loop3: rw=524288, sector=1056, nr_sectors = 16 limit=16 syz.3.1113: attempt to access beyond end of device loop3: rw=524288, sector=8, nr_sectors = 16 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 ffff0000f3d39000 by task syz.3.1113/9702 CPU: 1 PID: 9702 Comm: syz.3.1113 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/26/2026 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+0x14d4/0x1694 fs/erofs/zdata.c:1597 z_erofs_read_folio+0x2d8/0x5c8 fs/erofs/zdata.c:1687 filemap_read_folio+0x134/0x384 mm/filemap.c:2490 filemap_update_page mm/filemap.c:2575 [inline] filemap_get_pages mm/filemap.c:2689 [inline] filemap_read+0x12cc/0x2104 mm/filemap.c:2759 generic_file_read_iter+0xf8/0x5c4 mm/filemap.c:2941 call_read_iter include/linux/fs.h:2259 [inline] new_sync_read fs/read_write.c:389 [inline] vfs_read+0x3d4/0x7f0 fs/read_write.c:470 ksys_read+0x12c/0x224 fs/read_write.c:613 __do_sys_read fs/read_write.c:623 [inline] __se_sys_read fs/read_write.c:621 [inline] __arm64_sys_read+0x7c/0x90 fs/read_write.c:621 __invoke_syscall arch/arm64/kernel/syscall.c:38 [inline] invoke_syscall+0x98/0x2b4 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 7351: 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:467 dup_mmap kernel/fork.c:646 [inline] dup_mm kernel/fork.c:1546 [inline] copy_mm+0x824/0x11ec kernel/fork.c:1595 copy_process+0x18f8/0x36e4 kernel/fork.c:2356 kernel_clone+0x1ec/0x918 kernel/fork.c:2762 __do_sys_clone kernel/fork.c:2903 [inline] __se_sys_clone kernel/fork.c:2871 [inline] __arm64_sys_clone+0x154/0x1c0 kernel/fork.c:2871 __invoke_syscall arch/arm64/kernel/syscall.c:38 [inline] invoke_syscall+0x98/0x2b4 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 9534: 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:486 remove_vma mm/mmap.c:144 [inline] exit_mmap+0x3ac/0x938 mm/mmap.c:3272 __mmput+0xec/0x394 kernel/fork.c:1205 mmput+0x70/0xa8 kernel/fork.c:1227 exit_mm+0x140/0x220 kernel/exit.c:565 do_exit+0x4d0/0x19b0 kernel/exit.c:867 do_group_exit+0x194/0x22c kernel/exit.c:1022 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 ffff0000f3d39000 which belongs to the cache vm_area_struct of size 152 The buggy address is located 0 bytes inside of 152-byte region [ffff0000f3d39000, ffff0000f3d39098) The buggy address belongs to the physical page: page:0000000088ba7784 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x133d39 memcg:ffff0000cb8a3001 flags: 0x5ffc00000000200(slab|node=0|zone=2|lastcpupid=0x7ff) raw: 05ffc00000000200 fffffc0003936380 dead000000000007 ffff0000c03db680 raw: 0000000000000000 0000000000120012 00000001ffffffff ffff0000cb8a3001 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff0000f3d38f00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ffff0000f3d38f80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 >ffff0000f3d39000: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff0000f3d39080: fb fb fb fc fc fc fc fc fc fc fc fa fb fb fb fb ffff0000f3d39100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fc fc ================================================================== syz.3.1113: attempt to access beyond end of device loop3: rw=0, sector=1056, nr_sectors = 8 limit=16