Subject: general protection fault in rose_send_frame

From: syzbot <[email-masked]>
Date: Thu, 10 Jan 2019 09:38:06 -0800

Hello,

syzbot found the following crash on:

HEAD commit:    b71acb0e3721 Merge branch 'linus' of git://git.kernel.org/..
git tree:       net-next
console output: https://syzkaller.appspot.com/x/log.txt?x=13a9acf7400000
kernel config:  https://syzkaller.appspot.com/x/.config?x=b03c5892bb940c76
dashboard link: https://syzkaller.appspot.com/bug?extid=7078ae989d857fe17988
compiler:       gcc (GCC) 9.0.0 20181231 (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: [email-masked]

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: 10446 Comm: syz-executor4 Not tainted 4.20.0+ #3
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS  
Google 01/01/2011
RIP: 0010:rose_send_frame+0x1a8/0x280 net/rose/rose_link.c:104
Code: c1 ea 03 80 3c 02 00 0f 85 8d 00 00 00 48 b8 00 00 00 00 00 fc ff df  
4c 8b 63 20 49 8d bc 24 58 03 00 00 48 89 fa 48 c1 ea 03 <80> 3c 02 00 75  
7e 49 8b 94 24 58 03 00 00 e9 b8 fe ff ff e8 d0 e3
RSP: 0018:ffff8880ae707780 EFLAGS: 00010202
RAX: dffffc0000000000 RBX: ffff8882167d4540 RCX: ffffffff8703c0bb
RDX: 000000000000006b RSI: ffffffff8703c1ec RDI: 0000000000000358
kobject: 'loop1' (000000008f9686c7): kobject_uevent_env
RBP: ffff8880ae7077b0 R08: ffff888089dc0480 R09: ffffed1014360d0d
kobject: 'loop1' (000000008f9686c7): fill_kobj_path: path  
= '/devices/virtual/block/loop1'
R10: ffffed1014360d0c R11: ffff8880a1b06863 R12: 0000000000000000
R13: 0000000000000078 R14: 0000000000000005 R15: ffff888096c38a40
FS:  00007fb08678e700(0000) GS:ffff8880ae700000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000625208 CR3: 00000000645e0000 CR4: 00000000001406e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
  <IRQ>
  rose_transmit_clear_request+0x1de/0x2a0 net/rose/rose_link.c:258
  rose_rx_call_request+0x4f8/0x1c40 net/rose/af_rose.c:999
  rose_loopback_timer+0x26a/0x3f0 net/rose/rose_loopback.c:100
  call_timer_fn+0x254/0x900 kernel/time/timer.c:1325
  expire_timers kernel/time/timer.c:1362 [inline]
  __run_timers+0x6fc/0xd50 kernel/time/timer.c:1681
  run_timer_softirq+0x52/0xb0 kernel/time/timer.c:1694
  __do_softirq+0x30b/0xb11 kernel/softirq.c:292
  invoke_softirq kernel/softirq.c:373 [inline]
  irq_exit+0x180/0x1d0 kernel/softirq.c:413
  exiting_irq arch/x86/include/asm/apic.h:536 [inline]
  smp_apic_timer_interrupt+0x1b7/0x760 arch/x86/kernel/apic/apic.c:1062
  apic_timer_interrupt+0xf/0x20 arch/x86/entry/entry_64.S:807
  </IRQ>
RIP: 0010:arch_local_irq_restore arch/x86/include/asm/paravirt.h:766  
[inline]
RIP: 0010:lock_is_held_type+0x17e/0x210 kernel/locking/lockdep.c:3881
Code: 00 00 00 fc ff df 41 c7 85 7c 08 00 00 00 00 00 00 48 c1 e8 03 80 3c  
10 00 75 63 48 83 3d b9 0a 2f 08 00 74 30 48 89 df 57 9d <0f> 1f 44 00 00  
48 83 c4 08 44 89 e0 5b 41 5c 41 5d 5d c3 48 83 c4
RSP: 0018:ffff888065f8eea8 EFLAGS: 00000282 ORIG_RAX: ffffffffffffff13
