general protection fault in touch_atime

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syzbot

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Jun 7, 2018, 5:27:03 PM6/7/18
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Hello,

syzbot found the following crash on:

HEAD commit: 1c8c5a9d38f6 Merge git://git.kernel.org/pub/scm/linux/kern..
git tree: upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=132c2b9f800000
kernel config: https://syzkaller.appspot.com/x/.config?x=4f1acdf888c9d4e9
dashboard link: https://syzkaller.appspot.com/bug?extid=15f4f69fe22434607a97
compiler: gcc (GCC) 8.0.1 20180413 (experimental)
userspace arch: i386
CC: [linux-...@vger.kernel.org linux-...@vger.kernel.org
vi...@zeniv.linux.org.uk]

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

IMPORTANT: if you fix the bug, please add the following tag to the commit:
Reported-by: syzbot+15f4f6...@syzkaller.appspotmail.com

RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000296 R12: 0000000000000000
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
bpfilter: read fail -512
kasan: GPF could be caused by NULL-ptr deref or user memory access
general protection fault: 0000 [#1] SMP KASAN
CPU: 1 PID: 4544 Comm: syz-executor3 Not tainted 4.17.0+ #114
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS
Google 01/01/2011
RIP: 0010:touch_atime+0xaf/0x310 fs/inode.c:1724
Code: 89 fa 48 c1 ea 03 80 3c 02 00 0f 85 21 02 00 00 48 b8 00 00 00 00 00
fc ff df 4d 8b 6c 24 08 49 8d 7d 58 48 89 fa 48 c1 ea 03 <80> 3c 02 00 0f
85 f3 01 00 00 4d 8b 6d 58 4c 89 e7 31 d2 4c 89 ee
RSP: 0018:ffff8801957c7500 EFLAGS: 00010202
RAX: dffffc0000000000 RBX: 1ffff10032af8ea2 RCX: ffffffff81c34705
RDX: 000000000000000b RSI: ffffffff81c94c3f RDI: 0000000000000058
RBP: ffff8801957c7598 R08: ffff8801957be640 R09: ffffed0039b488f0
R10: ffffed0039b488f0 R11: ffff8801cda44787 R12: ffff8801cda45510
R13: 0000000000000000 R14: 0000000000000000 R15: dffffc0000000000
FS: 0000000000000000(0000) GS:ffff8801daf00000(0063) knlGS:00000000087c3900
CS: 0010 DS: 002b ES: 002b CR0: 0000000080050033
CR2: 000000000811dc8c CR3: 0000000195785000 CR4: 00000000001406e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
file_accessed include/linux/fs.h:2070 [inline]
pipe_read+0x7c5/0x940 fs/pipe.c:343
call_read_iter include/linux/fs.h:1785 [inline]
new_sync_read fs/read_write.c:406 [inline]
__vfs_read+0x696/0xa50 fs/read_write.c:418
vfs_read+0x17f/0x3d0 fs/read_write.c:452
