bisecting fixing commit since 614cb2751d3150850d459bee596c397f344a7936 building syzkaller on a2fe1cb58994e43fb14f141ecd6e6dcce9bb697a testing commit 614cb2751d3150850d459bee596c397f344a7936 compiler: gcc (GCC) 10.2.1 20210217, GNU ld (GNU Binutils for Debian) 2.35.2 kernel signature: a3a85bce4f45999e30949326e2fab7cc4578e19f6b96ef7dbd2ad10521d11990 all runs: crashed: kernel BUG in ext4_get_group_info testing current HEAD 519d81956ee277b4419c723adfb154603c2565ba testing commit 519d81956ee277b4419c723adfb154603c2565ba compiler: gcc (GCC) 10.2.1 20210217, GNU ld (GNU Binutils for Debian) 2.35.2 kernel signature: fcf707fd979ce2466260d9e7792e43d8b1f2c7b2210e5bc25d0f912545d31901 all runs: crashed: kernel BUG in ext4_get_group_info revisions tested: 2, total time: 23m11.264528299s (build: 13m45.929211619s, test: 8m49.083419778s) the crash still happens on HEAD commit msg: Linux 5.15-rc6 crash: kernel BUG in ext4_get_group_info EXT4-fs error (device loop3): ext4_ext_map_blocks:4081: inode #17: comm syz-executor.3: bad extent address lblock: 169, depth: 1 pblock 0 ------------[ cut here ]------------ kernel BUG at fs/ext4/ext4.h:3357! invalid opcode: 0000 [#1] PREEMPT SMP KASAN CPU: 0 PID: 13526 Comm: syz-executor.3 Not tainted 5.15.0-rc6-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:ext4_get_group_info fs/ext4/ext4.h:3357 [inline] RIP: 0010:ext4_get_group_info+0x280/0x2e0 fs/ext4/ext4.h:3352 Code: 0f 85 a8 fe ff ff 48 c7 c2 80 f6 de 88 be b0 02 00 00 48 c7 c7 a0 f0 de 88 c6 05 73 7d 75 0a 01 e8 ea ba 31 06 e9 84 fe ff ff <0f> 0b e8 e9 df b3 ff e9 d4 fd ff ff e8 df df b3 ff e9 fc fd ff ff RSP: 0018:ffffc900057bf5c8 EFLAGS: 00010213 RAX: 0000000000000000 RBX: ffff8880230d8000 RCX: 0000000000000001 RDX: 1ffff1100461b008 RSI: 00000000fffff95a RDI: ffff8880230d8040 RBP: ffff888075c0a000 R08: 0000000000000000 R09: ffff88805b0e397b R10: ffffed100b61c72f R11: 000000000000003b R12: 00000000fffff95a R13: ffff888075c0a678 R14: ffffc900057bf708 R15: ffff888075c0a000 FS: 00007f789ab1d700(0000) GS:ffff8880b9e00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f7f6d637b30 CR3: 0000000072503000 CR4: 00000000003506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: ext4_mb_load_buddy_gfp+0xc6/0xf50 fs/ext4/mballoc.c:1494 ext4_discard_preallocations+0x768/0xc60 fs/ext4/mballoc.c:5011 ext4_truncate+0x4c5/0x10c0 fs/ext4/inode.c:4201 ext4_truncate_failed_write fs/ext4/truncate.h:22 [inline] ext4_write_begin+0x7b3/0xff0 fs/ext4/inode.c:1235 ext4_da_write_begin+0x468/0x840 fs/ext4/inode.c:2944 generic_perform_write+0x1c6/0x440 mm/filemap.c:3770 ext4_buffered_write_iter+0x1ea/0x480 fs/ext4/file.c:269 ext4_file_write_iter+0x383/0x1160 fs/ext4/file.c:680 call_write_iter include/linux/fs.h:2163 [inline] new_sync_write+0x360/0x600 fs/read_write.c:507 vfs_write+0x60b/0x900 fs/read_write.c:594 ksys_write+0xf4/0x1d0 fs/read_write.c:647 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: 0033:0x4665e9 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:00007f789ab1d188 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 000000000056bf80 RCX: 00000000004665e9 RDX: 000000000d4ba0ff RSI: 00000000200009c0 RDI: 0000000000000007 RBP: 00000000004bfcc4 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 000000000056bf80 R13: 00007ffed0a9938f R14: 00007f789ab1d300 R15: 0000000000022000 Modules linked in: ---[ end trace 5fa28479f3a7de79 ]--- RIP: 0010:ext4_get_group_info fs/ext4/ext4.h:3357 [inline] RIP: 0010:ext4_get_group_info+0x280/0x2e0 fs/ext4/ext4.h:3352 Code: 0f 85 a8 fe ff ff 48 c7 c2 80 f6 de 88 be b0 02 00 00 48 c7 c7 a0 f0 de 88 c6 05 73 7d 75 0a 01 e8 ea ba 31 06 e9 84 fe ff ff <0f> 0b e8 e9 df b3 ff e9 d4 fd ff ff e8 df df b3 ff e9 fc fd ff ff RSP: 0018:ffffc900057bf5c8 EFLAGS: 00010213 RAX: 0000000000000000 RBX: ffff8880230d8000 RCX: 0000000000000001 RDX: 1ffff1100461b008 RSI: 00000000fffff95a RDI: ffff8880230d8040 RBP: ffff888075c0a000 R08: 0000000000000000 R09: ffff88805b0e397b R10: ffffed100b61c72f R11: 000000000000003b R12: 00000000fffff95a R13: ffff888075c0a678 R14: ffffc900057bf708 R15: ffff888075c0a000 FS: 00007f789ab1d700(0000) GS:ffff8880b9f00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000002c9a848 CR3: 0000000072503000 CR4: 00000000003506e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400