bisecting fixing commit since a35d65bedfbc38cffe2701798cd6810bbdf07892 building syzkaller on 3cd800e43d452c348a66ba475143831d94969a24 testing commit a35d65bedfbc38cffe2701798cd6810bbdf07892 compiler: gcc version 8.4.1 20210217 (GCC) kernel signature: d195ed193816f686a5ee1048c1e2571a599acc19b63c8b0f4fe98ce458dc3384 run #0: crashed: unregister_netdevice: waiting for DEV to become free run #1: crashed: unregister_netdevice: waiting for DEV to become free run #2: crashed: unregister_netdevice: waiting for DEV to become free run #3: crashed: unregister_netdevice: waiting for DEV to become free run #4: crashed: unregister_netdevice: waiting for DEV to become free run #5: crashed: unregister_netdevice: waiting for DEV to become free run #6: crashed: WARNING in __udf_add_aext run #7: crashed: unregister_netdevice: waiting for DEV to become free run #8: crashed: unregister_netdevice: waiting for DEV to become free run #9: crashed: unregister_netdevice: waiting for DEV to become free run #10: crashed: unregister_netdevice: waiting for DEV to become free run #11: crashed: unregister_netdevice: waiting for DEV to become free run #12: crashed: unregister_netdevice: waiting for DEV to become free run #13: crashed: WARNING in __udf_add_aext run #14: crashed: unregister_netdevice: waiting for DEV to become free run #15: crashed: WARNING in __udf_add_aext run #16: crashed: unregister_netdevice: waiting for DEV to become free run #17: crashed: unregister_netdevice: waiting for DEV to become free run #18: crashed: unregister_netdevice: waiting for DEV to become free run #19: crashed: unregister_netdevice: waiting for DEV to become free testing current HEAD 74766a973637a02c32c04c1c6496e114e4855239 testing commit 74766a973637a02c32c04c1c6496e114e4855239 compiler: gcc version 8.4.1 20210217 (GCC) kernel signature: 954ea1041b709fc447cba5c7195803a28ec4a8e2d8fb8a3604414e7be2a2c808 run #0: crashed: unregister_netdevice: waiting for DEV to become free run #1: crashed: unregister_netdevice: waiting for DEV to become free run #2: crashed: unregister_netdevice: waiting for DEV to become free run #3: crashed: unregister_netdevice: waiting for DEV to become free run #4: crashed: unregister_netdevice: waiting for DEV to become free run #5: crashed: unregister_netdevice: waiting for DEV to become free run #6: crashed: WARNING in __udf_add_aext run #7: crashed: unregister_netdevice: waiting for DEV to become free run #8: crashed: unregister_netdevice: waiting for DEV to become free run #9: crashed: unregister_netdevice: waiting for DEV to become free revisions tested: 2, total time: 20m40.680024149s (build: 14m8.780004699s, test: 6m10.994525529s) the crash still happens on HEAD commit msg: Linux 4.14.275 crash: unregister_netdevice: waiting for DEV to become free IPv6: ADDRCONF(NETDEV_CHANGE): veth1_to_batadv: link becomes ready IPv6: ADDRCONF(NETDEV_CHANGE): bond0: link becomes ready can: request_module (can-proto-0) failed. can: request_module (can-proto-0) failed. can: request_module (can-proto-0) failed. unregister_netdevice: waiting for ip6gre0 to become free. Usage count = -1 UDF-fs: INFO Mounting volume 'LinuxUDF', timestamp 