EXT4-fs error (device loop1): ext4_map_blocks:718: inode #17: block 424: comm syz-executor.1: lblock 296 mapped to illegal pblock 424 (length 1) ------------[ cut here ]------------ kernel BUG at fs/ext4/ext4.h:3295! invalid opcode: 0000 [#1] PREEMPT SMP KASAN CPU: 1 PID: 10426 Comm: syz-executor.1 Not tainted 5.14.0-rc6-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:ext4_get_group_info+0x34d/0x350 fs/ext4/ext4.h:3295 Code: 5c ff 8b 74 24 04 48 c7 c7 40 77 88 8c 4c 89 f2 e8 08 9f 05 02 43 80 3c 2c 00 0f 85 6d fd ff ff e9 70 fd ff ff e8 a3 46 5c ff <0f> 0b 90 55 41 57 41 56 41 55 41 54 53 48 83 ec 20 41 89 d5 89 f5 RSP: 0018:ffffc9000c49f320 EFLAGS: 00010293 RAX: ffffffff8223f12d RBX: 00000000fffff95a RCX: ffff88802d923880 RDX: 0000000000000000 RSI: 00000000fffff95a RDI: 0000000000000001 RBP: 0000000000000001 R08: ffffffff8223ee48 R09: ffffed1008f9ac2c R10: ffffed1008f9ac2c R11: 0000000000000000 R12: 1ffff110073d74cf R13: dffffc0000000000 R14: ffff8880328dc000 R15: ffff888039eba678 FS: 00007fe3035a4700(0000) GS:ffff8880b9d00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000002112848 CR3: 0000000033f2d000 CR4: 00000000001506e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: ext4_mb_load_buddy_gfp+0xc7/0x1370 fs/ext4/mballoc.c:1490 ext4_discard_preallocations+0x811/0x16a0 fs/ext4/mballoc.c:4940 ext4_truncate+0xa1a/0xec0 fs/ext4/inode.c:4259 ext4_truncate_failed_write fs/ext4/truncate.h:20 [inline] ext4_write_begin+0xa7b/0x1350 fs/ext4/inode.c:1234 ext4_da_write_begin+0x384/0x10c0 fs/ext4/inode.c:2960 generic_perform_write+0x262/0x580 mm/filemap.c:3656 ext4_buffered_write_iter+0x41c/0x590 fs/ext4/file.c:269 ext4_file_write_iter+0x8f7/0x1b90 fs/ext4/file.c:519 call_write_iter include/linux/fs.h:2114 [inline] new_sync_write fs/read_write.c:518 [inline] vfs_write+0xa39/0xc90 fs/read_write.c:605 ksys_write+0x171/0x2a0 fs/read_write.c:658 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x3d/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:00007fe3035a4188 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: 00007ffd1a1dd7ef R14: 00007fe3035a4300 R15: 0000000000022000 Modules linked in: ---[ end trace 6608a809acf19a79 ]--- RIP: 0010:ext4_get_group_info+0x34d/0x350 fs/ext4/ext4.h:3295 Code: 5c ff 8b 74 24 04 48 c7 c7 40 77 88 8c 4c 89 f2 e8 08 9f 05 02 43 80 3c 2c 00 0f 85 6d fd ff ff e9 70 fd ff ff e8 a3 46 5c ff <0f> 0b 90 55 41 57 41 56 41 55 41 54 53 48 83 ec 20 41 89 d5 89 f5 RSP: 0018:ffffc9000c49f320 EFLAGS: 00010293 RAX: ffffffff8223f12d RBX: 00000000fffff95a RCX: ffff88802d923880 RDX: 0000000000000000 RSI: 00000000fffff95a RDI: 0000000000000001 RBP: 0000000000000001 R08: ffffffff8223ee48 R09: ffffed1008f9ac2c R10: ffffed1008f9ac2c R11: 0000000000000000 R12: 1ffff110073d74cf R13: dffffc0000000000 R14: ffff8880328dc000 R15: ffff888039eba678 FS: 00007fe3035a4700(0000) GS:ffff8880b9d00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000000000000 CR3: 0000000033f2d000 CR4: 00000000001506e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 ---------------- Code disassembly (best guess): 0: 5c pop %rsp 1: ff 8b 74 24 04 48 decl 0x48042474(%rbx) 7: c7 c7 40 77 88 8c mov $0x8c887740,%edi d: 4c 89 f2 mov %r14,%rdx 10: e8 08 9f 05 02 callq 0x2059f1d 15: 43 80 3c 2c 00 cmpb $0x0,(%r12,%r13,1) 1a: 0f 85 6d fd ff ff jne 0xfffffd8d 20: e9 70 fd ff ff jmpq 0xfffffd95 25: e8 a3 46 5c ff callq 0xff5c46cd 2a: 0f 0b ud2 <-- trapping instruction 2c: 90 nop 2d: 55 push %rbp 2e: 41 57 push %r15 30: 41 56 push %r14 32: 41 55 push %r13 34: 41 54 push %r12 36: 53 push %rbx 37: 48 83 ec 20 sub $0x20,%rsp 3b: 41 89 d5 mov %edx,%r13d 3e: 89 f5 mov %esi,%ebp