loop2: detected capacity change from 0 to 16 erofs: (device loop2): mounted with root inode @ nid 36. syz.2.621: attempt to access beyond end of device loop2: rw=524288, sector=8, nr_sectors = 16 limit=16 syz.2.621: attempt to access beyond end of device loop2: rw=524288, sector=16, nr_sectors = 40 limit=16 ================================================================== BUG: KASAN: slab-use-after-free in memcpy_to_page include/linux/highmem.h:427 [inline] BUG: KASAN: slab-use-after-free in z_erofs_transform_plain+0x38c/0x460 fs/erofs/decompressor.c:347 Read of size 4096 at addr ffff88806495d000 by task syz.2.621/9484 CPU: 0 PID: 9484 Comm: syz.2.621 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026 Call Trace: dump_stack_lvl+0x18c/0x250 lib/dump_stack.c:106 print_address_description mm/kasan/report.c:364 [inline] print_report+0xa8/0x210 mm/kasan/report.c:468 kasan_report+0x117/0x150 mm/kasan/report.c:581 check_region_inline mm/kasan/generic.c:-1 [inline] kasan_check_range+0x241/0x290 mm/kasan/generic.c:187 __asan_memcpy+0x29/0x70 mm/kasan/shadow.c:105 memcpy_to_page include/linux/highmem.h:427 [inline] z_erofs_transform_plain+0x38c/0x460 fs/erofs/decompressor.c:347 z_erofs_decompress_pcluster fs/erofs/zdata.c:1296 [inline] z_erofs_decompress_queue+0x1780/0x26f0 fs/erofs/zdata.c:1377 z_erofs_runqueue+0x1a4e/0x1bf0 fs/erofs/zdata.c:1778 z_erofs_read_folio+0x323/0x5c0 fs/erofs/zdata.c:1863 filemap_read_folio+0x172/0x760 mm/filemap.c:2420 filemap_update_page mm/filemap.c:2504 [inline] filemap_get_pages+0x13c7/0x1e90 mm/filemap.c:2618 filemap_read+0x402/0xf00 mm/filemap.c:2690 __kernel_read+0x2f3/0x710 fs/read_write.c:428 integrity_kernel_read+0x8a/0xd0 security/integrity/iint.c:221 ima_calc_file_hash_tfm security/integrity/ima/ima_crypto.c:485 [inline] ima_calc_file_shash security/integrity/ima/ima_crypto.c:516 [inline] ima_calc_file_hash+0x91d/0x1910 security/integrity/ima/ima_crypto.c:573 ima_collect_measurement+0x4d4/0xa20 security/integrity/ima/ima_api.c:290 process_measurement+0x128e/0x1d70 security/integrity/ima/ima_main.c:370 ima_bprm_check+0xfb/0x200 security/integrity/ima/ima_main.c:543 search_binary_handler fs/exec.c:1763 [inline] exec_binprm fs/exec.c:1817 [inline] bprm_execve+0xa6e/0x1700 fs/exec.c:1892 do_execveat_common+0x51b/0x6c0 fs/exec.c:1998 do_execveat fs/exec.c:2083 [inline] __do_sys_execveat fs/exec.c:2157 [inline] __se_sys_execveat fs/exec.c:2151 [inline] __x64_sys_execveat+0xc4/0xe0 fs/exec.c:2151 do_syscall_x64 arch/x86/entry/common.c:46 [inline] do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:76 entry_SYSCALL_64_after_hwframe+0x68/0xd2 RIP: 0033:0x7f0e8939ce59 Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 e8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f0e8a2b1028 EFLAGS: 00000246 ORIG_RAX: 0000000000000142 RAX: ffffffffffffffda RBX: 00007f0e89615fa0 RCX: 00007f0e8939ce59 RDX: 0000000000000000 RSI: 0000200000000280 RDI: ffffffffffffff9c RBP: 00007f0e89432d6f R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f0e89616038 R14: 00007f0e89615fa0 R15: 00007fff00d27828 Allocated by task 969: kasan_save_stack mm/kasan/common.c:46 [inline] kasan_set_track+0x4e/0x70 mm/kasan/common.c:53 __kasan_slab_alloc+0x6c/0x80 mm/kasan/common.c:329 kasan_slab_alloc include/linux/kasan.h:188 [inline] slab_post_alloc_hook+0x6e/0x4b0 mm/slab.h:767 slab_alloc_node mm/slub.c:3495 [inline] slab_alloc mm/slub.c:3503 [inline] __kmem_cache_alloc_lru mm/slub.c:3510 [inline] kmem_cache_alloc+0x11a/0x2d0 mm/slub.c:3519 dst_alloc+0x105/0x170 net/core/dst.c:90 ip6_dst_alloc net/ipv6/route.c:344 [inline] icmp6_dst_alloc+0x7b/0x400 net/ipv6/route.c:3317 mld_sendpack+0x6bd/0xd50 net/ipv6/mcast.c:1812 mld_send_cr net/ipv6/mcast.c:2124 [inline] mld_ifc_work+0x835/0xb40 net/ipv6/mcast.c:2654 process_one_work kernel/workqueue.c:2653 [inline] process_scheduled_works+0xa5d/0x15d0 kernel/workqueue.c:2730 worker_thread+0xa55/0xfc0 kernel/workqueue.c:2811 kthread+0x2fa/0x390 kernel/kthread.c:388 ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:152 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:293 Freed by task 9449: kasan_save_stack mm/kasan/common.c:46 [inline] kasan_set_track+0x4e/0x70 mm/kasan/common.c:53 kasan_save_free_info+0x2e/0x50 mm/kasan/generic.c:522 ____kasan_slab_free+0x126/0x1e0 mm/kasan/common.c:237 kasan_slab_free include/linux/kasan.h:164 [inline] slab_free_hook mm/slub.c:1811 [inline] slab_free_freelist_hook+0x130/0x1a0 mm/slub.c:1837 slab_free mm/slub.c:3830 [inline] kmem_cache_free+0xf8/0x270 mm/slub.c:3852 dst_destroy+0x233/0x340 net/core/dst.c:122 rcu_do_batch kernel/rcu/tree.c:2194 [inline] rcu_core+0xcfb/0x1770 kernel/rcu/tree.c:2467 handle_softirqs+0x280/0x820 kernel/softirq.c:578 __do_softirq kernel/softirq.c:612 [inline] invoke_softirq kernel/softirq.c:452 [inline] __irq_exit_rcu+0xd3/0x190 kernel/softirq.c:661 irq_exit_rcu+0x9/0x20 kernel/softirq.c:673 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1088 [inline] sysvec_apic_timer_interrupt+0xa4/0xc0 arch/x86/kernel/apic/apic.c:1088 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:687 Last potentially related work creation: kasan_save_stack+0x3e/0x60 mm/kasan/common.c:46 __kasan_record_aux_stack+0xaf/0xc0 mm/kasan/generic.c:492 __call_rcu_common kernel/rcu/tree.c:2721 [inline] call_rcu+0x153/0x950 kernel/rcu/tree.c:2837 refdst_drop include/net/dst.h:270 [inline] skb_dst_drop include/net/dst.h:282 [inline] __dev_queue_xmit+0x97a/0x3660 net/core/dev.c:4405 dev_queue_xmit include/linux/netdevice.h:3113 [inline] neigh_hh_output include/net/neighbour.h:527 [inline] neigh_output include/net/neighbour.h:541 [inline] ip6_finish_output2+0xe06/0x1630 net/ipv6/ip6_output.c:141 dst_output include/net/dst.h:467 [inline] NF_HOOK+0x167/0x4a0 include/linux/netfilter.h:304 mld_sendpack+0x7f5/0xd50 net/ipv6/mcast.c:1823 mld_send_cr net/ipv6/mcast.c:2124 [inline] mld_ifc_work+0x835/0xb40 net/ipv6/mcast.c:2654 process_one_work kernel/workqueue.c:2653 [inline] process_scheduled_works+0xa5d/0x15d0 kernel/workqueue.c:2730 worker_thread+0xa55/0xfc0 kernel/workqueue.c:2811 kthread+0x2fa/0x390 kernel/kthread.c:388 ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:152 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:293 The buggy address belongs to the object at ffff88806495d000 which belongs to the cache ip6_dst_cache of size 232 The buggy address is located 0 bytes inside of freed 232-byte region [ffff88806495d000, ffff88806495d0e8) The buggy address belongs to the physical page: page:ffffea0001925740 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x6495d memcg:ffff888024d14381 flags: 0xfff00000000800(slab|node=0|zone=1|lastcpupid=0x7ff) page_type: 0xffffffff() raw: 00fff00000000800 ffff88802c5a4000 dead000000000122 