RAX: 1ffffffff1324a06 RBX: 0000000000000282 RCX: dffffc0000000000
RDX: dffffc0000000000 RSI: 0000000000000000 RDI: 0000000000000282
RBP: ffff888065f8eec8 R08: ffff888089dc0480 R09: ffffed100cbf1df3
R10: ffffed100cbf1df2 R11: 0000000000000003 R12: 0000000000000000
R13: ffff888089dc0480 R14: dffffc0000000000 R15: ffffea0001de25c0
  lock_is_held include/linux/lockdep.h:337 [inline]
  xa_entry include/linux/xarray.h:902 [inline]
  xas_reload include/linux/xarray.h:1250 [inline]
  find_get_pages_range_tag+0x1166/0x1540 mm/filemap.c:1848
  pagevec_lookup_range_tag+0x40/0x80 mm/swap.c:1005
  mpage_prepare_extent_to_map+0x402/0x1950 fs/ext4/inode.c:2661
  ext4_writepages+0x1a5e/0x4180 fs/ext4/inode.c:2881
  do_writepages+0x99/0x1a0 mm/page-writeback.c:2328
  __filemap_fdatawrite_range+0x352/0x470 mm/filemap.c:411
  filemap_write_and_wait_range mm/filemap.c:633 [inline]
  filemap_write_and_wait_range+0x4b/0xd0 mm/filemap.c:627
  __generic_file_write_iter+0x4ea/0x630 mm/filemap.c:3251
  ext4_file_write_iter+0x37a/0x1410 fs/ext4/file.c:266
  call_write_iter include/linux/fs.h:1857 [inline]
  new_sync_write fs/read_write.c:474 [inline]
  __vfs_write+0x6e5/0xa80 fs/read_write.c:487
  vfs_write+0x20c/0x560 fs/read_write.c:549
  ksys_write+0x105/0x260 fs/read_write.c:598
  __do_sys_write fs/read_write.c:610 [inline]
  __se_sys_write fs/read_write.c:607 [inline]
  __x64_sys_write+0x73/0xb0 fs/read_write.c:607
  do_syscall_64+0x1a3/0x800 arch/x86/entry/common.c:290
  entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x457ec9
Code: 6d b7 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 3b b7 fb ff c3 66 2e 0f 1f 84 00 00 00 00
RSP: 002b:00007fb08678dc78 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 0000000000457ec9
RDX: 00000000fffffcbe RSI: 0000000020000000 RDI: 0000000000000004
RBP: 000000000073bf00 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00007fb08678e6d4
R13: 00000000004c7155 R14: 00000000004dc898 R15: 00000000ffffffff
Modules linked in:
---[ end trace bd566e08b493d14b ]---
RIP: 0010:rose_send_frame+0x1a8/0x280 net/rose/rose_link.c:104
Code: c1 ea 03 80 3c 02 00 0f 85 8d 00 00 00 48 b8 00 00 00 00 00 fc ff df  
4c 8b 63 20 49 8d bc 24 58 03 00 00 48 89 fa 48 c1 ea 03 <80> 3c 02 00 75  
7e 49 8b 94 24 58 03 00 00 e9 b8 fe ff ff e8 d0 e3
RSP: 0018:ffff8880ae707780 EFLAGS: 00010202
RAX: dffffc0000000000 RBX: ffff8882167d4540 RCX: ffffffff8703c0bb
RDX: 000000000000006b RSI: ffffffff8703c1ec RDI: 0000000000000358
RBP: ffff8880ae7077b0 R08: ffff888089dc0480 R09: ffffed1014360d0d
R10: ffffed1014360d0c R11: ffff8880a1b06863 R12: 0000000000000000
R13: 0000000000000078 R14: 0000000000000005 R15: ffff888096c38a40
FS:  00007fb08678e700(0000) GS:ffff8880ae700000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000625208 CR3: 00000000645e0000 CR4: 00000000001406e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400

---
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