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BUG: KASAN: slab-out-of-bounds in is_tcf_tunnel_set include/net/tc_act/tc_tunnel_key.h:33 [inline]
BUG: KASAN: slab-out-of-bounds in tc_setup_flow_action+0x842/0x3280 net/sched/cls_api.c:3639
Read of size 8 at addr ffff8881262da0c0 by task syz.7.2944/10424

CPU: 0 PID: 10424 Comm: syz.7.2944 Tainted: G        W         syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026
Call Trace:
 __dump_stack+0x21/0x24 lib/dump_stack.c:77
 dump_stack_lvl+0x1a7/0x208 lib/dump_stack.c:118
 print_address_description+0x7f/0x2c0 mm/kasan/report.c:248
 __kasan_report mm/kasan/report.c:435 [inline]
 kasan_report+0xe2/0x130 mm/kasan/report.c:452
 __asan_report_load8_noabort+0x14/0x20 mm/kasan/report_generic.c:309
 is_tcf_tunnel_set include/net/tc_act/tc_tunnel_key.h:33 [inline]
 tc_setup_flow_action+0x842/0x3280 net/sched/cls_api.c:3639
 mall_replace_hw_filter+0x2cc/0x8a0 net/sched/cls_matchall.c:100
 mall_change+0x546/0x760 net/sched/cls_matchall.c:236
 tc_new_tfilter+0x1452/0x1a90 net/sched/cls_api.c:2134
 rtnetlink_rcv_msg+0x845/0xcc0 net/core/rtnetlink.c:5601
 netlink_rcv_skb+0x1f5/0x440 net/netlink/af_netlink.c:2503
 rtnetlink_rcv+0x1c/0x20 net/core/rtnetlink.c:5628
 netlink_unicast_kernel net/netlink/af_netlink.c:1314 [inline]
 netlink_unicast+0x876/0xa40 net/netlink/af_netlink.c:1340
 netlink_sendmsg+0x89c/0xb50 net/netlink/af_netlink.c:1914
 sock_sendmsg_nosec net/socket.c:652 [inline]
 __sock_sendmsg net/socket.c:664 [inline]
 ____sys_sendmsg+0x5b7/0x8f0 net/socket.c:2376
 ___sys_sendmsg+0x236/0x2e0 net/socket.c:2430
 __sys_sendmsg net/socket.c:2459 [inline]
 __do_sys_sendmsg net/socket.c:2468 [inline]
 __se_sys_sendmsg net/socket.c:2466 [inline]
 __x64_sys_sendmsg+0x1f9/0x2c0 net/socket.c:2466
 do_syscall_64+0x31/0x40 arch/x86/entry/common.c:46
 entry_SYSCALL_64_after_hwframe+0x61/0xcb
RIP: 0033:0x7ff4a247c819
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:00007ff4a0ed7028 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 00007ff4a26f5fa0 RCX: 00007ff4a247c819
RDX: 0000000020000000 RSI: 0000200000000400 RDI: 0000000000000004
RBP: 00007ff4a2512c91 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007ff4a26f6038 R14: 00007ff4a26f5fa0 R15: 00007ffdc76aa4e8

