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* [syzbot] WARNING in page_counter_cancel (3)
@ 2021-11-21 12:49 syzbot
  2021-12-18 14:04 ` syzbot
  2021-12-18 19:59 ` syzbot
  0 siblings, 2 replies; 14+ messages in thread
From: syzbot @ 2021-11-21 12:49 UTC (permalink / raw)
  To: akpm, linux-kernel, linux-mm, syzkaller-bugs

Hello,

syzbot found the following issue on:

HEAD commit:    42eb8fdac2fc Merge tag 'gfs2-v5.16-rc2-fixes' of git://git..
git tree:       upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=1483f0e9b00000
kernel config:  https://syzkaller.appspot.com/x/.config?x=b7264d1cb8ba2795
dashboard link: https://syzkaller.appspot.com/bug?extid=bc9e2d2dbcb347dd215a
compiler:       gcc (Debian 10.2.1-6) 10.2.1 20210110, GNU ld (GNU Binutils for Debian) 2.35.2

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+bc9e2d2dbcb347dd215a@syzkaller.appspotmail.com

------------[ cut here ]------------
page_counter underflow: -4294964789 nr_pages=4294967295
WARNING: CPU: 2 PID: 3785 at mm/page_counter.c:56 page_counter_cancel+0xcf/0xe0 mm/page_counter.c:56
Modules linked in:
CPU: 2 PID: 3785 Comm: kworker/2:6 Not tainted 5.16.0-rc1-syzkaller #0
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.14.0-2 04/01/2014
Workqueue: events mptcp_worker

RIP: 0010:page_counter_cancel+0xcf/0xe0 mm/page_counter.c:56
Code: c7 04 24 00 00 00 00 45 31 f6 eb 97 e8 2a 2b b5 ff 4c 89 ea 48 89 ee 48 c7 c7 00 9e b8 89 c6 05 a0 c1 ba 0b 01 e8 95 e4 4b 07 <0f> 0b eb a8 4c 89 e7 e8 25 5a fb ff eb c7 0f 1f 00 41 56 41 55 49
RSP: 0018:ffffc90002d4f918 EFLAGS: 00010082

RAX: 0000000000000000 RBX: ffff88806a494120 RCX: 0000000000000000
RDX: ffff8880688c41c0 RSI: ffffffff815e8f28 RDI: fffff520005a9f15
RBP: ffffffff000009cb R08: 0000000000000000 R09: 0000000000000000
R10: ffffffff815e2cfe R11: 0000000000000000 R12: ffff88806a494120
R13: 00000000ffffffff R14: 0000000000000000 R15: 0000000000000001
FS:  0000000000000000(0000) GS:ffff88802cc00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000001b2de21000 CR3: 000000005ad59000 CR4: 0000000000150ee0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 page_counter_uncharge+0x2e/0x60 mm/page_counter.c:160
 drain_stock+0xc1/0x180 mm/memcontrol.c:2219
 refill_stock+0x139/0x2f0 mm/memcontrol.c:2271
 __sk_mem_reduce_allocated+0x24d/0x550 net/core/sock.c:2945
 __mptcp_rmem_reclaim net/mptcp/protocol.c:167 [inline]
 __mptcp_mem_reclaim_partial+0x124/0x410 net/mptcp/protocol.c:975
 mptcp_mem_reclaim_partial net/mptcp/protocol.c:982 [inline]
 mptcp_alloc_tx_skb net/mptcp/protocol.c:1212 [inline]
 mptcp_sendmsg_frag+0x18c6/0x2190 net/mptcp/protocol.c:1279
 __mptcp_push_pending+0x232/0x720 net/mptcp/protocol.c:1545
 mptcp_release_cb+0xfe/0x200 net/mptcp/protocol.c:2975
 release_sock+0xb4/0x1b0 net/core/sock.c:3306
 mptcp_worker+0x51e/0xc10 net/mptcp/protocol.c:2443
 process_one_work+0x9b2/0x1690 kernel/workqueue.c:2298
 worker_thread+0x658/0x11f0 kernel/workqueue.c:2445
 kthread+0x405/0x4f0 kernel/kthread.c:327
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295
 </TASK>


---
This report 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 issue. See:
https://goo.gl/tpsmEJ#status for how to communicate with syzbot.

^ permalink raw reply	[flat|nested] 14+ messages in thread

* Re: [syzbot] WARNING in page_counter_cancel (3)
  2021-11-21 12:49 [syzbot] WARNING in page_counter_cancel (3) syzbot
@ 2021-12-18 14:04 ` syzbot
  2021-12-21 23:57   ` Andrew Morton
  2021-12-18 19:59 ` syzbot
  1 sibling, 1 reply; 14+ messages in thread
From: syzbot @ 2021-12-18 14:04 UTC (permalink / raw)
  To: akpm, linux-kernel, linux-mm, syzkaller-bugs

syzbot has found a reproducer for the following issue on:

HEAD commit:    fbf252e09678 Add linux-next specific files for 20211216
git tree:       linux-next
console output: https://syzkaller.appspot.com/x/log.txt?x=1797de99b00000
kernel config:  https://syzkaller.appspot.com/x/.config?x=7fcbb9aa19a433c8
dashboard link: https://syzkaller.appspot.com/bug?extid=bc9e2d2dbcb347dd215a
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=135d179db00000
C reproducer:   https://syzkaller.appspot.com/x/repro.c?x=113edb6db00000

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+bc9e2d2dbcb347dd215a@syzkaller.appspotmail.com

