==================================================================
BUG: KASAN: use-after-free in cpu_map_generic_redirect+0x1b9/0x5d0 kernel/bpf/cpumap.c:786
Read of size 8 at addr ffff88801ef6b218 by task kworker/0:8/4334

CPU: 0 PID: 4334 Comm: kworker/0:8 Not tainted 5.15.178-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025
Workqueue: wg-crypt-wg0 wg_packet_tx_worker
Call Trace:
 <IRQ>
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0x1e3/0x2d0 lib/dump_stack.c:106
 print_address_description+0x63/0x3b0 mm/kasan/report.c:248
 __kasan_report mm/kasan/report.c:434 [inline]
 kasan_report+0x16b/0x1c0 mm/kasan/report.c:451
 cpu_map_generic_redirect+0x1b9/0x5d0 kernel/bpf/cpumap.c:786
 xdp_do_generic_redirect_map net/core/filter.c:4189 [inline]
 xdp_do_generic_redirect+0x401/0x850 net/core/filter.c:4236
 do_xdp_generic+0x4f5/0x6c0 net/core/dev.c:4911
 __netif_receive_skb_core+0x1bf1/0x3df0 net/core/dev.c:5316
 __netif_receive_skb_one_core net/core/dev.c:5491 [inline]
 __netif_receive_skb+0x11c/0x530 net/core/dev.c:5607
 process_backlog+0x363/0x7f0 net/core/dev.c:6484
 __napi_poll+0xc7/0x440 net/core/dev.c:7043
 napi_poll net/core/dev.c:7110 [inline]
 net_rx_action+0x617/0xda0 net/core/dev.c:7200
 handle_softirqs+0x3a7/0x930 kernel/softirq.c:558
 do_softirq+0x162/0x240 kernel/softirq.c:459
 </IRQ>
 <TASK>
 __local_bh_enable_ip+0x1b1/0x1f0 kernel/softirq.c:383
 wg_socket_send_skb_to_peer+0x172/0x1d0 drivers/net/wireguard/socket.c:184
 wg_packet_create_data_done drivers/net/wireguard/send.c:251 [inline]
 wg_packet_tx_worker+0x1a1/0x7a0 drivers/net/wireguard/send.c:276
 process_one_work+0x8a1/0x10c0 kernel/workqueue.c:2310
 worker_thread+0xaca/0x1280 kernel/workqueue.c:2457
 kthread+0x3f6/0x4f0 kernel/kthread.c:334
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287
 </TASK>

Allocated by task 7633:
 kasan_save_stack mm/kasan/common.c:38 [inline]
 kasan_set_track mm/kasan/common.c:46 [inline]
 set_alloc_info mm/kasan/common.c:434 [inline]
 ____kasan_kmalloc+0xba/0xf0 mm/kasan/common.c:513
 kasan_kmalloc include/linux/kasan.h:264 [inline]
 __kmalloc_node+0x199/0x390 mm/slub.c:4455
 kmalloc_node include/linux/slab.h:614 [inline]
 bpf_map_kmalloc_node+0xdb/0x160 kernel/bpf/syscall.c:430
 __cpu_map_entry_alloc kernel/bpf/cpumap.c:442 [inline]
 cpu_map_update_elem+0x273/0xe50 kernel/bpf/cpumap.c:600
 map_update_elem+0x6a0/0x7c0 kernel/bpf/syscall.c:1185
 __sys_bpf+0x2fd/0x670 kernel/bpf/syscall.c:4644
 __do_sys_bpf kernel/bpf/syscall.c:4760 [inline]
 __se_sys_bpf kernel/bpf/syscall.c:4758 [inline]
 __x64_sys_bpf+0x78/0x90 kernel/bpf/syscall.c:4758
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x3b/0xb0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x66/0xd0

Last potentially related work creation:
 kasan_save_stack+0x36/0x60 mm/kasan/common.c:38
 kasan_record_aux_stack+0xba/0x100 mm/kasan/generic.c:348
 insert_work+0x54/0x3e0 kernel/workqueue.c:1366
 __queue_work+0x963/0xd00 kernel/workqueue.c:1532
 queue_work_on+0x14b/0x250 kernel/workqueue.c:1559
 cpu_map_free+0xd7/0x1b0 kernel/bpf/cpumap.c:638
 process_one_work+0x8a1/0x10c0 kernel/workqueue.c:2310
 worker_thread+0xaca/0x1280 kernel/workqueue.c:2457
 kthread+0x3f6/0x4f0 kernel/kthread.c:334
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287

Second to last potentially related work creation:
 kasan_save_stack+0x36/0x60 mm/kasan/common.c:38
 kasan_record_aux_stack+0xba/0x100 mm/kasan/generic.c:348
 __call_rcu kernel/rcu/tree.c:3007 [inline]
 call_rcu+0x1c4/0xa70 kernel/rcu/tree.c:3087
 __cpu_map_entry_replace+0x74/0x170 kernel/bpf/cpumap.c:553
 cpu_map_free+0xd7/0x1b0 kernel/bpf/cpumap.c:638
 process_one_work+0x8a1/0x10c0 kernel/workqueue.c:2310
 worker_thread+0xaca/0x1280 kernel/workqueue.c:2457
 kthread+0x3f6/0x4f0 kernel/kthread.c:334
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287

