syzbot


BUG: unable to handle kernel NULL pointer dereference in l2cap_sock_teardown_cb

Status: auto-closed as invalid on 2021/12/03 00:53
Reported-by: syzbot+f8cbd98b1ad2ac371025@syzkaller.appspotmail.com
First crash: 345d, last: 345d
similar bugs (1):
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream KMSAN: uninit-value in l2cap_sock_teardown_cb (2) 1 449d 449d 0/23 auto-closed as invalid on 2021/09/03 00:26

Sample crash report:
BUG: kernel NULL pointer dereference, address: 0000000000000000
#PF: supervisor instruction fetch in kernel mode
#PF: error_code(0x0010) - not-present page
PGD 74724067 P4D 74724067 PUD 74725067 PMD 0 
Oops: 0010 [#1] PREEMPT SMP KASAN
CPU: 0 PID: 22487 Comm: syz-executor.5 Not tainted 5.14.0-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
RIP: 0010:0x0
Code: Unable to access opcode bytes at RIP 0xffffffffffffffd6.
RSP: 0018:ffffc9000171f880 EFLAGS: 00010246
RAX: dffffc0000000000 RBX: ffff888085e8d000 RCX: 0000000000000000
RDX: 1ffff11010bd1a8d RSI: ffffffff8824748b RDI: ffff888085e8d000
RBP: 0000000000000000 R08: ffffffff8aa1ebe0 R09: ffffffff882470f6
R10: 0000000000000004 R11: 0000000000000005 R12: 0000000000000067
R13: ffff888085e8a000 R14: ffff888085e8a4b8 R15: 0000000000000067
FS:  0000000000000000(0000) GS:ffff8880b9c00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: ffffffffffffffd6 CR3: 0000000020d53000 CR4: 0000000000350ef0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000600
Call Trace:
 l2cap_sock_teardown_cb+0x496/0x660 net/bluetooth/l2cap_sock.c:1553
 l2cap_chan_del+0xbc/0xa80 net/bluetooth/l2cap_core.c:622
 l2cap_conn_del+0x3c0/0x7b0 net/bluetooth/l2cap_core.c:1898
 l2cap_disconn_cfm net/bluetooth/l2cap_core.c:8177 [inline]
 l2cap_disconn_cfm+0x95/0xd0 net/bluetooth/l2cap_core.c:8170
 hci_disconn_cfm include/net/bluetooth/hci_core.h:1518 [inline]
 hci_conn_hash_flush+0x127/0x260 net/bluetooth/hci_conn.c:1608
 hci_dev_do_close+0x57d/0x1130 net/bluetooth/hci_core.c:1793
 hci_unregister_dev+0x1c0/0x5a0 net/bluetooth/hci_core.c:4029
 vhci_release+0x70/0xe0 drivers/bluetooth/hci_vhci.c:340
 __fput+0x288/0x9f0 fs/file_table.c:280
 task_work_run+0xdd/0x1a0 kernel/task_work.c:164
 exit_task_work include/linux/task_work.h:32 [inline]
 do_exit+0xbae/0x2a30 kernel/exit.c:825
 do_group_exit+0x125/0x310 kernel/exit.c:922
 get_signal+0x47f/0x2160 kernel/signal.c:2868
 arch_do_signal_or_restart+0x2a9/0x1c40 arch/x86/kernel/signal.c:865
 handle_signal_work kernel/entry/common.c:148 [inline]
 exit_to_user_mode_loop kernel/entry/common.c:172 [inline]
 exit_to_user_mode_prepare+0x17d/0x290 kernel/entry/common.c:209
 __syscall_exit_to_user_mode_work kernel/entry/common.c:291 [inline]
 syscall_exit_to_user_mode+0x19/0x60 kernel/entry/common.c:302
 do_syscall_64+0x42/0xb0 arch/x86/entry/common.c:86
 entry_SYSCALL_64_after_hwframe+0x44/0xae
RIP: 0033:0x4665f9
Code: Unable to access opcode bytes at RIP 0x4665cf.
RSP: 002b:00007ffb75b11218 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca
RAX: fffffffffffffe00 RBX: 000000000056bf88 RCX: 00000000004665f9
RDX: 0000000000000000 RSI: 0000000000000080 RDI: 000000000056bf88
RBP: 000000000056bf80 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 000000000056bf8c
R13: 00007ffe9f1fd46f R14: 00007ffb75b11300 R15: 0000000000022000
Modules linked in:
CR2: 0000000000000000
---[ end trace 441200ec765b44cf ]---
RIP: 0010:0x0
Code: Unable to access opcode bytes at RIP 0xffffffffffffffd6.
RSP: 0018:ffffc9000171f880 EFLAGS: 00010246
RAX: dffffc0000000000 RBX: ffff888085e8d000 RCX: 0000000000000000
RDX: 1ffff11010bd1a8d RSI: ffffffff8824748b RDI: ffff888085e8d000
RBP: 0000000000000000 R08: ffffffff8aa1ebe0 R09: ffffffff882470f6
R10: 0000000000000004 R11: 0000000000000005 R12: 0000000000000067
R13: ffff888085e8a000 R14: ffff888085e8a4b8 R15: 0000000000000067
FS:  0000000000000000(0000) GS:ffff8880b9c00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: ffffffffffffffd6 CR3: 0000000020d53000 CR4: 0000000000350ef0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000600

Crashes (1):
Manager Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Title
ci-upstream-kasan-gce-root 2021/09/04 00:52 upstream 7cca308cfdc0 d236a457 .config log report info BUG: unable to handle kernel NULL pointer dereference in l2cap_sock_teardown_cb