R13: 00007ffdeb858640 R14: 00007ffdeb858680 R15: 0000000000000004
 </TASK>
------------[ cut here ]------------
page_counter underflow: -4294966651 nr_pages=4294967295
WARNING: CPU: 1 PID: 3665 at mm/page_counter.c:56 page_counter_cancel+0xcf/0xe0 mm/page_counter.c:56 mm/page_counter.c:56
Modules linked in:
CPU: 1 PID: 3665 Comm: syz-executor933 Not tainted 5.16.0-rc5-next-20211216-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
RIP: 0010:page_counter_cancel+0xcf/0xe0 mm/page_counter.c:56 mm/page_counter.c:56
Code: c7 04 24 00 00 00 00 45 31 f6 eb 97 e8 ba 77 af ff 4c 89 ea 48 89 ee 48 c7 c7 60 fe b8 89 c6 05 5f b3 b5 0b 01 e8 a6 85 48 07 <0f> 0b eb a8 4c 89 e7 e8 d5 85 fa ff eb c7 0f 1f 00 41 56 41 55 49
RSP: 0018:ffffc90002b1f620 EFLAGS: 00010086
RAX: 0000000000000000 RBX: ffff88807b6e8120 RCX: 0000000000000000
RDX: ffff88807ad31d40 RSI: ffffffff815f4748 RDI: fffff52000563eb6
RBP: ffffffff00000285 R08: 0000000000000000 R09: 0000000000000001
R10: ffffffff815ee4ae R11: 0000000000000000 R12: ffff88807b6e8120
R13: 00000000ffffffff R14: 0000000000000000 R15: 0000000000000001
FS:  000055555596c300(0000) GS:ffff8880b9d00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000020000080 CR3: 000000007f24a000 CR4: 00000000003506e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 page_counter_uncharge+0x2e/0x60 mm/page_counter.c:159 mm/page_counter.c:159
 drain_stock+0xc1/0x170 mm/memcontrol.c:2172 mm/memcontrol.c:2172
 refill_stock+0x131/0x1b0 mm/memcontrol.c:2224 mm/memcontrol.c:2224
 __sk_mem_reduce_allocated+0x24d/0x550 net/core/sock.c:2951 net/core/sock.c:2951
 __mptcp_rmem_reclaim net/mptcp/protocol.c:169 [inline]
 __mptcp_rmem_reclaim net/mptcp/protocol.c:169 [inline] net/mptcp/protocol.c:978
 __mptcp_mem_reclaim_partial+0x124/0x410 net/mptcp/protocol.c:978 net/mptcp/protocol.c:978
 mptcp_mem_reclaim_partial net/mptcp/protocol.c:985 [inline]
 mptcp_alloc_tx_skb net/mptcp/protocol.c:1215 [inline]
 mptcp_mem_reclaim_partial net/mptcp/protocol.c:985 [inline] net/mptcp/protocol.c:1282
 mptcp_alloc_tx_skb net/mptcp/protocol.c:1215 [inline] net/mptcp/protocol.c:1282
 mptcp_sendmsg_frag+0x1ada/0x2410 net/mptcp/protocol.c:1282 net/mptcp/protocol.c:1282
 __mptcp_push_pending+0x232/0x7a0 net/mptcp/protocol.c:1548 net/mptcp/protocol.c:1548
 mptcp_release_cb+0xfe/0x200 net/mptcp/protocol.c:3013 net/mptcp/protocol.c:3013
 release_sock+0xb4/0x1b0 net/core/sock.c:3312 net/core/sock.c:3312
 sk_stream_wait_memory+0x608/0xed0 net/core/stream.c:145 net/core/stream.c:145
 mptcp_sendmsg+0x8df/0x1300 net/mptcp/protocol.c:1745 net/mptcp/protocol.c:1745
 inet6_sendmsg+0x99/0xe0 net/ipv6/af_inet6.c:641 net/ipv6/af_inet6.c:641
 sock_sendmsg_nosec net/socket.c:704 [inline]
 sock_sendmsg_nosec net/socket.c:704 [inline] net/socket.c:724
 sock_sendmsg+0xcf/0x120 net/socket.c:724 net/socket.c:724
 sock_write_iter+0x289/0x3c0 net/socket.c:1057 net/socket.c:1057
 call_write_iter include/linux/fs.h:2079 [inline]
 call_write_iter include/linux/fs.h:2079 [inline] fs/read_write.c:503
 new_sync_write+0x429/0x660 fs/read_write.c:503 fs/read_write.c:503
 vfs_write+0x7cd/0xae0 fs/read_write.c:590 fs/read_write.c:590
 ksys_write+0x1ee/0x250 fs/read_write.c:643 fs/read_write.c:643
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_x64 arch/x86/entry/common.c:50 [inline] arch/x86/entry/common.c:80
 do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x44/0xae
RIP: 0033:0x7f4cc423cf49
Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 81 15 00 00 90 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 c0 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007ffdeb8585f8 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 00007f4cc423cf49
RDX: 0000000000017f88 RSI: 0000000020000000 RDI: 0000000000000003
RBP: 00007ffdeb858620 R08: 0000000000000001 R09: 00007ffdeb858630
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000004
R13: 00007ffdeb858640 R14: 00007ffdeb858680 R15: 0000000000000004
 </TASK>


