general protection fault in j1939_jsk_del (2)

[syzbot]

Hello,

syzbot found the following crash on:

HEAD commit: 81b6b964 Merge branch 'master' of git://git.kernel.org/pub..
git tree: upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=134af786e00000
kernel config: https://syzkaller.appspot.com/x/.config?x=773597fe8d7cb41a
dashboard link: https://syzkaller.appspot.com/bug?extid=99e9e1b200a1e363237d
compiler: gcc (GCC) 9.0.0 20181231 (experimental)
userspace arch: i386

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+99e9e1...@syzkaller.appspotmail.com

kasan: CONFIG_KASAN_INLINE enabled
kasan: GPF could be caused by NULL-ptr deref or user memory access
general protection fault: 0000 [#1] PREEMPT SMP KASAN
CPU: 0 PID: 18385 Comm: syz-executor.1 Not tainted 5.4.0-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS
Google 01/01/2011
RIP: 0010:__lock_acquire+0x1254/0x4a00 kernel/locking/lockdep.c:3828
Code: 00 0f 85 96 24 00 00 48 81 c4 f0 00 00 00 5b 41 5c 41 5d 41 5e 41 5f
5d c3 48 b8 00 00 00 00 00 fc ff df 4c 89 f2 48 c1 ea 03 <80> 3c 02 00 0f
85 0b 28 00 00 49 81 3e 20 59 2a 8a 0f 84 5f ee ff
RSP: 0018:ffff8880a0397b38 EFLAGS: 00010006
RAX: dffffc0000000000 RBX: 0000000000000000 RCX: 0000000000000000
RDX: 0000000000000218 RSI: 0000000000000000 RDI: 0000000000000001
RBP: ffff8880a0397c50 R08: 0000000000000001 R09: 0000000000000001
R10: fffffbfff13d4e58 R11: ffff888093b044c0 R12: 00000000000010c0
R13: 0000000000000000 R14: 00000000000010c0 R15: 0000000000000000
FS: 0000000000000000(0000) GS:ffff8880ae800000(0063) knlGS:00000000f5dcfb40
CS: 0010 DS: 002b ES: 002b CR0: 0000000080050033
CR2: 000000002e521000 CR3: 0000000097a51000 CR4: 00000000001426f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
lock_acquire+0x190/0x410 kernel/locking/lockdep.c:4485
__raw_spin_lock_bh include/linux/spinlock_api_smp.h:135 [inline]
_raw_spin_lock_bh+0x33/0x50 kernel/locking/spinlock.c:175
spin_lock_bh include/linux/spinlock.h:343 [inline]
j1939_jsk_del+0x32/0x210 net/can/j1939/socket.c:89
j1939_sk_bind+0x2ea/0x8f0 net/can/j1939/socket.c:448
__sys_bind+0x239/0x290 net/socket.c:1648
__do_sys_bind net/socket.c:1659 [inline]
__se_sys_bind net/socket.c:1657 [inline]
__ia32_sys_bind+0x72/0xb0 net/socket.c:1657
do_syscall_32_irqs_on arch/x86/entry/common.c:337 [inline]
do_fast_syscall_32+0x27b/0xe16 arch/x86/entry/common.c:408
entry_SYSENTER_compat+0x70/0x7f arch/x86/entry/entry_64_compat.S:139
RIP: 0023:0xf7ff4a39
Code: 00 00 00 89 d3 5b 5e 5f 5d c3 b8 80 96 98 00 eb c4 8b 04 24 c3 8b 1c
24 c3 8b 34 24 c3 8b 3c 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:00000000f5dcf0cc EFLAGS: 00000296 ORIG_RAX: 0000000000000169
RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 0000000020000000
RDX: 0000000000000018 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
Modules linked in:
------------[ cut here ]------------
WARNING: CPU: 0 PID: 18385 at kernel/locking/mutex.c:1419
mutex_trylock+0x279/0x2f0 kernel/locking/mutex.c:1427


---
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[syzbot]

syzbot has found a reproducer for the following crash on:

HEAD commit: 81b6b964 Merge branch 'master' of git://git.kernel.org/pub..

