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* general protection fault in __vfs_write
@ 2018-06-07 15:19 syzbot
  2018-06-07 15:28 ` Matthew Wilcox
  2018-06-09 15:36 ` syzbot
  0 siblings, 2 replies; 4+ messages in thread
From: syzbot @ 2018-06-07 15:19 UTC (permalink / raw)
  To: linux-fsdevel, linux-kernel, syzkaller-bugs, viro

Hello,

syzbot found 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=14bde74f800000
kernel config:  https://syzkaller.appspot.com/x/.config?x=a601a80fec461d44
dashboard link: https://syzkaller.appspot.com/bug?extid=7ade6c94abb2774c0fee
compiler:       gcc (GCC) 8.0.1 20180413 (experimental)

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+7ade6c94abb2774c0fee@syzkaller.appspotmail.com

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: 1 PID: 4590 Comm: syz-executor7 Not tainted 4.17.0-rc7+ #82
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS  
Google 01/01/2011
RIP: 0010:file_write_hint include/linux/fs.h:1925 [inline]
RIP: 0010:init_sync_kiocb include/linux/fs.h:1935 [inline]
RIP: 0010:new_sync_write fs/read_write.c:470 [inline]
RIP: 0010:__vfs_write+0x4a6/0x960 fs/read_write.c:487
RSP: 0018:ffff88019b5c7850 EFLAGS: 00010202
RAX: dffffc0000000000 RBX: ffff8801d2117c80 RCX: ffffffff81bfc6bb
RDX: 0000000000000019 RSI: ffffffff81bfc6ca RDI: 00000000000000c8
RBP: ffff88019b5c79c8 R08: ffff88019b5ba540 R09: fffffbfff12cae69
R10: ffff88019b5c7a10 R11: ffffffff8965734b R12: 0000000000000000
R13: ffff88019b5c79a0 R14: 0000000000000000 R15: ffff88019b5c7a88
FS:  0000000002a11940(0000) GS:ffff8801daf00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000700138 CR3: 000000019b410000 CR4: 00000000001406e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
  __kernel_write+0x10c/0x380 fs/read_write.c:506
  __bpfilter_process_sockopt+0x1d8/0x35b net/bpfilter/bpfilter_kern.c:66
  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: 0000000000000013
RBP: 0000000000705f20 R08: 0000000000a3e34c R09: 0000000000004000
R10: 0000000000a3e350 R11: 0000000000000246 R12: 0000000000000013
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000705860
Code: 48 c1 ea 03 80 3c 02 00 0f 85 1b 04 00 00 48 b8 00 00 00 00 00 fc ff  
df 4c 8b 63 20 49 8d bc 24 c8 00 00 00 48 89 fa 48 c1 ea 03 <0f> b6 04 02  
84 c0 74 08 3c 03 0f 8e ec 02 00 00 41 8b 84 24 c8
RIP: file_write_hint include/linux/fs.h:1925 [inline] RSP: ffff88019b5c7850
RIP: init_sync_kiocb include/linux/fs.h:1935 [inline] RSP: ffff88019b5c7850
RIP: new_sync_write fs/read_write.c:470 [inline] RSP: ffff88019b5c7850
RIP: __vfs_write+0x4a6/0x960 fs/read_write.c:487 RSP: ffff88019b5c7850
---[ end trace 556c3fc867e1de54 ]---


---
This bug is generated by a bot. It may contain errors.
See https://goo.gl/tpsmEJ for more information about syzbot.
syzbot engineers can be reached at syzkaller@googlegroups.com.

syzbot will keep track of this bug report. See:
https://goo.gl/tpsmEJ#bug-status-tracking for how to communicate with  
syzbot.

^ permalink raw reply	[flat|nested] 4+ messages in thread

* Re: general protection fault in __vfs_write
  2018-06-07 15:19 general protection fault in __vfs_write syzbot
@ 2018-06-07 15:28 ` Matthew Wilcox
  2018-06-07 21:58   ` Alexei Starovoitov
  2018-06-09 15:36 ` syzbot
  1 sibling, 1 reply; 4+ messages in thread
From: Matthew Wilcox @ 2018-06-07 15:28 UTC (permalink / raw)
  To: syzbot
  Cc: linux-fsdevel, linux-kernel, syzkaller-bugs, netdev,
	Alexei Starovoitov, Daniel Borkmann


I would suggest this is a BPF problem, not a VFS problem.