^ permalink raw reply	[flat|nested] 14+ messages in thread

* Re: [syzbot] WARNING in page_counter_cancel (3)
  2021-11-21 12:49 [syzbot] WARNING in page_counter_cancel (3) syzbot
  2021-12-18 14:04 ` syzbot
@ 2021-12-18 19:59 ` syzbot
  1 sibling, 0 replies; 14+ messages in thread
From: syzbot @ 2021-12-18 19:59 UTC (permalink / raw)
  To: akpm, davem, jiri, kuba, leonro, linux-kernel, linux-mm, netdev,
	syzkaller-bugs

syzbot has bisected this issue to:

commit 22849b5ea5952d853547cc5e0651f34a246b2a4f
Author: Leon Romanovsky <leonro@nvidia.com>
Date:   Thu Oct 21 14:16:14 2021 +0000

    devlink: Remove not-executed trap policer notifications

bisection log:  https://syzkaller.appspot.com/x/bisect.txt?x=16464095b00000
start commit:   158b515f703e tun: avoid double free in tun_free_netdev
git tree:       net
final oops:     https://syzkaller.appspot.com/x/report.txt?x=15464095b00000
console output: https://syzkaller.appspot.com/x/log.txt?x=11464095b00000
kernel config:  https://syzkaller.appspot.com/x/.config?x=fa556098924b78f0
dashboard link: https://syzkaller.appspot.com/bug?extid=bc9e2d2dbcb347dd215a
syz repro:      https://syzkaller.appspot.com/x/repro.syz?x=13ff127eb00000
C reproducer:   https://syzkaller.appspot.com/x/repro.c?x=11bedb6db00000

Reported-by: syzbot+bc9e2d2dbcb347dd215a@syzkaller.appspotmail.com
Fixes: 22849b5ea595 ("devlink: Remove not-executed trap policer notifications")

For information about bisection process see: https://goo.gl/tpsmEJ#bisection

^ permalink raw reply	[flat|nested] 14+ messages in thread

* Re: [syzbot] WARNING in page_counter_cancel (3)
  2021-12-18 14:04 ` syzbot
@ 2021-12-21 23:57   ` Andrew Morton
  2021-12-29  9:23     ` Michal Hocko
  0 siblings, 1 reply; 14+ messages in thread
From: Andrew Morton @ 2021-12-21 23:57 UTC (permalink / raw)
  To: syzbot; +Cc: linux-kernel, linux-mm, syzkaller-bugs, mptcp, netdev

On Sat, 18 Dec 2021 06:04:22 -0800 syzbot <syzbot+bc9e2d2dbcb347dd215a@syzkaller.appspotmail.com> wrote:

> syzbot has found a reproducer for the following issue on:
> 
> HEAD commit:    fbf252e09678 Add linux-next specific files for 20211216
> git tree:       linux-next
> console output: https://syzkaller.appspot.com/x/log.txt?x=1797de99b00000
> kernel config:  https://syzkaller.appspot.com/x/.config?x=7fcbb9aa19a433c8
> dashboard link: https://syzkaller.appspot.com/bug?extid=bc9e2d2dbcb347dd215a
> 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=135d179db00000
> C reproducer:   https://syzkaller.appspot.com/x/repro.c?x=113edb6db00000

Useful to have that, thanks.

I'm suspecting that mptcp is doing something strange.  Could I as the
developers to please take a look?


