6.18-stable patches

added patches:
	net-sched-sch_red-replace-direct-dequeue-call-with-peek-and-qdisc_dequeue_peeked.patch

diff --git a/queue-6.18/net-sched-sch_red-replace-direct-dequeue-call-with-peek-and-qdisc_dequeue_peeked.patch b/queue-6.18/net-sched-sch_red-replace-direct-dequeue-call-with-peek-and-qdisc_dequeue_peeked.patch
new file mode 100644 (file)
index 0000000..8338d5a
--- /dev/null
+++ b/queue-6.18/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 <jhs@mojatatu.com>
+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 <jhs@mojatatu.com>
+
+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]  <TASK>
+[   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 <ghandatmanas@gmail.com>
+Reported-by: Rakshit Awasthi <rakshitawasthi17@gmail.com>
+Signed-off-by: Jamal Hadi Salim <jhs@mojatatu.com>
+Reviewed-by: Eric Dumazet <edumazet@google.com>
+Link: https://patch.msgid.link/20260430152957.194015-2-jhs@mojatatu.com
+Signed-off-by: Jakub Kicinski <kuba@kernel.org>
+Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
+---
+ 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
+@@ -155,7 +155,7 @@ 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-6.18/series b/queue-6.18/series
index 2a447f862daf75195cccb863a58dac91893eb096..3b5264d7bb595d4bbf693fe1881d8209db918013 100644 (file)
--- a/queue-6.18/series
+++ b/queue-6.18/series
@@ -21,3 +21,4 @@ smb-client-smbdirect-fix-mr-registration-for-coalesc.patch
 net-af_key-zero-aligned-sockaddr-tail-in-pf_key-expo.patch
 kvm-svm-check-validity-of-vmcb-controls-when-returning-from-smm.patch
 net-stmmac-disable-eee-rx-clock-stop-when-vlan-is-enabled.patch
+net-sched-sch_red-replace-direct-dequeue-call-with-peek-and-qdisc_dequeue_peeked.patch