From af8edaeddbc52e53207d859c912b017fd9a77629 Mon Sep 17 00:00:00 2001 From: Eric Dumazet Date: Mon, 2 Dec 2024 10:05:58 +0000 Subject: [PATCH] net: hsr: must allocate more bytes for RedBox support Blamed commit forgot to change hsr_init_skb() to allocate larger skb for RedBox case. Indeed, send_hsr_supervision_frame() will add two additional components (struct hsr_sup_tlv and struct hsr_sup_payload) syzbot reported the following crash: skbuff: skb_over_panic: text:ffffffff8afd4b0a len:34 put:6 head:ffff88802ad29e00 data:ffff88802ad29f22 tail:0x144 end:0x140 dev:gretap0 ------------[ cut here ]------------ kernel BUG at net/core/skbuff.c:206 ! Oops: invalid opcode: 0000 [#1] PREEMPT SMP KASAN NOPTI CPU: 2 UID: 0 PID: 7611 Comm: syz-executor Not tainted 6.12.0-syzkaller #0 Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2~bpo12+1 04/01/2014 RIP: 0010:skb_panic+0x157/0x1d0 net/core/skbuff.c:206 Code: b6 04 01 84 c0 74 04 3c 03 7e 21 8b 4b 70 41 56 45 89 e8 48 c7 c7 a0 7d 9b 8c 41 57 56 48 89 ee 52 4c 89 e2 e8 9a 76 79 f8 90 <0f> 0b 4c 89 4c 24 10 48 89 54 24 08 48 89 34 24 e8 94 76 fb f8 4c RSP: 0018:ffffc90000858ab8 EFLAGS: 00010282 RAX: 0000000000000087 RBX: ffff8880598c08c0 RCX: ffffffff816d3e69 RDX: 0000000000000000 RSI: ffffffff816de786 RDI: 0000000000000005 RBP: ffffffff8c9b91c0 R08: 0000000000000005 R09: 0000000000000000 R10: 0000000000000302 R11: ffffffff961cc1d0 R12: ffffffff8afd4b0a R13: 0000000000000006 R14: ffff88804b938130 R15: 0000000000000140 FS: 000055558a3d6500(0000) GS:ffff88806a800000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f1295974ff8 CR3: 000000002ab6e000 CR4: 0000000000352ef0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: skb_over_panic net/core/skbuff.c:211 [inline] skb_put+0x174/0x1b0 net/core/skbuff.c:2617 send_hsr_supervision_frame+0x6fa/0x9e0 net/hsr/hsr_device.c:342 hsr_proxy_announce+0x1a3/0x4a0 net/hsr/hsr_device.c:436 call_timer_fn+0x1a0/0x610 kernel/time/timer.c:1794 expire_timers kernel/time/timer.c:1845 [inline] __run_timers+0x6e8/0x930 kernel/time/timer.c:2419 __run_timer_base kernel/time/timer.c:2430 [inline] __run_timer_base kernel/time/timer.c:2423 [inline] run_timer_base+0x111/0x190 kernel/time/timer.c:2439 run_timer_softirq+0x1a/0x40 kernel/time/timer.c:2449 handle_softirqs+0x213/0x8f0 kernel/softirq.c:554 __do_softirq kernel/softirq.c:588 [inline] invoke_softirq kernel/softirq.c:428 [inline] __irq_exit_rcu kernel/softirq.c:637 [inline] irq_exit_rcu+0xbb/0x120 kernel/softirq.c:649 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1049 [inline] sysvec_apic_timer_interrupt+0xa4/0xc0 arch/x86/kernel/apic/apic.c:1049 Fixes: 5055cccfc2d1 ("net: hsr: Provide RedBox support (HSR-SAN)") Reported-by: syzbot+7f4643b267cc680bfa1c@syzkaller.appspotmail.com Signed-off-by: Eric Dumazet Cc: Lukasz Majewski Link: https://patch.msgid.link/20241202100558.507765-1-edumazet@google.com Signed-off-by: Paolo Abeni --- net/hsr/hsr_device.c | 19 +++++++++++++------ 1 file changed, 13 insertions(+), 6 deletions(-) diff --git a/net/hsr/hsr_device.c b/net/hsr/hsr_device.c index 31a416ee21ad..03eadd6c51fd 100644 --- a/net/hsr/hsr_device.c +++ b/net/hsr/hsr_device.c @@ -246,20 +246,22 @@ static const struct header_ops hsr_header_ops = { .parse = eth_header_parse, }; -static struct sk_buff *hsr_init_skb(struct hsr_port *master) +static struct sk_buff *hsr_init_skb(struct hsr_port *master, int extra) { struct hsr_priv *hsr = master->hsr; struct sk_buff *skb; int hlen, tlen; + int len; hlen = LL_RESERVED_SPACE(master->dev); tlen = master->dev->needed_tailroom; + len = sizeof(struct hsr_sup_tag) + sizeof(struct hsr_sup_payload); /* skb size is same for PRP/HSR frames, only difference * being, for PRP it is a trailer and for HSR it is a - * header + * header. + * RedBox might use @extra more bytes. */ - skb = dev_alloc_skb(sizeof(struct hsr_sup_tag) + - sizeof(struct hsr_sup_payload) + hlen + tlen); + skb = dev_alloc_skb(len + extra + hlen + tlen); if (!skb) return skb; @@ -295,6 +297,7 @@ static void send_hsr_supervision_frame(struct hsr_port *port, struct hsr_sup_tlv *hsr_stlv; struct hsr_sup_tag *hsr_stag; struct sk_buff *skb; + int extra = 0; *interval = msecs_to_jiffies(HSR_LIFE_CHECK_INTERVAL); if (hsr->announce_count < 3 && hsr->prot_version == 0) { @@ -303,7 +306,11 @@ static void send_hsr_supervision_frame(struct hsr_port *port, hsr->announce_count++; } - skb = hsr_init_skb(port); + if (hsr->redbox) + extra = sizeof(struct hsr_sup_tlv) + + sizeof(struct hsr_sup_payload); + + skb = hsr_init_skb(port, extra); if (!skb) { netdev_warn_once(port->dev, "HSR: Could not send supervision frame\n"); return; @@ -362,7 +369,7 @@ static void send_prp_supervision_frame(struct hsr_port *master, struct hsr_sup_tag *hsr_stag; struct sk_buff *skb; - skb = hsr_init_skb(master); + skb = hsr_init_skb(master, 0); if (!skb) { netdev_warn_once(master->dev, "PRP: Could not send supervision frame\n"); return;