> IMPORTANT: if you fix the issue, please add the following tag to the commit:
> Reported-by: syzbot+bc9e2d2dbcb347dd215a@syzkaller.appspotmail.com
> 
> R13: 00007ffdeb858640 R14: 00007ffdeb858680 R15: 0000000000000004
>  </TASK>
> ------------[ cut here ]------------
> page_counter underflow: -4294966651 nr_pages=4294967295
> WARNING: CPU: 1 PID: 3665 at mm/page_counter.c:56 page_counter_cancel+0xcf/0xe0 mm/page_counter.c:56 mm/page_counter.c:56
> Modules linked in:
> CPU: 1 PID: 3665 Comm: syz-executor933 Not tainted 5.16.0-rc5-next-20211216-syzkaller #0
> Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
> RIP: 0010:page_counter_cancel+0xcf/0xe0 mm/page_counter.c:56 mm/page_counter.c:56
> Code: c7 04 24 00 00 00 00 45 31 f6 eb 97 e8 ba 77 af ff 4c 89 ea 48 89 ee 48 c7 c7 60 fe b8 89 c6 05 5f b3 b5 0b 01 e8 a6 85 48 07 <0f> 0b eb a8 4c 89 e7 e8 d5 85 fa ff eb c7 0f 1f 00 41 56 41 55 49
> RSP: 0018:ffffc90002b1f620 EFLAGS: 00010086
> RAX: 0000000000000000 RBX: ffff88807b6e8120 RCX: 0000000000000000
> RDX: ffff88807ad31d40 RSI: ffffffff815f4748 RDI: fffff52000563eb6
> RBP: ffffffff00000285 R08: 0000000000000000 R09: 0000000000000001
> R10: ffffffff815ee4ae R11: 0000000000000000 R12: ffff88807b6e8120
> R13: 00000000ffffffff R14: 0000000000000000 R15: 0000000000000001
> FS:  000055555596c300(0000) GS:ffff8880b9d00000(0000) knlGS:0000000000000000
> CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
> CR2: 0000000020000080 CR3: 000000007f24a000 CR4: 00000000003506e0
> DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
> DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
> Call Trace:
>  <TASK>
>  page_counter_uncharge+0x2e/0x60 mm/page_counter.c:159 mm/page_counter.c:159
>  drain_stock+0xc1/0x170 mm/memcontrol.c:2172 mm/memcontrol.c:2172
>  refill_stock+0x131/0x1b0 mm/memcontrol.c:2224 mm/memcontrol.c:2224
>  __sk_mem_reduce_allocated+0x24d/0x550 net/core/sock.c:2951 net/core/sock.c:2951
>  __mptcp_rmem_reclaim net/mptcp/protocol.c:169 [inline]
>  __mptcp_rmem_reclaim net/mptcp/protocol.c:169 [inline] net/mptcp/protocol.c:978
>  __mptcp_mem_reclaim_partial+0x124/0x410 net/mptcp/protocol.c:978 net/mptcp/protocol.c:978
>  mptcp_mem_reclaim_partial net/mptcp/protocol.c:985 [inline]
>  mptcp_alloc_tx_skb net/mptcp/protocol.c:1215 [inline]
>  mptcp_mem_reclaim_partial net/mptcp/protocol.c:985 [inline] net/mptcp/protocol.c:1282
>  mptcp_alloc_tx_skb net/mptcp/protocol.c:1215 [inline] net/mptcp/protocol.c:1282
>  mptcp_sendmsg_frag+0x1ada/0x2410 net/mptcp/protocol.c:1282 net/mptcp/protocol.c:1282
>  __mptcp_push_pending+0x232/0x7a0 net/mptcp/protocol.c:1548 net/mptcp/protocol.c:1548
>  mptcp_release_cb+0xfe/0x200 net/mptcp/protocol.c:3013 net/mptcp/protocol.c:3013
>  release_sock+0xb4/0x1b0 net/core/sock.c:3312 net/core/sock.c:3312
>  sk_stream_wait_memory+0x608/0xed0 net/core/stream.c:145 net/core/stream.c:145
>  mptcp_sendmsg+0x8df/0x1300 net/mptcp/protocol.c:1745 net/mptcp/protocol.c:1745
>  inet6_sendmsg+0x99/0xe0 net/ipv6/af_inet6.c:641 net/ipv6/af_inet6.c:641
>  sock_sendmsg_nosec net/socket.c:704 [inline]
>  sock_sendmsg_nosec net/socket.c:704 [inline] net/socket.c:724
>  sock_sendmsg+0xcf/0x120 net/socket.c:724 net/socket.c:724
>  sock_write_iter+0x289/0x3c0 net/socket.c:1057 net/socket.c:1057
>  call_write_iter include/linux/fs.h:2079 [inline]
>  call_write_iter include/linux/fs.h:2079 [inline] fs/read_write.c:503
>  new_sync_write+0x429/0x660 fs/read_write.c:503 fs/read_write.c:503
>  vfs_write+0x7cd/0xae0 fs/read_write.c:590 fs/read_write.c:590
>  ksys_write+0x1ee/0x250 fs/read_write.c:643 fs/read_write.c:643
>  do_syscall_x64 arch/x86/entry/common.c:50 [inline]
>  do_syscall_x64 arch/x86/entry/common.c:50 [inline] arch/x86/entry/common.c:80
>  do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80 arch/x86/entry/common.c:80
>  entry_SYSCALL_64_after_hwframe+0x44/0xae
> RIP: 0033:0x7f4cc423cf49
> Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 81 15 00 00 90 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 c0 ff ff ff f7 d8 64 89 01 48
> RSP: 002b:00007ffdeb8585f8 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
> RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 00007f4cc423cf49
> RDX: 0000000000017f88 RSI: 0000000020000000 RDI: 0000000000000003
> RBP: 00007ffdeb858620 R08: 0000000000000001 R09: 00007ffdeb858630
> R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000004
> R13: 00007ffdeb858640 R14: 00007ffdeb858680 R15: 0000000000000004
>  </TASK>

^ permalink raw reply	[flat|nested] 14+ messages in thread

* Re: [syzbot] WARNING in page_counter_cancel (3)
  2021-12-21 23:57   ` Andrew Morton
@ 2021-12-29  9:23     ` Michal Hocko
  2022-01-05  0:08       ` Mat Martineau
                         ` (4 more replies)
  0 siblings, 5 replies; 14+ messages in thread
From: Michal Hocko @ 2021-12-29  9:23 UTC (permalink / raw)
  To: Andrew Morton
  Cc: syzbot, linux-kernel, linux-mm, syzkaller-bugs, mptcp, netdev

On Tue 21-12-21 15:57:36, Andrew Morton wrote:
> On Sat, 18 Dec 2021 06:04:22 -0800 syzbot <syzbot+bc9e2d2dbcb347dd215a@syzkaller.appspotmail.com> wrote:
> 
> > syzbot has found a reproducer for the following issue on:
> > 
> > HEAD commit:    fbf252e09678 Add linux-next specific files for 20211216
> > git tree:       linux-next
> > console output: https://syzkaller.appspot.com/x/log.txt?x=1797de99b00000
> > kernel config:  https://syzkaller.appspot.com/x/.config?x=7fcbb9aa19a433c8
> > dashboard link: https://syzkaller.appspot.com/bug?extid=bc9e2d2dbcb347dd215a
> > 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=135d179db00000
> > C reproducer:   https://syzkaller.appspot.com/x/repro.c?x=113edb6db00000
> 
> Useful to have that, thanks.
> 
> I'm suspecting that mptcp is doing something strange.

Yes.

