From: Greg Kroah-Hartman Date: Mon, 11 May 2026 15:05:50 +0000 (+0200) Subject: 5.15-stable patches X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=a7ac4e718b5b18a066fbbbb1693749543bc06116;p=thirdparty%2Fkernel%2Fstable-queue.git 5.15-stable patches added patches: net-sched-sch_red-replace-direct-dequeue-call-with-peek-and-qdisc_dequeue_peeked.patch --- diff --git a/queue-5.15/net-sched-sch_red-replace-direct-dequeue-call-with-peek-and-qdisc_dequeue_peeked.patch b/queue-5.15/net-sched-sch_red-replace-direct-dequeue-call-with-peek-and-qdisc_dequeue_peeked.patch new file mode 100644 index 0000000000..e43d4fc55c --- /dev/null +++ b/queue-5.15/net-sched-sch_red-replace-direct-dequeue-call-with-peek-and-qdisc_dequeue_peeked.patch @@ -0,0 +1,76 @@ +From 458d5615272d3de535748342eb68ca492343048c Mon Sep 17 00:00:00 2001 +From: Jamal Hadi Salim +Date: Thu, 30 Apr 2026 11:29:55 -0400 +Subject: net/sched: sch_red: Replace direct dequeue call with peek and qdisc_dequeue_peeked + +From: Jamal Hadi Salim + +commit 458d5615272d3de535748342eb68ca492343048c upstream. + +When red qdisc has children (eg qfq qdisc) whose peek() callback is +qdisc_peek_dequeued(), we could get a kernel panic. When the parent of such +qdiscs (eg illustrated in patch #3 as tbf) wants to retrieve an skb from +its child (red in this case), it will do the following: + 1a. do a peek() - and when sensing there's an skb the child can offer, then + - the child in this case(red) calls its child's (qfq) peek. + qfq does the right thing and will return the gso_skb queue packet. + Note: if there wasnt a gso_skb entry then qfq will store it there. + 1b. invoke a dequeue() on the child (red). And herein lies the problem. + - red will call the child's dequeue() which will essentially just + try to grab something of qfq's queue. + +[ 78.667668][ T363] KASAN: null-ptr-deref in range [0x0000000000000048-0x000000000000004f] +[ 78.667927][ T363] CPU: 1 UID: 0 PID: 363 Comm: ping Not tainted 7.1.0-rc1-00033-g46f74a3f7d57-dirty #790 PREEMPT(full) +[ 78.668263][ T363] Hardware name: Bochs Bochs, BIOS Bochs 01/01/2011 +[ 78.668486][ T363] RIP: 0010:qfq_dequeue+0x446/0xc90 [sch_qfq] +[ 78.668718][ T363] Code: 54 c0 e8 dd 90 00 f1 48 c7 c7 e0 03 54 c0 48 89 de e8 ce 90 00 f1 48 8d 7b 48 b8 ff ff 37 00 48 89 fa 48 c1 e0 2a 48 c1 ea 03 <80> 3c 02 00 74 05 e8 ef a1 e1 f1 48 8b 7b 48 48 8d 54 24 58 48 8d +[ 78.669312][ T363] RSP: 0018:ffff88810de573e0 EFLAGS: 00010216 +[ 78.669533][ T363] RAX: dffffc0000000000 RBX: 0000000000000000 RCX: 0000000000000000 +[ 78.669790][ T363] RDX: 0000000000000009 RSI: 0000000000000004 RDI: 0000000000000048 +[ 78.670044][ T363] RBP: ffff888110dc4000 R08: ffffffffb1b0885a R09: fffffbfff6ba9078 +[ 78.670297][ T363] R10: 0000000000000003 R11: ffff888110e31c80 R12: 0000001880000000 +[ 78.670560][ T363] R13: ffff888110dc4150 R14: ffff888110dc42b8 R15: 0000000000000200 +[ 78.670814][ T363] FS: 00007f66a8f09c40(0000) GS:ffff888163428000(0000) knlGS:0000000000000000 +[ 78.671110][ T363] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 +[ 78.671324][ T363] CR2: 000055db4c6a30a8 CR3: 000000010da67000 CR4: 0000000000750ef0 +[ 78.671585][ T363] PKRU: 55555554 +[ 78.671713][ T363] Call Trace: +[ 78.671843][ T363] +[ 78.671936][ T363] ? __pfx_qfq_dequeue+0x10/0x10 [sch_qfq] +[ 78.672148][ T363] ? __pfx__printk+0x10/0x10 +[ 78.672322][ T363] ? srso_alias_return_thunk+0x5/0xfbef5 +[ 78.672496][ T363] ? lockdep_hardirqs_on_prepare+0xa8/0x1a0 +[ 78.672706][ T363] ? srso_alias_return_thunk+0x5/0xfbef5 +[ 78.672875][ T363] ? trace_hardirqs_on+0x19/0x1a0 +[ 78.673047][ T363] red_dequeue+0x65/0x270 [sch_red] +[ 78.673217][ T363] ? srso_alias_return_thunk+0x5/0xfbef5 +[ 78.673385][ T363] tbf_dequeue.cold+0xb0/0x70c [sch_tbf] +[ 78.673566][ T363] __qdisc_run+0x169/0x1900 + +The right thing to do in #1b is to grab the skb off gso_skb queue. +This patchset fixes that issue by changing #1b to use qdisc_dequeue_peeked() +method instead. + +Fixes: 77be155cba4e ("pkt_sched: Add peek emulation for non-work-conserving qdiscs.") +Reported-by: Manas +Reported-by: Rakshit Awasthi +Signed-off-by: Jamal Hadi Salim +Reviewed-by: Eric Dumazet +Link: https://patch.msgid.link/20260430152957.194015-2-jhs@mojatatu.com +Signed-off-by: Jakub Kicinski +Signed-off-by: Greg Kroah-Hartman +--- + net/sched/sch_red.c | 2 +- + 1 file changed, 1 insertion(+), 1 deletion(-) + +--- a/net/sched/sch_red.c ++++ b/net/sched/sch_red.c +@@ -153,7 +153,7 @@ static struct sk_buff *red_dequeue(struc + struct red_sched_data *q = qdisc_priv(sch); + struct Qdisc *child = q->qdisc; + +- skb = child->dequeue(child); ++ skb = qdisc_dequeue_peeked(child); + if (skb) { + qdisc_bstats_update(sch, skb); + qdisc_qstats_backlog_dec(sch, skb); diff --git a/queue-5.15/series b/queue-5.15/series index 3478d131d4..cb5e1d54d5 100644 --- a/queue-5.15/series +++ b/queue-5.15/series @@ -289,3 +289,4 @@ ksmbd-do-not-expire-session-on-binding-failure.patch spi-meson-spicc-fix-double-put-in-remove-path.patch um-virt-pci-fix-build-failure.patch octeontx2-pf-handle-otx2_mbox_get_rsp-errors-in-otx2.patch +net-sched-sch_red-replace-direct-dequeue-call-with-peek-and-qdisc_dequeue_peeked.patch