On Thu, Jun 07, 2018 at 08:19:01AM -0700, syzbot wrote:
> Hello,
> 
> syzbot found 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=14bde74f800000
> kernel config:  https://syzkaller.appspot.com/x/.config?x=a601a80fec461d44
> dashboard link: https://syzkaller.appspot.com/bug?extid=7ade6c94abb2774c0fee
> compiler:       gcc (GCC) 8.0.1 20180413 (experimental)
> 
> 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+7ade6c94abb2774c0fee@syzkaller.appspotmail.com
> 
> 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: 1 PID: 4590 Comm: syz-executor7 Not tainted 4.17.0-rc7+ #82
> Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS
> Google 01/01/2011
> RIP: 0010:file_write_hint include/linux/fs.h:1925 [inline]
> RIP: 0010:init_sync_kiocb include/linux/fs.h:1935 [inline]
> RIP: 0010:new_sync_write fs/read_write.c:470 [inline]
> RIP: 0010:__vfs_write+0x4a6/0x960 fs/read_write.c:487
> RSP: 0018:ffff88019b5c7850 EFLAGS: 00010202
> RAX: dffffc0000000000 RBX: ffff8801d2117c80 RCX: ffffffff81bfc6bb
> RDX: 0000000000000019 RSI: ffffffff81bfc6ca RDI: 00000000000000c8
> RBP: ffff88019b5c79c8 R08: ffff88019b5ba540 R09: fffffbfff12cae69
> R10: ffff88019b5c7a10 R11: ffffffff8965734b R12: 0000000000000000
> R13: ffff88019b5c79a0 R14: 0000000000000000 R15: ffff88019b5c7a88
> FS:  0000000002a11940(0000) GS:ffff8801daf00000(0000) knlGS:0000000000000000
> CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
> CR2: 0000000000700138 CR3: 000000019b410000 CR4: 00000000001406e0
> DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
> DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
> Call Trace:
>  __kernel_write+0x10c/0x380 fs/read_write.c:506
>  __bpfilter_process_sockopt+0x1d8/0x35b net/bpfilter/bpfilter_kern.c:66
>  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: 0000000000000013
> RBP: 0000000000705f20 R08: 0000000000a3e34c R09: 0000000000004000
> R10: 0000000000a3e350 R11: 0000000000000246 R12: 0000000000000013
> R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000705860
> Code: 48 c1 ea 03 80 3c 02 00 0f 85 1b 04 00 00 48 b8 00 00 00 00 00 fc ff
> df 4c 8b 63 20 49 8d bc 24 c8 00 00 00 48 89 fa 48 c1 ea 03 <0f> b6 04 02 84
> c0 74 08 3c 03 0f 8e ec 02 00 00 41 8b 84 24 c8
> RIP: file_write_hint include/linux/fs.h:1925 [inline] RSP: ffff88019b5c7850
> RIP: init_sync_kiocb include/linux/fs.h:1935 [inline] RSP: ffff88019b5c7850
> RIP: new_sync_write fs/read_write.c:470 [inline] RSP: ffff88019b5c7850
> RIP: __vfs_write+0x4a6/0x960 fs/read_write.c:487 RSP: ffff88019b5c7850
> ---[ end trace 556c3fc867e1de54 ]---
> 
> 
> ---
> This bug is generated by a bot. It may contain errors.
> See https://goo.gl/tpsmEJ for more information about syzbot.
> syzbot engineers can be reached at syzkaller@googlegroups.com.
> 
> syzbot will keep track of this bug report. See:
> https://goo.gl/tpsmEJ#bug-status-tracking for how to communicate with
> syzbot.

^ permalink raw reply	[flat|nested] 4+ messages in thread

* Re: general protection fault in __vfs_write
  2018-06-07 15:28 ` Matthew Wilcox
@ 2018-06-07 21:58   ` Alexei Starovoitov
  0 siblings, 0 replies; 4+ messages in thread
From: Alexei Starovoitov @ 2018-06-07 21:58 UTC (permalink / raw)
  To: Matthew Wilcox
  Cc: syzbot, linux-fsdevel, linux-kernel, syzkaller-bugs, netdev,
	Alexei Starovoitov, Daniel Borkmann

