loop4: rw=524288, sector=88, nr_sectors = 48 limit=16 syz.4.36: attempt to access beyond end of device loop4: 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 ffff0000d5fa5000 by task syz.4.36/4541 CPU: 1 PID: 4541 Comm: syz.4.36 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_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+0x1cac/0x2fb0 mm/memory.c:5292 faultin_page mm/gup.c:1026 [inline] __get_user_pages+0x33c/0x754 mm/gup.c:1250 faultin_vma_page_range+0x1d0/0x26c mm/gup.c:1670 madvise_populate mm/madvise.c:928 [inline] madvise_vma_behavior mm/madvise.c:1037 [inline] madvise_walk_vmas mm/madvise.c:1259 [inline] do_madvise+0x11f8/0x28e4 mm/madvise.c:1438 __do_sys_madvise mm/madvise.c:1451 [inline] __se_sys_madvise mm/madvise.c:1449 [inline] __arm64_sys_madvise+0xa4/0xc0 mm/madvise.c:1449 __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 22: 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] kmalloc_trace+0x7c/0x94 mm/slab_common.c:1031 kmalloc include/linux/slab.h:563 [inline] dst_cow_metrics_generic+0x60/0x220 net/core/dst.c:202 dst_metrics_write_ptr include/net/dst.h:119 [inline] dst_metric_set include/net/dst.h:180 [inline] icmp6_dst_alloc+0x240/0x404 net/ipv6/route.c:3322 mld_sendpack+0x790/0x10ec net/ipv6/mcast.c:1814 mld_send_initial_cr+0x1dc/0x26c net/ipv6/mcast.c:2244 ipv6_mc_dad_complete+0x74/0x214 net/ipv6/mcast.c:2252 addrconf_dad_completed+0x600/0xb28 net/ipv6/addrconf.c:4276 addrconf_dad_work+0x93c/0x10d4 net/ipv6/addrconf.c:-1 process_one_work+0x7f8/0x13a4 kernel/workqueue.c:2292 worker_thread+0x8c4/0xfec kernel/workqueue.c:2439 kthread+0x250/0x2d8 kernel/kthread.c:376 ret_from_fork+0x10/0x20 arch/arm64/kernel/entry.S:850 Freed by task 21: 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/0x218 mm/slub.c:3700 kfree+0xd0/0x1a8 mm/slab_common.c:988 ip_dst_metrics_put include/net/ip.h:527 [inline] ip6_dst_destroy+0xb4/0x3d8 net/ipv6/route.c:363 dst_destroy+0xc4/0x314 net/core/dst.c:112 dst_destroy_rcu+0x20/0x30 net/core/dst.c:133 rcu_do_batch kernel/rcu/tree.c:2297 [inline] rcu_core+0x828/0x18b0 kernel/rcu/tree.c:2557 rcu_core_si+0x10/0x1c kernel/rcu/tree.c:2574 handle_softirqs+0x318/0xc60 kernel/softirq.c:596 run_ksoftirqd+0x7c/0x2ac kernel/softirq.c:968 smpboot_thread_fn+0x4b0/0x964 kernel/smpboot.c:164 kthread+0x250/0x2d8 kernel/kthread.c:376 ret_from_fork+0x10/0x20 arch/arm64/kernel/entry.S:850 The buggy address belongs to the object at ffff0000d5fa5000 which belongs to the cache kmalloc-128 of size 128 The buggy address is located 0 bytes inside of 128-byte region [ffff0000d5fa5000, ffff0000d5fa5080) The buggy address belongs to the physical page: page:000000000f793731 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x115fa5 flags: 0x5ffc00000000200(slab|node=0|zone=2|lastcpupid=0x7ff) raw: 05ffc00000000200 0000000000000000 dead000000000122 ffff0000c0002300 raw: 0000000000000000 0000000000100010 00000001ffffffff 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff0000d5fa4f00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ffff0000d5fa4f80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 >ffff0000d5fa5000: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff0000d5fa5080: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff0000d5fa5100: 00 00 00 00 fc fc fc fc fc fc fc fc fc fc fc fc ================================================================== syz.4.36: attempt to access beyond end of device loop4: rw=0, sector=34359738360, nr_sectors = 8 limit=16 syz.4.36: attempt to access beyond end of device loop4: rw=0, sector=34359738360, nr_sectors = 8 limit=16 syz.4.36: attempt to access beyond end of device loop4: rw=0, sector=34359738360, nr_sectors = 8 limit=16 syz.4.36: attempt to access beyond end of device loop4: rw=0, sector=34359738360, nr_sectors = 8 limit=16 syz.4.36: attempt to access beyond end of device loop4: rw=0, sector=34359738360, nr_sectors = 8 limit=16 syz.4.36: attempt to access beyond end of device loop4: rw=0, sector=34359738360, nr_sectors = 8 limit=16