loop2: rw=524288, sector=34359738360, nr_sectors = 8 limit=16 syz.2.179: attempt to access beyond end of device loop2: 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+0x39c/0x494 fs/erofs/decompressor.c:347 Read of size 4096 at addr ffff0000c4685000 by task syz.2.179/5083 CPU: 1 PID: 5083 Comm: syz.2.179 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/23/2026 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:1159 [inline] z_erofs_decompress_queue+0x103c/0x1bf4 fs/erofs/zdata.c:1240 z_erofs_runqueue+0x1508/0x16a8 fs/erofs/zdata.c:1612 z_erofs_read_folio+0x2dc/0x5cc fs/erofs/zdata.c:1702 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+0x1290/0x20dc mm/filemap.c:2759 generic_file_read_iter+0xf8/0x5ac mm/filemap.c:2941 call_read_iter include/linux/fs.h:2265 [inline] new_sync_read fs/read_write.c:389 [inline] vfs_read+0x3cc/0x7b8 fs/read_write.c:470 ksys_read+0x12c/0x228 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+0x98/0x290 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:585 Allocated by task 5038: 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_kmalloc mm/kasan/common.c:375 [inline] __kasan_kmalloc+0xa0/0xb8 mm/kasan/common.c:384 kasan_kmalloc include/linux/kasan.h:211 [inline] __do_kmalloc_node mm/slab_common.c:936 [inline] __kmalloc_node+0xdc/0x184 mm/slab_common.c:943 kmalloc_node include/linux/slab.h:589 [inline] kvmalloc_node+0x88/0x1d4 mm/util.c:581 kvmalloc include/linux/slab.h:716 [inline] f2fs_kvmalloc fs/f2fs/f2fs.h:3377 [inline] f2fs_kvzalloc+0x11c/0x2f8 fs/f2fs/f2fs.h:3383 init_free_nid_cache fs/f2fs/node.c:3325 [inline] f2fs_build_node_manager+0xc90/0x1b48 fs/f2fs/node.c:3358 f2fs_fill_super+0x369c/0x57b8 fs/f2fs/super.c:4404 mount_bdev+0x264/0x35c fs/super.c:1454 f2fs_mount+0x44/0x58 fs/f2fs/super.c:4682 legacy_get_tree+0xd8/0x174 fs/fs_context.c:632 vfs_get_tree+0x90/0x278 fs/super.c:1584 do_new_mount+0x228/0x804 fs/namespace.c:3078 path_mount+0x5ac/0xe6c fs/namespace.c:3408 do_mount fs/namespace.c:3421 [inline] __do_sys_mount fs/namespace.c:3629 [inline] __se_sys_mount fs/namespace.c:3606 [inline] __arm64_sys_mount+0x4a0/0x5a0 fs/namespace.c:3606 __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:585 Freed by task 4335: 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+0xbc/0x21c mm/slub.c:3700 kfree+0xd0/0x1a8 mm/slab_common.c:988 kvfree+0x40/0x50 mm/util.c:627 f2fs_destroy_node_manager+0xa94/0xce0 fs/f2fs/node.c:3431 f2fs_put_super+0x574/0xa2c fs/f2fs/super.c:1663 generic_shutdown_super+0x138/0x32c fs/super.c:501 kill_block_super+0x78/0xe0 fs/super.c:1481 kill_f2fs_super+0x278/0x350 fs/f2fs/super.c:4714 deactivate_locked_super+0xb4/0x128 fs/super.c:332 deactivate_super+0xe4/0x104 fs/super.c:363 cleanup_mnt+0x3a8/0x430 fs/namespace.c:1191 __cleanup_mnt+0x20/0x30 fs/namespace.c:1198 task_work_run+0x1f4/0x280 kernel/task_work.c:203 resume_user_mode_work include/linux/resume_user_mode.h:49 [inline] do_notify_resume+0x20f8/0x2c84 arch/arm64/kernel/signal.c:1151 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+0x9c/0x12c 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 ffff0000c4685000 which belongs to the cache kmalloc-128 of size 128 The buggy address is located 0 bytes inside of 128-byte region [ffff0000c4685000, ffff0000c4685080) The buggy address belongs to the physical page: page:0000000034f8830e refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x104685 flags: 0x5ffc00000000200(slab|node=0|zone=2|lastcpupid=0x7ff) raw: 05ffc00000000200 fffffc0003581940 dead000000000003 ffff0000c0002300 raw: 0000000000000000 0000000000100010 00000001ffffffff 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff0000c4684f00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ffff0000c4684f80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 >ffff0000c4685000: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff0000c4685080: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff0000c4685100: 00 00 00 00 fc fc fc fc fc fc fc fc fc fc fc fc ================================================================== syz.2.179: attempt to access beyond end of device loop2: rw=0, sector=34359738360, nr_sectors = 8 limit=16