Commit 4d08c0d1 authored Aug 24, 2023 by Budimir Markovic Committed by Treehugger Robot Sep 27, 2023

UPSTREAM: net/sched: sch_hfsc: Ensure inner classes have fsc curve



[ Upstream commit b3d26c5702c7d6c45456326e56d2ccf3f103e60f ]

HFSC assumes that inner classes have an fsc curve, but it is currently
possible for classes without an fsc curve to become parents. This leads
to bugs including a use-after-free.

Don't allow non-root classes without HFSC_FSC to become parents.

Bug: 299921101
Fixes: 1da177e4 ("Linux-2.6.12-rc2")
Reported-by: Budimir Markovic <markovicbudimir@gmail.com>
Signed-off-by: Budimir Markovic <markovicbudimir@gmail.com>
Acked-by: Jamal Hadi Salim <jhs@mojatatu.com>
Link: https://lore.kernel.org/r/20230824084905.422-1-markovicbudimir@gmail.com


Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
(cherry picked from commit 4cf994d3f4ff42d604fae2b461bdd5195a7dfabd)
Signed-off-by: Lee Jones <joneslee@google.com>
Change-Id: I5b44ae6bb340b978372ed9657ba2e23f75b850e5

parent 8daba3e0

net/sched/sch_hfsc.c

+4 −0

Original line number	Diff line number	Diff line
		@@ -1021,6 +1021,10 @@ hfsc_change_class(struct Qdisc *sch, u32 classid, u32 parentid,
		if (parent == NULL)
		return -ENOENT;
		}
		if (!(parent->cl_flags & HFSC_FSC) && parent != &q->root) {
		NL_SET_ERR_MSG(extack, "Invalid parent - parent class must have FSC");
		return -EINVAL;
		}

		if (classid == 0 \|\| TC_H_MAJ(classid ^ sch->handle) != 0)
		return -EINVAL;