bisecting fixing commit since ac3a0c8472969a03c0496ae774b3a29eb26c8d5a building syzkaller on 63a7334112fa63edb0c0a3f317d3d92135a6ead9 testing commit ac3a0c8472969a03c0496ae774b3a29eb26c8d5a with gcc (GCC) 8.1.0 kernel signature: aa4e6625d0d706c397a35271cffe4e6487df44dc4ae98792c96c5ddaf77f496c run #0: crashed: BUG: unable to handle kernel NULL pointer dereference in hci_send_acl run #1: crashed: general protection fault in hci_send_acl run #2: crashed: stack segment 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: general protection fault 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: BUG: unable to handle kernel NULL pointer dereference in hci_send_acl run #9: crashed: BUG: unable to handle kernel paging request in hci_send_acl testing current HEAD 9c7d619be5a002ea29c172df5e3c1227c22cbb41 testing commit 9c7d619be5a002ea29c172df5e3c1227c22cbb41 with gcc (GCC) 8.1.0 kernel signature: 18e2967e95784dea94c55cb9e654c9f89ba02bef5bafafd1e5348507d3ef6914 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: general protection fault in hci_send_acl run #3: crashed: general protection fault 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: general protection fault in hci_send_acl run #8: crashed: general protection fault in hci_send_acl run #9: crashed: general protection fault in hci_send_acl revisions tested: 2, total time: 15m46.239960571s (build: 9m13.537289323s, test: 6m2.419733324s) the crash still happens on HEAD commit msg: Merge tag 'perf-tools-fixes-for-v5.9-2020-09-01' of git://git.kernel.org/pub/scm/linux/kernel/git/acme/linux crash: general protection fault in hci_send_acl general protection fault, probably for non-canonical address 0x7365742d72656c6c: 0000 [#1] PREEMPT SMP CPU: 1 PID: 8202 Comm: kworker/u5:2 Not tainted 5.9.0-rc3-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Workqueue: hci2 hci_rx_work RIP: 0010:hci_send_acl+0x20/0x160 net/bluetooth/hci_core.c:4174 Code: c3 66 0f 1f 84 00 00 00 00 00 41 57 49 89 ff 41 56 49 89 f6 41 55 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 RSP: 0018:ffffc90002d6fcd8 EFLAGS: 00010286 RAX: 0000000000000000 RBX: 0000000000000002 RCX: ffff88810e4b4000 RDX: 0000000000000002 RSI: ffff888120525700 RDI: ffff88810ef7bc00 RBP: 0000000000000004 R08: 00000000000000c0 R09: ffff88810e428000 R10: ffff88810f308540 R11: b7e83a0c63ee4c2e R12: 7365742d72656c6c R13: ffff88810e561e11 R14: ffff888120525700 R15: ffff88810ef7bc00 FS: 0000000000000000(0000) GS:ffff88812c100000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000000000078c061 CR3: 000000010e551000 CR4: 00000000001506e0 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: ---[ end trace 37b9143877f15e26 ]--- RIP: 0010:hci_send_acl+0x20/0x160 net/bluetooth/hci_core.c:4174 Code: c3 66 0f 1f 84 00 00 00 00 00 41 57 49 89 ff 41 56 49 89 f6 41 55 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 RSP: 0018:ffffc90002d6fcd8 EFLAGS: 00010286 RAX: 0000000000000000 RBX: 0000000000000002 RCX: ffff88810e4b4000 RDX: 0000000000000002 RSI: ffff888120525700 RDI: ffff88810ef7bc00 RBP: 0000000000000004 R08: 00000000000000c0 R09: ffff88810e428000 R10: ffff88810f308540 R11: b7e83a0c63ee4c2e R12: 7365742d72656c6c R13: ffff88810e561e11 R14: ffff888120525700 R15: ffff88810ef7bc00 FS: 0000000000000000(0000) GS:ffff88812c100000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00005579bdbdda08 CR3: 000000011d647000 CR4: 00000000001506e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400