> Could I as the
> developers to please take a look?
> 
> 
> > IMPORTANT: if you fix the issue, please add the following tag to the commit:
> > Reported-by: syzbot+bc9e2d2dbcb347dd215a@syzkaller.appspotmail.com
> > 
> > R13: 00007ffdeb858640 R14: 00007ffdeb858680 R15: 0000000000000004
> >  </TASK>
> > ------------[ cut here ]------------
> > page_counter underflow: -4294966651 nr_pages=4294967295

__mptcp_mem_reclaim_partial is trying to uncharge (via
__sk_mem_reduce_allocated) negative amount. nr_pages has overflown when
converted from int to unsigned int (-1). I would say that
__mptcp_mem_reclaim_partial has evaluated
	reclaimable = mptcp_sk(sk)->rmem_fwd_alloc - sk_unused_reserved_mem(sk)
to 0 and __mptcp_rmem_reclaim(sk, reclaimable - 1) made it -1.
-- 
Michal Hocko
SUSE Labs

^ permalink raw reply	[flat|nested] 14+ messages in thread

* Re: [syzbot] WARNING in page_counter_cancel (3)
  2021-12-29  9:23     ` Michal Hocko
@ 2022-01-05  0:08       ` Mat Martineau
  2022-01-05  0:35       ` Mat Martineau
                         ` (3 subsequent siblings)
  4 siblings, 0 replies; 14+ messages in thread
From: Mat Martineau @ 2022-01-05  0:08 UTC (permalink / raw)
  To: Andrew Morton, Michal Hocko
  Cc: syzbot, linux-kernel, linux-mm, syzkaller-bugs, mptcp, netdev,
	Paolo Abeni

On Wed, 29 Dec 2021, Michal Hocko wrote:

> On Tue 21-12-21 15:57:36, Andrew Morton wrote:
>> On Sat, 18 Dec 2021 06:04:22 -0800 syzbot <syzbot+bc9e2d2dbcb347dd215a@syzkaller.appspotmail.com> wrote:
>>
>>> syzbot has found a reproducer for the following issue on:
>>>
>>> HEAD commit:    fbf252e09678 Add linux-next specific files for 20211216
>>> git tree:       linux-next
>>> console output: https://syzkaller.appspot.com/x/log.txt?x=1797de99b00000
>>> kernel config:  https://syzkaller.appspot.com/x/.config?x=7fcbb9aa19a433c8
>>> dashboard link: https://syzkaller.appspot.com/bug?extid=bc9e2d2dbcb347dd215a
>>> 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=135d179db00000
>>> C reproducer:   https://syzkaller.appspot.com/x/repro.c?x=113edb6db00000
>>
>> Useful to have that, thanks.
>>
>> I'm suspecting that mptcp is doing something strange.
>
> Yes.
>
>> Could I as the
>> developers to please take a look?
>>

Andrew -

Yes, we'll get a fix in to net-next soon - thanks for adding the mptcp & 
netdev lists.

>>
>>> IMPORTANT: if you fix the issue, please add the following tag to the commit:
>>> Reported-by: syzbot+bc9e2d2dbcb347dd215a@syzkaller.appspotmail.com
>>>
>>> R13: 00007ffdeb858640 R14: 00007ffdeb858680 R15: 0000000000000004
>>>  </TASK>
>>> ------------[ cut here ]------------
>>> page_counter underflow: -4294966651 nr_pages=4294967295
>
> __mptcp_mem_reclaim_partial is trying to uncharge (via
> __sk_mem_reduce_allocated) negative amount. nr_pages has overflown when
> converted from int to unsigned int (-1). I would say that
> __mptcp_mem_reclaim_partial has evaluated
> 	reclaimable = mptcp_sk(sk)->rmem_fwd_alloc - sk_unused_reserved_mem(sk)
> to 0 and __mptcp_rmem_reclaim(sk, reclaimable - 1) made it -1.

Thanks for the analysis Michal.

--
Mat Martineau
Intel

^ permalink raw reply	[flat|nested] 14+ messages in thread

* Re: [syzbot] WARNING in page_counter_cancel (3)
  2021-12-29  9:23     ` Michal Hocko
  2022-01-05  0:08       ` Mat Martineau
@ 2022-01-05  0:35       ` Mat Martineau
  2022-01-05  2:41         ` syzbot
  2022-01-05  1:06       ` Mat Martineau
                         ` (2 subsequent siblings)
  4 siblings, 1 reply; 14+ messages in thread
From: Mat Martineau @ 2022-01-05  0:35 UTC (permalink / raw)
  To: syzbot; +Cc: syzkaller-bugs, mptcp, Paolo Abeni

On Wed, 29 Dec 2021, Michal Hocko wrote:

> On Tue 21-12-21 15:57:36, Andrew Morton wrote:
>> On Sat, 18 Dec 2021 06:04:22 -0800 syzbot <syzbot+bc9e2d2dbcb347dd215a@syzkaller.appspotmail.com> wrote:
>>
>>> syzbot has found a reproducer for the following issue on:
>>>
>>> HEAD commit:    fbf252e09678 Add linux-next specific files for 20211216
>>> git tree:       linux-next
>>> console output: https://syzkaller.appspot.com/x/log.txt?x=1797de99b00000
>>> kernel config:  https://syzkaller.appspot.com/x/.config?x=7fcbb9aa19a433c8
>>> dashboard link: https://syzkaller.appspot.com/bug?extid=bc9e2d2dbcb347dd215a
>>> 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=135d179db00000
>>> C reproducer:   https://syzkaller.appspot.com/x/repro.c?x=113edb6db00000
>>
>> Useful to have that, thanks.
>>
>> I'm suspecting that mptcp is doing something strange.
>
> Yes.
>
>> Could I as the
>> developers to please take a look?
>>
>>
>>> IMPORTANT: if you fix the issue, please add the following tag to the commit:
>>> Reported-by: syzbot+bc9e2d2dbcb347dd215a@syzkaller.appspotmail.com
>>>
>>> R13: 00007ffdeb858640 R14: 00007ffdeb858680 R15: 0000000000000004
>>>  </TASK>
>>> ------------[ cut here ]------------
>>> page_counter underflow: -4294966651 nr_pages=4294967295
>
> __mptcp_mem_reclaim_partial is trying to uncharge (via
> __sk_mem_reduce_allocated) negative amount. nr_pages has overflown when
> converted from int to unsigned int (-1). I would say that
> __mptcp_mem_reclaim_partial has evaluated
> 	reclaimable = mptcp_sk(sk)->rmem_fwd_alloc - sk_unused_reserved_mem(sk)
> to 0 and __mptcp_rmem_reclaim(sk, reclaimable - 1) made it -1.

