Messages in this thread Patch in this message | | | From | Marina Makienko <> | Subject | [PATCH 05/13] ide: Potential null pointer dereference in ide_raw_taskfile() | Date | Thu, 9 Aug 2012 17:55:22 +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/ide/ide-taskfile.c | 4 ++++ 1 files changed, 4 insertions(+), 0 deletions(-)
diff --git a/drivers/ide/ide-taskfile.c b/drivers/ide/ide-taskfile.c index 729428e..655d894 100644 --- a/drivers/ide/ide-taskfile.c +++ b/drivers/ide/ide-taskfile.c @@ -432,6 +432,10 @@ int ide_raw_taskfile(ide_drive_t *drive, struct ide_cmd *cmd, u8 *buf, int rw = !(cmd->tf_flags & IDE_TFLAG_WRITE) ? READ : WRITE; rq = blk_get_request(drive->queue, rw, __GFP_WAIT); + + if (!rq) + return -EIO; + rq->cmd_type = REQ_TYPE_ATA_TASKFILE; /* -- 1.7.7
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