[syzbot] [netfilter?] KASAN: slab-use-after-free Read in ip_skb_dst_mtu

syzbot
2024-03-06T10:57:19Z

Hello,

syzbot found the following issue on:

HEAD commit: 805d849d7c3c Merge tag 'acpi-6.8-rc7' of git://git.kernel...
git tree: upstream
console+strace: https://syzkaller.appspot.com/x/log.txt?x=14e106ac180000
kernel config: https://syzkaller.appspot.com/x/.config?x=fad652894fc96962
dashboard link: https://syzkaller.appspot.com/bug?extid=e5167d7144a62715044c
compiler: Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40
syz repro: https://syzkaller.appspot.com/x/repro.syz?x=16d490ca180000
C reproducer: https://syzkaller.appspot.com/x/repro.c?x=1025fa6a180000

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/17c4652fa589/disk-805d849d.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/7fc3b5760ca4/vmlinux-805d849d.xz
kernel image: https://storage.googleapis.com/syzbot-assets/d88bfccc316a/bzImage-805d849d.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+e5167d7144a62715044c@syzkaller.appspotmail.com

==================================================================
BUG: KASAN: slab-use-after-free in sk_fullsock include/net/sock.h:2823 [inline]
BUG: KASAN: slab-use-after-free in ip_skb_dst_mtu+0x830/0x9b0 include/net/ip.h:499
Read of size 1 at addr ffff88802dc5a012 by task swapper/1/0

CPU: 1 PID: 0 Comm: swapper/1 Not tainted 6.8.0-rc6-syzkaller-00037-g805d849d7c3c #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/25/2024
Call Trace:
<IRQ>
__dump_stack lib/dump_stack.c:88 [inline]
dump_stack_lvl+0x1e7/0x2e0 lib/dump_stack.c:106
print_address_description mm/kasan/report.c:377 [inline]
print_report+0x167/0x540 mm/kasan/report.c:488
kasan_report+0x142/0x180 mm/kasan/report.c:601
sk_fullsock include/net/sock.h:2823 [inline]
ip_skb_dst_mtu+0x830/0x9b0 include/net/ip.h:499
__ip_finish_output+0x12b/0x400 net/ipv4/ip_output.c:306
ipvlan_process_v4_outbound+0x3ef/0x700 drivers/net/ipvlan/ipvlan_core.c:442
ipvlan_process_outbound drivers/net/ipvlan/ipvlan_core.c:540 [inline]
ipvlan_xmit_mode_l3 drivers/net/ipvlan/ipvlan_core.c:602 [inline]
ipvlan_queue_xmit+0xaa2/0x11f0 drivers/net/ipvlan/ipvlan_core.c:668
ipvlan_start_xmit+0x4a/0x150 drivers/net/ipvlan/ipvlan_main.c:222
__netdev_start_xmit include/linux/netdevice.h:4989 [inline]
netdev_start_xmit include/linux/netdevice.h:5003 [inline]
xmit_one net/core/dev.c:3547 [inline]
dev_hard_start_xmit+0x242/0x770 net/core/dev.c:3563
sch_direct_xmit+0x2b6/0x5f0 net/sched/sch_generic.c:342
qdisc_restart net/sched/sch_generic.c:407 [inline]
__qdisc_run+0xbed/0x2150 net/sched/sch_generic.c:415
qdisc_run+0xda/0x270 include/net/pkt_sched.h:125
net_tx_action+0x877/0xa30 net/core/dev.c:5197
__do_softirq+0x2bb/0x942 kernel/softirq.c:553

---
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