#syz test: git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next.git master

diff --git a/net/mptcp/protocol.c b/net/mptcp/protocol.c
index df5a0cf431c1..7ed86e81181e 100644
--- a/net/mptcp/protocol.c
+++ b/net/mptcp/protocol.c
@@ -975,7 +975,9 @@ static void __mptcp_mem_reclaim_partial(struct sock 
*sk)

         lockdep_assert_held_once(&sk->sk_lock.slock);

-       __mptcp_rmem_reclaim(sk, reclaimable - 1);
+       if (reclaimable >= SK_MEM_QUANTUM )
+               __mptcp_rmem_reclaim(sk, reclaimable - 1);
+
         sk_mem_reclaim_partial(sk);
  }


--
Mat Martineau
Intel

^ permalink raw reply related	[flat|nested] 14+ messages in thread

* Re: [syzbot] WARNING in page_counter_cancel (3)
  2021-12-29  9:23     ` Michal Hocko
  2022-01-05  0:08       ` Mat Martineau
  2022-01-05  0:35       ` Mat Martineau
@ 2022-01-05  1:06       ` Mat Martineau
  2022-01-05  2:41         ` syzbot
  2022-01-05 23:24       ` Mat Martineau
  2022-01-05 23:53       ` Mat Martineau
  4 siblings, 1 reply; 14+ messages in thread
From: Mat Martineau @ 2022-01-05  1:06 UTC (permalink / raw)
  To: syzbot; +Cc: syzkaller-bugs, mptcp, Paolo Abeni

On Wed, 29 Dec 2021, Michal Hocko wrote:

> On Tue 21-12-21 15:57:36, Andrew Morton wrote:
>> On Sat, 18 Dec 2021 06:04:22 -0800 syzbot <syzbot+bc9e2d2dbcb347dd215a@syzkaller.appspotmail.com> wrote:
>>
>>> syzbot has found a reproducer for the following issue on:
>>>
>>> HEAD commit:    fbf252e09678 Add linux-next specific files for 20211216
>>> git tree:       linux-next
>>> console output: https://syzkaller.appspot.com/x/log.txt?x=1797de99b00000
>>> kernel config:  https://syzkaller.appspot.com/x/.config?x=7fcbb9aa19a433c8
>>> dashboard link: https://syzkaller.appspot.com/bug?extid=bc9e2d2dbcb347dd215a
>>> 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=135d179db00000
>>> C reproducer:   https://syzkaller.appspot.com/x/repro.c?x=113edb6db00000
>>
>> Useful to have that, thanks.
>>
>> I'm suspecting that mptcp is doing something strange.
>
> Yes.
>
>> Could I as the
>> developers to please take a look?
>>
>>
>>> IMPORTANT: if you fix the issue, please add the following tag to the commit:
>>> Reported-by: syzbot+bc9e2d2dbcb347dd215a@syzkaller.appspotmail.com
>>>
>>> R13: 00007ffdeb858640 R14: 00007ffdeb858680 R15: 0000000000000004
>>>  </TASK>
>>> ------------[ cut here ]------------
>>> page_counter underflow: -4294966651 nr_pages=4294967295
>
> __mptcp_mem_reclaim_partial is trying to uncharge (via
> __sk_mem_reduce_allocated) negative amount. nr_pages has overflown when
> converted from int to unsigned int (-1). I would say that
> __mptcp_mem_reclaim_partial has evaluated
> 	reclaimable = mptcp_sk(sk)->rmem_fwd_alloc - sk_unused_reserved_mem(sk)
> to 0 and __mptcp_rmem_reclaim(sk, reclaimable - 1) made it -1.

Trying again with fixed syntax for the bot:

#syz test: git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next.git master

---
diff --git a/net/mptcp/protocol.c b/net/mptcp/protocol.c
index df5a0cf431c1..7ed86e81181e 100644
--- a/net/mptcp/protocol.c
+++ b/net/mptcp/protocol.c
@@ -975,7 +975,9 @@ static void __mptcp_mem_reclaim_partial(struct sock 
*sk)

         lockdep_assert_held_once(&sk->sk_lock.slock);

-       __mptcp_rmem_reclaim(sk, reclaimable - 1);
+       if (reclaimable >= SK_MEM_QUANTUM )
+               __mptcp_rmem_reclaim(sk, reclaimable - 1);
+
         sk_mem_reclaim_partial(sk);
  }

--
Mat Martineau
Intel

^ permalink raw reply related	[flat|nested] 14+ messages in thread

* Re: [syzbot] WARNING in page_counter_cancel (3)
  2022-01-05  0:35       ` Mat Martineau
@ 2022-01-05  2:41         ` syzbot
  0 siblings, 0 replies; 14+ messages in thread
From: syzbot @ 2022-01-05  2:41 UTC (permalink / raw)
  To: mathew.j.martineau, mptcp, pabeni, syzkaller-bugs

Hello,

syzbot tried to test the proposed patch but the build/boot failed:

failed to apply patch:
checking file net/mptcp/protocol.c
patch: **** unexpected end of file in patch



