* FAILED: patch "[PATCH] nvmet-tcp: check INIT_FAILED before nvmet_req_uninit in" failed to apply to 5.10-stable tree
@ 2026-07-19 12:13 gregkh
2026-07-20 13:54 ` [PATCH 5.10.y] nvmet-tcp: check INIT_FAILED before nvmet_req_uninit in digest error path Shivam Kumar
0 siblings, 1 reply; 3+ messages in thread
From: gregkh @ 2026-07-19 12:13 UTC (permalink / raw)
To: kumar.shivam43666, hch, kbusch; +Cc: stable
The patch below does not apply to the 5.10-stable tree.
If someone wants it applied there, or to any other stable or longterm
tree, then please email the backport, including the original git commit
id to <stable@vger.kernel.org>.
To reproduce the conflict and resubmit, you may use the following commands:
git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-5.10.y
git checkout FETCH_HEAD
git cherry-pick -x 4606467a75cfc16721937272ed29462a750b60c8
# <resolve conflicts, build, test, etc.>
git commit -s
git send-email --to '<stable@vger.kernel.org>' --in-reply-to '2026071925-skimmer-retainer-3785@gregkh' --subject-prefix 'PATCH 5.10.y' 'HEAD^..'
Possible dependencies:
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
From 4606467a75cfc16721937272ed29462a750b60c8 Mon Sep 17 00:00:00 2001
From: Shivam Kumar <kumar.shivam43666@gmail.com>
Date: Wed, 18 Mar 2026 18:56:58 -0400
Subject: [PATCH] nvmet-tcp: check INIT_FAILED before nvmet_req_uninit in
digest error path
In nvmet_tcp_try_recv_ddgst(), when a data digest mismatch is detected,
nvmet_req_uninit() is called unconditionally. However, if the command
arrived via the nvmet_tcp_handle_req_failure() path, nvmet_req_init()
had returned false and percpu_ref_tryget_live() was never executed. The
unconditional percpu_ref_put() inside nvmet_req_uninit() then causes a
refcount underflow, leading to a WARNING in
percpu_ref_switch_to_atomic_rcu, a use-after-free diagnostic, and
eventually a permanent workqueue deadlock.
Check cmd->flags & NVMET_TCP_F_INIT_FAILED before calling
nvmet_req_uninit(), matching the existing pattern in
nvmet_tcp_execute_request().
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Shivam Kumar <kumar.shivam43666@gmail.com>
Signed-off-by: Keith Busch <kbusch@kernel.org>
diff --git a/drivers/nvme/target/tcp.c b/drivers/nvme/target/tcp.c
index 4b8b02341ddc..69e971b179ae 100644
--- a/drivers/nvme/target/tcp.c
+++ b/drivers/nvme/target/tcp.c
@@ -1310,7 +1310,8 @@ static int nvmet_tcp_try_recv_ddgst(struct nvmet_tcp_queue *queue)
queue->idx, cmd->req.cmd->common.command_id,
queue->pdu.cmd.hdr.type, le32_to_cpu(cmd->recv_ddgst),
le32_to_cpu(cmd->exp_ddgst));
- nvmet_req_uninit(&cmd->req);
+ if (!(cmd->flags & NVMET_TCP_F_INIT_FAILED))
+ nvmet_req_uninit(&cmd->req);
nvmet_tcp_free_cmd_buffers(cmd);
nvmet_tcp_fatal_error(queue);
ret = -EPROTO;
^ permalink raw reply related [flat|nested] 3+ messages in thread
* [PATCH 5.10.y] nvmet-tcp: check INIT_FAILED before nvmet_req_uninit in digest error path
2026-07-19 12:13 FAILED: patch "[PATCH] nvmet-tcp: check INIT_FAILED before nvmet_req_uninit in" failed to apply to 5.10-stable tree gregkh
@ 2026-07-20 13:54 ` Shivam Kumar
2026-07-21 0:56 ` Sasha Levin
0 siblings, 1 reply; 3+ messages in thread
From: Shivam Kumar @ 2026-07-20 13:54 UTC (permalink / raw)
To: stable; +Cc: Shivam Kumar, Christoph Hellwig, Keith Busch
commit 4606467a75cfc16721937272ed29462a750b60c8 upstream.
In nvmet_tcp_try_recv_ddgst(), when a data digest mismatch is detected,
nvmet_req_uninit() is called unconditionally. However, if the command
arrived via the nvmet_tcp_handle_req_failure() path, nvmet_req_init()
had returned false and percpu_ref_tryget_live() was never executed. The
unconditional percpu_ref_put() inside nvmet_req_uninit() then causes a
refcount underflow, leading to a WARNING in
percpu_ref_switch_to_atomic_rcu, a use-after-free diagnostic, and
eventually a permanent workqueue deadlock.
Check cmd->flags & NVMET_TCP_F_INIT_FAILED before calling
nvmet_req_uninit(), matching the existing pattern in
nvmet_tcp_execute_request().
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Shivam Kumar <kumar.shivam43666@gmail.com>
Signed-off-by: Keith Busch <kbusch@kernel.org>
[shivam: inlined nvmet_tcp_finish_cmd() at the fix site for 5.10.y]
Signed-off-by: Shivam Kumar <kumar.shivam43666@gmail.com>
---
drivers/nvme/target/tcp.c | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)
diff --git a/drivers/nvme/target/tcp.c b/drivers/nvme/target/tcp.c
index edcc0662c..ba5817006 100644
--- a/drivers/nvme/target/tcp.c
+++ b/drivers/nvme/target/tcp.c
@@ -1200,7 +1200,9 @@ static int nvmet_tcp_try_recv_ddgst(struct nvmet_tcp_queue *queue)
queue->idx, cmd->req.cmd->common.command_id,
queue->pdu.cmd.hdr.type, le32_to_cpu(cmd->recv_ddgst),
le32_to_cpu(cmd->exp_ddgst));
- nvmet_tcp_finish_cmd(cmd);
+ if (!(cmd->flags & NVMET_TCP_F_INIT_FAILED))
+ nvmet_req_uninit(&cmd->req);
+ nvmet_tcp_free_cmd_buffers(cmd);
nvmet_tcp_fatal_error(queue);
ret = -EPROTO;
goto out;
--
2.50.1 (Apple Git-155)
^ permalink raw reply related [flat|nested] 3+ messages in thread
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2026-07-19 12:13 FAILED: patch "[PATCH] nvmet-tcp: check INIT_FAILED before nvmet_req_uninit in" failed to apply to 5.10-stable tree gregkh
2026-07-20 13:54 ` [PATCH 5.10.y] nvmet-tcp: check INIT_FAILED before nvmet_req_uninit in digest error path Shivam Kumar
2026-07-21 0:56 ` Sasha Levin
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