bisecting fixing commit since aea8526edf59da3ff5306ca408e13d8f6ab89b34 building syzkaller on 1656845f45f284c574eb4f8bfe85dd7916a47a3a testing commit aea8526edf59da3ff5306ca408e13d8f6ab89b34 with gcc (GCC) 8.1.0 kernel signature: cb78c32cdddfdfa5d9890463cc64c2618fe7dd6ff78b24326473b6e6c6918a4d run #0: crashed: general protection fault in skb_put run #1: crashed: general protection fault in skb_put run #2: crashed: KASAN: use-after-free Read in h5_rx_3wire_hdr run #3: crashed: general protection fault in skb_put run #4: crashed: KASAN: use-after-free Read in h5_rx_3wire_hdr run #5: crashed: KASAN: use-after-free Read in h5_rx_3wire_hdr run #6: crashed: KASAN: use-after-free Read in h5_rx_3wire_hdr run #7: crashed: KASAN: use-after-free Read in h5_rx_3wire_hdr run #8: crashed: KASAN: invalid-free in skb_free_head run #9: OK testing current HEAD ab9dfda232481dcfaf549ce774004d116fc80c13 testing commit ab9dfda232481dcfaf549ce774004d116fc80c13 with gcc (GCC) 8.1.0 kernel signature: c88d1efe676469332ceb66455fbbe4528e30ad521243eee5213cbc655ed92ea8 run #0: crashed: KASAN: invalid-free in skb_free_head run #1: crashed: general protection fault in skb_put run #2: crashed: general protection fault in skb_put run #3: crashed: general protection fault in skb_put run #4: crashed: KASAN: use-after-free Read in skb_release_data run #5: crashed: general protection fault in skb_put run #6: crashed: KASAN: use-after-free Read in h5_rx_3wire_hdr run #7: crashed: KASAN: use-after-free Read in h5_reset_rx run #8: crashed: general protection fault in skb_put run #9: crashed: general protection fault in skb_put revisions tested: 2, total time: 35m28.449663259s (build: 17m49.064816206s, test: 16m35.524787505s) the crash still happens on HEAD commit msg: Linux 4.14.180 crash: general protection fault in skb_put Bluetooth: Invalid header checksum Bluetooth: Invalid header checksum kasan: CONFIG_KASAN_INLINE enabled Bluetooth: Invalid header checksum kasan: GPF could be caused by NULL-ptr deref or user memory access general protection fault: 0000 [#1] PREEMPT SMP KASAN Modules linked in: CPU: 1 PID: 27013 Comm: syz-executor.4 Not tainted 4.14.180-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 task: ffff8880962a4580 task.stack: ffff8880969c0000 RIP: 0010:skb_put+0x28/0x1e0 net/core/skbuff.c:1694 RSP: 0018:ffff8880969c79a0 EFLAGS: 00010286 RAX: dffffc0000000000 RBX: 0000000000000000 RCX: 0000000000000000 RDX: 0000000000000019 RSI: 0000000000000001 RDI: 0000000000000000 RBP: ffff8880969c79c8 R08: ffff8880962a4e50 R09: 00000000000017a5 R10: 0000000000000000 R11: ffff8880962a4580 R12: 0000000000000001 R13: 00000000000000c8 R14: ffff8880969c7bb8 R15: dffffc0000000000 FS: 00007f08dfef6700(0000) GS:ffff8880aef00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000000000075c091 CR3: 00000000953e6000 CR4: 00000000001406e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: skb_put_data include/linux/skbuff.h:2097 [inline] h5_unslip_one_byte drivers/bluetooth/hci_h5.c:490 [inline] h5_recv+0x2a3/0x410 drivers/bluetooth/hci_h5.c:526 hci_uart_tty_receive+0x1ce/0x460 drivers/bluetooth/hci_ldisc.c:616 tiocsti drivers/tty/tty_io.c:2186 [inline] tty_ioctl+0x625/0x1260 drivers/tty/tty_io.c:2572 vfs_ioctl fs/ioctl.c:46 [inline] file_ioctl fs/ioctl.c:500 [inline] do_vfs_ioctl+0x180/0xfb0 fs/ioctl.c:684 SYSC_ioctl fs/ioctl.c:701 [inline] SyS_ioctl+0x74/0x80 fs/ioctl.c:692 do_syscall_64+0x1c7/0x5b0 arch/x86/entry/common.c:292 entry_SYSCALL_64_after_hwframe+0x42/0xb7 RIP: 0033:0x459819 RSP: 002b:00007f08dfef5c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 0000000000459819 RDX: 0000000020000080 RSI: 0000000000005412 RDI: 0000000000000003 RBP: 000000000075bf20 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007f08dfef66d4 R13: 00000000004c408a R14: 00000000004d7ff0 R15: 00000000ffffffff Code: 00 00 00 48 b8 00 00 00 00 00 fc ff df 55 48 89 e5 41 55 4c 8d af c8 00 00 00 41 54 4c 89 ea 53 48 89 fb 48 c1 ea 03 48 83 ec 10 <0f> b6 14 02 4c 89 e8 83 e0 07 83 c0 03 38 d0 7c 08 84 d2 0f 85 RIP: skb_put+0x28/0x1e0 net/core/skbuff.c:1694 RSP: ffff8880969c79a0 ---[ end trace c1966df7c38ff0f5 ]--- Bluetooth: Invalid header checksum