[syzbot] general protection fault in ieee80211_subif_start_xmit (2)

From: syzbot
Date: Sun Oct 23 2022 - 14:32:41 EST


Hello,

syzbot found the following issue on:

HEAD commit: 4d48f589d294 Add linux-next specific files for 20221021
git tree: linux-next
console+strace: https://syzkaller.appspot.com/x/log.txt?x=11d36de2880000
kernel config: https://syzkaller.appspot.com/x/.config?x=2c4b7d600a5739a6
dashboard link: https://syzkaller.appspot.com/bug?extid=c6e8fca81c294fd5620a
compiler: gcc (Debian 10.2.1-6) 10.2.1 20210110, GNU ld (GNU Binutils for Debian) 2.35.2
syz repro: https://syzkaller.appspot.com/x/repro.syz?x=12a9544a880000
C reproducer: https://syzkaller.appspot.com/x/repro.c?x=1662d48c880000

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/0c86bd0b39a0/disk-4d48f589.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/074059d37f1f/vmlinux-4d48f589.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+c6e8fca81c294fd5620a@xxxxxxxxxxxxxxxxxxxxxxxxx

general protection fault, probably for non-canonical address 0xdffffc000000002f: 0000 [#1] PREEMPT SMP KASAN
KASAN: null-ptr-deref in range [0x0000000000000178-0x000000000000017f]
CPU: 1 PID: 147 Comm: kworker/1:2 Not tainted 6.1.0-rc1-next-20221021-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/11/2022
Workqueue: mld mld_ifc_work
RIP: 0010:ieee80211_multicast_to_unicast net/mac80211/tx.c:4281 [inline]
RIP: 0010:ieee80211_subif_start_xmit+0x25b/0x1310 net/mac80211/tx.c:4409
Code: 80 3c 02 00 0f 85 94 10 00 00 49 8b 8c 24 28 19 00 00 48 b8 00 00 00 00 00 fc ff df 48 8d b9 7c 01 00 00 48 89 fa 48 c1 ea 03 <0f> b6 04 02 48 89 fa 83 e2 07 38 d0 7f 08 84 c0 0f 85 68 10 00 00
RSP: 0000:ffffc90002d3f628 EFLAGS: 00010203
RAX: dffffc0000000000 RBX: 0000000000000003 RCX: 0000000000000000
RDX: 000000000000002f RSI: ffffffff88dc6bf8 RDI: 000000000000017c
RBP: ffff88807b8cf140 R08: 0000000000000005 R09: 0000000000000004
R10: 0000000000000003 R11: 000000000008c001 R12: ffff8880200b4000
R13: ffff88807b8cf218 R14: ffff888020ea4042 R15: 1ffff920005a7ecf
FS: 0000000000000000(0000) GS:ffff8880b9b00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000055b3e4199708 CR3: 000000007b8d0000 CR4: 00000000003506e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
<TASK>
__netdev_start_xmit include/linux/netdevice.h:4840 [inline]
netdev_start_xmit include/linux/netdevice.h:4854 [inline]
xmit_one net/core/dev.c:3590 [inline]
dev_hard_start_xmit+0x1be/0x990 net/core/dev.c:3606
__dev_queue_xmit+0x2c9a/0x3b60 net/core/dev.c:4256
dev_queue_xmit include/linux/netdevice.h:3008 [inline]
neigh_resolve_output net/core/neighbour.c:1552 [inline]
neigh_resolve_output+0x517/0x840 net/core/neighbour.c:1532
neigh_output include/net/neighbour.h:546 [inline]
ip6_finish_output2+0x564/0x1520 net/ipv6/ip6_output.c:134
__ip6_finish_output net/ipv6/ip6_output.c:195 [inline]
ip6_finish_output+0x690/0x1160 net/ipv6/ip6_output.c:206
NF_HOOK_COND include/linux/netfilter.h:291 [inline]
ip6_output+0x1ed/0x540 net/ipv6/ip6_output.c:227
dst_output include/net/dst.h:445 [inline]
NF_HOOK include/linux/netfilter.h:302 [inline]
NF_HOOK include/linux/netfilter.h:296 [inline]
mld_sendpack+0xa09/0xe70 net/ipv6/mcast.c:1820
mld_send_cr net/ipv6/mcast.c:2121 [inline]
mld_ifc_work+0x71c/0xdb0 net/ipv6/mcast.c:2653
process_one_work+0x9bf/0x1710 kernel/workqueue.c:2289
worker_thread+0x665/0x1080 kernel/workqueue.c:2436
kthread+0x2e4/0x3a0 kernel/kthread.c:376
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:308
</TASK>
Modules linked in:
---[ end trace 0000000000000000 ]---
RIP: 0010:ieee80211_multicast_to_unicast net/mac80211/tx.c:4281 [inline]
RIP: 0010:ieee80211_subif_start_xmit+0x25b/0x1310 net/mac80211/tx.c:4409
Code: 80 3c 02 00 0f 85 94 10 00 00 49 8b 8c 24 28 19 00 00 48 b8 00 00 00 00 00 fc ff df 48 8d b9 7c 01 00 00 48 89 fa 48 c1 ea 03 <0f> b6 04 02 48 89 fa 83 e2 07 38 d0 7f 08 84 c0 0f 85 68 10 00 00
RSP: 0000:ffffc90002d3f628 EFLAGS: 00010203
RAX: dffffc0000000000 RBX: 0000000000000003 RCX: 0000000000000000
RDX: 000000000000002f RSI: ffffffff88dc6bf8 RDI: 000000000000017c
RBP: ffff88807b8cf140 R08: 0000000000000005 R09: 0000000000000004
R10: 0000000000000003 R11: 000000000008c001 R12: ffff8880200b4000
R13: ffff88807b8cf218 R14: ffff888020ea4042 R15: 1ffff920005a7ecf
FS: 0000000000000000(0000) GS:ffff8880b9b00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000055b3e4199708 CR3: 000000000ba8e000 CR4: 00000000003506e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
----------------
Code disassembly (best guess):
0: 80 3c 02 00 cmpb $0x0,(%rdx,%rax,1)
4: 0f 85 94 10 00 00 jne 0x109e
a: 49 8b 8c 24 28 19 00 mov 0x1928(%r12),%rcx
11: 00
12: 48 b8 00 00 00 00 00 movabs $0xdffffc0000000000,%rax
19: fc ff df
1c: 48 8d b9 7c 01 00 00 lea 0x17c(%rcx),%rdi
23: 48 89 fa mov %rdi,%rdx
26: 48 c1 ea 03 shr $0x3,%rdx
* 2a: 0f b6 04 02 movzbl (%rdx,%rax,1),%eax <-- trapping instruction
2e: 48 89 fa mov %rdi,%rdx
31: 83 e2 07 and $0x7,%edx
34: 38 d0 cmp %dl,%al
36: 7f 08 jg 0x40
38: 84 c0 test %al,%al
3a: 0f 85 68 10 00 00 jne 0x10a8


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