------------[ cut here ]------------ UBSAN: array-index-out-of-bounds in fs/jfs/jfs_dmap.c:2902:18 index -3 is out of range for type 's8[1365]' (aka 'signed char[1365]') CPU: 0 UID: 0 PID: 3319 Comm: syz.4.5612 Not tainted 6.11.0-rc1-syzkaller-00233-g948752d2e010 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/27/2024 Call Trace: __dump_stack lib/dump_stack.c:93 [inline] dump_stack_lvl+0x241/0x360 lib/dump_stack.c:119 ubsan_epilogue lib/ubsan.c:231 [inline] __ubsan_handle_out_of_bounds+0x121/0x150 lib/ubsan.c:429 dbAdjTree+0x377/0x520 fs/jfs/jfs_dmap.c:2902 dbAllocBits+0x4ea/0x990 fs/jfs/jfs_dmap.c:2193 dbAllocDmap+0x6d/0x150 fs/jfs/jfs_dmap.c:2034 dbAlloc+0x509/0xca0 fs/jfs/jfs_dmap.c:816 extBalloc fs/jfs/jfs_extent.c:326 [inline] extAlloc+0x4f8/0x1010 fs/jfs/jfs_extent.c:122 jfs_get_block+0x41b/0xe60 fs/jfs/inode.c:248 __block_write_begin_int+0x50e/0x1a70 fs/buffer.c:2125 __block_write_begin fs/buffer.c:2174 [inline] block_write_begin+0x9b/0x1e0 fs/buffer.c:2235 jfs_write_begin+0x31/0x70 fs/jfs/inode.c:299 generic_perform_write+0x39b/0x840 mm/filemap.c:4019 generic_file_write_iter+0xaf/0x310 mm/filemap.c:4147 new_sync_write fs/read_write.c:497 [inline] vfs_write+0xa74/0xc90 fs/read_write.c:590 ksys_write+0x1a0/0x2c0 fs/read_write.c:643 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f62e71779f9 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 a8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f62e6bde048 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 00007f62e7306130 RCX: 00007f62e71779f9 RDX: 000000000208e24b RSI: 0000000020000340 RDI: 0000000000000009 RBP: 00007f62e71e58ee R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 000000000000006e R14: 00007f62e7306130 R15: 00007ffc8834bf48 ---[ end trace ]---