On 08.11.21 09:38, Yafang Shao wrote: > It is better to use get_task_comm() instead of the open coded string > copy as we do in other places. > > struct elf_prpsinfo is used to dump the task information in userspace > coredump or kernel vmcore. Below is the verfication of vmcore, > > crash> ps > PID PPID CPU TASK ST %MEM VSZ RSS COMM > 0 0 0 ffffffff9d21a940 RU 0.0 0 0 [swapper/0] >> 0 0 1 ffffa09e40f85e80 RU 0.0 0 0 [swapper/1] >> 0 0 2 ffffa09e40f81f80 RU 0.0 0 0 [swapper/2] >> 0 0 3 ffffa09e40f83f00 RU 0.0 0 0 [swapper/3] >> 0 0 4 ffffa09e40f80000 RU 0.0 0 0 [swapper/4] >> 0 0 5 ffffa09e40f89f80 RU 0.0 0 0 [swapper/5] > 0 0 6 ffffa09e40f8bf00 RU 0.0 0 0 [swapper/6] >> 0 0 7 ffffa09e40f88000 RU 0.0 0 0 [swapper/7] >> 0 0 8 ffffa09e40f8de80 RU 0.0 0 0 [swapper/8] >> 0 0 9 ffffa09e40f95e80 RU 0.0 0 0 [swapper/9] >> 0 0 10 ffffa09e40f91f80 RU 0.0 0 0 [swapper/10] >> 0 0 11 ffffa09e40f93f00 RU 0.0 0 0 [swapper/11] >> 0 0 12 ffffa09e40f90000 RU 0.0 0 0 [swapper/12] >> 0 0 13 ffffa09e40f9bf00 RU 0.0 0 0 [swapper/13] >> 0 0 14 ffffa09e40f98000 RU 0.0 0 0 [swapper/14] >> 0 0 15 ffffa09e40f9de80 RU 0.0 0 0 [swapper/15] > > It works well as expected. > > Suggested-by: Kees Cook <keescook@xxxxxxxxxxxx> > Signed-off-by: Yafang Shao <laoar.shao@xxxxxxxxx> > Cc: Mathieu Desnoyers <mathieu.desnoyers@xxxxxxxxxxxx> > Cc: Arnaldo Carvalho de Melo <arnaldo.melo@xxxxxxxxx> > Cc: Andrii Nakryiko <andrii.nakryiko@xxxxxxxxx> > Cc: Michal Miroslaw <mirq-linux@xxxxxxxxxxxx> > Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx> > Cc: Steven Rostedt <rostedt@xxxxxxxxxxx> > Cc: Matthew Wilcox <willy@xxxxxxxxxxxxx> > Cc: David Hildenbrand <david@xxxxxxxxxx> > Cc: Al Viro <viro@xxxxxxxxxxxxxxxxxx> > Cc: Kees Cook <keescook@xxxxxxxxxxxx> > Cc: Petr Mladek <pmladek@xxxxxxxx> > --- > fs/binfmt_elf.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/fs/binfmt_elf.c b/fs/binfmt_elf.c > index a813b70f594e..138956fd4a88 100644 > --- a/fs/binfmt_elf.c > +++ b/fs/binfmt_elf.c > @@ -1572,7 +1572,7 @@ static int fill_psinfo(struct elf_prpsinfo *psinfo, struct task_struct *p, > SET_UID(psinfo->pr_uid, from_kuid_munged(cred->user_ns, cred->uid)); > SET_GID(psinfo->pr_gid, from_kgid_munged(cred->user_ns, cred->gid)); > rcu_read_unlock(); > - strncpy(psinfo->pr_fname, p->comm, sizeof(psinfo->pr_fname)); > + get_task_comm(psinfo->pr_fname, p); > > return 0; > } > We have a hard-coded "pr_fname[16]" as well, not sure if we want to adjust that to use TASK_COMM_LEN? Anyhow Reviewed-by: David Hildenbrand <david@xxxxxxxxxx> -- Thanks, David / dhildenb
