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| author | Peter Zijlstra <peterz@infradead.org> | 2022-12-19 15:40:04 +0100 |
|---|---|---|
| committer | Peter Zijlstra <peterz@infradead.org> | 2022-12-27 12:44:01 +0100 |
| commit | a551844e345ba2a1c533dee4b55cb0efddb1bcda (patch) | |
| tree | b9e9745bfecbd4c4739d4511fc76802bbae2bb4c | |
| parent | 08245672cdc6505550d1a5020603b0a8d4a6dcc7 (diff) | |
| download | linux-a551844e345ba2a1c533dee4b55cb0efddb1bcda.tar.bz2 | |
perf: Fix use-after-free in error path
The syscall error path has a use-after-free; put_pmu_ctx() will
reference ctx, therefore we must ensure ctx is destroyed after pmu_ctx
is.
Fixes: bd2756811766 ("perf: Rewrite core context handling")
Reported-by: syzbot+b8e8c01c8ade4fe6e48f@syzkaller.appspotmail.com
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Tested-by: Chengming Zhou <zhouchengming@bytedance.com>
Link: https://lkml.kernel.org/r/Y6B3xEgkbmFUCeni@hirez.programming.kicks-ass.net
| -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 37c0f04d7a00..63d674c9b70e 100644 --- a/kernel/events/core.c +++ b/kernel/events/core.c @@ -12671,7 +12671,8 @@ SYSCALL_DEFINE5(perf_event_open, return event_fd; err_context: - /* event->pmu_ctx freed by free_event() */ + put_pmu_ctx(event->pmu_ctx); + event->pmu_ctx = NULL; /* _free_event() */ err_locked: mutex_unlock(&ctx->mutex); perf_unpin_context(ctx); @@ -12784,6 +12785,7 @@ perf_event_create_kernel_counter(struct perf_event_attr *attr, int cpu, err_pmu_ctx: put_pmu_ctx(pmu_ctx); + event->pmu_ctx = NULL; /* _free_event() */ err_unlock: mutex_unlock(&ctx->mutex); perf_unpin_context(ctx); |