[PATCH 1/2] scsi: don't reference freed command in scsi_init_sgtable

From: Christoph Hellwig
Date: Fri Apr 25 2014 - 07:09:29 EST


When scsi_init_io fails we have to release our device reference, but
we do this trying to reference the just freed command. Add a local
scsi_device pointer to fix this.

Reported-by: Sander Eikelenboom <linux@xxxxxxxxxxxxxx>
Signed-off-by: Christoph Hellwig <hch@xxxxxx>
---
drivers/scsi/scsi_lib.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/scsi/scsi_lib.c b/drivers/scsi/scsi_lib.c
index 65a123d..54eff6a 100644
--- a/drivers/scsi/scsi_lib.c
+++ b/drivers/scsi/scsi_lib.c
@@ -1044,6 +1044,7 @@ static int scsi_init_sgtable(struct request *req, struct scsi_data_buffer *sdb,
*/
int scsi_init_io(struct scsi_cmnd *cmd, gfp_t gfp_mask)
{
+ struct scsi_device *sdev = cmd->device;
struct request *rq = cmd->request;

int error = scsi_init_sgtable(rq, &cmd->sdb, gfp_mask);
@@ -1091,7 +1092,7 @@ err_exit:
scsi_release_buffers(cmd);
cmd->request->special = NULL;
scsi_put_command(cmd);
- put_device(&cmd->device->sdev_gendev);
+ put_device(&sdev->sdev_gendev);
return error;
}
EXPORT_SYMBOL(scsi_init_io);
--
1.7.10.4

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/