Commit 541ebf6a authored by Eric Dumazet's avatar Eric Dumazet Committed by Liu Jian
Browse files

net/sched: taprio: always validate TCA_TAPRIO_ATTR_PRIOMAP 

mainline inclusion
from mainline-v6.10-rc3
commit f921a58ae20852d188f70842431ce6519c4fdc36
category: bugfix
bugzilla: https://gitee.com/src-openeuler/kernel/issues/IA6H2M
CVE: CVE-2024-36974

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=f921a58ae20852d188f70842431ce6519c4fdc36



---------------------------

If one TCA_TAPRIO_ATTR_PRIOMAP attribute has been provided,
taprio_parse_mqprio_opt() must validate it, or userspace
can inject arbitrary data to the kernel, the second time
taprio_change() is called.

First call (with valid attributes) sets dev->num_tc
to a non zero value.

Second call (with arbitrary mqprio attributes)
returns early from taprio_parse_mqprio_opt()
and bad things can happen.

Fixes: a3d43c0d ("taprio: Add support adding an admin schedule")
Reported-by: default avatarNoam Rathaus <noamr@ssd-disclosure.com>
Signed-off-by: default avatarEric Dumazet <edumazet@google.com>
Acked-by: default avatarVinicius Costa Gomes <vinicius.gomes@intel.com>
Reviewed-by: default avatarVladimir Oltean <vladimir.oltean@nxp.com>
Link: https://lore.kernel.org/r/20240604181511.769870-1-edumazet@google.com


Signed-off-by: default avatarJakub Kicinski <kuba@kernel.org>
Signed-off-by: default avatarLiu Jian <liujian56@huawei.com>
parent 2f2eaf1a

net/sched/sch_taprio.c

+6 −9
Original line number Diff line number Diff line
@@ -925,16 +925,13 @@ static int taprio_parse_mqprio_opt(struct net_device *dev, 
{

	int i, j;



	if (!qopt && !dev->num_tc) {

	if (!qopt) {

		if (!dev->num_tc) {

			NL_SET_ERR_MSG(extack, "'mqprio' configuration is necessary");

			return -EINVAL;

		}



	/* If num_tc is already set, it means that the user already

	 * configured the mqprio part

	 */

	if (dev->num_tc)

		return 0;

	}



	/* Verify num_tc is not out of max range */

	if (qopt->num_tc > TC_MAX_QUEUE) {