2020/09/19 18:44 (1000) ------------[ cut here ]------------ WARNING: CPU: 0 PID: 8290 at fs/udf/inode.c:1991 __udf_add_aext+0x4d1/0x6c0 fs/udf/inode.c:2008 Kernel panic - not syncing: panic_on_warn set ... CPU: 0 PID: 8290 Comm: syz-executor116 Not tainted 4.14.275-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:17 [inline] dump_stack+0x14b/0x1e7 lib/dump_stack.c:58 panic+0x1b0/0x358 kernel/panic.c:183 __warn.cold.7+0x25/0x25 kernel/panic.c:547 report_bug+0x1a1/0x200 lib/bug.c:183 fixup_bug arch/x86/kernel/traps.c:177 [inline] fixup_bug arch/x86/kernel/traps.c:172 [inline] do_error_trap+0x1bd/0x310 arch/x86/kernel/traps.c:295 do_invalid_op+0x1b/0x20 arch/x86/kernel/traps.c:314 invalid_op+0x1b/0x40 arch/x86/entry/entry_64.S:964 RIP: 0010:__udf_add_aext+0x4d1/0x6c0 fs/udf/inode.c:1990 RSP: 0018:ffff8880b2b46b90 EFLAGS: 00010287 RAX: 0000000000000000 RBX: ffff8880b2b47140 RCX: 00000000c0000200 RDX: ffff8880b2b46ccc RSI: 0000000000000001 RDI: 0000000000000000 RBP: ffff8880b2b46be0 R08: 00000000000001e8 R09: ffff88808e1cce14 R10: ffff88808e1cce17 R11: 0000000000000001 R12: ffff888089d3c160 R13: 0000000000000010 R14: 00000000000001d0 R15: ffff888089d3c040 udf_setup_indirect_aext+0x5d7/0x780 fs/udf/inode.c:1956 udf_add_aext+0x1aa/0x2a0 fs/udf/inode.c:2043 udf_insert_aext fs/udf/inode.c:2209 [inline] udf_update_extents fs/udf/inode.c:1186 [inline] inode_getblk+0x1761/0x3c90 fs/udf/inode.c:889 udf_get_block fs/udf/inode.c:438 [inline] udf_get_block+0x115/0x480 fs/udf/inode.c:413 __block_write_begin_int+0x327/0x1640 fs/buffer.c:2038 __block_write_begin fs/buffer.c:2088 [inline] block_write_begin+0x48/0x240 fs/buffer.c:2147 udf_write_begin+0x2f/0x90 fs/udf/inode.c:206 generic_perform_write+0x227/0x450 mm/filemap.c:3055 __generic_file_write_iter+0x205/0x590 mm/filemap.c:3180 udf_file_write_iter+0x247/0x470 fs/udf/file.c:169 call_write_iter include/linux/fs.h:1780 [inline] new_sync_write fs/read_write.c:469 [inline] __vfs_write+0x413/0x840 fs/read_write.c:482 __kernel_write+0xe4/0x360 fs/read_write.c:501 write_pipe_buf+0x14c/0x1e0 fs/splice.c:797 splice_from_pipe_feed fs/splice.c:502 [inline] __splice_from_pipe+0x2cb/0x720 fs/splice.c:626 splice_from_pipe+0xb5/0x110 fs/splice.c:661 default_file_splice_write+0x18/0x50 fs/splice.c:809 do_splice_from fs/splice.c:851 [inline] direct_splice_actor+0x104/0x1c0 fs/splice.c:1018 splice_direct_to_actor+0x27c/0x750 fs/splice.c:973 do_splice_direct+0x144/0x250 fs/splice.c:1061 do_sendfile+0x46c/0xcf0 fs/read_write.c:1441 SYSC_sendfile64 fs/read_write.c:1496 [inline] SyS_sendfile64+0x97/0x110 fs/read_write.c:1488 do_syscall_64+0x1c7/0x5b0 arch/x86/entry/common.c:292 entry_SYSCALL_64_after_hwframe+0x46/0xbb RIP: 0033:0x7fc6f26b1679 RSP: 002b:00007ffc90954f78 EFLAGS: 00000246 ORIG_RAX: 0000000000000028 RAX: ffffffffffffffda RBX: 0000000000000014 RCX: 00007fc6f26b1679 RDX: 0000000020000240 RSI: 0000000000000004 RDI: 0000000000000004 RBP: 00007fc6f2670e70 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000007fff R11: 0000000000000246 R12: 00007fc6f2670f00 R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 Kernel Offset: disabled Rebooting in 86400 seconds..