bisecting fixing commit since b98aebd298246df37b472c52a2ee1023256d02e3 building syzkaller on 8c88c9c1c99c8cd8dabc951164c820b9c9f25114 testing commit b98aebd298246df37b472c52a2ee1023256d02e3 with gcc (GCC) 8.1.0 kernel signature: cd3a91e0dd682767668e9ab64b02afc85d240542f94349254d0a83f49cc8d0e9 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: 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: KASAN: slab-out-of-bounds Read in do_blockdev_direct_IO run #9: crashed: general protection fault in do_blockdev_direct_IO testing current HEAD 4520f06b03ae667e442da1ab9351fd28cd7ac598 testing commit 4520f06b03ae667e442da1ab9351fd28cd7ac598 with gcc (GCC) 8.1.0 kernel signature: c627af2f5020a43cc74bb1faaa07dd226dcdc5892c006b6cb43ececb0bf9f39c all runs: crashed: general protection fault in do_blockdev_direct_IO revisions tested: 2, total time: 22m56.463164104s (build: 16m15.914016666s, test: 6m0.335353029s) the crash still happens on HEAD commit msg: Linux 4.14.175 crash: general protection fault in do_blockdev_direct_IO audit: type=1800 audit(1586592799.226:11): pid=7119 uid=0 auid=0 ses=8 subj=system_u:system_r:kernel_t:s0 op="collect_data" cause="failed(directio)" comm="syz-executor.2" name="bus" dev="sda1" ino=15753 res=0 IPv6: ADDRCONF(NETDEV_CHANGE): veth0_to_bridge: link becomes ready kasan: CONFIG_KASAN_INLINE enabled kasan: GPF could be caused by NULL-ptr deref or user memory access IPv6: ADDRCONF(NETDEV_CHANGE): bridge_slave_0: link becomes ready general protection fault: 0000 [#1] PREEMPT SMP KASAN bridge0: port 1(bridge_slave_0) entered blocking state Modules linked in: CPU: 0 PID: 7119 Comm: syz-executor.2 Not tainted 4.14.175-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 task: ffff88809276c300 task.stack: ffff888093230000 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:ffff888093237490 EFLAGS: 00010202 bridge0: port 1(bridge_slave_0) entered forwarding state IPv6: ADDRCONF(NETDEV_UP): veth1_to_bond: link is not ready RAX: 0000000000000004 RBX: ffffea000213981c RCX: 000000000000000c IPv6: ADDRCONF(NETDEV_UP): veth0_to_team: link is not ready RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000020 RBP: ffff8880932377a0 R08: 0000000000000000 R09: ffff8880a0838dc0 R10: ffffed10141071c8 R11: 0000000000000000 R12: dffffc0000000000 R13: 0000000000000000 R14: ffffea0002139800 R15: ffff888094dbfa40 FS: 00007f2b46606700(0000) GS:ffff8880aee00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 IPv6: ADDRCONF(NETDEV_UP): veth1_to_team: link is not ready CR2: 000055ba98408517 CR3: 00000000929e7000 CR4: 00000000001406f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: IPv6: ADDRCONF(NETDEV_UP): veth0_to_hsr: link is not ready IPv6: ADDRCONF(NETDEV_UP): veth1_to_hsr: link is not ready hsr0: Slave A (hsr_slave_0) is not up; please bring it up to get a fully working HSR network __blockdev_direct_IO+0x72/0xd9 fs/direct-io.c:1422 ext4_direct_IO_write fs/ext4/inode.c:3712 [inline] ext4_direct_IO+0x6ed/0x1b80 fs/ext4/inode.c:3848 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 hsr0: Slave B (hsr_slave_1) is not up; please bring it up to get a fully working HSR network do_iter_write+0x12b/0x520 fs/read_write.c:954 IPv6: ADDRCONF(NETDEV_UP): hsr0: link is not ready 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 IPv6: ADDRCONF(NETDEV_UP): vxcan1: link is not ready do_syscall_64+0x1c7/0x5b0 arch/x86/entry/common.c:292 entry_SYSCALL_64_after_hwframe+0x42/0xb7 RIP: 0033:0x459a59 8021q: adding VLAN 0 to HW filter on device batadv0 RSP: 002b:00007f2b46605c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000113 RAX: ffffffffffffffda RBX: 0000000000000006 RCX: 0000000000459a59 RDX: 0000000000000007 RSI: 0000000000000000 RDI: 0000000000000004 RBP: 000000000075bf20 R08: 00000000ffffffff R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007f2b466066d4 R13: 00000000004c954e R14: 00000000004dffb0 R15: 00000000ffffffff Code: ff ff 48 8b bc 24 e0 00 00 00 48 c7 c6 20 83 94 86 e8 f4 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: ffff888093237490 RIP: compound_head include/linux/page-flags.h:147 [inline] RSP: ffff888093237490 RIP: get_page include/linux/mm.h:828 [inline] RSP: ffff888093237490 RIP: submit_page_section fs/direct-io.c:890 [inline] RSP: ffff888093237490 RIP: do_direct_IO fs/direct-io.c:1097 [inline] RSP: ffff888093237490 RIP: do_blockdev_direct_IO+0x18f1/0x6be0 fs/direct-io.c:1336 RSP: ffff888093237490 8021q: adding VLAN 0 to HW filter on device bond0 ---[ end trace c3b69b13662bc7c4 ]--- IPv6: ADDRCONF(NETDEV_UP): vxcan1: link is not ready