linux-kernel - [syzbot] [bluetooth?] general protection fault in l2cap_conn

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Message-ID: <6759aa73.050a0220.17f54a.003d.GAE@google.com>
Date: Wed, 11 Dec 2024 07:06:27 -0800
From: syzbot <syzbot+f0e2ed7be2c4537cceb7@...kaller.appspotmail.com>
To: johan.hedberg@...il.com, linux-bluetooth@...r.kernel.org, 
	linux-kernel@...r.kernel.org, luiz.dentz@...il.com, marcel@...tmann.org, 
	syzkaller-bugs@...glegroups.com
Subject: [syzbot] [bluetooth?] general protection fault in l2cap_conn_del

Hello,

syzbot found the following issue on:

HEAD commit:    b5f217084ab3 Merge tag 'bpf-fixes' of git://git.kernel.org..
git tree:       upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=112e0820580000
kernel config:  https://syzkaller.appspot.com/x/.config?x=9d99f0bff41614d0
dashboard link: https://syzkaller.appspot.com/bug?extid=f0e2ed7be2c4537cceb7
compiler:       gcc (Debian 12.2.0-14) 12.2.0, GNU ld (GNU Binutils for Debian) 2.40

Unfortunately, I don't have any reproducer for this issue yet.

Downloadable assets:
disk image (non-bootable): https://storage.googleapis.com/syzbot-assets/7feb34a89c2a/non_bootable_disk-b5f21708.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/4a2037d50b27/vmlinux-b5f21708.xz
kernel image: https://storage.googleapis.com/syzbot-assets/e9e9c9c88191/bzImage-b5f21708.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+f0e2ed7be2c4537cceb7@...kaller.appspotmail.com

Oops: general protection fault, probably for non-canonical address 0xfbd59c0000000020: 0000 [#1] PREEMPT SMP KASAN NOPTI
KASAN: maybe wild-memory-access in range [0xdead000000000100-0xdead000000000107]
CPU: 1 UID: 0 PID: 7416 Comm: syz-executor Not tainted 6.13.0-rc1-syzkaller-00316-gb5f217084ab3 #0
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2~bpo12+1 04/01/2014
RIP: 0010:l2cap_conn_del+0x3dd/0x730 net/bluetooth/l2cap_core.c:1781
Code: 8b 40 20 48 89 df ff d0 0f 1f 00 4c 89 f7 e8 ca 2f fb 00 4d 8d b4 24 80 04 00 00 48 89 df e8 8a 42 ff ff 4c 89 f0 48 c1 e8 03 <42> 80 3c 28 00 0f 85 24 02 00 00 49 8b 84 24 80 04 00 00 4c 89 e3
RSP: 0018:ffffc9000371fad8 EFLAGS: 00010a02
RAX: 1bd5a00000000020 RBX: ffff88804aaa6000 RCX: ffffffff8a2f4f3e
RDX: ffff888020602440 RSI: ffffffff8a300c56 RDI: 0000000000000005
RBP: ffff8880341df800 R08: 0000000000000005 R09: 0000000000000001
R10: 0000000000000002 R11: 0000000000000000 R12: deacfffffffffc80
R13: dffffc0000000000 R14: dead000000000100 R15: 0000000000000067
FS:  0000000000000000(0000) GS:ffff88806a700000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007ffcd90480a0 CR3: 000000000df7e000 CR4: 0000000000352ef0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 l2cap_disconn_cfm net/bluetooth/l2cap_core.c:7299 [inline]
 l2cap_disconn_cfm+0x96/0xd0 net/bluetooth/l2cap_core.c:7292
 hci_disconn_cfm include/net/bluetooth/hci_core.h:2050 [inline]
 hci_conn_hash_flush+0x10b/0x260 net/bluetooth/hci_conn.c:2698
 hci_dev_close_sync+0x603/0x11a0 net/bluetooth/hci_sync.c:5212
 hci_dev_do_close+0x2e/0x90 net/bluetooth/hci_core.c:483
 hci_unregister_dev+0x213/0x620 net/bluetooth/hci_core.c:2698
 vhci_release+0x79/0xf0 drivers/bluetooth/hci_vhci.c:664
 __fput+0x3f8/0xb60 fs/file_table.c:450
 task_work_run+0x14e/0x250 kernel/task_work.c:239
 exit_task_work include/linux/task_work.h:43 [inline]
 do_exit+0xadd/0x2d70 kernel/exit.c:938
 do_group_exit+0xd3/0x2a0 kernel/exit.c:1087
 __do_sys_exit_group kernel/exit.c:1098 [inline]
 __se_sys_exit_group kernel/exit.c:1096 [inline]
 __x64_sys_exit_group+0x3e/0x50 kernel/exit.c:1096
 x64_sys_call+0x151f/0x1720 arch/x86/include/generated/asm/syscalls_64.h:232
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xcd/0x250 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f5ad877fed9
Code: Unable to access opcode bytes at 0x7f5ad877feaf.
RSP: 002b:00007ffcd904a1b8 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f5ad877fed9
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000043
RBP: 00007f5ad87e0840 R08: 00007ffcd9047f57 R09: 0000000000000003
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000001
R13: 0000000000000003 R14: 00000000ffffffff R15: 00007ffcd904a360
 </TASK>
Modules linked in:
---[ end trace 0000000000000000 ]---
RIP: 0010:l2cap_conn_del+0x3dd/0x730 net/bluetooth/l2cap_core.c:1781
Code: 8b 40 20 48 89 df ff d0 0f 1f 00 4c 89 f7 e8 ca 2f fb 00 4d 8d b4 24 80 04 00 00 48 89 df e8 8a 42 ff ff 4c 89 f0 48 c1 e8 03 <42> 80 3c 28 00 0f 85 24 02 00 00 49 8b 84 24 80 04 00 00 4c 89 e3
RSP: 0018:ffffc9000371fad8 EFLAGS: 00010a02
RAX: 1bd5a00000000020 RBX: ffff88804aaa6000 RCX: ffffffff8a2f4f3e
RDX: ffff888020602440 RSI: ffffffff8a300c56 RDI: 0000000000000005
RBP: ffff8880341df800 R08: 0000000000000005 R09: 0000000000000001
R10: 0000000000000002 R11: 0000000000000000 R12: deacfffffffffc80
R13: dffffc0000000000 R14: dead000000000100 R15: 0000000000000067
FS:  0000000000000000(0000) GS:ffff88806a600000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fb5df3d4fb8 CR3: 00000000506a0000 CR4: 0000000000352ef0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
----------------
Code disassembly (best guess):
   0:	8b 40 20             	mov    0x20(%rax),%eax
   3:	48 89 df             	mov    %rbx,%rdi
   6:	ff d0                	call   *%rax
   8:	0f 1f 00             	nopl   (%rax)
   b:	4c 89 f7             	mov    %r14,%rdi
   e:	e8 ca 2f fb 00       	call   0xfb2fdd
  13:	4d 8d b4 24 80 04 00 	lea    0x480(%r12),%r14
  1a:	00
  1b:	48 89 df             	mov    %rbx,%rdi
  1e:	e8 8a 42 ff ff       	call   0xffff42ad
  23:	4c 89 f0             	mov    %r14,%rax
  26:	48 c1 e8 03          	shr    $0x3,%rax
* 2a:	42 80 3c 28 00       	cmpb   $0x0,(%rax,%r13,1) <-- trapping instruction
  2f:	0f 85 24 02 00 00    	jne    0x259
  35:	49 8b 84 24 80 04 00 	mov    0x480(%r12),%rax
  3c:	00
  3d:	4c 89 e3             	mov    %r12,%rbx


---
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