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| author | Peter Zijlstra <peterz@infradead.org> | 2014-09-29 12:12:01 +0200 |
|---|---|---|
| committer | Ingo Molnar <mingo@kernel.org> | 2014-10-03 05:41:08 +0200 |
| commit | 9c2b9d30e28559a78c9e431cdd7f2c6bf5a9ee67 (patch) | |
| tree | 63e8e2f6c3a9fb68ed907b69e85cbce333d7ff2b /kernel/events | |
| parent | perf: Fix unclone_ctx() vs. locking (diff) | |
| download | linux-9c2b9d30e28559a78c9e431cdd7f2c6bf5a9ee67.tar.xz linux-9c2b9d30e28559a78c9e431cdd7f2c6bf5a9ee67.zip | |
perf: Fix perf bug in fork()
Oleg noticed that a cleanup by Sylvain actually uncovered a bug; by
calling perf_event_free_task() when failing sched_fork() we will not yet
have done the memset() on ->perf_event_ctxp[] and will therefore try and
'free' the inherited contexts, which are still in use by the parent
process.
This is bad and might explain some outstanding fuzzer failures ...
Suggested-by: Oleg Nesterov <oleg@redhat.com>
Reported-by: Oleg Nesterov <oleg@redhat.com>
Reported-by: Sylvain 'ythier' Hitier <sylvain.hitier@gmail.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Aaron Tomlin <atomlin@redhat.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Daeseok Youn <daeseok.youn@gmail.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Rik van Riel <riel@redhat.com>
Cc: Vladimir Davydov <vdavydov@parallels.com>
Cc: <stable@vger.kernel.org>
Link: http://lkml.kernel.org/r/20140929101201.GE5430@worktop
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'kernel/events')
| -rw-r--r-- | kernel/events/core.c | 4 |
1 files changed, 3 insertions, 1 deletions
diff --git a/kernel/events/core.c b/kernel/events/core.c index afdd9e1d7144..658f232af04c 100644 --- a/kernel/events/core.c +++ b/kernel/events/core.c @@ -7956,8 +7956,10 @@ int perf_event_init_task(struct task_struct *child) for_each_task_context_nr(ctxn) { ret = perf_event_init_context(child, ctxn); - if (ret) + if (ret) { + perf_event_free_task(child); return ret; + } } return 0; |