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scsi: core: free sgtables in case command setup fails

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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>
This commit is contained in:
Johannes Thumshirn 2020-04-28 19:45:55 +09:00 committed by Martin K. Petersen
parent ea941016ab
commit 20a66f2bf2
1 changed files with 11 additions and 5 deletions
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16
drivers/scsi/scsi_lib.c
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@ -531,7 +531,7 @@ 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,
@ -543,7 +543,7 @@ 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);
}
@ -1032,7 +1032,7 @@ 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);
@ -1163,6 +1163,7 @@ 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;
@ -1172,9 +1173,14 @@ 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