loop0: detected capacity change from 0 to 32768 ------------[ cut here ]------------ UBSAN: array-index-out-of-bounds in fs/jfs/jfs_dtree.c:1598:11 index 24 is out of range for type 'struct lv[20]' CPU: 0 UID: 0 PID: 5309 Comm: syz.0.0 Not tainted syzkaller #0 PREEMPT(full) Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2 04/01/2014 Call Trace: dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120 ubsan_epilogue+0xa/0x30 lib/ubsan.c:233 __ubsan_handle_out_of_bounds+0xe8/0xf0 lib/ubsan.c:455 dtSplitPage+0x34bc/0x36a0 fs/jfs/jfs_dtree.c:1598 dtSplitUp fs/jfs/jfs_dtree.c:1089 [inline] dtInsert+0x1080/0x5cb0 fs/jfs/jfs_dtree.c:868 jfs_mkdir+0x76b/0xb00 fs/jfs/namei.c:271 vfs_mkdir+0x406/0x620 fs/namei.c:5276 filename_mkdirat+0x285/0x510 fs/namei.c:5309 __do_sys_mkdirat fs/namei.c:5330 [inline] __se_sys_mkdirat+0x35/0x150 fs/namei.c:5327 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x174/0x580 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f554fb9cf47 Code: 00 66 90 48 89 f2 b9 00 01 00 00 48 89 fe bf 9c ff ff ff e9 db f7 ff ff 66 2e 0f 1f 84 00 00 00 00 00 90 b8 02 01 00 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 e8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f5550a2ae18 EFLAGS: 00000246 ORIG_RAX: 0000000000000102 RAX: ffffffffffffffda RBX: 00007f5550a2aea0 RCX: 00007f554fb9cf47 RDX: 00000000000001ff RSI: 0000200000000c40 RDI: 00000000ffffff9c RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000200000000c40 R13: 00007f5550a2ae60 R14: 0000000000000000 R15: 0000000000000000 ---[ end trace ]---