The buggy address belongs to the object at ffff88801ef6b200
 which belongs to the cache kmalloc-cg-256 of size 256
The buggy address is located 24 bytes inside of
 256-byte region [ffff88801ef6b200, ffff88801ef6b300)
The buggy address belongs to the page:
page:ffffea00007bda80 refcount:1 mapcount:0 mapping:0000000000000000 index:0xffff88801ef6aa00 pfn:0x1ef6a
head:ffffea00007bda80 order:1 compound_mapcount:0
memcg:ffff888061d9cd01
flags: 0xfff00000010200(slab|head|node=0|zone=1|lastcpupid=0x7ff)
raw: 00fff00000010200 0000000000000000 0000000100000001 ffff888017442c80
raw: ffff88801ef6aa00 000000008010000c 00000001ffffffff ffff888061d9cd01
page dumped because: kasan: bad access detected
page_owner tracks the page as allocated
page last allocated via order 1, migratetype Unmovable, gfp_mask 0xd20c0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 4162, ts 55401907135, free_ts 25661301383
 prep_new_page mm/page_alloc.c:2426 [inline]
 get_page_from_freelist+0x3b78/0x3d40 mm/page_alloc.c:4192
 __alloc_pages+0x272/0x700 mm/page_alloc.c:5465
 alloc_slab_page mm/slub.c:1775 [inline]
 allocate_slab mm/slub.c:1912 [inline]
 new_slab+0xbb/0x4b0 mm/slub.c:1975
 ___slab_alloc+0x6f6/0xe10 mm/slub.c:3008
 __slab_alloc mm/slub.c:3095 [inline]
 slab_alloc_node mm/slub.c:3186 [inline]
 slab_alloc mm/slub.c:3228 [inline]
 __kmalloc+0x1c9/0x300 mm/slub.c:4403
 kmalloc include/linux/slab.h:596 [inline]
 kzalloc include/linux/slab.h:721 [inline]
 __seq_open_private+0x24/0x1b0 fs/seq_file.c:653
 kallsyms_open+0x24/0x280 kernel/kallsyms.c:819
 proc_reg_open+0x202/0x500 fs/proc/inode.c:524
 do_dentry_open+0x807/0xfb0 fs/open.c:826
 do_open fs/namei.c:3608 [inline]
 path_openat+0x2705/0x2f20 fs/namei.c:3742
 do_filp_open+0x21c/0x460 fs/namei.c:3769
 do_sys_openat2+0x13b/0x4f0 fs/open.c:1253
 do_sys_open fs/open.c:1269 [inline]
 __do_sys_openat fs/open.c:1285 [inline]
 __se_sys_openat fs/open.c:1280 [inline]
 __x64_sys_openat+0x243/0x290 fs/open.c:1280
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x3b/0xb0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x66/0xd0
page last free stack trace:
 reset_page_owner include/linux/page_owner.h:24 [inline]
 free_pages_prepare mm/page_alloc.c:1340 [inline]
 free_pcp_prepare mm/page_alloc.c:1391 [inline]
 free_unref_page_prepare+0xc34/0xcf0 mm/page_alloc.c:3317
 free_unref_page+0x95/0x2d0 mm/page_alloc.c:3396
 free_slab mm/slub.c:2015 [inline]
 discard_slab mm/slub.c:2021 [inline]
 __unfreeze_partials+0x1b7/0x210 mm/slub.c:2507
 put_cpu_partial+0x132/0x1a0 mm/slub.c:2587
 do_slab_free mm/slub.c:3487 [inline]
 ___cache_free+0xe3/0x100 mm/slub.c:3506
 qlist_free_all+0x36/0x90 mm/kasan/quarantine.c:176
 kasan_quarantine_reduce+0x162/0x180 mm/kasan/quarantine.c:283
 __kasan_slab_alloc+0x2f/0xc0 mm/kasan/common.c:444
 kasan_slab_alloc include/linux/kasan.h:254 [inline]
 slab_post_alloc_hook+0x53/0x380 mm/slab.h:519
 slab_alloc_node mm/slub.c:3220 [inline]
 __kmalloc_node+0x151/0x390 mm/slub.c:4451
 kmalloc_node include/linux/slab.h:614 [inline]
 kvmalloc_node+0x80/0x140 mm/util.c:619
 kvmalloc include/linux/mm.h:805 [inline]
 seq_buf_alloc fs/seq_file.c:38 [inline]
 seq_read_iter+0x1fe/0xd10 fs/seq_file.c:210
 call_read_iter include/linux/fs.h:2168 [inline]
 new_sync_read fs/read_write.c:404 [inline]
 vfs_read+0xa93/0xe10 fs/read_write.c:485
 ksys_read+0x1a2/0x2c0 fs/read_write.c:623
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x3b/0xb0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x66/0xd0

Memory state around the buggy address:
 ffff88801ef6b100: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
 ffff88801ef6b180: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
>ffff88801ef6b200: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                            ^
 ffff88801ef6b280: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff88801ef6b300: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
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