From: Dmitry Bogdanov <d.bogdanov@xxxxxxxxx> [ Upstream commit 4a8f71014b4d56c4fb287607e844c0a9f68f46d9 ] The sgl is freed in the target stack in target_release_cmd_kref() before calling qlt_free_cmd() but there is an unmap of sgl in qlt_free_cmd() that causes a panic if sgl is not yet DMA unmapped: NIP dma_direct_unmap_sg+0xdc/0x180 LR dma_direct_unmap_sg+0xc8/0x180 Call Trace: ql_dbg_prefix+0x68/0xc0 [qla2xxx] (unreliable) dma_unmap_sg_attrs+0x54/0xf0 qlt_unmap_sg.part.19+0x54/0x1c0 [qla2xxx] qlt_free_cmd+0x124/0x1d0 [qla2xxx] tcm_qla2xxx_release_cmd+0x4c/0xa0 [tcm_qla2xxx] target_put_sess_cmd+0x198/0x370 [target_core_mod] transport_generic_free_cmd+0x6c/0x1b0 [target_core_mod] tcm_qla2xxx_complete_free+0x6c/0x90 [tcm_qla2xxx] The sgl may be left unmapped in error cases of response sending. For instance, qlt_rdy_to_xfer() maps sgl and exits when session is being deleted keeping the sgl mapped. This patch removes use-after-free of the sgl and ensures that the sgl is unmapped for any command that was not sent to firmware. Link: https://lore.kernel.org/r/20211018122650.11846-1-d.bogdanov@xxxxxxxxx Reviewed-by: Himanshu Madhani <himanshu.madhani@xxxxxxxxxx> Signed-off-by: Dmitry Bogdanov <d.bogdanov@xxxxxxxxx> Signed-off-by: Martin K. Petersen <martin.petersen@xxxxxxxxxx> Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> --- drivers/scsi/qla2xxx/qla_target.c | 14 +++++--------- 1 file changed, 5 insertions(+), 9 deletions(-) diff --git a/drivers/scsi/qla2xxx/qla_target.c b/drivers/scsi/qla2xxx/qla_target.c index 8d4976725a75..ebed14bed783 100644 --- a/drivers/scsi/qla2xxx/qla_target.c +++ b/drivers/scsi/qla2xxx/qla_target.c @@ -3256,8 +3256,7 @@ int qlt_xmit_response(struct qla_tgt_cmd *cmd, int xmit_type, "RESET-RSP online/active/old-count/new-count = %d/%d/%d/%d.\n", vha->flags.online, qla2x00_reset_active(vha), cmd->reset_count, qpair->chip_reset); - spin_unlock_irqrestore(qpair->qp_lock_ptr, flags); - return 0; + goto out_unmap_unlock; } /* Does F/W have an IOCBs for this request */ @@ -3380,10 +3379,6 @@ int qlt_rdy_to_xfer(struct qla_tgt_cmd *cmd) prm.sg = NULL; prm.req_cnt = 1; - /* Calculate number of entries and segments required */ - if (qlt_pci_map_calc_cnt(&prm) != 0) - return -EAGAIN; - if (!qpair->fw_started || (cmd->reset_count != qpair->chip_reset) || (cmd->sess && cmd->sess->deleted)) { /* @@ -3401,6 +3396,10 @@ int qlt_rdy_to_xfer(struct qla_tgt_cmd *cmd) return 0; } + /* Calculate number of entries and segments required */ + if (qlt_pci_map_calc_cnt(&prm) != 0) + return -EAGAIN; + spin_lock_irqsave(qpair->qp_lock_ptr, flags); /* Does F/W have an IOCBs for this request */ res = qlt_check_reserve_free_req(qpair, prm.req_cnt); @@ -3805,9 +3804,6 @@ void qlt_free_cmd(struct qla_tgt_cmd *cmd) BUG_ON(cmd->cmd_in_wq); - if (cmd->sg_mapped) - qlt_unmap_sg(cmd->vha, cmd); - if (!cmd->q_full) qlt_decr_num_pend_cmds(cmd->vha); -- 2.33.0
