diff options
| author | Peter Zijlstra <[email protected]> | 2014-09-29 12:12:01 +0200 |
|---|---|---|
| committer | Ingo Molnar <[email protected]> | 2014-10-03 05:41:08 +0200 |
| commit | 9c2b9d30e28559a78c9e431cdd7f2c6bf5a9ee67 (patch) | |
| tree | 63e8e2f6c3a9fb68ed907b69e85cbce333d7ff2b | |
| parent | 211de6eba8960521e2be450a7d07db85fba4604c (diff) | |
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 <[email protected]>
Reported-by: Oleg Nesterov <[email protected]>
Reported-by: Sylvain 'ythier' Hitier <[email protected]>
Signed-off-by: Peter Zijlstra (Intel) <[email protected]>
Cc: Aaron Tomlin <[email protected]>
Cc: Andrew Morton <[email protected]>
Cc: Arnaldo Carvalho de Melo <[email protected]>
Cc: Daeseok Youn <[email protected]>
Cc: David Rientjes <[email protected]>
Cc: Kees Cook <[email protected]>
Cc: Linus Torvalds <[email protected]>
Cc: Paul Mackerras <[email protected]>
Cc: Rik van Riel <[email protected]>
Cc: Vladimir Davydov <[email protected]>
Cc: <[email protected]>
Link: http://lkml.kernel.org/r/20140929101201.GE5430@worktop
Signed-off-by: Ingo Molnar <[email protected]>
| -rw-r--r-- | kernel/events/core.c | 4 | ||||
| -rw-r--r-- | kernel/fork.c | 5 |
2 files changed, 6 insertions, 3 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; diff --git a/kernel/fork.c b/kernel/fork.c index 0cf9cdb6e491..a91e47d86de2 100644 --- a/kernel/fork.c +++ b/kernel/fork.c @@ -1360,7 +1360,7 @@ static struct task_struct *copy_process(unsigned long clone_flags, goto bad_fork_cleanup_policy; retval = audit_alloc(p); if (retval) - goto bad_fork_cleanup_policy; + goto bad_fork_cleanup_perf; /* copy all the process information */ shm_init_task(p); retval = copy_semundo(clone_flags, p); @@ -1566,8 +1566,9 @@ bad_fork_cleanup_semundo: exit_sem(p); bad_fork_cleanup_audit: audit_free(p); -bad_fork_cleanup_policy: +bad_fork_cleanup_perf: perf_event_free_task(p); +bad_fork_cleanup_policy: #ifdef CONFIG_NUMA mpol_put(p->mempolicy); bad_fork_cleanup_threadgroup_lock: |