general protection fault in ax25cmp

From: syzbot
Date: Fri Dec 28 2018 - 14:51:08 EST


Hello,

syzbot found the following crash on:

HEAD commit: d8924c0d76aa Merge tag 'devprop-4.21-rc1' of git://git.ker..
git tree: upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=145051dd400000
kernel config: https://syzkaller.appspot.com/x/.config?x=91a256823ef17263
dashboard link: https://syzkaller.appspot.com/bug?extid=1a2c456a1ea08fa5b5f7
compiler: gcc (GCC) 8.0.1 20180413 (experimental)
syz repro: https://syzkaller.appspot.com/x/repro.syz?x=1683ae57400000
C reproducer: https://syzkaller.appspot.com/x/repro.c?x=1410f3af400000

IMPORTANT: if you fix the bug, please add the following tag to the commit:
Reported-by: syzbot+1a2c456a1ea08fa5b5f7@xxxxxxxxxxxxxxxxxxxxxxxxx

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: 1 PID: 2660 Comm: aoe_tx0 Not tainted 4.20.0+ #388
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
RIP: 0010:ax25cmp+0x3e/0x180 net/ax25/ax25_addr.c:122
Code: f6 41 55 49 89 fd 41 54 49 89 f4 53 48 83 ec 10 48 89 7d d0 48 89 75 c8 e8 ff 46 7f fa 4c 89 e8 4c 89 ea 48 c1 e8 03 83 e2 07 <42> 0f b6 04 38 38 d0 7f 08 84 c0 0f 85 23 01 00 00 4c 89 e0 4c 89
RSP: 0018:ffff8881ce3cf3c8 EFLAGS: 00010202
RAX: 0000000000000002 RBX: ffff8881c5a59800 RCX: 0000000000000001
RDX: 0000000000000007 RSI: ffffffff86ff11d1 RDI: 0000000000000017
RBP: ffff8881ce3cf400 R08: ffffed1039c79e70 R09: ffffed1039c79e6f
R10: ffffed1039c79e6f R11: 0000000000000003 R12: ffff8881c5a59808
R13: 0000000000000017 R14: 0000000000000000 R15: dffffc0000000000
FS: 0000000000000000(0000) GS:ffff8881daf00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007ffe5864d7d4 CR3: 000000000946a000 CR4: 00000000001406e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
rose_route_frame+0x2d6/0x19b0 net/rose/rose_route.c:885
rose_xmit+0x8e/0x180 net/rose/rose_dev.c:110
__netdev_start_xmit include/linux/netdevice.h:4356 [inline]
netdev_start_xmit include/linux/netdevice.h:4365 [inline]
xmit_one net/core/dev.c:3257 [inline]
dev_hard_start_xmit+0x295/0xc90 net/core/dev.c:3273
__dev_queue_xmit+0x2f0d/0x3950 net/core/dev.c:3843
dev_queue_xmit+0x17/0x20 net/core/dev.c:3876
tx+0x77/0xd0 drivers/block/aoe/aoenet.c:63
kthread+0x296/0x4a0 drivers/block/aoe/aoecmd.c:1248
kthread+0x35a/0x440 kernel/kthread.c:246
ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:352
Modules linked in:
---[ end trace 623634688d1951e4 ]---
RIP: 0010:ax25cmp+0x3e/0x180 net/ax25/ax25_addr.c:122
Code: f6 41 55 49 89 fd 41 54 49 89 f4 53 48 83 ec 10 48 89 7d d0 48 89 75 c8 e8 ff 46 7f fa 4c 89 e8 4c 89 ea 48 c1 e8 03 83 e2 07 <42> 0f b6 04 38 38 d0 7f 08 84 c0 0f 85 23 01 00 00 4c 89 e0 4c 89
RSP: 0018:ffff8881ce3cf3c8 EFLAGS: 00010202
RAX: 0000000000000002 RBX: ffff8881c5a59800 RCX: 0000000000000001
RDX: 0000000000000007 RSI: ffffffff86ff11d1 RDI: 0000000000000017
RBP: ffff8881ce3cf400 R08: ffffed1039c79e70 R09: ffffed1039c79e6f
R10: ffffed1039c79e6f R11: 0000000000000003 R12: ffff8881c5a59808
R13: 0000000000000017 R14: 0000000000000000 R15: dffffc0000000000
FS: 0000000000000000(0000) GS:ffff8881daf00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007ffe5864d7d4 CR3: 000000000946a000 CR4: 00000000001406e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400


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