This is a note to let you know that I've just added the patch titled
mei: protect mei_cl_mtu from null dereference
to the 5.9-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:
mei-protect-mei_cl_mtu-from-null-dereference.patch
and it can be found in the queue-5.9 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From bcbc0b2e275f0a797de11a10eff495b4571863fc Mon Sep 17 00:00:00 2001
From: Alexander Usyskin <alexander.usyskin@xxxxxxxxx>
Date: Thu, 29 Oct 2020 11:54:42 +0200
Subject: mei: protect mei_cl_mtu from null dereference
From: Alexander Usyskin <alexander.usyskin@xxxxxxxxx>
commit bcbc0b2e275f0a797de11a10eff495b4571863fc upstream.
A receive callback is queued while the client is still connected
but can still be called after the client was disconnected. Upon
disconnect cl->me_cl is set to NULL, hence we need to check
that ME client is not-NULL in mei_cl_mtu to avoid
null dereference.
Cc: <stable@xxxxxxxxxxxxxxx>
Signed-off-by: Alexander Usyskin <alexander.usyskin@xxxxxxxxx>
Signed-off-by: Tomas Winkler <tomas.winkler@xxxxxxxxx>
Link: https://lore.kernel.org/r/20201029095444.957924-2-tomas.winkler@xxxxxxxxx
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/misc/mei/client.h | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
--- a/drivers/misc/mei/client.h
+++ b/drivers/misc/mei/client.h
@@ -164,11 +164,11 @@ static inline u8 mei_cl_me_id(const stru
*
* @cl: host client
*
- * Return: mtu
+ * Return: mtu or 0 if client is not connected
*/
static inline size_t mei_cl_mtu(const struct mei_cl *cl)
{
- return cl->me_cl->props.max_msg_length;
+ return cl->me_cl ? cl->me_cl->props.max_msg_length : 0;
}
/**
Patches currently in stable-queue which might be from alexander.usyskin@xxxxxxxxx are
queue-5.9/mei-protect-mei_cl_mtu-from-null-dereference.patch
