diff options
| author | Robin Holt <holt@sgi.com> | 2009-12-15 16:47:57 -0800 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2009-12-16 07:20:14 -0800 |
| commit | 15b87d67ff3dc042bee42f991858d6b121b3b3ca (patch) | |
| tree | 48e72a7ce8b4113b3dfcdcd31ca9bdce38ee3cd9 | |
| parent | c2c9f115741453715d6b4da1cd2de65af8c7ad86 (diff) | |
x86: uv: xpc NULL deref when mesq becomes empty
Under heavy load conditions, our set of xpc messages may become exhausted.
The code handles this correctly with the exception of the management code
which hits a NULL pointer dereference.
Signed-off-by: Robin Holt <holt@sgi.com>
Cc: Jack Steiner <steiner@sgi.com>
Cc: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| -rw-r--r-- | drivers/misc/sgi-xp/xpc_uv.c | 8 |
1 files changed, 5 insertions, 3 deletions
diff --git a/drivers/misc/sgi-xp/xpc_uv.c b/drivers/misc/sgi-xp/xpc_uv.c index bbf0e2ee6fd..19bd7b0ede9 100644 --- a/drivers/misc/sgi-xp/xpc_uv.c +++ b/drivers/misc/sgi-xp/xpc_uv.c @@ -949,11 +949,13 @@ xpc_get_fifo_entry_uv(struct xpc_fifo_head_uv *head) head->first = first->next; if (head->first == NULL) head->last = NULL; + + head->n_entries--; + BUG_ON(head->n_entries < 0); + + first->next = NULL; } - head->n_entries--; - BUG_ON(head->n_entries < 0); spin_unlock_irqrestore(&head->lock, irq_flags); - first->next = NULL; return first; } |