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UBSAN: array-index-out-of-bounds in fs/jfs/jfs_dtree.c:3688:8
index -1 is out of range for type 'struct dtslot[128]'
CPU: 0 PID: 27410 Comm: syz.6.6332 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/18/2026
Call Trace:
 <TASK>
 dump_stack_lvl+0x18c/0x250 lib/dump_stack.c:106
 ubsan_epilogue+0xa/0x30 lib/ubsan.c:217
 __ubsan_handle_out_of_bounds+0xe3/0xf0 lib/ubsan.c:348
 dtInsertEntry+0x93b/0x13e0 fs/jfs/jfs_dtree.c:3688
 dtSplitPage+0x2925/0x37d0 fs/jfs/jfs_dtree.c:1596
 dtSplitUp fs/jfs/jfs_dtree.c:1092 [inline]
 dtInsert+0x1072/0x5de0 fs/jfs/jfs_dtree.c:871
 jfs_mkdir+0x75c/0xac0 fs/jfs/namei.c:270
 vfs_mkdir+0x296/0x440 fs/namei.c:4121
 do_mkdirat+0x1dc/0x450 fs/namei.c:4144
 __do_sys_mkdirat fs/namei.c:4159 [inline]
 __se_sys_mkdirat fs/namei.c:4157 [inline]
 __x64_sys_mkdirat+0x89/0xa0 fs/namei.c:4157
 do_syscall_x64 arch/x86/entry/common.c:46 [inline]
 do_syscall_64+0x55/0xa0 arch/x86/entry/common.c:76
 entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7f36c559b687
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:00007f36c6395e58 EFLAGS: 00000246 ORIG_RAX: 0000000000000102
RAX: ffffffffffffffda RBX: 00007f36c6395ee0 RCX: 00007f36c559b687
RDX: 00000000000001ff RSI: 00002000000003c0 RDI: 00000000ffffff9c
RBP: 0000000000000000 R08: 0000200000000140 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00002000000003c0
R13: 00007f36c6395ea0 R14: 0000000000000000 R15: 0000000000000000
 </TASK>
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