This is a note to let you know that I've just added the patch titled scsi: qla2xxx: Fix use after free in bsg to the 5.4-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: scsi-qla2xxx-fix-use-after-free-in-bsg.patch and it can be found in the queue-5.4 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. commit 81c5e751b663363b04310668c8aa2431917aa288 Author: Quinn Tran <qutran@xxxxxxxxxxx> Date: Mon Mar 29 01:52:22 2021 -0700 scsi: qla2xxx: Fix use after free in bsg [ Upstream commit 2ce35c0821afc2acd5ee1c3f60d149f8b2520ce8 ] On bsg command completion, bsg_job_done() was called while qla driver continued to access the bsg_job buffer. bsg_job_done() would free up resources that ended up being reused by other task while the driver continued to access the buffers. As a result, driver was reading garbage data. localhost kernel: BUG: KASAN: use-after-free in sg_next+0x64/0x80 localhost kernel: Read of size 8 at addr ffff8883228a3330 by task swapper/26/0 localhost kernel: localhost kernel: CPU: 26 PID: 0 Comm: swapper/26 Kdump: loaded Tainted: G OE --------- - - 4.18.0-193.el8.x86_64+debug #1 localhost kernel: Hardware name: HP ProLiant DL360 Gen9/ProLiant DL360 Gen9, BIOS P89 08/12/2016 localhost kernel: Call Trace: localhost kernel: <IRQ> localhost kernel: dump_stack+0x9a/0xf0 localhost kernel: print_address_description.cold.3+0x9/0x23b localhost kernel: kasan_report.cold.4+0x65/0x95 localhost kernel: debug_dma_unmap_sg.part.12+0x10d/0x2d0 localhost kernel: qla2x00_bsg_sp_free+0xaf6/0x1010 [qla2xxx] Link: https://lore.kernel.org/r/20210329085229.4367-6-njavali@xxxxxxxxxxx Reviewed-by: Himanshu Madhani <himanshu.madhani@xxxxxxxxxx> Signed-off-by: Quinn Tran <qutran@xxxxxxxxxxx> Signed-off-by: Saurav Kashyap <skashyap@xxxxxxxxxxx> Signed-off-by: Nilesh Javali <njavali@xxxxxxxxxxx> Signed-off-by: Martin K. Petersen <martin.petersen@xxxxxxxxxx> Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> diff --git a/drivers/scsi/qla2xxx/qla_bsg.c b/drivers/scsi/qla2xxx/qla_bsg.c index cbaf178fc979..ce55121910e8 100644 --- a/drivers/scsi/qla2xxx/qla_bsg.c +++ b/drivers/scsi/qla2xxx/qla_bsg.c @@ -17,10 +17,11 @@ void qla2x00_bsg_job_done(srb_t *sp, int res) struct bsg_job *bsg_job = sp->u.bsg_job; struct fc_bsg_reply *bsg_reply = bsg_job->reply; + sp->free(sp); + bsg_reply->result = res; bsg_job_done(bsg_job, bsg_reply->result, bsg_reply->reply_payload_rcv_len); - sp->free(sp); } void qla2x00_bsg_sp_free(srb_t *sp)