------------[ cut here ]------------ UBSAN: array-index-out-of-bounds in fs/jfs/jfs_dmap.c:2257:2 index 2621480 is out of range for type 's64[128]' (aka 'long long[128]') CPU: 1 UID: 0 PID: 67 Comm: kworker/u8:4 Tainted: G W 6.16.0-syzkaller-12250-gc30a13538d9f #0 PREEMPT_{RT,(full)} Tainted: [W]=WARN Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025 Workqueue: writeback wb_workfn (flush-7:0) Call Trace: dump_stack_lvl+0x189/0x250 lib/dump_stack.c:120 ubsan_epilogue+0xa/0x40 lib/ubsan.c:233 __ubsan_handle_out_of_bounds+0xe9/0xf0 lib/ubsan.c:455 dbAllocBits+0xa07/0xa60 fs/jfs/jfs_dmap.c:2257 dbAllocDmap fs/jfs/jfs_dmap.c:2034 [inline] dbAllocNear+0x2aa/0x3d0 fs/jfs/jfs_dmap.c:1247 dbAlloc+0x933/0xba0 fs/jfs/jfs_dmap.c:832 extBalloc fs/jfs/jfs_extent.c:336 [inline] extAlloc+0x54a/0xfb0 fs/jfs/jfs_extent.c:127 jfs_get_block+0x346/0xab0 fs/jfs/inode.c:248 mpage_write_folio fs/mpage.c:539 [inline] mpage_writepages+0x7e8/0x1cc0 fs/mpage.c:664 do_writepages+0x32e/0x550 mm/page-writeback.c:2634 __writeback_single_inode+0x145/0x1000 fs/fs-writeback.c:1680 writeback_sb_inodes+0x6b7/0xf60 fs/fs-writeback.c:1976 wb_writeback+0x43b/0xaf0 fs/fs-writeback.c:2156 wb_do_writeback fs/fs-writeback.c:2303 [inline] wb_workfn+0x40e/0xf00 fs/fs-writeback.c:2343 process_one_work kernel/workqueue.c:3236 [inline] process_scheduled_works+0xae1/0x17b0 kernel/workqueue.c:3319 worker_thread+0x8a0/0xda0 kernel/workqueue.c:3400 kthread+0x711/0x8a0 kernel/kthread.c:463 ret_from_fork+0x3f9/0x770 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 ---[ end trace ]---