Tested on:

commit:         ffd32ea6 Revert "net: wwan: iosm: Keep device at D0 fo..
git tree:       git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next.git master
dashboard link: https://syzkaller.appspot.com/bug?extid=bc9e2d2dbcb347dd215a
compiler:       
patch:          https://syzkaller.appspot.com/x/patch.diff?x=1050454fb00000


^ permalink raw reply	[flat|nested] 14+ messages in thread

* Re: [syzbot] WARNING in page_counter_cancel (3)
  2022-01-05  1:06       ` Mat Martineau
@ 2022-01-05  2:41         ` syzbot
  0 siblings, 0 replies; 14+ messages in thread
From: syzbot @ 2022-01-05  2:41 UTC (permalink / raw)
  To: mathew.j.martineau, mptcp, pabeni, syzkaller-bugs

Hello,

syzbot tried to test the proposed patch but the build/boot failed:

failed to apply patch:
checking file net/mptcp/protocol.c
patch: **** unexpected end of file in patch



Tested on:

commit:         ffd32ea6 Revert "net: wwan: iosm: Keep device at D0 fo..
git tree:       git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next.git master
dashboard link: https://syzkaller.appspot.com/bug?extid=bc9e2d2dbcb347dd215a
compiler:       
patch:          https://syzkaller.appspot.com/x/patch.diff?x=1216323bb00000


^ permalink raw reply	[flat|nested] 14+ messages in thread

* Re: [syzbot] WARNING in page_counter_cancel (3)
  2021-12-29  9:23     ` Michal Hocko
                         ` (2 preceding siblings ...)
  2022-01-05  1:06       ` Mat Martineau
@ 2022-01-05 23:24       ` Mat Martineau
  2022-01-05 23:26         ` syzbot
  2022-01-05 23:53       ` Mat Martineau
  4 siblings, 1 reply; 14+ messages in thread
From: Mat Martineau @ 2022-01-05 23:24 UTC (permalink / raw)
  To: syzbot; +Cc: syzkaller-bugs, mptcp, Paolo Abeni

On Wed, 29 Dec 2021, Michal Hocko wrote:

> On Tue 21-12-21 15:57:36, Andrew Morton wrote:
>> On Sat, 18 Dec 2021 06:04:22 -0800 syzbot <syzbot+bc9e2d2dbcb347dd215a@syzkaller.appspotmail.com> wrote:
>>
>>> syzbot has found a reproducer for the following issue on:
>>>
>>> HEAD commit:    fbf252e09678 Add linux-next specific files for 20211216
>>> git tree:       linux-next
>>> console output: https://syzkaller.appspot.com/x/log.txt?x=1797de99b00000
>>> kernel config:  https://syzkaller.appspot.com/x/.config?x=7fcbb9aa19a433c8
>>> dashboard link: https://syzkaller.appspot.com/bug?extid=bc9e2d2dbcb347dd215a
>>> 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=135d179db00000
>>> C reproducer:   https://syzkaller.appspot.com/x/repro.c?x=113edb6db00000
>>
>> Useful to have that, thanks.
>>
>> I'm suspecting that mptcp is doing something strange.
>
> Yes.
>
>> Could I as the
>> developers to please take a look?
>>
>>
>>> IMPORTANT: if you fix the issue, please add the following tag to the commit:
>>> Reported-by: syzbot+bc9e2d2dbcb347dd215a@syzkaller.appspotmail.com
>>>
>>> R13: 00007ffdeb858640 R14: 00007ffdeb858680 R15: 0000000000000004
>>>  </TASK>
>>> ------------[ cut here ]------------
>>> page_counter underflow: -4294966651 nr_pages=4294967295
>
> __mptcp_mem_reclaim_partial is trying to uncharge (via
> __sk_mem_reduce_allocated) negative amount. nr_pages has overflown when
> converted from int to unsigned int (-1). I would say that
> __mptcp_mem_reclaim_partial has evaluated
> 	reclaimable = mptcp_sk(sk)->rmem_fwd_alloc - sk_unused_reserved_mem(sk)
> to 0 and __mptcp_rmem_reclaim(sk, reclaimable - 1) made it -1.

Ok, formatting really fixed this time (I hope), trailing whitespace and 
all:

#syz test: git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next.git master

---
diff --git a/net/mptcp/protocol.c b/net/mptcp/protocol.c
index df5a0cf431c1..8fa56b9651a2 100644
--- a/net/mptcp/protocol.c
+++ b/net/mptcp/protocol.c
@@ -975,7 +975,9 @@ static void __mptcp_mem_reclaim_partial(struct sock *sk)

  	lockdep_assert_held_once(&sk->sk_lock.slock);

-	__mptcp_rmem_reclaim(sk, reclaimable - 1);
+	if (reclaimable >= SK_MEM_QUANTUM)
+		__mptcp_rmem_reclaim(sk, reclaimable - 1);
+
  	sk_mem_reclaim_partial(sk);
  }


^ permalink raw reply related	[flat|nested] 14+ messages in thread

* Re: [syzbot] WARNING in page_counter_cancel (3)
  2022-01-05 23:24       ` Mat Martineau
@ 2022-01-05 23:26         ` syzbot
  0 siblings, 0 replies; 14+ messages in thread
From: syzbot @ 2022-01-05 23:26 UTC (permalink / raw)
  To: mathew.j.martineau, mptcp, pabeni, syzkaller-bugs

Hello,

syzbot tried to test the proposed patch but the build/boot failed:

failed to apply patch:
checking file net/mptcp/protocol.c
patch: **** unexpected end of file in patch