kernel_read+0xab/0x120 fs/read_write.c:431
__bpfilter_process_sockopt+0x238/0x35b net/bpfilter/bpfilter_kern.c:74
bpfilter_mbox_request+0x4d/0xb0 net/ipv4/bpfilter/sockopt.c:25
bpfilter_ip_get_sockopt+0x6b/0x90 net/ipv4/bpfilter/sockopt.c:42
compat_ip_getsockopt+0x256/0x2f0 net/ipv4/ip_sockglue.c:1600
inet_csk_compat_getsockopt+0x97/0x120 net/ipv4/inet_connection_sock.c:1023
compat_tcp_getsockopt+0x49/0x80 net/ipv4/tcp.c:3543
compat_sock_common_getsockopt+0xb4/0x150 net/core/sock.c:3023
__compat_sys_getsockopt+0x1ae/0x880 net/compat.c:532
__do_compat_sys_socketcall net/compat.c:916 [inline]
__se_compat_sys_socketcall net/compat.c:844 [inline]
__ia32_compat_sys_socketcall+0xcd1/0x1070 net/compat.c:844
do_syscall_32_irqs_on arch/x86/entry/common.c:323 [inline]
do_fast_syscall_32+0x345/0xf9b arch/x86/entry/common.c:394
entry_SYSENTER_compat+0x70/0x7f arch/x86/entry/entry_64_compat.S:139
RIP: 0023:0xf7fd9cb9
Code: 55 08 8b 88 64 cd ff ff 8b 98 68 cd ff ff 89 c8 85 d2 74 02 89 0a 5b
5d c3 8b 04 24 c3 8b 1c 24 c3 51 52 55 89 e5 0f 34 cd 80 <5d> 5a 59 c3 90
90 90 90 eb 0d 90 90 90 90 90 90 90 90 90 90 90 90
RSP: 002b:000000000845e340 EFLAGS: 00000206 ORIG_RAX: 0000000000000066
RAX: ffffffffffffffda RBX: 000000000000000f RCX: 000000000845e35c
RDX: 000000000845e3b4 RSI: 000000000845e3b4 RDI: 000000000845e408
RBP: 000000000811fe18 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000206 R12: 0000000000000000
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
Modules linked in:
Dumping ftrace buffer:
(ftrace buffer empty)
---[ end trace 4ba2b1524fe29341 ]---
RIP: 0010:touch_atime+0xaf/0x310 fs/inode.c:1724
Code: 89 fa 48 c1 ea 03 80 3c 02 00 0f 85 21 02 00 00 48 b8 00 00 00 00 00
fc ff df 4d 8b 6c 24 08 49 8d 7d 58 48 89 fa 48 c1 ea 03 <80> 3c 02 00 0f
85 f3 01 00 00 4d 8b 6d 58 4c 89 e7 31 d2 4c 89 ee
RSP: 0018:ffff8801957c7500 EFLAGS: 00010202
RAX: dffffc0000000000 RBX: 1ffff10032af8ea2 RCX: ffffffff81c34705
RDX: 000000000000000b RSI: ffffffff81c94c3f RDI: 0000000000000058
RBP: ffff8801957c7598 R08: ffff8801957be640 R09: ffffed0039b488f0
R10: ffffed0039b488f0 R11: ffff8801cda44787 R12: ffff8801cda45510
R13: 0000000000000000 R14: 0000000000000000 R15: dffffc0000000000
FS: 0000000000000000(0000) GS:ffff8801daf00000(0063) knlGS:00000000087c3900
CS: 0010 DS: 002b ES: 002b CR0: 0000000080050033
CR2: 000000000811dc8c CR3: 0000000195785000 CR4: 00000000001406e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400


