From: Alexander Usyskin <alexander.usyskin@intel.com> 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@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 64e318f589b4..0d23efcc74ff 100644 --- a/drivers/misc/mei/client.h +++ b/drivers/misc/mei/client.h @@ -138,11 +138,11 @@ 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; } /** -- 2.25.1