git tree: net-next
console output: https://syzkaller.appspot.com/x/log.txt?x=14d2aabce00000
kernel config: https://syzkaller.appspot.com/x/.config?x=333b76551307b2a0

dashboard link: https://syzkaller.appspot.com/bug?extid=99e9e1b200a1e363237d
compiler: gcc (GCC) 9.0.0 20181231 (experimental)

syz repro: https://syzkaller.appspot.com/x/repro.syz?x=1671bcdae00000

IMPORTANT: if you fix the bug, please add the following tag to the commit:
Reported-by: syzbot+99e9e1...@syzkaller.appspotmail.com

kasan: CONFIG_KASAN_INLINE enabled
kasan: GPF could be caused by NULL-ptr deref or user memory access
general protection fault: 0000 [#1] PREEMPT SMP KASAN

CPU: 0 PID: 9409 Comm: syz-executor.0 Not tainted 5.4.0-syzkaller #0

Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS
Google 01/01/2011
RIP: 0010:__lock_acquire+0x1254/0x4a00 kernel/locking/lockdep.c:3828
Code: 00 0f 85 96 24 00 00 48 81 c4 f0 00 00 00 5b 41 5c 41 5d 41 5e 41 5f
5d c3 48 b8 00 00 00 00 00 fc ff df 4c 89 f2 48 c1 ea 03 <80> 3c 02 00 0f

85 0b 28 00 00 49 81 3e 20 e9 77 8a 0f 84 5f ee ff
RSP: 0018:ffff8880a393fb48 EFLAGS: 00010006

RAX: dffffc0000000000 RBX: 0000000000000000 RCX: 0000000000000000
RDX: 0000000000000218 RSI: 0000000000000000 RDI: 0000000000000001

RBP: ffff8880a393fc60 R08: 0000000000000001 R09: 0000000000000001
R10: fffffbfff146dba0 R11: ffff8880a084e300 R12: 00000000000010c0

R13: 0000000000000000 R14: 00000000000010c0 R15: 0000000000000000

FS: 00007f996d50d700(0000) GS:ffff8880ae800000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000000000075c000 CR3: 000000008f718000 CR4: 00000000001406f0

DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
lock_acquire+0x190/0x410 kernel/locking/lockdep.c:4485
__raw_spin_lock_bh include/linux/spinlock_api_smp.h:135 [inline]
_raw_spin_lock_bh+0x33/0x50 kernel/locking/spinlock.c:175
spin_lock_bh include/linux/spinlock.h:343 [inline]
j1939_jsk_del+0x32/0x210 net/can/j1939/socket.c:89
j1939_sk_bind+0x2ea/0x8f0 net/can/j1939/socket.c:448
__sys_bind+0x239/0x290 net/socket.c:1648
__do_sys_bind net/socket.c:1659 [inline]
__se_sys_bind net/socket.c:1657 [inline]

__x64_sys_bind+0x73/0xb0 net/socket.c:1657
do_syscall_64+0xfa/0x790 arch/x86/entry/common.c:294
entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x45a679
Code: ad b6 fb ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 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 0f 83 7b b6 fb ff c3 66 2e 0f 1f 84 00 00 00 00
RSP: 002b:00007f996d50cc78 EFLAGS: 00000246 ORIG_RAX: 0000000000000031
RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 000000000045a679
RDX: 0000000000000018 RSI: 00000000200000c0 RDI: 0000000000000003
RBP: 000000000075bfc8 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00007f996d50d6d4
R13: 00000000004c09e9 R14: 00000000004d37d0 R15: 00000000ffffffff

Modules linked in:
------------[ cut here ]------------

WARNING: CPU: 0 PID: 9409 at kernel/locking/mutex.c:1419
mutex_trylock+0x279/0x2f0 kernel/locking/mutex.c:1427

[Hillf Danton]

On Fri, 29 Nov 2019 23:19:08 -0800
> Hello,
>
> syzbot found the following crash on:

>
> HEAD commit: 81b6b964 Merge branch 'master' of git://git.kernel.org/pub..

