================================================================== BUG: KASAN: slab-use-after-free in __list_del_entry_valid_or_report+0xb5/0x190 lib/list_debug.c:65 Read of size 8 at addr ffff8880321f8208 by task syz.4.93/6695 CPU: 1 UID: 0 PID: 6695 Comm: syz.4.93 Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025 Call Trace: dump_stack_lvl+0x189/0x250 lib/dump_stack.c:120 print_address_description mm/kasan/report.c:378 [inline] print_report+0xca/0x240 mm/kasan/report.c:482 kasan_report+0x118/0x150 mm/kasan/report.c:595 __list_del_entry_valid_or_report+0xb5/0x190 lib/list_debug.c:65 __list_del_entry_valid include/linux/list.h:132 [inline] __list_del_entry include/linux/list.h:223 [inline] list_del include/linux/list.h:237 [inline] flow_block_cb_setup_simple+0x62d/0x740 net/core/flow_offload.c:369 nft_block_offload_cmd net/netfilter/nf_tables_offload.c:397 [inline] nft_chain_offload_cmd+0x293/0x660 net/netfilter/nf_tables_offload.c:451 nft_flow_block_chain net/netfilter/nf_tables_offload.c:471 [inline] nft_flow_offload_chain net/netfilter/nf_tables_offload.c:513 [inline] nft_flow_rule_offload_commit+0x40d/0x1b60 net/netfilter/nf_tables_offload.c:592 nf_tables_commit+0x684/0xa290 net/netfilter/nf_tables_api.c:10923 nfnetlink_rcv_batch net/netfilter/nfnetlink.c:576 [inline] nfnetlink_rcv_skb_batch net/netfilter/nfnetlink.c:649 [inline] nfnetlink_rcv+0x1ac9/0x2590 net/netfilter/nfnetlink.c:667 netlink_unicast_kernel net/netlink/af_netlink.c:1318 [inline] netlink_unicast+0x82f/0x9e0 net/netlink/af_netlink.c:1344 netlink_sendmsg+0x805/0xb30 net/netlink/af_netlink.c:1894 sock_sendmsg_nosec net/socket.c:727 [inline] __sock_sendmsg+0x21c/0x270 net/socket.c:742 ____sys_sendmsg+0x505/0x820 net/socket.c:2592 ___sys_sendmsg+0x21f/0x2a0 net/socket.c:2646 __sys_sendmsg net/socket.c:2678 [inline] __do_sys_sendmsg net/socket.c:2683 [inline] __se_sys_sendmsg net/socket.c:2681 [inline] __x64_sys_sendmsg+0x19b/0x260 net/socket.c:2681 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f25ff18eba9 Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 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 a8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f26000bb038 EFLAGS: 00000246 ORIG_RAX: 000000000000002e RAX: ffffffffffffffda RBX: 00007f25ff3d5fa0 RCX: 00007f25ff18eba9 RDX: 000000000000c050 RSI: 0000200000000cc0 RDI: 0000000000000003 RBP: 00007f25ff211e19 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f25ff3d6038 R14: 00007f25ff3d5fa0 R15: 00007ffd358d8ae8 Allocated by task 6694: kasan_save_stack mm/kasan/common.c:56 [inline] kasan_save_track+0x3e/0x80 mm/kasan/common.c:77 poison_kmalloc_redzone mm/kasan/common.c:397 [inline] __kasan_kmalloc+0x93/0xb0 mm/kasan/common.c:414 kasan_kmalloc include/linux/kasan.h:262 [inline] __kmalloc_cache_noprof+0x3e2/0x700 mm/slub.c:5776 kmalloc_noprof include/linux/slab.h:957 [inline] kzalloc_noprof include/linux/slab.h:1094 [inline] flow_block_cb_alloc net/core/flow_offload.c:267 [inline] flow_block_cb_setup_simple+0x2a1/0x740 net/core/flow_offload.c:356 nft_block_offload_cmd net/netfilter/nf_tables_offload.c:397 [inline] nft_chain_offload_cmd+0x293/0x660 net/netfilter/nf_tables_offload.c:451 nft_flow_block_chain net/netfilter/nf_tables_offload.c:471 [inline] nft_flow_offload_chain net/netfilter/nf_tables_offload.c:513 [inline] nft_flow_rule_offload_commit+0x814/0x1b60 net/netfilter/nf_tables_offload.c:584 nf_tables_commit+0x684/0xa290 net/netfilter/nf_tables_api.c:10923 nfnetlink_rcv_batch net/netfilter/nfnetlink.c:576 [inline] nfnetlink_rcv_skb_batch net/netfilter/nfnetlink.c:649 [inline] nfnetlink_rcv+0x1ac9/0x2590 net/netfilter/nfnetlink.c:667 netlink_unicast_kernel net/netlink/af_netlink.c:1318 [inline] netlink_unicast+0x82f/0x9e0 net/netlink/af_netlink.c:1344 netlink_sendmsg+0x805/0xb30 net/netlink/af_netlink.c:1894 sock_sendmsg_nosec net/socket.c:727 [inline] __sock_sendmsg+0x21c/0x270 net/socket.c:742 ____sys_sendmsg+0x505/0x820 net/socket.c:2592 ___sys_sendmsg+0x21f/0x2a0 net/socket.c:2646 __sys_sendmsg net/socket.c:2678 [inline] __do_sys_sendmsg net/socket.c:2683 [inline] __se_sys_sendmsg net/socket.c:2681 [inline] __x64_sys_sendmsg+0x19b/0x260 net/socket.c:2681 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f Freed by task 6694: kasan_save_stack mm/kasan/common.c:56 [inline] kasan_save_track+0x3e/0x80 mm/kasan/common.c:77 kasan_save_free_info+0x46/0x50 mm/kasan/generic.c:584 poison_slab_object mm/kasan/common.c:252 [inline] __kasan_slab_free+0x5c/0x80 mm/kasan/common.c:284 kasan_slab_free include/linux/kasan.h:234 [inline] slab_free_hook mm/slub.c:2540 [inline] slab_free mm/slub.c:6668 [inline] kfree+0x1c0/0x660 mm/slub.c:6876 nft_flow_offload_unbind+0x3c0/0x440 net/netfilter/nf_tables_offload.c:344 nft_chain_offload_cmd+0x43f/0x660 net/netfilter/nf_tables_offload.c:-1 nft_flow_block_chain net/netfilter/nf_tables_offload.c:471 [inline] nft_flow_offload_chain net/netfilter/nf_tables_offload.c:513 [inline] nft_flow_rule_offload_commit+0x40d/0x1b60 net/netfilter/nf_tables_offload.c:592 nf_tables_commit+0x684/0xa290 net/netfilter/nf_tables_api.c:10923 nfnetlink_rcv_batch net/netfilter/nfnetlink.c:576 [inline] nfnetlink_rcv_skb_batch net/netfilter/nfnetlink.c:649 [inline] nfnetlink_rcv+0x1ac9/0x2590 net/netfilter/nfnetlink.c:667 netlink_unicast_kernel net/netlink/af_netlink.c:1318 [inline] netlink_unicast+0x82f/0x9e0 net/netlink/af_netlink.c:1344 netlink_sendmsg+0x805/0xb30 net/netlink/af_netlink.c:1894 sock_sendmsg_nosec net/socket.c:727 [inline] __sock_sendmsg+0x21c/0x270 net/socket.c:742 ____sys_sendmsg+0x505/0x820 net/socket.c:2592 ___sys_sendmsg+0x21f/0x2a0 net/socket.c:2646 __sys_sendmsg net/socket.c:2678 [inline] __do_sys_sendmsg net/socket.c:2683 [inline] __se_sys_sendmsg net/socket.c:2681 [inline] __x64_sys_sendmsg+0x19b/0x260 net/socket.c:2681 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f The buggy address belongs to the object at ffff8880321f8200 which belongs to the cache kmalloc-192 of size 192 The buggy address is located 8 bytes inside of freed 192-byte region [ffff8880321f8200, ffff8880321f82c0) The buggy address belongs to the physical page: page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x321f8 anon flags: 0xfff00000000000(node=0|zone=1|lastcpupid=0x7ff) page_type: f5(slab) raw: 00fff00000000000 ffff88813ffa63c0 0000000000000000 dead000000000001 raw: 0000000000000000 0000000080100010 00000000f5000000 0000000000000000 page dumped because: kasan: bad access detected page_owner tracks the page as allocated page last allocated via order 0, migratetype Unmovable, gfp_mask 0x52cc0(GFP_KERNEL|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP), pid 1, tgid 1 (swapper/0), ts 21331007972, free_ts 21280302495 set_page_owner include/linux/page_owner.h:32 [inline] post_alloc_hook+0x234/0x290 mm/page_alloc.c:1846 prep_new_page mm/page_alloc.c:1854 [inline] get_page_from_freelist+0x2365/0x2440 mm/page_alloc.c:3915 __alloc_frozen_pages_noprof+0x181/0x370 mm/page_alloc.c:5210 alloc_pages_mpol+0x232/0x4a0 mm/mempolicy.c:2486 alloc_slab_page mm/slub.c:3075 [inline] allocate_slab+0x86/0x3b0 mm/slub.c:3248 new_slab mm/slub.c:3302 [inline] ___slab_alloc+0xf2b/0x1960 mm/slub.c:4656 __slab_alloc+0x65/0x100 mm/slub.c:4779 __slab_alloc_node mm/slub.c:4855 [inline] slab_alloc_node mm/slub.c:5251 [inline] __kmalloc_cache_noprof+0x41e/0x700 mm/slub.c:5771 kmalloc_noprof include/linux/slab.h:957 [inline] kzalloc_noprof include/linux/slab.h:1094 [inline] call_usermodehelper_setup+0x8e/0x270 kernel/umh.c:362 kobject_uevent_env+0x658/0x9f0 lib/kobject_uevent.c:628 kernel_add_sysfs_param+0xb1/0xe0 kernel/params.c:816 param_sysfs_builtin+0x18a/0x230 kernel/params.c:851 param_sysfs_builtin_init+0x23/0x30 kernel/params.c:987 do_one_initcall+0x1fb/0x820 init/main.c:1378 do_initcall_level+0x104/0x190 init/main.c:1440 do_initcalls+0x59/0xa0 init/main.c:1456 page last free pid 10 tgid 10 stack trace: reset_page_owner include/linux/page_owner.h:25 [inline] free_pages_prepare mm/page_alloc.c:1395 [inline] __free_frozen_pages+0xbc8/0xd30 mm/page_alloc.c:2943 vfree+0x25a/0x400 mm/vmalloc.c:3466 delayed_vfree_work+0x55/0x80 mm/vmalloc.c:3385 process_one_work kernel/workqueue.c:3257 [inline] process_scheduled_works+0xad1/0x1770 kernel/workqueue.c:3340 worker_thread+0x8a0/0xda0 kernel/workqueue.c:3421 kthread+0x711/0x8a0 kernel/kthread.c:463 ret_from_fork+0x599/0xb30 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246 Memory state around the buggy address: ffff8880321f8100: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff8880321f8180: fb fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc >ffff8880321f8200: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff8880321f8280: fb fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc ffff8880321f8300: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ==================================================================