bisecting fixing commit since b98aebd298246df37b472c52a2ee1023256d02e3
building syzkaller on 8c88c9c1c99c8cd8dabc951164c820b9c9f25114
testing commit b98aebd298246df37b472c52a2ee1023256d02e3 with gcc (GCC) 8.1.0
kernel signature: 2e270aa2e42d38ad316b1d28ced83f1941925803947ebd09236099bff00787fd
all runs: crashed: general protection fault in do_blockdev_direct_IO
testing current HEAD e0f8b8a65a473a8baa439cf865a694bbeb83fe90
testing commit e0f8b8a65a473a8baa439cf865a694bbeb83fe90 with gcc (GCC) 8.1.0
kernel signature: 3874e811f41c4af7d6ab4098527734eec5844a2b77d71165964319a215dc2a86
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: kernel BUG at include/linux/mm.h:LINE!
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: 22m55.683064682s (build: 15m57.65505742s, test: 6m26.329574767s)
the crash still happens on HEAD
commit msg: Linux 4.14.170
crash: general protection fault in do_blockdev_direct_IO
audit: type=1800 audit(1581405917.374:41): pid=7156 uid=0 auid=4294967295 ses=4294967295 subj=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 op="collect_data" cause="failed(directio)" comm="syz-executor.2" name="bus" dev="sda1" ino=16525 res=0
kasan: GPF could be caused by NULL-ptr deref or user memory access
bridge0: port 2(bridge_slave_1) entered blocking state
bridge0: port 2(bridge_slave_1) entered forwarding state
general protection fault: 0000 [#1] PREEMPT SMP KASAN
IPv6: ADDRCONF(NETDEV_UP): bridge0: link is not ready
Modules linked in:
CPU: 0 PID: 7156 Comm: syz-executor.2 Not tainted 4.14.170-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
task: ffff8880a689c200 task.stack: ffff8880771a0000
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:ffff8880771a7490 EFLAGS: 00010202
RAX: 0000000000000004 RBX: ffffea0001dfc01c RCX: 000000000000000c
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000020
RBP: ffff8880771a77a0 R08: 0000000000000000 R09: ffff888099e7d2c0
R10: ffffed10133cfa68 R11: 0000000000000000 R12: dffffc0000000000
R13: 0000000000000000 R14: ffffea0001dfc000 R15: ffff8880909efa40
FS:  00007f7c70ef1700(0000) GS:ffff8880aee00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00000000016c8a90 CR3: 00000000a4ff1000 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:3712 [inline]
 ext4_direct_IO+0x6ed/0x1b00 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+0x279/0xe70 fs/ext4/file.c:268
 call_write_iter include/linux/fs.h:1777 [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: 0033:0x459a59
RSP: 002b:00007f7c70ef0c78 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: 00007f7c70ef16d4
R13: 00000000004c954e R14: 00000000004dffb0 R15: 00000000ffffffff
Code: ff ff 48 8b bc 24 
IPv6: ADDRCONF(NETDEV_UP): veth0_to_bridge: link is not ready
e0 
IPv6: ADDRCONF(NETDEV_UP): veth1_to_bridge: link is not ready
00 00 00 48 c7 c6 00 85 94 86 e8 24 fb e0 ff 0f 0b 48 
IPv6: ADDRCONF(NETDEV_UP): veth0_to_bond: link is not ready
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: ffff8880771a7490
RIP: compound_head include/linux/page-flags.h:147 [inline] RSP: ffff8880771a7490
RIP: get_page include/linux/mm.h:828 [inline] RSP: ffff8880771a7490
RIP: submit_page_section fs/direct-io.c:890 [inline] RSP: ffff8880771a7490
RIP: do_direct_IO fs/direct-io.c:1097 [inline] RSP: ffff8880771a7490
RIP: do_blockdev_direct_IO+0x18f1/0x6be0 fs/direct-io.c:1336 RSP: ffff8880771a7490
---[ end trace 366edc60b5e560dd ]---