bisecting fixing commit since ddef1e8e3f6eb26034833b7255e3fa584d54a230 building syzkaller on 5ea87a6638e52a94361b26b8576a1605585815fb testing commit ddef1e8e3f6eb26034833b7255e3fa584d54a230 with gcc (GCC) 8.1.0 kernel signature: 67dc0841a8fde8a1303a0aad319cc85974372f0bea5a43dd29a5c0b3744d625c run #0: crashed: general protection fault in do_blockdev_direct_IO run #1: crashed: general protection fault in do_blockdev_direct_IO run #2: crashed: general protection fault in do_blockdev_direct_IO run #3: crashed: general protection fault in do_blockdev_direct_IO run #4: crashed: general protection fault in do_blockdev_direct_IO run #5: crashed: KASAN: slab-out-of-bounds Read in do_blockdev_direct_IO run #6: crashed: general protection fault in do_blockdev_direct_IO run #7: crashed: general protection fault in do_blockdev_direct_IO run #8: crashed: general protection fault in do_blockdev_direct_IO run #9: crashed: general protection fault in do_blockdev_direct_IO testing current HEAD ab9dfda232481dcfaf549ce774004d116fc80c13 testing commit ab9dfda232481dcfaf549ce774004d116fc80c13 with gcc (GCC) 8.1.0 kernel signature: 56427ce173da6693c25ff2ce1de7aa6d837989b4cb7aa06065c28696ff5c229b run #0: crashed: general protection fault in do_blockdev_direct_IO run #1: crashed: KASAN: slab-out-of-bounds Read in do_blockdev_direct_IO run #2: crashed: general protection fault in do_blockdev_direct_IO run #3: crashed: general protection fault in do_blockdev_direct_IO run #4: crashed: general protection fault in do_blockdev_direct_IO run #5: crashed: general protection fault in do_blockdev_direct_IO run #6: crashed: general protection fault in do_blockdev_direct_IO run #7: crashed: general protection fault in do_blockdev_direct_IO run #8: crashed: general protection fault in do_blockdev_direct_IO run #9: crashed: general protection fault in do_blockdev_direct_IO revisions tested: 2, total time: 24m34.844887628s (build: 17m27.693962107s, test: 6m0.117268164s) the crash still happens on HEAD commit msg: Linux 4.14.180 crash: general protection fault in do_blockdev_direct_IO IPv6: ADDRCONF(NETDEV_UP): bridge_slave_0: link is not ready IPv6: ADDRCONF(NETDEV_UP): hsr0: link is not ready kasan: CONFIG_KASAN_INLINE enabled IPv6: ADDRCONF(NETDEV_CHANGE): hsr0: link becomes ready 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: 0 PID: 7136 Comm: syz-executor.2 Not tainted 4.14.180-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 task: ffff888091f5e580 task.stack: ffff88808d590000 RIP: 0010:__read_once_size include/linux/compiler.h:183 [inline] RIP: 0010:compound_head include/linux/page-flags.h:147 [inline] RIP: 0010:get_page include/linux/mm.h:828 [inline] RIP: 0010:submit_page_section fs/direct-io.c:890 [inline] RIP: 0010:do_direct_IO fs/direct-io.c:1097 [inline] RIP: 0010:do_blockdev_direct_IO+0x18f1/0x6be0 fs/direct-io.c:1336 RSP: 0018:ffff88808d597490 EFLAGS: 00010202 RAX: 0000000000000004 RBX: ffffea00024ca81c RCX: 000000000000000c RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000020 RBP: ffff88808d5977a0 R08: 0000000000000000 R09: ffff8880a117eac0 R10: ffffed101422fd68 R11: 0000000000000000 R12: dffffc0000000000 R13: 0000000000000000 R14: ffffea00024ca800 R15: ffff888082e6da40 FS: 00007eff9e3ee700(0000) GS:ffff8880aee00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fc33003a148 CR3: 0000000091825000 CR4: 00000000001406f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: __blockdev_direct_IO+0x72/0xd9 fs/direct-io.c:1422 ext4_direct_IO_write fs/ext4/inode.c:3716 [inline] ext4_direct_IO+0x6ed/0x1b80 fs/ext4/inode.c:3852 generic_file_direct_write+0x1ee/0x410 mm/filemap.c:2950 __generic_file_write_iter+0x270/0x580 mm/filemap.c:3129 ext4_file_write_iter+0x27a/0xe40 fs/ext4/file.c:270 call_write_iter include/linux/fs.h:1778 [inline] do_iter_readv_writev+0x460/0x900 fs/read_write.c:675 do_iter_write+0x12b/0x520 fs/read_write.c:954 vfs_iter_write+0x5b/0xb0 fs/read_write.c:967 iter_file_splice_write+0x540/0xc20 fs/splice.c:749 do_splice_from fs/splice.c:851 [inline] do_splice fs/splice.c:1147 [inline] SYSC_splice fs/splice.c:1402 [inline] SyS_splice+0x6e9/0x1580 fs/splice.c:1382 do_syscall_64+0x1c7/0x5b0 arch/x86/entry/common.c:292 entry_SYSCALL_64_after_hwframe+0x42/0xb7 RIP: 0033:0x459f49 RSP: 002b:00007eff9e3edc78 EFLAGS: 00000246 ORIG_RAX: 0000000000000113 RAX: ffffffffffffffda RBX: 0000000000000006 RCX: 0000000000459f49 RDX: 0000000000000007 RSI: 0000000000000000 RDI: 0000000000000004 RBP: 000000000075bf20 R08: 00000000ffffffff R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007eff9e3ee6d4 R13: 00000000004c9c8b R14: 00000000004e0af8 R15: 00000000ffffffff Code: ff ff 48 8b bc 24 e0 00 00 00 48 c7 c6 a0 83 94 86 e8 b4 f8 e0 ff 0f 0b 48 8b 84 24 e0 00 00 00 48 8d 78 20 48 89 f8 48 c1 e8 03 <42> 80 3c 20 00 0f 85 f3 44 00 00 48 8b 9c 24 e0 00 00 00 48 8b RIP: __read_once_size include/linux/compiler.h:183 [inline] RSP: ffff88808d597490 RIP: compound_head include/linux/page-flags.h:147 [inline] RSP: ffff88808d597490 RIP: get_page include/linux/mm.h:828 [inline] RSP: ffff88808d597490 RIP: submit_page_section fs/direct-io.c:890 [inline] RSP: ffff88808d597490 RIP: do_direct_IO fs/direct-io.c:1097 [inline] RSP: ffff88808d597490 RIP: do_blockdev_direct_IO+0x18f1/0x6be0 fs/direct-io.c:1336 RSP: ffff88808d597490 IPv6: ADDRCONF(NETDEV_CHANGE): veth0_to_bond: link becomes ready IPv6: ADDRCONF(NETDEV_CHANGE): veth1_to_bond: link becomes ready ---[ end trace 82336802748adc0c ]--- IPv6: ADDRCONF(NETDEV_CHANGE): veth1: link becomes ready IPv6: ADDRCONF(NETDEV_CHANGE): veth0: link becomes ready