Allocated by task 10424:
 kasan_save_stack mm/kasan/common.c:38 [inline]
 kasan_set_track mm/kasan/common.c:45 [inline]
 set_alloc_info mm/kasan/common.c:430 [inline]
 ____kasan_kmalloc mm/kasan/common.c:509 [inline]
 __kasan_kmalloc+0xda/0x110 mm/kasan/common.c:518
 kasan_kmalloc include/linux/kasan.h:254 [inline]
 __kmalloc+0x1a4/0x330 mm/slub.c:4038
 kmalloc include/linux/slab.h:560 [inline]
 kzalloc include/linux/slab.h:667 [inline]
 tcf_idr_create+0x5f/0x790 net/sched/act_api.c:430
 tcf_idr_create_from_flags+0x61/0x70 net/sched/act_api.c:488
 tcf_gact_init+0x2e6/0x560 net/sched/act_gact.c:102
 tcf_action_init_1+0x443/0x6e0 net/sched/act_api.c:1052
 tcf_action_init+0x227/0x780 net/sched/act_api.c:1109
 tcf_exts_validate+0x248/0x570 net/sched/cls_api.c:3086
 mall_set_parms+0x4b/0x410 net/sched/cls_matchall.c:171
 mall_change+0x47a/0x760 net/sched/cls_matchall.c:230
 tc_new_tfilter+0x1452/0x1a90 net/sched/cls_api.c:2134
 rtnetlink_rcv_msg+0x845/0xcc0 net/core/rtnetlink.c:5601
 netlink_rcv_skb+0x1f5/0x440 net/netlink/af_netlink.c:2503
 rtnetlink_rcv+0x1c/0x20 net/core/rtnetlink.c:5628
 netlink_unicast_kernel net/netlink/af_netlink.c:1314 [inline]
 netlink_unicast+0x876/0xa40 net/netlink/af_netlink.c:1340
 netlink_sendmsg+0x89c/0xb50 net/netlink/af_netlink.c:1914
 sock_sendmsg_nosec net/socket.c:652 [inline]
 __sock_sendmsg net/socket.c:664 [inline]
 ____sys_sendmsg+0x5b7/0x8f0 net/socket.c:2376
 ___sys_sendmsg+0x236/0x2e0 net/socket.c:2430
 __sys_sendmsg net/socket.c:2459 [inline]
 __do_sys_sendmsg net/socket.c:2468 [inline]
 __se_sys_sendmsg net/socket.c:2466 [inline]
 __x64_sys_sendmsg+0x1f9/0x2c0 net/socket.c:2466
 do_syscall_64+0x31/0x40 arch/x86/entry/common.c:46
 entry_SYSCALL_64_after_hwframe+0x61/0xcb

Last potentially related work creation:
 kasan_save_stack+0x3a/0x60 mm/kasan/common.c:38
 __kasan_record_aux_stack+0xd2/0x100 mm/kasan/generic.c:348
 kasan_record_aux_stack_noalloc+0xb/0x10 mm/kasan/generic.c:358
 kvfree_call_rcu+0x11c/0x650 kernel/rcu/tree.c:3539
 fib_rules_unregister+0x35c/0x380 net/core/fib_rules.c:207
 fib4_rules_exit+0x3b/0x40 net/ipv4/fib_rules.c:434
 ip_fib_net_exit+0x307/0x350 net/ipv4/fib_frontend.c:1592
 fib_net_exit+0x6c/0x80 net/ipv4/fib_frontend.c:1629
 ops_exit_list net/core/net_namespace.c:185 [inline]
 cleanup_net+0x58e/0xb80 net/core/net_namespace.c:609
 process_one_work+0x6e1/0xba0 kernel/workqueue.c:2301
 worker_thread+0xa6a/0x13c0 kernel/workqueue.c:2447
 kthread+0x346/0x3d0 kernel/kthread.c:313
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:298

