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 my char-misc git tree which can be found at git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc.git in the char-misc-linus branch.

The patch will show up in the next release of the linux-next tree (usually sometime within the next 24 hours during the week.)

The patch will hopefully also be merged in Linus's tree for the next -rc kernel release.

If you have any questions about this process, please let me know.

From bcbc0b2e275f0a797de11a10eff495b4571863fc Mon Sep 17 00:00:00 2001

From: Alexander Usyskin alexander.usyskin@intel.com Date: Thu, 29 Oct 2020 11:54:42 +0200 Subject: mei: protect mei_cl_mtu from null dereference

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@vger.kernel.org Signed-off-by: Alexander Usyskin alexander.usyskin@intel.com Signed-off-by: Tomas Winkler tomas.winkler@intel.com Link: https://lore.kernel.org/r/20201029095444.957924-2-tomas.winkler@intel.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- drivers/misc/mei/client.h | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/misc/mei/client.h b/drivers/misc/mei/client.h index 64143d4ec758..9e08a9843bba 100644 --- a/drivers/misc/mei/client.h +++ b/drivers/misc/mei/client.h @@ -182,11 +182,11 @@ static inline u8 mei_cl_me_id(const struct mei_cl *cl) * * @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; }

/**