fs/exec: replace strlcpy with strscpy_pad in __set_task_comm

Patch series "task comm cleanups", v2.

This patchset is part of the patchset "extend task comm from 16 to
24"[1].  Now we have different opinion that dynamically allocates memory
to store kthread's long name into a separate pointer, so I decide to
take the useful cleanups apart from the original patchset and send it
separately[2].

These useful cleanups can make the usage around task comm less
error-prone.  Furthermore, it will be useful if we want to extend task
comm in the future.

[1]. https://lore.kernel.org/lkml/[email protected]/
[2]. https://lore.kernel.org/lkml/CALOAHbAx55AUo3bm8ZepZSZnw7A08cvKPdPyNTf=E_tPqmw5hw@mail.gmail.com/

This patch (of 7):

strlcpy() can trigger out-of-bound reads on the source string[1], we'd
better use strscpy() instead.  To make it be robust against full tsk->comm
copies that got noticed in other places, we should make sure it's zero
padded.

[1] https://github.com/KSPP/linux/issues/89

Link: https://lkml.kernel.org/r/[email protected]
Link: https://lkml.kernel.org/r/[email protected]
Signed-off-by: Yafang Shao <[email protected]>
Reviewed-by: Kees Cook <[email protected]>
Reviewed-by: David Hildenbrand <[email protected]>
Cc: Mathieu Desnoyers <[email protected]>
Cc: Arnaldo Carvalho de Melo <[email protected]>
Cc: Alexei Starovoitov <[email protected]>
Cc: Andrii Nakryiko <[email protected]>
Cc: Michal Miroslaw <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Cc: Steven Rostedt <[email protected]>
Cc: Matthew Wilcox <[email protected]>
Cc: David Hildenbrand <[email protected]>
Cc: Al Viro <[email protected]>
Cc: Kees Cook <[email protected]>
Cc: Petr Mladek <[email protected]>
Cc: Andrii Nakryiko <[email protected]>
Cc: Dennis Dalessandro <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>

0 files changed, 0 insertions, 0 deletions