BUG: unable to handle kernel NULL pointer dereference in qlist_free_all (2)

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: cf256fbc Linux 4.14.231
git tree: linux-4.14.y
console output: https://syzkaller.appspot.com/x/log.txt?x=1779bfadd00000
kernel config: https://syzkaller.appspot.com/x/.config?x=403e68efdb1dcca6
dashboard link: https://syzkaller.appspot.com/bug?extid=0b130c434d702f883cc6

Unfortunately, I don't have any reproducer for this issue yet.

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+0b130c...@syzkaller.appspotmail.com

sock: process `syz-executor.3' is using obsolete setsockopt SO_BSDCOMPAT
sock: process `syz-executor.4' is using obsolete setsockopt SO_BSDCOMPAT
BUG: unable to handle kernel NULL pointer dereference at 00000000000000fc
IP: qlink_to_object mm/kasan/quarantine.c:136 [inline]
IP: qlink_free mm/kasan/quarantine.c:141 [inline]
IP: qlist_free_all+0x28/0x140 mm/kasan/quarantine.c:166
PGD 9d0c3067 P4D 9d0c3067 PUD 9c80b067 PMD 0
Oops: 0000 [#1] PREEMPT SMP KASAN
Modules linked in:
CPU: 1 PID: 7966 Comm: syz-fuzzer Not tainted 4.14.231-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
task: ffff88809839e040 task.stack: ffff8880962c8000
RIP: 0010:qlink_to_object mm/kasan/quarantine.c:136 [inline]
RIP: 0010:qlink_free mm/kasan/quarantine.c:141 [inline]
RIP: 0010:qlist_free_all+0x28/0x140 mm/kasan/quarantine.c:166
RSP: 0018:ffff8880962cf678 EFLAGS: 00010246
RAX: ffffea0000000000 RBX: ffff888000000000 RCX: ffffea000000001f
RDX: 0000000000000000 RSI: ffff88809839e8f0 RDI: ffff888000000000
RBP: 0000000000000000 R08: 0000000000001d80 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000000 R12: ffff888000000000
R13: ffff8880962cf6b0 R14: 0000000000000000 R15: 0000000000000286
FS: 000000c00002ec90(0000) GS:ffff8880ba500000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00000000000000fc CR3: 0000000097dd4000 CR4: 00000000001406e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
quarantine_reduce+0x185/0x200 mm/kasan/quarantine.c:259
kasan_kmalloc+0xa2/0x160 mm/kasan/kasan.c:536
slab_post_alloc_hook mm/slab.h:442 [inline]
slab_alloc_node mm/slab.c:3333 [inline]
kmem_cache_alloc_node+0x133/0x410 mm/slab.c:3640
__alloc_skb+0x5c/0x510 net/core/skbuff.c:193
alloc_skb_fclone include/linux/skbuff.h:1022 [inline]
sk_stream_alloc_skb+0xb1/0x760 net/ipv4/tcp.c:855
tcp_sendmsg_locked+0xed8/0x2ef0 net/ipv4/tcp.c:1301
tcp_sendmsg+0x2b/0x40 net/ipv4/tcp.c:1457
inet_sendmsg+0x11a/0x4e0 net/ipv4/af_inet.c:762
sock_sendmsg_nosec net/socket.c:646 [inline]
sock_sendmsg+0xb5/0x100 net/socket.c:656
sock_write_iter+0x22c/0x370 net/socket.c:925
call_write_iter include/linux/fs.h:1778 [inline]
new_sync_write fs/read_write.c:469 [inline]
__vfs_write+0x44c/0x630 fs/read_write.c:482
vfs_write+0x17f/0x4d0 fs/read_write.c:544
SYSC_write fs/read_write.c:590 [inline]
SyS_write+0xf2/0x210 fs/read_write.c:582
do_syscall_64+0x1d5/0x640 arch/x86/entry/common.c:292
entry_SYSCALL_64_after_hwframe+0x46/0xbb
RIP: 0033:0x4af19b
RSP: 002b:000000c0147df450 EFLAGS: 00000206 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 000000c00001c000 RCX: 00000000004af19b
RDX: 00000000000000f0 RSI: 000000c00000a200 RDI: 0000000000000006
RBP: 000000c0147df4a0 R08: 000000c0147df501 R09: 0000000000000004
R10: 000000c00000a1e0 R11: 0000000000000206 R12: 000000000000011e
R13: 000000c00047a000 R14: 000000000000007f R15: fffffffffffebc04
Code: 90 90 90 41 57 41 56 41 55 41 54 55 53 48 8b 1f 48 85 db 0f 84 08 01 00 00 48 89 f5 49 89 fd 48 85 ed 49 89 ee 0f 84 8b 00 00 00 <49> 63 86 fc 00 00 00 4c 8b 23 48 29 c3 48 83 3d f3 c3 71 07 00