Tested on:

commit:         b9adba35 Merge git://git.kernel.org/pub/scm/linux/kern..
git tree:       git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next.git master
dashboard link: https://syzkaller.appspot.com/bug?extid=bc9e2d2dbcb347dd215a
compiler:       
patch:          https://syzkaller.appspot.com/x/patch.diff?x=168e0c07b00000


^ permalink raw reply	[flat|nested] 14+ messages in thread

* Re: [syzbot] WARNING in page_counter_cancel (3)
  2021-12-29  9:23     ` Michal Hocko
                         ` (3 preceding siblings ...)
  2022-01-05 23:24       ` Mat Martineau
@ 2022-01-05 23:53       ` Mat Martineau
  2022-01-06  0:06         ` syzbot
  4 siblings, 1 reply; 14+ messages in thread
From: Mat Martineau @ 2022-01-05 23:53 UTC (permalink / raw)
  To: syzbot; +Cc: syzkaller-bugs, mptcp, Paolo Abeni

On Wed, 29 Dec 2021, Michal Hocko wrote:

> On Tue 21-12-21 15:57:36, Andrew Morton wrote:
>> On Sat, 18 Dec 2021 06:04:22 -0800 syzbot <syzbot+bc9e2d2dbcb347dd215a@syzkaller.appspotmail.com> wrote:
>>
>>> syzbot has found a reproducer for the following issue on:
>>>
>>> HEAD commit:    fbf252e09678 Add linux-next specific files for 20211216
>>> git tree:       linux-next
>>> console output: https://syzkaller.appspot.com/x/log.txt?x=1797de99b00000
>>> kernel config:  https://syzkaller.appspot.com/x/.config?x=7fcbb9aa19a433c8
>>> dashboard link: https://syzkaller.appspot.com/bug?extid=bc9e2d2dbcb347dd215a
>>> 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=135d179db00000
>>> C reproducer:   https://syzkaller.appspot.com/x/repro.c?x=113edb6db00000
>>
>> Useful to have that, thanks.
>>
>> I'm suspecting that mptcp is doing something strange.
>
> Yes.
>
>> Could I as the
>> developers to please take a look?
>>
>>
>>> IMPORTANT: if you fix the issue, please add the following tag to the commit:
>>> Reported-by: syzbot+bc9e2d2dbcb347dd215a@syzkaller.appspotmail.com
>>>
>>> R13: 00007ffdeb858640 R14: 00007ffdeb858680 R15: 0000000000000004
>>>  </TASK>
>>> ------------[ cut here ]------------
>>> page_counter underflow: -4294966651 nr_pages=4294967295
>
> __mptcp_mem_reclaim_partial is trying to uncharge (via
> __sk_mem_reduce_allocated) negative amount. nr_pages has overflown when
> converted from int to unsigned int (-1). I would say that
> __mptcp_mem_reclaim_partial has evaluated
> 	reclaimable = mptcp_sk(sk)->rmem_fwd_alloc - sk_unused_reserved_mem(sk)
> to 0 and __mptcp_rmem_reclaim(sk, reclaimable - 1) made it -1.

Well, given that the inline patch isn't working out, I'll try having 
syzbot directly access my git tree:

#syz test: https://git.kernel.org/pub/scm/linux/kernel/git/martineau/linux.git syz-test-reclaim


--
Mat Martineau
Intel

^ permalink raw reply	[flat|nested] 14+ messages in thread

* Re: [syzbot] WARNING in page_counter_cancel (3)
  2022-01-05 23:53       ` Mat Martineau
@ 2022-01-06  0:06         ` syzbot
  0 siblings, 0 replies; 14+ messages in thread
From: syzbot @ 2022-01-06  0:06 UTC (permalink / raw)
  To: mathew.j.martineau, mptcp, pabeni, syzkaller-bugs

Hello,

syzbot has tested the proposed patch and the reproducer did not trigger any issue:

Reported-and-tested-by: syzbot+bc9e2d2dbcb347dd215a@syzkaller.appspotmail.com

Tested on:

commit:         7b501ffb mptcp: Test fix for syzkaller failure
git tree:       https://git.kernel.org/pub/scm/linux/kernel/git/martineau/linux.git syz-test-reclaim
kernel config:  https://syzkaller.appspot.com/x/.config?x=34274384f56cbb7e
dashboard link: https://syzkaller.appspot.com/bug?extid=bc9e2d2dbcb347dd215a
compiler:       gcc (Debian 10.2.1-6) 10.2.1 20210110, GNU ld (GNU Binutils for Debian) 2.35.2

Note: testing is done by a robot and is best-effort only.

^ permalink raw reply	[flat|nested] 14+ messages in thread

end of thread, other threads:[~2022-01-06  0:06 UTC | newest]

Thread overview: 14+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2021-11-21 12:49 [syzbot] WARNING in page_counter_cancel (3) syzbot
2021-12-18 14:04 ` syzbot
2021-12-21 23:57   ` Andrew Morton
2021-12-29  9:23     ` Michal Hocko
2022-01-05  0:08       ` Mat Martineau
2022-01-05  0:35       ` Mat Martineau
2022-01-05  2:41         ` syzbot
2022-01-05  1:06       ` Mat Martineau
2022-01-05  2:41         ` syzbot
2022-01-05 23:24       ` Mat Martineau
2022-01-05 23:26         ` syzbot
2022-01-05 23:53       ` Mat Martineau
2022-01-06  0:06         ` syzbot
2021-12-18 19:59 ` syzbot

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