syz.0.100: attempt to access beyond end of device loop0: 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+0x3a4/0x490 fs/erofs/decompressor.c:346 Read of size 4096 at addr ffff0000d8c11000 by task syz.0.100/4709 CPU: 1 PID: 4709 Comm: syz.0.100 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/18/2026 Call trace: dump_backtrace+0x1c0/0x1ec 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+0x3a4/0x490 fs/erofs/decompressor.c:346 z_erofs_decompress+0x9c/0xd4 fs/erofs/decompressor.c:434 z_erofs_decompress_pcluster fs/erofs/zdata.c:1159 [inline] z_erofs_decompress_queue+0x100c/0x1b40 fs/erofs/zdata.c:1240 z_erofs_runqueue+0x152c/0x16cc fs/erofs/zdata.c:1603 z_erofs_read_folio+0x2d8/0x5c8 fs/erofs/zdata.c:1693 filemap_read_folio+0x134/0x384 mm/filemap.c:2490 filemap_fault+0x98c/0xe98 mm/filemap.c:3340 __do_fault+0x11c/0x3d8 mm/memory.c:4278 do_cow_fault mm/memory.c:4659 [inline] do_fault mm/memory.c:4760 [inline] handle_pte_fault mm/memory.c:5029 [inline] __handle_mm_fault mm/memory.c:5171 [inline] handle_mm_fault+0x18b4/0x2fb0 mm/memory.c:5292 faultin_page mm/gup.c:1026 [inline] __get_user_pages+0x33c/0x754 mm/gup.c:1250 populate_vma_page_range+0x1f4/0x298 mm/gup.c:1607 __mm_populate+0x210/0x334 mm/gup.c:1721 mm_populate include/linux/mm.h:2891 [inline] vm_mmap_pgoff+0x1d8/0x294 mm/util.c:525 ksys_mmap_pgoff+0x3b8/0x5a0 mm/mmap.c:1482 __do_sys_mmap arch/arm64/kernel/sys.c:28 [inline] __se_sys_mmap arch/arm64/kernel/sys.c:21 [inline] __arm64_sys_mmap+0xf8/0x110 arch/arm64/kernel/sys.c:21 __invoke_syscall arch/arm64/kernel/syscall.c:38 [inline] invoke_syscall+0x98/0x290 arch/arm64/kernel/syscall.c:52 el0_svc_common+0x138/0x258 arch/arm64/kernel/syscall.c:140 do_el0_svc+0x58/0x130 arch/arm64/kernel/syscall.c:204 el0_svc+0x58/0x128 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:585 Allocated by task 4335: 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:737 slab_alloc_node mm/slub.c:3359 [inline] slab_alloc mm/slub.c:3367 [inline] __kmem_cache_alloc_lru mm/slub.c:3374 [inline] kmem_cache_alloc+0x22c/0x308 mm/slub.c:3383 vm_area_dup+0x30/0x1c4 kernel/fork.c:468 dup_mmap kernel/fork.c:647 [inline] dup_mm kernel/fork.c:1547 [inline] copy_mm+0x824/0x11ec kernel/fork.c:1596 copy_process+0x18f8/0x3724 kernel/fork.c:2357 kernel_clone+0x1ec/0x918 kernel/fork.c:2764 __do_sys_clone kernel/fork.c:2905 [inline] __se_sys_clone kernel/fork.c:2873 [inline] __arm64_sys_clone+0x154/0x1c0 kernel/fork.c:2873 __invoke_syscall arch/arm64/kernel/syscall.c:38 [inline] invoke_syscall+0x98/0x290 arch/arm64/kernel/syscall.c:52 el0_svc_common+0x138/0x258 arch/arm64/kernel/syscall.c:140 do_el0_svc+0x58/0x130 arch/arm64/kernel/syscall.c:204 el0_svc+0x58/0x128 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:585 Freed by task 4690: kasan_save_stack mm/kasan/common.c:46 [inline] kasan_set_track+0x4c/0x80 mm/kasan/common.c:53 kasan_save_free_info+0x38/0x5c mm/kasan/generic.c:516 ____kasan_slab_free+0x148/0x1b0 mm/kasan/common.c:237 __kasan_slab_free+0x18/0x28 mm/kasan/common.c:245 kasan_slab_free include/linux/kasan.h:177 [inline] slab_free_hook mm/slub.c:1729 [inline] slab_free_freelist_hook+0x16c/0x1e8 mm/slub.c:1755 slab_free mm/slub.c:3687 [inline] kmem_cache_free+0x118/0x314 mm/slub.c:3709 vm_area_free+0x58/0x128 kernel/fork.c:487 remove_vma mm/mmap.c:144 [inline] exit_mmap+0x3ac/0x938 mm/mmap.c:3272 __mmput+0xec/0x394 kernel/fork.c:1206 mmput+0x70/0xa8 kernel/fork.c:1228 exit_mm+0x210/0x29c kernel/exit.c:566 do_exit+0x4d0/0x19b0 kernel/exit.c:868 do_group_exit+0x194/0x22c kernel/exit.c:1024 get_signal+0x11cc/0x1304 kernel/signal.c:2871 do_signal arch/arm64/kernel/signal.c:1095 [inline] do_notify_resume+0x33c/0x2aa4 arch/arm64/kernel/signal.c:1148 prepare_exit_to_user_mode arch/arm64/kernel/entry-common.c:137 [inline] exit_to_user_mode arch/arm64/kernel/entry-common.c:142 [inline] el0_svc+0x98/0x128 arch/arm64/kernel/entry-common.c:638 el0t_64_sync_handler+0x84/0xf0 arch/arm64/kernel/entry-common.c:655 el0t_64_sync+0x18c/0x190 arch/arm64/kernel/entry.S:585 The buggy address belongs to the object at ffff0000d8c11000 which belongs to the cache vm_area_struct of size 152 The buggy address is located 0 bytes inside of 152-byte region [ffff0000d8c11000, ffff0000d8c11098) The buggy address belongs to the physical page: page:00000000aa0a7e43 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x118c11 memcg:ffff0000d1625201 flags: 0x5ffc00000000200(slab|node=0|zone=2|lastcpupid=0x7ff) raw: 05ffc00000000200 fffffc0003458b80 dead000000000008 ffff0000c03db680 raw: 0000000000000000 0000000000120012 00000001ffffffff ffff0000d1625201 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff0000d8c10f00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ffff0000d8c10f80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 >ffff0000d8c11000: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff0000d8c11080: fb fb fb fc fc fc fc fc fc fc fc fa fb fb fb fb ffff0000d8c11100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fc fc ================================================================== syz.0.100: attempt to access beyond end of device loop0: rw=0, sector=16, nr_sectors = 8 limit=16 syz.0.100: attempt to access beyond end of device loop0: rw=0, sector=16, nr_sectors = 8 limit=16 syz.0.100: attempt to access beyond end of device loop0: rw=0, sector=16, nr_sectors = 8 limit=16 syz.0.100: attempt to access beyond end of device loop0: rw=0, sector=16, nr_sectors = 8 limit=16 syz.0.100: attempt to access beyond end of device loop0: rw=0, sector=16, nr_sectors = 8 limit=16 syz.0.100: attempt to access beyond end of device loop0: rw=0, sector=16, nr_sectors = 8 limit=16 syz.0.100: attempt to access beyond end of device loop0: rw=0, sector=16, nr_sectors = 8 limit=16 syz.0.100: attempt to access beyond end of device loop0: rw=0, sector=16, nr_sectors = 8 limit=16