> git tree: upstream
> console output: https://syzkaller.appspot.com/x/log.txt?x=134af786e00000
> kernel config: https://syzkaller.appspot.com/x/.config?x=773597fe8d7cb41a

> dashboard link: https://syzkaller.appspot.com/bug?extid=99e9e1b200a1e363237d
> compiler: gcc (GCC) 9.0.0 20181231 (experimental)

> userspace arch: i386
>
> 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+99e9e1...@syzkaller.appspotmail.com
>
> kasan: CONFIG_KASAN_INLINE enabled
> kasan: GPF could be caused by NULL-ptr deref or user memory access
> general protection fault: 0000 [#1] PREEMPT SMP KASAN

> CPU: 0 PID: 18385 Comm: syz-executor.1 Not tainted 5.4.0-syzkaller #0

> Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS
> Google 01/01/2011
> RIP: 0010:__lock_acquire+0x1254/0x4a00 kernel/locking/lockdep.c:3828
> Code: 00 0f 85 96 24 00 00 48 81 c4 f0 00 00 00 5b 41 5c 41 5d 41 5e 41 5f
> 5d c3 48 b8 00 00 00 00 00 fc ff df 4c 89 f2 48 c1 ea 03 <80> 3c 02 00 0f

> 85 0b 28 00 00 49 81 3e 20 59 2a 8a 0f 84 5f ee ff
> RSP: 0018:ffff8880a0397b38 EFLAGS: 00010006

> RAX: dffffc0000000000 RBX: 0000000000000000 RCX: 0000000000000000
> RDX: 0000000000000218 RSI: 0000000000000000 RDI: 0000000000000001

> RBP: ffff8880a0397c50 R08: 0000000000000001 R09: 0000000000000001
> R10: fffffbfff13d4e58 R11: ffff888093b044c0 R12: 00000000000010c0

> R13: 0000000000000000 R14: 00000000000010c0 R15: 0000000000000000

> FS: 0000000000000000(0000) GS:ffff8880ae800000(0063) knlGS:00000000f5dcfb40
> CS: 0010 DS: 002b ES: 002b CR0: 0000000080050033
> CR2: 000000002e521000 CR3: 0000000097a51000 CR4: 00000000001426f0

> DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
> DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
> Call Trace:
> lock_acquire+0x190/0x410 kernel/locking/lockdep.c:4485
> __raw_spin_lock_bh include/linux/spinlock_api_smp.h:135 [inline]
> _raw_spin_lock_bh+0x33/0x50 kernel/locking/spinlock.c:175
> spin_lock_bh include/linux/spinlock.h:343 [inline]
> j1939_jsk_del+0x32/0x210 net/can/j1939/socket.c:89
> j1939_sk_bind+0x2ea/0x8f0 net/can/j1939/socket.c:448
> __sys_bind+0x239/0x290 net/socket.c:1648
> __do_sys_bind net/socket.c:1659 [inline]
> __se_sys_bind net/socket.c:1657 [inline]

> __ia32_sys_bind+0x72/0xb0 net/socket.c:1657
> do_syscall_32_irqs_on arch/x86/entry/common.c:337 [inline]
> do_fast_syscall_32+0x27b/0xe16 arch/x86/entry/common.c:408
> entry_SYSENTER_compat+0x70/0x7f arch/x86/entry/entry_64_compat.S:139
> RIP: 0023:0xf7ff4a39
> Code: 00 00 00 89 d3 5b 5e 5f 5d c3 b8 80 96 98 00 eb c4 8b 04 24 c3 8b 1c
> 24 c3 8b 34 24 c3 8b 3c 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:00000000f5dcf0cc EFLAGS: 00000296 ORIG_RAX: 0000000000000169
> RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 0000000020000000
> RDX: 0000000000000018 RSI: 0000000000000000 RDI: 0000000000000000
> RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000
> R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000
> R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000

Prevent repeated jsk deletion using cmpxchg.

--- a/net/can/j1939/socket.c
+++ b/net/can/j1939/socket.c
@@ -86,6 +86,10 @@ static void j1939_jsk_add(struct j1939_p

static void j1939_jsk_del(struct j1939_priv *priv, struct j1939_sock *jsk)
{
+ if (!(J1939_SOCK_BOUND & jsk->state) ||
+ !(J1939_SOCK_BOUND & cmpxchg(&jsk->state, jsk->state,
+ jsk->state & ~J1939_SOCK_BOUND)))
+ return;
spin_lock_bh(&priv->j1939_socks_lock);
list_del_init(&jsk->list);
spin_unlock_bh(&priv->j1939_socks_lock);