---
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syzbot

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Jun 7, 2018, 9:09:02 PM6/7/18
to syzkaller-upst...@googlegroups.com
syzbot has found a reproducer for the following crash on:

HEAD commit: 7170e6045a6a strparser: Add __strp_unpause and use it in k..
git tree: net-next
console output: https://syzkaller.appspot.com/x/log.txt?x=160eb8cf800000
kernel config: https://syzkaller.appspot.com/x/.config?x=a601a80fec461d44
dashboard link: https://syzkaller.appspot.com/bug?extid=15f4f69fe22434607a97
compiler: gcc (GCC) 8.0.1 20180413 (experimental)
syzkaller repro:https://syzkaller.appspot.com/x/repro.syz?x=16dd1aaf800000
CC: [linux-...@vger.kernel.org linux-...@vger.kernel.org
vi...@zeniv.linux.org.uk]

IMPORTANT: if you fix the bug, please add the following tag to the commit:
Reported-by: syzbot+15f4f6...@syzkaller.appspotmail.com

8021q: adding VLAN 0 to HW filter on device team0
8021q: adding VLAN 0 to HW filter on device team0
8021q: adding VLAN 0 to HW filter on device team0
bpfilter: read fail -512
kasan: GPF could be caused by NULL-ptr deref or user memory access
general protection fault: 0000 [#1] SMP KASAN
Dumping ftrace buffer:
(ftrace buffer empty)
Modules linked in:
CPU: 0 PID: 4517 Comm: syz-executor6 Not tainted 4.17.0-rc7+ #82
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS
Google 01/01/2011
RIP: 0010:touch_atime+0xaf/0x310 fs/inode.c:1724
RSP: 0018:ffff8801d917f6c0 EFLAGS: 00010202
RAX: dffffc0000000000 RBX: 1ffff1003b22feda RCX: ffffffff81c236e5
RDX: 000000000000000b RSI: ffffffff81c83d0f RDI: 0000000000000058
RBP: ffff8801d917f758 R08: ffff8801acfde540 R09: ffffed0039b7d000
R10: ffffed0039b7d000 R11: ffff8801cdbe8007 R12: ffff8801cdbeba10
R13: 0000000000000000 R14: 0000000000000000 R15: dffffc0000000000
FS: 0000000002535940(0000) GS:ffff8801dae00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f6d94826730 CR3: 00000001d90fa000 CR4: 00000000001406f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
file_accessed include/linux/fs.h:2063 [inline]
pipe_read+0x7c5/0x940 fs/pipe.c:343
call_read_iter include/linux/fs.h:1778 [inline]
new_sync_read fs/read_write.c:406 [inline]
__vfs_read+0x696/0xa50 fs/read_write.c:418
vfs_read+0x17f/0x3d0 fs/read_write.c:452
kernel_read+0xab/0x120 fs/read_write.c:431
__bpfilter_process_sockopt+0x238/0x35b net/bpfilter/bpfilter_kern.c:74
bpfilter_mbox_request+0x4d/0xb0 net/ipv4/bpfilter/sockopt.c:25
bpfilter_ip_get_sockopt+0x6b/0x90 net/ipv4/bpfilter/sockopt.c:42
ip_getsockopt+0x238/0x2a0 net/ipv4/ip_sockglue.c:1563
tcp_getsockopt+0x93/0xe0 net/ipv4/tcp.c:3543
sock_common_getsockopt+0x9a/0xe0 net/core/sock.c:3018
__sys_getsockopt+0x1a5/0x370 net/socket.c:1940
__do_sys_getsockopt net/socket.c:1951 [inline]
__se_sys_getsockopt net/socket.c:1948 [inline]
__x64_sys_getsockopt+0xbe/0x150 net/socket.c:1948
do_syscall_64+0x1b1/0x800 arch/x86/entry/common.c:287
entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x4584ea
RSP: 002b:0000000000a3e328 EFLAGS: 00000246 ORIG_RAX: 0000000000000037
RAX: ffffffffffffffda RBX: 0000000000a3e350 RCX: 00000000004584ea
RDX: 0000000000000040 RSI: 0000000000000000 RDI: 0000000000000003
RBP: 0000000000705f20 R08: 0000000000a3e34c R09: 0000000000004000
R10: 0000000000a3e350 R11: 0000000000000246 R12: 0000000000000003
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000703d60
Code: 48 89 fa 48 c1 ea 03 80 3c 02 00 0f 85 21 02 00 00 48 b8 00 00 00 00
00 fc ff df 4d 8b 6c 24 08 49 8d 7d 58 48 89 fa 48 c1 ea 03 <80> 3c 02 00
0f 85 f3 01 00 00 4d 8b 6d 58 4c 89 e7 31 d2 4c 89
RIP: touch_atime+0xaf/0x310 fs/inode.c:1724 RSP: ffff8801d917f6c0
---[ end trace 2fb02adff506b932 ]---

Dmitry Vyukov

unread,
Jun 8, 2018, 3:48:53 AM6/8/18
to syzbot, 'Dmitry Vyukov' via syzkaller-upstream-moderation
#syz fix: bpfilter: fix race in pipe access
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