The buggy address belongs to the object at ffff8881262da000
 which belongs to the cache kmalloc-192 of size 192
The buggy address is located 0 bytes to the right of
 192-byte region [ffff8881262da000, ffff8881262da0c0)
The buggy address belongs to the page:
page:ffffea000498b680 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x1262da
flags: 0x4000000000000200(slab)
raw: 4000000000000200 ffffea0004a1eb40 0000000400000004 ffff888100043380
raw: 0000000000000000 0000000080100010 00000001ffffffff 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 0x112a20(GFP_ATOMIC|__GFP_NOWARN|__GFP_NORETRY|__GFP_HARDWALL), pid 25, ts 535246088335, free_ts 535236315232
 set_page_owner include/linux/page_owner.h:35 [inline]
 post_alloc_hook mm/page_alloc.c:2456 [inline]
 prep_new_page+0x179/0x180 mm/page_alloc.c:2462
 get_page_from_freelist+0x223b/0x23d0 mm/page_alloc.c:4254
 __alloc_pages_nodemask+0x290/0x620 mm/page_alloc.c:5384
 alloc_slab_page mm/slub.c:-1 [inline]
 allocate_slab mm/slub.c:1813 [inline]
 new_slab+0x84/0x3f0 mm/slub.c:1874
 new_slab_objects mm/slub.c:2632 [inline]
 ___slab_alloc+0x2a6/0x450 mm/slub.c:2796
 __slab_alloc+0x63/0xa0 mm/slub.c:2836
 slab_alloc_node mm/slub.c:2918 [inline]
 slab_alloc mm/slub.c:2960 [inline]
 kmem_cache_alloc_trace+0x1b0/0x2e0 mm/slub.c:2977
 kmalloc include/linux/slab.h:555 [inline]
 kzalloc include/linux/slab.h:667 [inline]
 mca_alloc net/ipv6/mcast.c:853 [inline]
 __ipv6_dev_mc_inc+0x39e/0x9b0 net/ipv6/mcast.c:911
 ipv6_dev_mc_inc+0x1f/0x30 net/ipv6/mcast.c:935
 addrconf_join_solict net/ipv6/addrconf.c:2198 [inline]
 addrconf_dad_begin net/ipv6/addrconf.c:4028 [inline]
 addrconf_dad_work+0x3b5/0x1440 net/ipv6/addrconf.c:4155
 process_one_work+0x6e1/0xba0 kernel/workqueue.c:2301
 worker_thread+0xa6a/0x13c0 kernel/workqueue.c:2447
 kthread+0x346/0x3d0 kernel/kthread.c:313
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:298
page last free stack trace:
 reset_page_owner include/linux/page_owner.h:28 [inline]
 free_pages_prepare mm/page_alloc.c:1349 [inline]
 free_pcp_prepare mm/page_alloc.c:1421 [inline]
 free_unref_page_prepare+0x2b7/0x2d0 mm/page_alloc.c:3336
 free_unref_page mm/page_alloc.c:3391 [inline]
 free_the_page mm/page_alloc.c:5443 [inline]
 __free_pages+0x146/0x3b0 mm/page_alloc.c:5454
 free_pages+0x82/0x90 mm/page_alloc.c:5465
 _pgd_free arch/x86/mm/pgtable.c:420 [inline]
 pgd_free+0x187/0x1a0 arch/x86/mm/pgtable.c:476
 mm_free_pgd kernel/fork.c:675 [inline]
 __mmdrop+0xad/0x490 kernel/fork.c:726
 mmdrop include/linux/sched/mm.h:49 [inline]
 finish_task_switch+0x1e2/0x5a0 kernel/sched/core.c:3905
 context_switch kernel/sched/core.c:4051 [inline]
 __schedule+0xb5b/0x1320 kernel/sched/core.c:4806
 schedule+0x13c/0x1d0 kernel/sched/core.c:4884
 synchronize_rcu_expedited+0x4c7/0x640 kernel/rcu/tree_exp.h:946
 synchronize_net+0x28/0x40 net/core/dev.c:10685
 wg_socket_reinit+0x13c/0x210 drivers/net/wireguard/socket.c:434
 wg_socket_init+0x72c/0x8b0 drivers/net/wireguard/socket.c:412
 wg_open+0x18a/0x300 drivers/net/wireguard/device.c:50
 __dev_open+0x379/0x500 net/core/dev.c:1542
 __dev_change_flags+0x20d/0x6a0 net/core/dev.c:8547
 dev_change_flags+0x88/0x1a0 net/core/dev.c:8618

Memory state around the buggy address:
 ffff8881262d9f80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
 ffff8881262da000: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
>ffff8881262da080: 00 00 00 00 00 00 00 00 fc fc fc fc fc fc fc fc
                                           ^
 ffff8881262da100: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
 ffff8881262da180: 00 00 00 00 fc fc fc fc fc fc fc fc fc fc fc fc
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