0000000000000000 raw: 0000000000000000 00000000000c000c 00000001ffffffff ffff888024d14381 page dumped because: kasan: bad access detected page_owner tracks the page as allocated page last allocated via order 0, migratetype Unmovable, gfp_mask 0x112820(GFP_ATOMIC|__GFP_NOWARN|__GFP_NORETRY|__GFP_HARDWALL), pid 969, tgid 969 (kworker/0:2), ts 454130154395, free_ts 451919348157 set_page_owner include/linux/page_owner.h:31 [inline] post_alloc_hook+0x1c1/0x200 mm/page_alloc.c:1581 prep_new_page mm/page_alloc.c:1588 [inline] get_page_from_freelist+0x1951/0x19e0 mm/page_alloc.c:3220 __alloc_pages+0x1f0/0x460 mm/page_alloc.c:4500 alloc_slab_page+0x5d/0x160 mm/slub.c:1881 allocate_slab mm/slub.c:2028 [inline] new_slab+0x87/0x2d0 mm/slub.c:2081 ___slab_alloc+0xc5d/0x12f0 mm/slub.c:3253 __slab_alloc mm/slub.c:3339 [inline] __slab_alloc_node mm/slub.c:3392 [inline] slab_alloc_node mm/slub.c:3485 [inline] slab_alloc mm/slub.c:3503 [inline] __kmem_cache_alloc_lru mm/slub.c:3510 [inline] kmem_cache_alloc+0x1b3/0x2d0 mm/slub.c:3519 dst_alloc+0x105/0x170 net/core/dst.c:90 ip6_dst_alloc net/ipv6/route.c:344 [inline] icmp6_dst_alloc+0x7b/0x400 net/ipv6/route.c:3317 mld_sendpack+0x6bd/0xd50 net/ipv6/mcast.c:1812 mld_send_cr net/ipv6/mcast.c:2124 [inline] mld_ifc_work+0x835/0xb40 net/ipv6/mcast.c:2654 process_one_work kernel/workqueue.c:2653 [inline] process_scheduled_works+0xa5d/0x15d0 kernel/workqueue.c:2730 worker_thread+0xa55/0xfc0 kernel/workqueue.c:2811 kthread+0x2fa/0x390 kernel/kthread.c:388 ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:152 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:293 page last free stack trace: reset_page_owner include/linux/page_owner.h:24 [inline] free_pages_prepare mm/page_alloc.c:1181 [inline] free_unref_page_prepare+0x7b2/0x8c0 mm/page_alloc.c:2365 free_unref_page+0x32/0x2e0 mm/page_alloc.c:2458 discard_slab mm/slub.c:2127 [inline] __unfreeze_partials+0x1cf/0x210 mm/slub.c:2667 put_cpu_partial+0x17c/0x250 mm/slub.c:2743 __slab_free+0x319/0x400 mm/slub.c:3700 qlink_free mm/kasan/quarantine.c:166 [inline] qlist_free_all+0x75/0xd0 mm/kasan/quarantine.c:185 kasan_quarantine_reduce+0x143/0x160 mm/kasan/quarantine.c:292 __kasan_slab_alloc+0x22/0x80 mm/kasan/common.c:306 kasan_slab_alloc include/linux/kasan.h:188 [inline] slab_post_alloc_hook+0x6e/0x4b0 mm/slab.h:767 slab_alloc_node mm/slub.c:3495 [inline] kmem_cache_alloc_node+0x14c/0x320 mm/slub.c:3540 __alloc_skb+0x103/0x2c0 net/core/skbuff.c:643 alloc_skb include/linux/skbuff.h:1316 [inline] alloc_skb_with_frags+0xca/0x7b0 net/core/skbuff.c:6340 sock_alloc_send_pskb+0x883/0x9a0 net/core/sock.c:2821 unix_dgram_sendmsg+0x5a2/0x16d0 net/unix/af_unix.c:2003 sock_sendmsg_nosec net/socket.c:730 [inline] __sock_sendmsg net/socket.c:745 [inline] __sys_sendto+0x4a9/0x6b0 net/socket.c:2200 __do_sys_sendto net/socket.c:2212 [inline] __se_sys_sendto net/socket.c:2208 [inline] __x64_sys_sendto+0xde/0xf0 net/socket.c:2208 Memory state around the buggy address: ffff88806495cf00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ffff88806495cf80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 >ffff88806495d000: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff88806495d080: fb fb fb fb fb fb fb fb fb fb fb fb fb fc fc fc ffff88806495d100: fc fc fc fc fc fc fc fc 00 00 00 00 00 00 00 00 ==================================================================