loop3: rw=524288, sector=1056, nr_sectors = 16 limit=16 syz.3.68: 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 ffff0000d5474000 by task syz.3.68/4713 CPU: 1 PID: 4713 Comm: syz.3.68 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 4370: 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_track_caller+0xe0/0x16c mm/slab_common.c:956 kmalloc_reserve net/core/skbuff.c:446 [inline] __alloc_skb+0x264/0x714 net/core/skbuff.c:515 alloc_skb include/linux/skbuff.h:1303 [inline] nlmsg_new include/net/netlink.h:991 [inline] inet6_ifa_notify net/ipv6/addrconf.c:5543 [inline] __ipv6_ifa_notify+0x1d4/0xc34 net/ipv6/addrconf.c:6201 ipv6_ifa_notify net/ipv6/addrconf.c:6253 [inline] addrconf_dad_completed+0x16c/0xb28 net/ipv6/addrconf.c:4257 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 4370: 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 skb_free_head net/core/skbuff.c:762 [inline] skb_release_data+0x434/0x63c net/core/skbuff.c:791 skb_release_all net/core/skbuff.c:856 [inline] __kfree_skb net/core/skbuff.c:870 [inline] consume_skb+0xa0/0x104 net/core/skbuff.c:1035 netlink_broadcast+0xf04/0x1058 net/netlink/af_netlink.c:1521 nlmsg_multicast include/net/netlink.h:1071 [inline] nlmsg_notify+0xf4/0x1d4 net/netlink/af_netlink.c:2554 rtnl_notify+0xa0/0xd8 net/core/rtnetlink.c:796 inet6_ifa_notify net/ipv6/addrconf.c:5554 [inline] __ipv6_ifa_notify+0x21c/0xc34 net/ipv6/addrconf.c:6201 ipv6_ifa_notify net/ipv6/addrconf.c:6253 [inline] addrconf_dad_completed+0x16c/0xb28 net/ipv6/addrconf.c:4257 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 The buggy address belongs to the object at ffff0000d5474000 which belongs to the cache kmalloc-512 of size 512 The buggy address is located 0 bytes inside of 512-byte region [ffff0000d5474000, ffff0000d5474200) The buggy address belongs to the physical page: page:00000000edea5a95 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x115474 head:00000000edea5a95 order:2 compound_mapcount:0 compound_pincount:0 flags: 0x5ffc00000010200(slab|head|node=0|zone=2|lastcpupid=0x7ff) raw: 05ffc00000010200 dead000000000100 dead000000000122 ffff0000c0002600 raw: 0000000000000000 0000000000100010 00000001ffffffff 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff0000d5473f00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ffff0000d5473f80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 >ffff0000d5474000: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff0000d5474080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff0000d5474100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ================================================================== syz.3.68: attempt to access beyond end of device loop3: rw=0, sector=1056, nr_sectors = 8 limit=16