RIP: qlink_to_object mm/kasan/quarantine.c:136 [inline] RSP: ffff8880962cf678
RIP: qlink_free mm/kasan/quarantine.c:141 [inline] RSP: ffff8880962cf678
RIP: qlist_free_all+0x28/0x140 mm/kasan/quarantine.c:166 RSP: ffff8880962cf678
CR2: 00000000000000fc
BUG: unable to handle kernel NULL pointer dereference at 00000000000000fc
IP: qlink_to_object mm/kasan/quarantine.c:136 [inline]
IP: qlink_free mm/kasan/quarantine.c:141 [inline]
IP: qlist_free_all+0x28/0x140 mm/kasan/quarantine.c:166
PGD 0 P4D 0
Oops: 0000 [#2] PREEMPT SMP KASAN
Modules linked in:
CPU: 0 PID: 4636 Comm: systemd-udevd Tainted: G D 4.14.231-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
task: ffff888098ffc440 task.stack: ffff888098400000
RIP: 0010:qlink_to_object mm/kasan/quarantine.c:136 [inline]
RIP: 0010:qlink_free mm/kasan/quarantine.c:141 [inline]
RIP: 0010:qlist_free_all+0x28/0x140 mm/kasan/quarantine.c:166
RSP: 0018:ffff888098407ae0 EFLAGS: 00010246
RAX: ffffea0000000000 RBX: ffff888000000000 RCX: ffffea000000001f
RDX: 0000000000000000 RSI: ffffffff87cce9c0 RDI: ffff888000000000
RBP: 0000000000000000 R08: ffffea000184a300 R09: 0000000000000000
R10: 0000000000000000 R11: 000000000006128c R12: ffff888000000000
R13: ffff888098407b18 R14: 0000000000000000 R15: 0000000000000286
FS: 00007f7d6fd788c0(0000) GS:ffff8880ba400000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00000000000000fc CR3: 0000000098798000 CR4: 00000000001406f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
quarantine_reduce+0x185/0x200 mm/kasan/quarantine.c:259
kasan_kmalloc+0xa2/0x160 mm/kasan/kasan.c:536
------------[ cut here ]------------
kernel BUG at arch/x86/mm/physaddr.c:27!
sock: process `syz-executor.3' is using obsolete setsockopt SO_BSDCOMPAT
slab_post_alloc_hook mm/slab.h:442 [inline]
slab_alloc mm/slab.c:3390 [inline]
kmem_cache_alloc+0x111/0x3c0 mm/slab.c:3550
sock: process `syz-executor.4' is using obsolete setsockopt SO_BSDCOMPAT
getname_flags+0xc8/0x550 fs/namei.c:138
user_path_at_empty+0x2a/0x50 fs/namei.c:2631
SYSC_readlinkat fs/stat.c:394 [inline]
SyS_readlinkat+0xa8/0x270 fs/stat.c:382
do_syscall_64+0x1d5/0x640 arch/x86/entry/common.c:292
entry_SYSCALL_64_after_hwframe+0x46/0xbb
RIP: 0033:0x7f7d6ebec0ba
RSP: 002b:00007fffb480e5f8 EFLAGS: 00000206 ORIG_RAX: 000000000000010b
RAX: ffffffffffffffda RBX: 0000555e7a51e900 RCX: 00007f7d6ebec0ba
RDX: 0000555e7a51e900 RSI: 0000555e7a52c720 RDI: 00000000ffffff9c
RBP: 0000000000000064 R08: 0000555e79424670 R09: 0000000000000070
R10: 0000000000000063 R11: 0000000000000206 R12: 0000555e7a52c720
R13: 00000000ffffff9c R14: 00007fffb480e650 R15: 0000000000000063
Code: 90 90 90 41 57 41 56 41 55 41 54 55 53 48 8b 1f 48 85 db 0f 84 08 01 00 00 48 89 f5 49 89 fd 48 85 ed 49 89 ee 0f 84 8b 00 00 00 <49> 63 86 fc 00 00 00 4c 8b 23 48 29 c3 48 83 3d f3 c3 71 07 00
RIP: qlink_to_object mm/kasan/quarantine.c:136 [inline] RSP: ffff888098407ae0
RIP: qlink_free mm/kasan/quarantine.c:141 [inline] RSP: ffff888098407ae0
RIP: qlist_free_all+0x28/0x140 mm/kasan/quarantine.c:166 RSP: ffff888098407ae0
CR2: 00000000000000fc
invalid opcode: 0000 [#3] PREEMPT SMP KASAN
Modules linked in:
---[ end trace c18de1d9f47ef0ab ]---
CPU: 1 PID: 4622 Comm: systemd-journal Tainted: G D 4.14.231-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
task: ffff8880a17ca0c0 task.stack: ffff8880a17d0000
RIP: 0010:__phys_addr+0x80/0xe0 arch/x86/mm/physaddr.c:27


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[syzbot]

Auto-closing this bug as obsolete.
Crashes did not happen for a while, no reproducer and no activity.