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| author | Peter Zijlstra <peterz@infradead.org> | 2017-12-06 17:32:47 +0100 |
|---|---|---|
| committer | Ingo Molnar <mingo@kernel.org> | 2017-12-06 19:29:56 +0100 |
| commit | 5e351ad106997e06b2dc3da9c6b939b95f67fb88 (patch) | |
| tree | c3f2ca916c260a9abc2b92a2d528ab093a4a4878 /kernel/locking | |
| parent | 328b4ed93b69a6f2083d52f31a240a09e5de386a (diff) | |
| download | lwn-5e351ad106997e06b2dc3da9c6b939b95f67fb88.tar.gz lwn-5e351ad106997e06b2dc3da9c6b939b95f67fb88.zip | |
locking/lockdep: Fix possible NULL deref
We can't invalidate xhlocks when we've not yet allocated any.
Reported-by: Dmitry Vyukov <dvyukov@google.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-kernel@vger.kernel.org
Fixes: f52be5708076 ("locking/lockdep: Untangle xhlock history save/restore from task independence")
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'kernel/locking')
| -rw-r--r-- | kernel/locking/lockdep.c | 3 |
1 files changed, 2 insertions, 1 deletions
diff --git a/kernel/locking/lockdep.c b/kernel/locking/lockdep.c index 9776da8db180..670d8d7d8087 100644 --- a/kernel/locking/lockdep.c +++ b/kernel/locking/lockdep.c @@ -4790,7 +4790,8 @@ void lockdep_invariant_state(bool force) * Verify the former, enforce the latter. */ WARN_ON_ONCE(!force && current->lockdep_depth); - invalidate_xhlock(&xhlock(current->xhlock_idx)); + if (current->xhlocks) + invalidate_xhlock(&xhlock(current->xhlock_idx)); } static int cross_lock(struct lockdep_map *lock) |