bisecting fixing commit since ad347abe4a9876b1f65f408ab467137e88f77eb4 building syzkaller on 1ba81399e2d03b53a7e631c4ab05f25af1fb1911 testing commit ad347abe4a9876b1f65f408ab467137e88f77eb4 compiler: gcc (GCC) 10.2.1 20210217, GNU ld (GNU Binutils for Debian) 2.35.2 kernel signature: 865d3c40c172cafc1eeff01355f98b9738f56605a5dc669616daa8f5df3b4827 all runs: crashed: kernel BUG in ext4_writepages testing current HEAD daadb3bd0e8d3e317e36bc2c1542e86c528665e5 testing commit daadb3bd0e8d3e317e36bc2c1542e86c528665e5 compiler: gcc (GCC) 10.2.1 20210217, GNU ld (GNU Binutils for Debian) 2.35.2 kernel signature: 577fb8dacc102d303beb989c64e2a6e9a3566900360926434c217ebc6693850e all runs: crashed: kernel BUG in ext4_writepages revisions tested: 2, total time: 19m43.843235259s (build: 13m0.630820909s, test: 5m55.36887557s) the crash still happens on HEAD commit msg: Merge tag 'locking_core_for_v5.17_rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip crash: kernel BUG in ext4_writepages ------------[ cut here ]------------ kernel BUG at fs/ext4/inode.c:2681! invalid opcode: 0000 [#1] PREEMPT SMP KASAN CPU: 0 PID: 4036 Comm: syz-executor.3 Not tainted 5.16.0-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:ext4_writepages+0x1a88/0x2d10 fs/ext4/inode.c:2681 Code: 0f 87 e0 f2 4b 06 be 00 10 00 00 ba 01 00 00 00 4c 89 e7 48 d3 ee e8 47 61 fe ff 83 c0 01 89 84 24 c8 00 00 00 e9 48 eb ff ff <0f> 0b 89 44 24 08 e9 94 ef ff ff 48 8b 7c 24 28 e8 03 3b b6 ff e9 RSP: 0018:ffffc90002a0f538 EFLAGS: 00010247 RAX: 000000c410000000 RBX: ffff88807c900000 RCX: ffffffff81f264f2 RDX: 1ffff1100e9bd8c3 RSI: 0000000000000008 RDI: ffff888074dec618 RBP: ffff888074dec618 R08: 0000000000000000 R09: ffff888074dec61f R10: ffffed100e9bd8c3 R11: 0000000000000000 R12: ffff888074dec868 R13: ffffc90002a0fa70 R14: 0000000000000001 R15: ffff88807c900000 FS: 00007f76ed862700(0000) GS:ffff8880b9e00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00005605176b82d8 CR3: 0000000062eaf000 CR4: 0000000000350ef0 Call Trace: do_writepages+0x16e/0x5f0 mm/page-writeback.c:2364 filemap_fdatawrite_wbc mm/filemap.c:407 [inline] filemap_fdatawrite_wbc+0x107/0x170 mm/filemap.c:397 __filemap_fdatawrite_range mm/filemap.c:440 [inline] file_write_and_wait_range+0x142/0x1a0 mm/filemap.c:824 ext4_sync_file+0x1c8/0xc90 fs/ext4/fsync.c:151 generic_write_sync include/linux/fs.h:2894 [inline] ext4_buffered_write_iter+0x23b/0x320 fs/ext4/file.c:275 ext4_file_write_iter+0x383/0x1150 fs/ext4/file.c:677 call_write_iter include/linux/fs.h:2086 [inline] new_sync_write+0x360/0x600 fs/read_write.c:503 vfs_write+0x609/0x900 fs/read_write.c:590 ksys_write+0xf4/0x1d0 fs/read_write.c:643 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x44/0xae RIP: 0033:0x4665d9 Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 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 73 01 c3 48 c7 c1 bc ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f76ed862188 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 000000000056bf80 RCX: 00000000004665d9 RDX: 0000000000000082 RSI: 0000000020000180 RDI: 0000000000000004 RBP: 00000000004bfcb9 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 000000000056bf80 R13: 00007ffcd0c3162f R14: 00007f76ed862300 R15: 0000000000022000 Modules linked in: ---[ end trace 07811f948a72f748 ]--- RIP: 0010:ext4_writepages+0x1a88/0x2d10 fs/ext4/inode.c:2681 Code: 0f 87 e0 f2 4b 06 be 00 10 00 00 ba 01 00 00 00 4c 89 e7 48 d3 ee e8 47 61 fe ff 83 c0 01 89 84 24 c8 00 00 00 e9 48 eb ff ff <0f> 0b 89 44 24 08 e9 94 ef ff ff 48 8b 7c 24 28 e8 03 3b b6 ff e9 RSP: 0018:ffffc90002a0f538 EFLAGS: 00010247 RAX: 000000c410000000 RBX: ffff88807c900000 RCX: ffffffff81f264f2 RDX: 1ffff1100e9bd8c3 RSI: 0000000000000008 RDI: ffff888074dec618 RBP: ffff888074dec618 R08: 0000000000000000 R09: ffff888074dec61f R10: ffffed100e9bd8c3 R11: 0000000000000000 R12: ffff888074dec868 R13: ffffc90002a0fa70 R14: 0000000000000001 R15: ffff88807c900000 FS: 00007f76ed862700(0000) GS:ffff8880b9e00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00000000005230f0 CR3: 0000000062eaf000 CR4: 0000000000350ef0