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| author | Oleg Nesterov <oleg@redhat.com> | 2024-02-26 17:56:50 +0100 |
|---|---|---|
| committer | Andrew Morton <akpm@linux-foundation.org> | 2024-03-06 13:07:39 -0800 |
| commit | dd69edd643a8263f9a96d0a3a82d8d50d9df9b48 (patch) | |
| tree | e90e0026e66f87f09d0fe323ad052ca499f722b4 | |
| parent | 49fd5f5ac4b59dcd53b5788d56d4ae7a8a1e1434 (diff) | |
| download | lwn-dd69edd643a8263f9a96d0a3a82d8d50d9df9b48.tar.gz lwn-dd69edd643a8263f9a96d0a3a82d8d50d9df9b48.zip | |
get_signal: hide_si_addr_tag_bits: fix the usage of uninitialized ksig
ksig->ka and ksig->info are not initialized if get_signal() returns 0 or
if the caller is PF_USER_WORKER.
Check signr != 0 before SA_EXPOSE_TAGBITS and move the "out" label down.
The latter means that ksig->sig won't be initialized if a PF_USER_WORKER
thread gets a fatal signal but this is fine, PF_USER_WORKER's don't use
ksig. And there is nothing new, in this case ksig->ka and ksig-info are
not initialized anyway. Add a comment.
Link: https://lkml.kernel.org/r/20240226165650.GA20829@redhat.com
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Cc: Christian Brauner <brauner@kernel.org>
Cc: Eric W. Biederman <ebiederm@xmission.com>
Cc: Peter Collingbourne <pcc@google.com>
Cc: Wen Yang <wenyang.linux@foxmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
| -rw-r--r-- | kernel/signal.c | 11 |
1 files changed, 6 insertions, 5 deletions
diff --git a/kernel/signal.c b/kernel/signal.c index 09a6dd07cf6b..a69d3069067a 100644 --- a/kernel/signal.c +++ b/kernel/signal.c @@ -2881,8 +2881,9 @@ relock: /* * PF_USER_WORKER threads will catch and exit on fatal signals - * themselves. They have cleanup that must be performed, so - * we cannot call do_exit() on their behalf. + * themselves. They have cleanup that must be performed, so we + * cannot call do_exit() on their behalf. Note that ksig won't + * be properly initialized, PF_USER_WORKER's shouldn't use it. */ if (current->flags & PF_USER_WORKER) goto out; @@ -2894,12 +2895,12 @@ relock: /* NOTREACHED */ } spin_unlock_irq(&sighand->siglock); -out: + ksig->sig = signr; - if (!(ksig->ka.sa.sa_flags & SA_EXPOSE_TAGBITS)) + if (signr && !(ksig->ka.sa.sa_flags & SA_EXPOSE_TAGBITS)) hide_si_addr_tag_bits(ksig); - +out: return signr > 0; } |