FAILED: patch "[PATCH] wifi: libertas: fix use-after-free in lbs_free_adapter()" failed to apply to 6.1-stable tree

FAILED: patch "[PATCH] wifi: libertas: fix use-after-free in lbs_free_adapter()" failed to apply to 6.1-stable tree

[gregkh]

The patch below does not apply to the 6.1-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-6.1.y
git checkout FETCH_HEAD
git cherry-pick -x 03cc8f90d0537fcd4985c3319b4fafbf2e3fb1f0
# <resolve conflicts, build, test, etc.>
git commit -s
git send-email --to '<stable@vger.kernel.org>' --in-reply-to '2026030917-carry-easily-7913@gregkh' --subject-prefix 'PATCH 6.1.y' HEAD^..

Possible dependencies:



thanks,

greg k-h

------------------ original commit in Linus's tree ------------------

From 03cc8f90d0537fcd4985c3319b4fafbf2e3fb1f0 Mon Sep 17 00:00:00 2001
From: Daniel Hodges <git@danielhodges.dev>
Date: Fri, 6 Feb 2026 14:53:56 -0500
Subject: [PATCH] wifi: libertas: fix use-after-free in lbs_free_adapter()

The lbs_free_adapter() function uses timer_delete() (non-synchronous)
for both command_timer and tx_lockup_timer before the structure is
freed. This is incorrect because timer_delete() does not wait for
any running timer callback to complete.

If a timer callback is executing when lbs_free_adapter() is called,
the callback will access freed memory since lbs_cfg_free() frees the
containing structure immediately after lbs_free_adapter() returns.

Both timer callbacks (lbs_cmd_timeout_handler and lbs_tx_lockup_handler)
access priv->driver_lock, priv->cur_cmd, priv->dev, and other fields,
which would all be use-after-free violations.

Use timer_delete_sync() instead to ensure any running timer callback
has completed before returning.

This bug was introduced in commit 8f641d93c38a ("libertas: detect TX
lockups and reset hardware") where del_timer() was used instead of
del_timer_sync() in the cleanup path. The command_timer has had the
same issue since the driver was first written.

Fixes: 8f641d93c38a ("libertas: detect TX lockups and reset hardware")
Fixes: 954ee164f4f4 ("[PATCH] libertas: reorganize and simplify init sequence")
Cc: stable@vger.kernel.org
Signed-off-by: Daniel Hodges <git@danielhodges.dev>
Link: https://patch.msgid.link/20260206195356.15647-1-git@danielhodges.dev
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

diff --git a/drivers/net/wireless/marvell/libertas/main.c b/drivers/net/wireless/marvell/libertas/main.c
index d44e02c6fe38..dd97f1b61f4d 100644
--- a/drivers/net/wireless/marvell/libertas/main.c
+++ b/drivers/net/wireless/marvell/libertas/main.c
@@ -799,8 +799,8 @@ static void lbs_free_adapter(struct lbs_private *priv)
 {
 	lbs_free_cmd_buffer(priv);
 	kfifo_free(&priv->event_fifo);
-	timer_delete(&priv->command_timer);
-	timer_delete(&priv->tx_lockup_timer);
+	timer_delete_sync(&priv->command_timer);
+	timer_delete_sync(&priv->tx_lockup_timer);
 }
 
 static const struct net_device_ops lbs_netdev_ops = {

[PATCH 6.1.y] wifi: libertas: fix use-after-free in lbs_free_adapter()

[Sasha Levin]

From: Daniel Hodges <git@danielhodges.dev>

[ Upstream commit 03cc8f90d0537fcd4985c3319b4fafbf2e3fb1f0 ]

The lbs_free_adapter() function uses timer_delete() (non-synchronous)
for both command_timer and tx_lockup_timer before the structure is
freed. This is incorrect because timer_delete() does not wait for
any running timer callback to complete.

If a timer callback is executing when lbs_free_adapter() is called,
the callback will access freed memory since lbs_cfg_free() frees the
containing structure immediately after lbs_free_adapter() returns.

Both timer callbacks (lbs_cmd_timeout_handler and lbs_tx_lockup_handler)
access priv->driver_lock, priv->cur_cmd, priv->dev, and other fields,
which would all be use-after-free violations.

Use timer_delete_sync() instead to ensure any running timer callback
has completed before returning.

This bug was introduced in commit 8f641d93c38a ("libertas: detect TX
lockups and reset hardware") where del_timer() was used instead of
del_timer_sync() in the cleanup path. The command_timer has had the
same issue since the driver was first written.

Fixes: 8f641d93c38a ("libertas: detect TX lockups and reset hardware")
Fixes: 954ee164f4f4 ("[PATCH] libertas: reorganize and simplify init sequence")
Cc: stable@vger.kernel.org
Signed-off-by: Daniel Hodges <git@danielhodges.dev>
Link: https://patch.msgid.link/20260206195356.15647-1-git@danielhodges.dev
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
[ del_timer() => timer_delete_sync() ]
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/net/wireless/marvell/libertas/main.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/net/wireless/marvell/libertas/main.c b/drivers/net/wireless/marvell/libertas/main.c
index 78e8b5aecec0e..91b9501c6d8cb 100644
--- a/drivers/net/wireless/marvell/libertas/main.c
+++ b/drivers/net/wireless/marvell/libertas/main.c
@@ -881,8 +881,8 @@ static void lbs_free_adapter(struct lbs_private *priv)
 {
 	lbs_free_cmd_buffer(priv);
 	kfifo_free(&priv->event_fifo);
-	del_timer(&priv->command_timer);
-	del_timer(&priv->tx_lockup_timer);
+	timer_delete_sync(&priv->command_timer);
+	timer_delete_sync(&priv->tx_lockup_timer);
 	del_timer(&priv->auto_deepsleep_timer);
 }
 
-- 
2.51.0