bisecting fixing commit since c9c9735c46f589b9877b7fc00c89ef1b61a31e18
building syzkaller on 424dd8e7b52828cad44ce653a5d4ac30670f5e2c
testing commit c9c9735c46f589b9877b7fc00c89ef1b61a31e18 with gcc (GCC) 8.1.0
kernel signature: 8487b90a996f1fe8416aa8c49ed56e118f27dbddf7c48e67fc1e82f3a0e1a4d5
run #0: crashed: BUG: unable to handle kernel NULL pointer dereference in hci_send_acl
run #1: crashed: BUG: unable to handle kernel NULL pointer dereference in hci_send_acl
run #2: crashed: BUG: unable to handle kernel NULL pointer dereference in hci_send_acl
run #3: crashed: BUG: unable to handle kernel NULL pointer dereference in hci_send_acl
run #4: crashed: general protection fault in hci_send_acl
run #5: crashed: BUG: unable to handle kernel NULL pointer dereference in hci_send_acl
run #6: crashed: general protection fault in hci_send_acl
run #7: crashed: BUG: unable to handle kernel NULL pointer dereference in hci_send_acl
run #8: crashed: general protection fault in hci_send_acl
run #9: crashed: BUG: unable to handle kernel NULL pointer dereference in hci_send_acl
testing current HEAD fc4f28bb3daf3265d6bc5f73b497306985bb23ab
testing commit fc4f28bb3daf3265d6bc5f73b497306985bb23ab with gcc (GCC) 8.1.0
kernel signature: 57e7a9aab3824ec6fd5ba4a41b6f8540760827312b6593be38f7e27bdcf25eb8
run #0: crashed: general protection fault in hci_send_acl
run #1: crashed: general protection fault in hci_send_acl
run #2: crashed: general protection fault in hci_send_acl
run #3: crashed: BUG: unable to handle kernel NULL pointer dereference in hci_send_acl
run #4: crashed: BUG: unable to handle kernel NULL pointer dereference in hci_send_acl
run #5: crashed: BUG: unable to handle kernel NULL pointer dereference in hci_send_acl
run #6: crashed: BUG: unable to handle kernel NULL pointer dereference in hci_send_acl
run #7: crashed: BUG: unable to handle kernel NULL pointer dereference in hci_send_acl
run #8: crashed: BUG: unable to handle kernel NULL pointer dereference in hci_send_acl
run #9: crashed: BUG: unable to handle kernel NULL pointer dereference in hci_send_acl
revisions tested: 2, total time: 15m57.297493479s (build: 9m46.439145581s, test: 5m46.006807266s)
the crash still happens on HEAD
commit msg: Merge tag 'for-5.9-rc5-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux
crash: BUG: unable to handle kernel NULL pointer dereference in hci_send_acl
BUG: kernel NULL pointer dereference, address: 00000000000000b3
#PF: supervisor read access in kernel mode
#PF: error_code(0x0000) - not-present page
PGD 0 P4D 0 
Oops: 0000 [#1] PREEMPT SMP
CPU: 0 PID: 6973 Comm: kworker/u5:4 Not tainted 5.9.0-rc5-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Workqueue: hci2 hci_rx_work
RIP: 0010:hci_queue_acl net/bluetooth/hci_core.c:4122 [inline]
RIP: 0010:hci_send_acl+0x36/0x160 net/bluetooth/hci_core.c:4178
Code: 41 54 55 53 89 d3 0f b7 d2 48 83 ec 10 4c 8b 67 18 8b 46 74 49 8b ac 24 18 09 00 00 c7 46 74 00 00 00 00 29 46 70 c6 46 28 02 <0f> b6 85 b3 00 00 00 84 c0 74 44 3c 01 0f 84 f6 00 00 00 0f b6 d0
RSP: 0018:ffffc90000f4fcd8 EFLAGS: 00010206
RAX: 0000000000000000 RBX: 0000000000000002 RCX: ffff88812ad38000
RDX: 0000000000000002 RSI: ffff88811f13aa00 RDI: ffff88812b23e680
RBP: 0000000000000000 R08: 00000000000000c0 R09: ffff88810f1b4e00
R10: ffff88811f0a04c0 R11: d1ad1b54fc766645 R12: ffff888110231200
R13: ffff8881243359d8 R14: ffff88811f13aa00 R15: ffff88812b23e680
FS:  0000000000000000(0000) GS:ffff88812c000000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00000000000000b3 CR3: 000000012427a000 CR4: 00000000001506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 l2cap_send_move_chan_cfm_icid+0x46/0x70 net/bluetooth/l2cap_core.c:4916
 l2cap_move_fail net/bluetooth/l2cap_core.c:5400 [inline]
 l2cap_move_channel_rsp net/bluetooth/l2cap_core.c:5439 [inline]
 l2cap_bredr_sig_cmd net/bluetooth/l2cap_core.c:5718 [inline]
 l2cap_sig_channel net/bluetooth/l2cap_core.c:6417 [inline]
 l2cap_recv_frame+0xc2b/0x2b70 net/bluetooth/l2cap_core.c:7659
 hci_acldata_packet net/bluetooth/hci_core.c:4703 [inline]
 hci_rx_work+0x1d3/0x500 net/bluetooth/hci_core.c:4894
 process_one_work+0x26a/0x5f0 kernel/workqueue.c:2269
 worker_thread+0x38/0x380 kernel/workqueue.c:2415
 kthread+0x148/0x170 kernel/kthread.c:292
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:294
Modules linked in:
CR2: 00000000000000b3
---[ end trace 8539106ef50c5b68 ]---
RIP: 0010:hci_queue_acl net/bluetooth/hci_core.c:4122 [inline]
RIP: 0010:hci_send_acl+0x36/0x160 net/bluetooth/hci_core.c:4178
Code: 41 54 55 53 89 d3 0f b7 d2 48 83 ec 10 4c 8b 67 18 8b 46 74 49 8b ac 24 18 09 00 00 c7 46 74 00 00 00 00 29 46 70 c6 46 28 02 <0f> b6 85 b3 00 00 00 84 c0 74 44 3c 01 0f 84 f6 00 00 00 0f b6 d0
RSP: 0018:ffffc90000f4fcd8 EFLAGS: 00010206
RAX: 0000000000000000 RBX: 0000000000000002 RCX: ffff88812ad38000
RDX: 0000000000000002 RSI: ffff88811f13aa00 RDI: ffff88812b23e680
RBP: 0000000000000000 R08: 00000000000000c0 R09: ffff88810f1b4e00
R10: ffff88811f0a04c0 R11: d1ad1b54fc766645 R12: ffff888110231200
R13: ffff8881243359d8 R14: ffff88811f13aa00 R15: ffff88812b23e680
FS:  0000000000000000(0000) GS:ffff88812c000000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00000000000000b3 CR3: 000000012427a000 CR4: 00000000001506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400