From: Budimir Markovic Date: Thu, 24 Aug 2023 08:49:05 +0000 (-0700) Subject: net/sched: sch_hfsc: Ensure inner classes have fsc curve X-Git-Tag: v4.14.327~25 X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=3c0bd0b79733b7f628af1c967269db339eeef8d3;p=thirdparty%2Fkernel%2Fstable.git net/sched: sch_hfsc: Ensure inner classes have fsc curve commit b3d26c5702c7d6c45456326e56d2ccf3f103e60f upstream. 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. Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Reported-by: Budimir Markovic Signed-off-by: Budimir Markovic Acked-by: Jamal Hadi Salim Link: https://lore.kernel.org/r/20230824084905.422-1-markovicbudimir@gmail.com Signed-off-by: Jakub Kicinski [ v4.14: Delete NL_SET_ERR_MSG because extack is not added to hfsc_change_class ] Signed-off-by: Shaoying Xu Signed-off-by: Greg Kroah-Hartman --- diff --git a/net/sched/sch_hfsc.c b/net/sched/sch_hfsc.c index 3f88b75488b03..3a43abe4d9c4c 100644 --- a/net/sched/sch_hfsc.c +++ b/net/sched/sch_hfsc.c @@ -1020,6 +1020,8 @@ hfsc_change_class(struct Qdisc *sch, u32 classid, u32 parentid, if (parent == NULL) return -ENOENT; } + if (!(parent->cl_flags & HFSC_FSC) && parent != &q->root) + return -EINVAL; if (classid == 0 || TC_H_MAJ(classid ^ sch->handle) != 0) return -EINVAL;