bisecting fixing commit since c3d8f220d01220a5b253e422be407d068dc65511
building syzkaller on 1da71ab086c5d9e6a32beae37b109efaa856b257
testing commit c3d8f220d01220a5b253e422be407d068dc65511 with gcc (GCC) 8.1.0
kernel signature: 05c8d7830c28fca934ca90691a45490109eba3fdc7cbbaab6bbdc032ae63ada5
run #0: crashed: kernel BUG at fs/ext4/inode.c:LINE!
run #1: crashed: kernel BUG at fs/ext4/inode.c:LINE!
run #2: crashed: kernel BUG at fs/ext4/inode.c:LINE!
run #3: crashed: kernel BUG at fs/ext4/inode.c:LINE!
run #4: crashed: kernel BUG at fs/ext4/inode.c:LINE!
run #5: crashed: kernel BUG at fs/ext4/inode.c:LINE!
run #6: OK
run #7: OK
run #8: OK
run #9: OK
testing current HEAD e28c0d7c92c89016c12a677616668957351e7542
testing commit e28c0d7c92c89016c12a677616668957351e7542 with gcc (GCC) 8.1.0
kernel signature: 0d75e64fcc03c0d6f438c1aed0d9606caf5fe4041105ecdfec0c26c169b33dd0
run #0: crashed: kernel BUG at fs/ext4/inode.c:LINE!
run #1: crashed: kernel BUG at fs/ext4/inode.c:LINE!
run #2: crashed: kernel BUG at fs/ext4/inode.c:LINE!
run #3: crashed: kernel BUG at fs/ext4/inode.c:LINE!
run #4: crashed: kernel BUG at fs/ext4/inode.c:LINE!
run #5: crashed: kernel BUG at fs/ext4/inode.c:LINE!
run #6: crashed: kernel BUG at fs/ext4/inode.c:LINE!
run #7: crashed: kernel BUG at fs/ext4/inode.c:LINE!
run #8: crashed: kernel BUG at fs/ext4/inode.c:LINE!
run #9: OK
revisions tested: 2, total time: 30m42.247041237s (build: 9m23.109650792s, test: 20m48.341375125s)
the crash still happens on HEAD
commit msg: Merge branch 'akpm' (patches from Andrew)
crash: kernel BUG at fs/ext4/inode.c:LINE!
------------[ cut here ]------------
kernel BUG at fs/ext4/inode.c:2609!
invalid opcode: 0000 [#1] PREEMPT SMP
CPU: 0 PID: 24381 Comm: syz-executor.4 Not tainted 5.10.0-rc3-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
RIP: 0010:mpage_prepare_extent_to_map+0x2ff/0x370 fs/ext4/inode.c:2609
Code: f2 4c 89 f7 e8 12 8d e2 ff 0f 0b 49 8b 46 08 48 c7 c6 60 05 e9 83 48 8d 50 ff a8 01 4c 0f 45 f2 4c 89 f7 e8 f3 8c e2 ff 0f 0b <0f> 0b 48 c7 c6 c8 e7 e8 83 4c 89 f7 e8 e0 8c e2 ff 0f 0b 0f 0b 80
RSP: 0018:ffffc90005dbb920 EFLAGS: 00010282
RAX: 017ffe000000a01f RBX: ffffc90005dbb950 RCX: ffff88811f3a84c0
RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffffffff8420e7f0
RBP: 0000000000000002 R08: 0000000000000001 R09: 0000000000000001
R10: 0000000000000001 R11: 0000000000000002 R12: 7fffffffffffffff
R13: ffff88811f40e7a0 R14: ffffea00044a00c0 R15: ffffc90005dbba90
FS:  00007fdeb0dd6700(0000) GS:ffff88813bc00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f94cbaa9000 CR3: 000000010c772000 CR4: 00000000001506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 ext4_writepages+0x331/0x11a0 fs/ext4/inode.c:2746
 do_writepages+0x39/0xe0 mm/page-writeback.c:2352
 __filemap_fdatawrite_range+0xc2/0x100 mm/filemap.c:422
 filemap_write_and_wait_range+0x36/0x90 mm/filemap.c:655
 __iomap_dio_rw+0x185/0x550 fs/iomap/direct-io.c:489
 iomap_dio_rw+0x9/0x30 fs/iomap/direct-io.c:605
 ext4_dio_read_iter fs/ext4/file.c:77 [inline]
 ext4_file_read_iter+0x102/0x160 fs/ext4/file.c:129
 call_read_iter include/linux/fs.h:1897 [inline]
 generic_file_splice_read+0xf7/0x1a0 fs/splice.c:311
 splice_direct_to_actor+0xd7/0x240 fs/splice.c:867
 do_splice_direct+0x9a/0xd0 fs/splice.c:976
 do_sendfile+0x1c8/0x530 fs/read_write.c:1257
 __do_sys_sendfile64 fs/read_write.c:1318 [inline]
 __se_sys_sendfile64 fs/read_write.c:1304 [inline]
 __x64_sys_sendfile64+0xab/0xc0 fs/read_write.c:1304
 do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46
 entry_SYSCALL_64_after_hwframe+0x44/0xa9
RIP: 0033:0x45d4d9
Code: 5d b4 fb ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 0f 83 2b b4 fb ff c3 66 2e 0f 1f 84 00 00 00 00
RSP: 002b:00007fdeb0dd5c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000028
RAX: ffffffffffffffda RBX: 0000000000027880 RCX: 000000000045d4d9
RDX: 0000000000000000 RSI: 0000000000000006 RDI: 0000000000000004
RBP: 000000000118cf88 R08: 0000000000000000 R09: 0000000000000000
R10: 00008400fffffffb R11: 0000000000000246 R12: 000000000118cf4c
R13: 00007ffd01ce4daf R14: 00007fdeb0dd69c0 R15: 000000000118cf4c
Modules linked in:
---[ end trace 67ea990d32c14785 ]---
RIP: 0010:mpage_prepare_extent_to_map+0x2ff/0x370 fs/ext4/inode.c:2609
Code: f2 4c 89 f7 e8 12 8d e2 ff 0f 0b 49 8b 46 08 48 c7 c6 60 05 e9 83 48 8d 50 ff a8 01 4c 0f 45 f2 4c 89 f7 e8 f3 8c e2 ff 0f 0b <0f> 0b 48 c7 c6 c8 e7 e8 83 4c 89 f7 e8 e0 8c e2 ff 0f 0b 0f 0b 80
RSP: 0018:ffffc90005dbb920 EFLAGS: 00010282
RAX: 017ffe000000a01f RBX: ffffc90005dbb950 RCX: ffff88811f3a84c0
RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffffffff8420e7f0
RBP: 0000000000000002 R08: 0000000000000001 R09: 0000000000000001
R10: 0000000000000001 R11: 0000000000000002 R12: 7fffffffffffffff
R13: ffff88811f40e7a0 R14: ffffea00044a00c0 R15: ffffc90005dbba90
FS:  00007fdeb0dd6700(0000) GS:ffff88813bc00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fc008931000 CR3: 000000010c772000 CR4: 00000000001506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400