[PATCH AUTOSEL 6.1 47/58] scsi: ufs: core: Fix device management cmd timeout flow

Sasha Levin
2023-02-27T02:36:14Z

From: Mason Zhang <Mason.Zhang@mediatek.com>

[ Upstream commit 36822124f9de200cedc2f42516301b50d386a6cd ]

In the UFS error handling flow, the host will send a device management cmd
(NOP OUT) to the device for link recovery. If this cmd times out and
clearing the doorbell fails, ufshcd_wait_for_dev_cmd() will do nothing and
return. hba->dev_cmd.complete struct is not set to NULL.

When this happens, if cmd has been completed by device, then we will call
complete() in __ufshcd_transfer_req_compl(). Because the complete struct is
allocated on the stack, the following crash will occur:

ipanic_die+0x24/0x38 [mrdump]
die+0x344/0x748
arm64_notify_die+0x44/0x104
do_debug_exception+0x104/0x1e0
el1_dbg+0x38/0x54
el1_sync_handler+0x40/0x88
el1_sync+0x8c/0x140
queued_spin_lock_slowpath+0x2e4/0x3c0
__ufshcd_transfer_req_compl+0x3b0/0x1164
ufshcd_trc_handler+0x15c/0x308
ufshcd_host_reset_and_restore+0x54/0x260
ufshcd_reset_and_restore+0x28c/0x57c
ufshcd_err_handler+0xeb8/0x1b6c
process_one_work+0x288/0x964
worker_thread+0x4bc/0xc7c
kthread+0x15c/0x264
ret_from_fork+0x10/0x30

Link: https://lore.kernel.org/r/20221216032532.1280-1-mason.zhang@mediatek.com
Signed-off-by: Mason Zhang <Mason.Zhang@mediatek.com>
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/ufs/core/ufshcd.c | 16 ++++++++++++++++
1 file changed, 16 insertions(+)

diff --git a/drivers/ufs/core/ufshcd.c b/drivers/ufs/core/ufshcd.c
index fb5c9e2fc5348..dae49530201bf 100644
--- a/drivers/ufs/core/ufshcd.c
+++ b/drivers/ufs/core/ufshcd.c
@@ -3006,6 +3006,22 @@ static int ufshcd_wait_for_dev_cmd(struct ufs_hba *hba,
} else {
dev_err(hba->dev, "%s: failed to clear tag %d\n",
__func__, lrbp->task_tag);
+
+ spin_lock_irqsave(&hba->outstanding_lock, flags);
+ pending = test_bit(lrbp->task_tag,
+ &hba->outstanding_reqs);
+ if (pending)
+ hba->dev_cmd.complete = NULL;
+ spin_unlock_irqrestore(&hba->outstanding_lock, flags);
+
+ if (!pending) {
+ /*
+ * The completion handler ran while we tried to
+ * clear the command.
+ */
+ time_left = 1;
+ goto retry;
+ }
}
}

--
2.39.0