syzbot


general protection fault in bnep_session

Status: upstream: reported on 2025/06/28 12:06
Reported-by: syzbot+851c709ec37e4e7a19c2@syzkaller.appspotmail.com
First crash: 15d, last: 12d
Similar bugs (2)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream general protection fault in bnep_session kernel 2 syz 731 41m 231d 0/29 upstream: reported syz repro on 2024/11/23 23:04
linux-5.15 general protection fault in bnep_session 2 2 94d 142d 0/3 upstream: reported on 2025/02/20 21:41

Sample crash report:
general protection fault, probably for non-canonical address 0xdffffc000000000b: 0000 [#1] PREEMPT SMP KASAN
KASAN: null-ptr-deref in range [0x0000000000000058-0x000000000000005f]
CPU: 0 PID: 14470 Comm: kbnepd bnep0 Not tainted 6.6.95-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
RIP: 0010:klist_put lib/klist.c:212 [inline]
RIP: 0010:klist_del+0x49/0x110 lib/klist.c:230
Code: 33 f7 49 89 dc 49 c1 ec 03 43 80 3c 3c 00 74 08 48 89 df e8 59 fd 8b f7 4c 8b 33 49 83 e6 fe 49 8d 7e 58 48 89 f8 48 c1 e8 03 <42> 80 3c 38 00 74 05 e8 3b fd 8b f7 49 8b 46 58 48 89 04 24 4c 89
RSP: 0018:ffffc9000f1e78a0 EFLAGS: 00010202
RAX: 000000000000000b RBX: ffff88802f631860 RCX: ffff8880671a1e00
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000058
RBP: ffffc9000f1e79d0 R08: ffff888031b9c3e3 R09: 1ffff1100637387c
R10: dffffc0000000000 R11: ffffed100637387d R12: 1ffff11005ec630c
R13: 0000000000000001 R14: 0000000000000000 R15: dffffc0000000000
FS:  0000000000000000(0000) GS:ffff8880b8e00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000001b3141bff8 CR3: 000000005d40a000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 device_del+0x280/0x900 drivers/base/core.c:3849
 unregister_netdevice_many_notify+0x135e/0x1810 net/core/dev.c:11104
 unregister_netdevice_many net/core/dev.c:11130 [inline]
 unregister_netdevice_queue net/core/dev.c:11010 [inline]
 unregister_netdevice include/linux/netdevice.h:3137 [inline]
 unregister_netdev+0x148/0x1b0 net/core/dev.c:11148
 bnep_session+0x2903/0x2af0 net/bluetooth/bnep/core.c:525
 kthread+0x2fa/0x390 kernel/kthread.c:388
 ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:152
 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:293
 </TASK>
Modules linked in:
---[ end trace 0000000000000000 ]---
RIP: 0010:klist_put lib/klist.c:212 [inline]
RIP: 0010:klist_del+0x49/0x110 lib/klist.c:230
Code: 33 f7 49 89 dc 49 c1 ec 03 43 80 3c 3c 00 74 08 48 89 df e8 59 fd 8b f7 4c 8b 33 49 83 e6 fe 49 8d 7e 58 48 89 f8 48 c1 e8 03 <42> 80 3c 38 00 74 05 e8 3b fd 8b f7 49 8b 46 58 48 89 04 24 4c 89
RSP: 0018:ffffc9000f1e78a0 EFLAGS: 00010202
RAX: 000000000000000b RBX: ffff88802f631860 RCX: ffff8880671a1e00
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000058
RBP: ffffc9000f1e79d0 R08: ffff888031b9c3e3 R09: 1ffff1100637387c
R10: dffffc0000000000 R11: ffffed100637387d R12: 1ffff11005ec630c
R13: 0000000000000001 R14: 0000000000000000 R15: dffffc0000000000
FS:  0000000000000000(0000) GS:ffff8880b8e00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000001b3141bff8 CR3: 000000005d40a000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
----------------
Code disassembly (best guess):
   0:	33 f7                	xor    %edi,%esi
   2:	49 89 dc             	mov    %rbx,%r12
   5:	49 c1 ec 03          	shr    $0x3,%r12
   9:	43 80 3c 3c 00       	cmpb   $0x0,(%r12,%r15,1)
   e:	74 08                	je     0x18
  10:	48 89 df             	mov    %rbx,%rdi
  13:	e8 59 fd 8b f7       	call   0xf78bfd71
  18:	4c 8b 33             	mov    (%rbx),%r14
  1b:	49 83 e6 fe          	and    $0xfffffffffffffffe,%r14
  1f:	49 8d 7e 58          	lea    0x58(%r14),%rdi
  23:	48 89 f8             	mov    %rdi,%rax
  26:	48 c1 e8 03          	shr    $0x3,%rax
* 2a:	42 80 3c 38 00       	cmpb   $0x0,(%rax,%r15,1) <-- trapping instruction
  2f:	74 05                	je     0x36
  31:	e8 3b fd 8b f7       	call   0xf78bfd71
  36:	49 8b 46 58          	mov    0x58(%r14),%rax
  3a:	48 89 04 24          	mov    %rax,(%rsp)
  3e:	4c                   	rex.WR
  3f:	89                   	.byte 0x89

Crashes (2):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2025/07/01 15:39 linux-6.6.y 3f5b4c104b7d 091a06cd .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan general protection fault in bnep_session
2025/06/28 12:06 linux-6.6.y 3f5b4c104b7d fc9d8ee5 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan general protection fault in bnep_session
* Struck through repros no longer work on HEAD.