On Thu, Jun 07, 2018 at 08:28:46AM -0700, Matthew Wilcox wrote:
> 
> I would suggest this is a BPF problem, not a VFS problem.
> 
> On Thu, Jun 07, 2018 at 08:19:01AM -0700, syzbot wrote:
> > Hello,
> > 
> > syzbot found 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=14bde74f800000
> > kernel config:  https://syzkaller.appspot.com/x/.config?x=a601a80fec461d44
> > dashboard link: https://syzkaller.appspot.com/bug?extid=7ade6c94abb2774c0fee
> > compiler:       gcc (GCC) 8.0.1 20180413 (experimental)
> > 
> > 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+7ade6c94abb2774c0fee@syzkaller.appspotmail.com
> > 
> > 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: 1 PID: 4590 Comm: syz-executor7 Not tainted 4.17.0-rc7+ #82
> > Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS
> > Google 01/01/2011
> > RIP: 0010:file_write_hint include/linux/fs.h:1925 [inline]
> > RIP: 0010:init_sync_kiocb include/linux/fs.h:1935 [inline]
> > RIP: 0010:new_sync_write fs/read_write.c:470 [inline]
> > RIP: 0010:__vfs_write+0x4a6/0x960 fs/read_write.c:487
> > RSP: 0018:ffff88019b5c7850 EFLAGS: 00010202
> > RAX: dffffc0000000000 RBX: ffff8801d2117c80 RCX: ffffffff81bfc6bb
> > RDX: 0000000000000019 RSI: ffffffff81bfc6ca RDI: 00000000000000c8
> > RBP: ffff88019b5c79c8 R08: ffff88019b5ba540 R09: fffffbfff12cae69
> > R10: ffff88019b5c7a10 R11: ffffffff8965734b R12: 0000000000000000
> > R13: ffff88019b5c79a0 R14: 0000000000000000 R15: ffff88019b5c7a88
> > FS:  0000000002a11940(0000) GS:ffff8801daf00000(0000) knlGS:0000000000000000
> > CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
> > CR2: 0000000000700138 CR3: 000000019b410000 CR4: 00000000001406e0
> > DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
> > DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
> > Call Trace:
> >  __kernel_write+0x10c/0x380 fs/read_write.c:506
> >  __bpfilter_process_sockopt+0x1d8/0x35b net/bpfilter/bpfilter_kern.c:66

I think I see the problem. Will send the fix soon.

^ permalink raw reply	[flat|nested] 4+ messages in thread

* Re: general protection fault in __vfs_write
  2018-06-07 15:19 general protection fault in __vfs_write syzbot
  2018-06-07 15:28 ` Matthew Wilcox
@ 2018-06-09 15:36 ` syzbot
  1 sibling, 0 replies; 4+ messages in thread
From: syzbot @ 2018-06-09 15:36 UTC (permalink / raw)
  To: alexei.starovoitov, ast, daniel, linux-fsdevel, linux-kernel,
	netdev, syzkaller-bugs, viro, willy

syzbot has found a reproducer for the following crash on:

HEAD commit:    3a979e8c07e3 Merge tag 'mailbox-v4.18' of git://git.linaro..
git tree:       net-next
console output: https://syzkaller.appspot.com/x/log.txt?x=11e0c81f800000
kernel config:  https://syzkaller.appspot.com/x/.config?x=412e35656a3f7c09
dashboard link: https://syzkaller.appspot.com/bug?extid=7ade6c94abb2774c0fee
compiler:       gcc (GCC) 8.0.1 20180413 (experimental)
syzkaller repro:https://syzkaller.appspot.com/x/repro.syz?x=1665abf7800000

IMPORTANT: if you fix the bug, please add the following tag to the commit:
Reported-by: syzbot+7ade6c94abb2774c0fee@syzkaller.appspotmail.com

