From: Alexander Usyskin Date: Thu, 29 Oct 2020 09:54:42 +0000 (+0200) Subject: mei: protect mei_cl_mtu from null dereference X-Git-Tag: v5.9.9~51 X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=67c433c290285db464f45c4159004c87d3e28a0e;p=thirdparty%2Fkernel%2Fstable.git mei: protect mei_cl_mtu from null dereference 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: Signed-off-by: Alexander Usyskin Signed-off-by: Tomas Winkler Link: https://lore.kernel.org/r/20201029095444.957924-2-tomas.winkler@intel.com Signed-off-by: Greg Kroah-Hartman --- diff --git a/drivers/misc/mei/client.h b/drivers/misc/mei/client.h index 2f8954def591b..98ff7af531a1c 100644 --- a/drivers/misc/mei/client.h +++ b/drivers/misc/mei/client.h @@ -164,11 +164,11 @@ 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; } /**