Messages in this thread Patch in this message | | | From | Marina Makienko <> | Subject | [PATCH 13/13] scsi: Potential null pointer dereference in scsi_eh_lock_door() | Date | Thu, 9 Aug 2012 17:55:50 +0400 |
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The function blk_get_request() can return NULL in some cases. There are checks on it if function is called with argumetns one of which is GFP_ATOMIC/GFP_NOIO/etc. If system couldn't find request blk_get_request() return NULL.
But if there is function call with argument __GFP_WAIT the system will wait until get request or the queue becomes dead. If something kills the queue, blk_get_request() return NULL and next operations will lead to errors.
Found by Linux Driver Verification project (linuxtesting.org).
Signed-off-by: Marina Makienko <makienko@ispras.ru> --- drivers/scsi/scsi_error.c | 3 +++ 1 files changed, 3 insertions(+), 0 deletions(-)
diff --git a/drivers/scsi/scsi_error.c b/drivers/scsi/scsi_error.c index 4a6381c..7dd67d4 100644 --- a/drivers/scsi/scsi_error.c +++ b/drivers/scsi/scsi_error.c @@ -1624,6 +1624,9 @@ static void scsi_eh_lock_door(struct scsi_device *sdev) */ req = blk_get_request(sdev->request_queue, READ, GFP_KERNEL); + if (!req) + return; + req->cmd[0] = ALLOW_MEDIUM_REMOVAL; req->cmd[1] = 0; req->cmd[2] = 0; -- 1.7.7
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