[PATCH 3.19.y-ckt 073/170] bcache: fix cache_set_flush() NULL pointer dereference on OOM

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



3.19.8-ckt18 -stable review patch.  If anyone has any objections, please let me know.

---8<------------------------------------------------------------

From: Eric Wheeler <git@xxxxxxxxxxxxxxxxxx>

commit f8b11260a445169989d01df75d35af0f56178f95 upstream.

When bch_cache_set_alloc() fails to kzalloc the cache_set, the
asyncronous closure handling tries to dereference a cache_set that
hadn't yet been allocated inside of cache_set_flush() which is called
by __cache_set_unregister() during cleanup.  This appears to happen only
during an OOM condition on bcache_register.

Signed-off-by: Eric Wheeler <bcache@xxxxxxxxxxxxxxxxxx>
Signed-off-by: Kamal Mostafa <kamal@xxxxxxxxxxxxx>
---
 drivers/md/bcache/super.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/drivers/md/bcache/super.c b/drivers/md/bcache/super.c
index 2d0650de..2a10283 100644
--- a/drivers/md/bcache/super.c
+++ b/drivers/md/bcache/super.c
@@ -1404,6 +1404,9 @@ static void cache_set_flush(struct closure *cl)
 	struct btree *b;
 	unsigned i;
 
+	if (!c)
+		closure_return(cl);
+
 	bch_cache_accounting_destroy(&c->accounting);
 
 	kobject_put(&c->internal);
-- 
2.7.4

--
To unsubscribe from this list: send the line "unsubscribe stable" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html



[Index of Archives]     [Linux Kernel]     [Kernel Development Newbies]     [Linux USB Devel]     [Video for Linux]     [Linux Audio Users]     [Yosemite Hiking]     [Linux Kernel]     [Linux SCSI]