() with __get_task_comm() drm: Replace strcpy() with __get_task_comm() drivers/gpu/drm/drm_framebuffer.c | 2 +- drivers/gpu/drm/i915/i915_gpu_error.c | 2 +- fs/exec.c | 10 ++++++++-- include/linux/sched.h | 4 ++-- kernel/auditsc.c | 6 +++--- kernel/trace/trace.c | 2 +- kernel/trace/trace_events_hist.c | 2 +- kernel/tsacct.c | 2 +- mm/internal.h | 24 ++++++++++++++++++++++++ mm/kmemleak.c | 8 +------- mm/util.c | 21 ++++----------------- net/ipv6/ndisc.c | 2 +- security/lsm_audit.c | 4 ++-- security/selinux/selinuxfs.c | 2 +- tools/bpf/bpftool/pids.c | 2 ++ 15 files changed, 53 insertions(+), 40 deletions(-)