bisecting fixing commit since 6f2f486d57c4d562cdf4932320b66fbb878ab1c4 building syzkaller on 4a77ae0bdc5cd75ebe88ce7c896aae6bbf457a29 testing commit 6f2f486d57c4d562cdf4932320b66fbb878ab1c4 with gcc (GCC) 8.4.1 20210217 kernel signature: 05f38585c13dd5f31655ba9a2c6ef7a8d7deb20472e27586c2c5ebe69c136925 run #0: crashed: kernel BUG in ext4_write_inline_data_end run #1: crashed: kernel BUG in ext4_write_inline_data_end run #2: crashed: kernel BUG in ext4_write_inline_data_end run #3: crashed: kernel BUG in ext4_write_inline_data_end run #4: crashed: kernel BUG in ext4_write_inline_data_end run #5: crashed: kernel BUG in ext4_write_inline_data_end run #6: crashed: kernel BUG in ext4_write_inline_data_end run #7: crashed: kernel BUG in ext4_write_inline_data_end run #8: crashed: kernel BUG in ext4_write_inline_data_end run #9: crashed: kernel BUG in ext4_write_inline_data_end run #10: OK run #11: OK run #12: OK run #13: crashed: kernel BUG in ext4_write_inline_data_end run #14: OK run #15: OK run #16: OK run #17: OK run #18: crashed: kernel BUG in ext4_write_inline_data_end run #19: OK testing current HEAD e73f0f0ee7541171d89f2e2491130c7771ba58d3 testing commit e73f0f0ee7541171d89f2e2491130c7771ba58d3 with gcc (GCC) 10.2.1 20210217 kernel signature: 15b56950449e58d20493831f39eefddbcaa360831c3b3012e22dbd40f8c4384e run #0: crashed: BUG: sleeping function called from invalid context in lock_sock_nested run #1: crashed: kernel BUG in __block_commit_write run #2: OK run #3: OK run #4: OK run #5: OK run #6: OK run #7: OK run #8: OK run #9: OK reproducer seems to be flaky Reproducer flagged being flaky revisions tested: 2, total time: 35m35.746009646s (build: 16m35.983088419s, test: 18m2.234903028s) the crash still happens on HEAD commit msg: Linux 5.14-rc1 crash: kernel BUG in __block_commit_write loop2: detected capacity change from 0 to 512 ------------[ cut here ]------------ kernel BUG at fs/buffer.c:2068! invalid opcode: 0000 [#1] PREEMPT SMP KASAN CPU: 1 PID: 1154 Comm: syz-executor.2 Not tainted 5.14.0-rc1-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:__block_commit_write.constprop.0.isra.0+0x213/0x290 fs/buffer.c:2068 Code: 53 7c e8 ff f0 41 80 0c 24 04 48 83 c4 10 5b 5d 41 5c 41 5d 41 5e 41 5f c3 48 c7 c6 40 e1 38 88 4c 89 e7 e8 ff 4b d8 ff 0f 0b <0f> 0b 48 c7 c6 20 e6 38 88 4c 89 e7 e8 ec 4b d8 ff 0f 0b 4c 89 ff RSP: 0018:ffffc900036ff7d8 EFLAGS: 00010246 RAX: 017ffe0000000005 RBX: 0000000000000000 RCX: ffffffff81c35f7c RDX: 1ffffd40009a1c18 RSI: 0000000000000008 RDI: ffffea0004d0e0c0 RBP: 0000000000000000 R08: 0000000000000000 R09: ffffea0004d0e0c7 R10: fffff940009a1c18 R11: 0000000000000000 R12: ffffea0004d0e0c0 R13: 0000000000000001 R14: 0000000000000000 R15: ffffea0004d0e0c0 FS: 00007ff140c0e700(0000) GS:ffff8881f6300000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000000558000 CR3: 0000000112bfd003 CR4: 00000000001706e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: block_write_end+0x30/0x100 fs/buffer.c:2158 ext4_write_end+0x1f5/0xbc0 fs/ext4/inode.c:1299 generic_perform_write+0x260/0x430 mm/filemap.c:3667 ext4_buffered_write_iter+0x1ea/0x440 fs/ext4/file.c:269 ext4_file_write_iter+0x3ad/0x1310 fs/ext4/file.c:680 call_write_iter include/linux/fs.h:2114 [inline] do_iter_readv_writev+0x333/0x6d0 fs/read_write.c:740 do_iter_write+0x12a/0x5b0 fs/read_write.c:866 vfs_writev+0x16c/0x520 fs/read_write.c:939 do_pwritev fs/read_write.c:1036 [inline] __do_sys_pwritev fs/read_write.c:1083 [inline] __se_sys_pwritev fs/read_write.c:1078 [inline] __x64_sys_pwritev+0x1d7/0x290 fs/read_write.c:1078 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: 0033:0x465849 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:00007ff140c0e188 EFLAGS: 00000246 ORIG_RAX: 0000000000000128 RAX: ffffffffffffffda RBX: 000000000055bf00 RCX: 0000000000465849 RDX: 0000000000000001 RSI: 00000000200014c0 RDI: 0000000000000003 RBP: 00000000004af675 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 000000000055bf00 R13: 00007ffe3859c99f R14: 00007ff140c0e300 R15: 0000000000022000 Modules linked in: ---[ end trace b84bf31f7159912d ]--- RIP: 0010:__block_commit_write.constprop.0.isra.0+0x213/0x290 fs/buffer.c:2068 Code: 53 7c e8 ff f0 41 80 0c 24 04 48 83 c4 10 5b 5d 41 5c 41 5d 41 5e 41 5f c3 48 c7 c6 40 e1 38 88 4c 89 e7 e8 ff 4b d8 ff 0f 0b <0f> 0b 48 c7 c6 20 e6 38 88 4c 89 e7 e8 ec 4b d8 ff 0f 0b 4c 89 ff RSP: 0018:ffffc900036ff7d8 EFLAGS: 00010246 RAX: 017ffe0000000005 RBX: 0000000000000000 RCX: ffffffff81c35f7c RDX: 1ffffd40009a1c18 RSI: 0000000000000008 RDI: ffffea0004d0e0c0 RBP: 0000000000000000 R08: 0000000000000000 R09: ffffea0004d0e0c7 R10: fffff940009a1c18 R11: 0000000000000000 R12: ffffea0004d0e0c0 R13: 0000000000000001 R14: 0000000000000000 R15: ffffea0004d0e0c0 FS: 00007ff140c0e700(0000) GS:ffff8881f6200000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fccbecb6008 CR3: 0000000112bfd005 CR4: 00000000001706f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400