loop1: rw=524288, sector=96, nr_sectors = 40 limit=16 syz.1.734: attempt to access beyond end of device loop1: rw=524288, sector=8, nr_sectors = 80 limit=16 ================================================================== BUG: KASAN: use-after-free in memcpy_to_page include/linux/highmem.h:403 [inline] BUG: KASAN: use-after-free in z_erofs_transform_plain+0x39c/0x494 fs/erofs/decompressor.c:347 Read of size 4096 at addr ffff0000f82d3000 by task syz.1.734/6561 CPU: 0 PID: 6561 Comm: syz.1.734 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 11/06/2026 Call trace: dump_backtrace+0x1c4/0x1f0 arch/arm64/kernel/stacktrace.c:158 show_stack+0x2c/0x3c arch/arm64/kernel/stacktrace.c:165 __dump_stack+0x30/0x40 lib/dump_stack.c:88 dump_stack_lvl+0xf4/0x15c lib/dump_stack.c:106 print_address_description+0x88/0x218 mm/kasan/report.c:316 print_report+0x50/0x68 mm/kasan/report.c:420 kasan_report+0xa8/0xfc mm/kasan/report.c:524 check_region_inline mm/kasan/generic.c:-1 [inline] kasan_check_range+0x258/0x290 mm/kasan/generic.c:189 memcpy+0x48/0x90 mm/kasan/shadow.c:65 memcpy_to_page include/linux/highmem.h:403 [inline] z_erofs_transform_plain+0x39c/0x494 fs/erofs/decompressor.c:347 z_erofs_decompress+0x9c/0xd4 fs/erofs/decompressor.c:435 z_erofs_decompress_pcluster fs/erofs/zdata.c:1161 [inline] z_erofs_decompress_queue+0x103c/0x1bf4 fs/erofs/zdata.c:1242 z_erofs_runqueue+0x1540/0x16a8 fs/erofs/zdata.c:-1 z_erofs_read_folio+0x2dc/0x5cc fs/erofs/zdata.c:1704 filemap_read_folio+0x134/0x384 mm/filemap.c:2490 filemap_fault+0x990/0xe98 mm/filemap.c:3340 __do_fault+0x11c/0x3d8 mm/memory.c:4278 do_read_fault mm/memory.c:4629 [inline] do_fault mm/memory.c:4758 [inline] handle_pte_fault mm/memory.c:5029 [inline] __handle_mm_fault mm/memory.c:5171 [inline] handle_mm_fault+0x1d04/0x3018 mm/memory.c:5292 __do_page_fault arch/arm64/mm/fault.c:506 [inline] do_page_fault+0x310/0xa5c arch/arm64/mm/fault.c:590 do_translation_fault+0x94/0xc8 arch/arm64/mm/fault.c:674 do_mem_abort+0x70/0x198 arch/arm64/mm/fault.c:811 el1_abort+0x48/0x6c arch/arm64/kernel/entry-common.c:367 el1h_64_sync_handler+0x50/0xac arch/arm64/kernel/entry-common.c:427 el1h_64_sync+0x64/0x68 arch/arm64/kernel/entry.S:584 __arch_copy_from_user+0x180/0x230 arch/arm64/lib/copy_template.S:146 __invoke_syscall arch/arm64/kernel/syscall.c:38 [inline] invoke_syscall+0x98/0x290 arch/arm64/kernel/syscall.c:52 el0_svc_common+0x200/0x258 arch/arm64/kernel/syscall.c:140 do_el0_svc+0x5c/0x134 arch/arm64/kernel/syscall.c:204 el0_svc+0x58/0x12c arch/arm64/kernel/entry-common.c:637 el0t_64_sync_handler+0x84/0xf0 arch/arm64/kernel/entry-common.c:655 el0t_64_sync+0x18c/0x190 arch/arm64/kernel/entry.S:589 Allocated by task 4467: kasan_save_stack mm/kasan/common.c:46 [inline] kasan_set_track+0x4c/0x80 mm/kasan/common.c:53 kasan_save_alloc_info+0x24/0x30 mm/kasan/generic.c:505 __kasan_slab_alloc+0x70/0x88 mm/kasan/common.c:329 kasan_slab_alloc include/linux/kasan.h:201 [inline] slab_post_alloc_hook+0x74/0x430 mm/slab.h:742 slab_alloc_node mm/slub.c:3366 [inline] slab_alloc mm/slub.c:3374 [inline] __kmem_cache_alloc_lru mm/slub.c:3381 [inline] kmem_cache_alloc+0x234/0x310 mm/slub.c:3390 kmem_cache_zalloc include/linux/slab.h:689 [inline] xfs_buf_item_init+0x70/0x54c fs/xfs/xfs_buf_item.c:975 _xfs_trans_bjoin+0x54/0x138 fs/xfs/xfs_trans_buf.c:75 xfs_trans_read_buf_map+0x2cc/0xae8 fs/xfs/xfs_trans_buf.c:310 xfs_trans_read_buf fs/xfs/xfs_trans.h:211 [inline] xfs_alloc_read_agfl+0x1a0/0x358 fs/xfs/libxfs/xfs_alloc.c:714 xfs_alloc_fix_freelist+0x8a4/0x106c fs/xfs/libxfs/xfs_alloc.c:2752 xfs_alloc_vextent+0xb44/0x1c00 fs/xfs/libxfs/xfs_alloc.c:3335 xfs_bmap_btalloc+0xadc/0x182c fs/xfs/libxfs/xfs_bmap.c:3662 xfs_bmapi_allocate+0x3fc/0xbfc fs/xfs/libxfs/xfs_bmap.c:-1 xfs_bmapi_convert_one_delalloc fs/xfs/libxfs/xfs_bmap.c:4639 [inline] xfs_bmapi_convert_delalloc+0x690/0x129c fs/xfs/libxfs/xfs_bmap.c:4698 xfs_map_blocks+0x7d4/0x12bc fs/xfs/xfs_aops.c:352 iomap_writepage_map fs/iomap/buffered-io.c:1622 [inline] iomap_do_writepage+0x7e8/0x22c0 fs/iomap/buffered-io.c:1788 write_cache_pages+0x760/0xe00 mm/page-writeback.c:2382 iomap_writepages+0x6c/0x1f4 fs/iomap/buffered-io.c:1805 xfs_vm_writepages+0x13c/0x1b0 fs/xfs/xfs_aops.c:477 do_writepages+0x2c4/0x50c mm/page-writeback.c:2491 filemap_fdatawrite_wbc+0x124/0x174 mm/filemap.c:388 __filemap_fdatawrite_range mm/filemap.c:421 [inline] file_write_and_wait_range+0x11c/0x1f4 mm/filemap.c:774 xfs_file_fsync+0x1b4/0x95c fs/xfs/xfs_file.c:144 vfs_fsync_range+0x168/0x188 fs/sync.c:188 generic_write_sync include/linux/fs.h:2973 [inline] xfs_file_buffered_write+0x91c/0xa80 fs/xfs/xfs_file.c:794 xfs_file_write_iter+0x2b0/0x60c fs/xfs/xfs_file.c:832 call_write_iter include/linux/fs.h:2271 [inline] new_sync_write fs/read_write.c:491 [inline] vfs_write+0x3c8/0x7c8 fs/read_write.c:584 ksys_pwrite64 fs/read_write.c:699 [inline] __do_sys_pwrite64 fs/read_write.c:709 [inline] __se_sys_pwrite64 fs/read_write.c:706 [inline] __arm64_sys_pwrite64+0x178/0x210 fs/read_write.c:706 __invoke_syscall arch/arm64/kernel/syscall.c:38 [inline] invoke_syscall+0x98/0x290 arch/arm64/kernel/syscall.c:52 el0_svc_common+0x13c/0x258 arch/arm64/kernel/syscall.c:140 do_el0_svc+0x5c/0x134 arch/arm64/kernel/syscall.c:204 el0_svc+0x58/0x12c arch/arm64/kernel/entry-common.c:637 el0t_64_sync_handler+0x84/0xf0 arch/arm64/kernel/entry-common.c:655 el0t_64_sync+0x18c/0x190 arch/arm64/kernel/entry.S:589 The buggy address belongs to the object at ffff0000f82d3000 which belongs to the cache xfs_buf_item of size 272 The buggy address is located 0 bytes inside of 272-byte region [ffff0000f82d3000, ffff0000f82d3110) The buggy address belongs to the physical page: page:0000000040744a01 refcount:1 mapcount:0 mapping:0000000000000000 index:0xffff0000f82d3e70 pfn:0x1382d3 flags: 0x5ffc00000000200(slab|node=0|zone=2|lastcpupid=0x7ff) raw: 05ffc00000000200 0000000000000000 dead000000000001 ffff0000c4d13680 raw: ffff0000f82d3e70 00000000800c0000 00000001ffffffff 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff0000f82d2f00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ffff0000f82d2f80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 >ffff0000f82d3000: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff0000f82d3080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff0000f82d3100: fb fb fc fc fc fc fc fc fc fc fb fb fb fb fb fb ================================================================== syz.1.734: attempt to access beyond end of device loop1: rw=0, sector=34359738360, nr_sectors = 8 limit=16 syz.1.734: attempt to access beyond end of device loop1: rw=0, sector=34359738360, nr_sectors = 8 limit=16 syz.1.734: attempt to access beyond end of device loop1: rw=0, sector=34359738360, nr_sectors = 8 limit=16 syz.1.734: attempt to access beyond end of device loop1: rw=0, sector=34359738360, nr_sectors = 8 limit=16