From: Johannes Thumshirn johannes.thumshirn@wdc.com
[ Upstream commit 20a66f2bf280277ab5bb22e27445153b4eb0ac88 ]
In case scsi_setup_fs_cmnd() fails we're not freeing the sgtables allocated by scsi_init_io(), thus we leak the allocated memory.
Free the sgtables allocated by scsi_init_io() in case scsi_setup_fs_cmnd() fails.
Technically scsi_setup_scsi_cmnd() does not suffer from this problem as it can only fail if scsi_init_io() fails, so it does not have sgtables allocated. But to maintain symmetry and as a measure of defensive programming, free the sgtables on scsi_setup_scsi_cmnd() failure as well. scsi_mq_free_sgtables() has safeguards against double-freeing of memory so this is safe to do.
While we're at it, rename scsi_mq_free_sgtables() to scsi_free_sgtables().
Link: https://bugzilla.kernel.org/show_bug.cgi?id=205595 Link: https://lore.kernel.org/r/20200428104605.8143-2-johannes.thumshirn@wdc.com Reviewed-by: Christoph Hellwig hch@lst.de Reviewed-by: Daniel Wagner dwagner@suse.de Reviewed-by: Hannes Reinecke hare@suse.de Signed-off-by: Johannes Thumshirn johannes.thumshirn@wdc.com Signed-off-by: Martin K. Petersen martin.petersen@oracle.com Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/scsi/scsi_lib.c | 16 +++++++++++----- 1 file changed, 11 insertions(+), 5 deletions(-)
diff --git a/drivers/scsi/scsi_lib.c b/drivers/scsi/scsi_lib.c index 91c007d26c1e..206c9f53e9e7 100644 --- a/drivers/scsi/scsi_lib.c +++ b/drivers/scsi/scsi_lib.c @@ -551,7 +551,7 @@ static void scsi_uninit_cmd(struct scsi_cmnd *cmd) } }
-static void scsi_mq_free_sgtables(struct scsi_cmnd *cmd) +static void scsi_free_sgtables(struct scsi_cmnd *cmd) { if (cmd->sdb.table.nents) sg_free_table_chained(&cmd->sdb.table, @@ -563,7 +563,7 @@ static void scsi_mq_free_sgtables(struct scsi_cmnd *cmd)
static void scsi_mq_uninit_cmd(struct scsi_cmnd *cmd) { - scsi_mq_free_sgtables(cmd); + scsi_free_sgtables(cmd); scsi_uninit_cmd(cmd); scsi_del_cmd_from_list(cmd); } @@ -1063,7 +1063,7 @@ blk_status_t scsi_init_io(struct scsi_cmnd *cmd)
return BLK_STS_OK; out_free_sgtables: - scsi_mq_free_sgtables(cmd); + scsi_free_sgtables(cmd); return ret; } EXPORT_SYMBOL(scsi_init_io); @@ -1214,6 +1214,7 @@ static blk_status_t scsi_setup_cmnd(struct scsi_device *sdev, struct request *req) { struct scsi_cmnd *cmd = blk_mq_rq_to_pdu(req); + blk_status_t ret;
if (!blk_rq_bytes(req)) cmd->sc_data_direction = DMA_NONE; @@ -1223,9 +1224,14 @@ static blk_status_t scsi_setup_cmnd(struct scsi_device *sdev, cmd->sc_data_direction = DMA_FROM_DEVICE;
if (blk_rq_is_scsi(req)) - return scsi_setup_scsi_cmnd(sdev, req); + ret = scsi_setup_scsi_cmnd(sdev, req); else - return scsi_setup_fs_cmnd(sdev, req); + ret = scsi_setup_fs_cmnd(sdev, req); + + if (ret != BLK_STS_OK) + scsi_free_sgtables(cmd); + + return ret; }
static blk_status_t