IPv6: ADDRCONF(NETDEV_CHANGE): veth0: link becomes ready
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
CPU: 0 PID: 4546 Comm: syz-executor6 Not tainted 4.17.0+ #83
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS  
Google 01/01/2011
RIP: 0010:file_write_hint include/linux/fs.h:1932 [inline]
RIP: 0010:init_sync_kiocb include/linux/fs.h:1942 [inline]
RIP: 0010:new_sync_write fs/read_write.c:470 [inline]
RIP: 0010:__vfs_write+0x4a6/0x960 fs/read_write.c:487
Code: c1 ea 03 80 3c 02 00 0f 85 1b 04 00 00 48 b8 00 00 00 00 00 fc ff df  
4c 8b 63 20 49 8d bc 24 c8 00 00 00 48 89 fa 48 c1 ea 03 <0f> b6 04 02 84  
c0 74 08 3c 03 0f 8e ec 02 00 00 41 8b 84 24 c8 00
RSP: 0018:ffff8801ae407850 EFLAGS: 00010202
RAX: dffffc0000000000 RBX: ffff8801cd88f580 RCX: ffffffff81c0d6fb
RDX: 0000000000000019 RSI: ffffffff81c0d70a RDI: 00000000000000c8
RBP: ffff8801ae4079c8 R08: ffff8801d88ee680 R09: fffffbfff130c5d9
R10: ffff8801ae407a10 R11: ffffffff89862ecb R12: 0000000000000000
R13: ffff8801ae4079a0 R14: 0000000000000000 R15: ffff8801ae407a88
FS:  000000000102f940(0000) GS:ffff8801dae00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f5f52ac0518 CR3: 00000001d8d8a000 CR4: 00000000001406f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
  __kernel_write+0x10c/0x380 fs/read_write.c:506
  __bpfilter_process_sockopt+0x1d8/0x35b net/bpfilter/bpfilter_kern.c:66
  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:3532
  sock_common_getsockopt+0x9a/0xe0 net/core/sock.c:3012
  __sys_getsockopt+0x1a5/0x370 net/socket.c:1972
  __do_sys_getsockopt net/socket.c:1983 [inline]
  __se_sys_getsockopt net/socket.c:1980 [inline]
  __x64_sys_getsockopt+0xbe/0x150 net/socket.c:1980
  do_syscall_64+0x1b1/0x800 arch/x86/entry/common.c:287
  entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x4584ea
Code: b8 34 01 00 00 0f 05 48 3d 01 f0 ff ff 0f 83 1d 8f fb ff c3 66 2e 0f  
1f 84 00 00 00 00 00 66 90 49 89 ca b8 37 00 00 00 0f 05 <48> 3d 01 f0 ff  
ff 0f 83 fa 8e fb ff c3 66 0f 1f 84 00 00 00 00 00
RSP: 002b:0000000000a3e328 EFLAGS: 00000246 ORIG_RAX: 0000000000000037
RAX: ffffffffffffffda RBX: 0000000000a3e350 RCX: 00000000004584ea
RDX: 0000000000000040 RSI: 0000000000000000 RDI: 0000000000000003
RBP: 0000000000706f20 R08: 0000000000a3e34c R09: 0000000000004000
R10: 0000000000a3e350 R11: 0000000000000246 R12: 0000000000000003
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000706860
Modules linked in:
Dumping ftrace buffer:
    (ftrace buffer empty)
---[ end trace 9a583fc95516c106 ]---
RIP: 0010:file_write_hint include/linux/fs.h:1932 [inline]
RIP: 0010:init_sync_kiocb include/linux/fs.h:1942 [inline]
RIP: 0010:new_sync_write fs/read_write.c:470 [inline]
RIP: 0010:__vfs_write+0x4a6/0x960 fs/read_write.c:487
Code: c1 ea 03 80 3c 02 00 0f 85 1b 04 00 00 48 b8 00 00 00 00 00 fc ff df  
4c 8b 63 20 49 8d bc 24 c8 00 00 00 48 89 fa 48 c1 ea 03 <0f> b6 04 02 84  
c0 74 08 3c 03 0f 8e ec 02 00 00 41 8b 84 24 c8 00
RSP: 0018:ffff8801ae407850 EFLAGS: 00010202
RAX: dffffc0000000000 RBX: ffff8801cd88f580 RCX: ffffffff81c0d6fb
RDX: 0000000000000019 RSI: ffffffff81c0d70a RDI: 00000000000000c8
RBP: ffff8801ae4079c8 R08: ffff8801d88ee680 R09: fffffbfff130c5d9
R10: ffff8801ae407a10 R11: ffffffff89862ecb R12: 0000000000000000
R13: ffff8801ae4079a0 R14: 0000000000000000 R15: ffff8801ae407a88
FS:  000000000102f940(0000) GS:ffff8801dae00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f5f52ac0518 CR3: 00000001d8d8a000 CR4: 00000000001406f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400

^ permalink raw reply	[flat|nested] 4+ messages in thread

end of thread, other threads:[~2018-06-09 15:36 UTC | newest]

Thread overview: 4+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2018-06-07 15:19 general protection fault in __vfs_write syzbot
2018-06-07 15:28 ` Matthew Wilcox
2018-06-07 21:58   ` Alexei Starovoitov
2018-06-09 15:36 ` syzbot

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