syzbot

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BUG: KASAN: slab-use-after-free in __sk_msg_recvmsg+0x19b/0xf30 net/core/skmsg.c:432
Read of size 8 at addr ffff88807ca99ab0 by task syz.0.35/5926

CPU: 1 UID: 0 PID: 5926 Comm: syz.0.35 Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/09/2026
Call Trace:
 <TASK>
 dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120
 print_address_description+0x55/0x1e0 mm/kasan/report.c:378
 print_report+0x58/0x70 mm/kasan/report.c:482
 kasan_report+0x117/0x150 mm/kasan/report.c:595
 __sk_msg_recvmsg+0x19b/0xf30 net/core/skmsg.c:432
 udp_bpf_recvmsg+0x18b/0xa90 net/ipv4/udp_bpf.c:83
 sock_recvmsg_nosec net/socket.c:1128 [inline]
 sock_recvmsg+0x155/0x1b0 net/socket.c:1148
 ____sys_recvmsg+0x1e6/0x4a0 net/socket.c:2904
 ___sys_recvmsg+0x213/0x5a0 net/socket.c:2946
 __sys_recvmsg net/socket.c:2979 [inline]
 __do_sys_recvmsg net/socket.c:2985 [inline]
 __se_sys_recvmsg net/socket.c:2982 [inline]
 __x64_sys_recvmsg+0x1ae/0x290 net/socket.c:2982
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0x174/0x580 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f4ce339ce59
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:00007f4ce4230028 EFLAGS: 00000246 ORIG_RAX: 000000000000002f
RAX: ffffffffffffffda RBX: 00007f4ce3616180 RCX: 00007f4ce339ce59
RDX: 0000000060000001 RSI: 00002000000018c0 RDI: 0000000000000003
RBP: 00007f4ce3432e6f R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f4ce3616218 R14: 00007f4ce3616180 R15: 00007ffc3a47d478
 </TASK>

Allocated by task 5924:
 kasan_save_stack mm/kasan/common.c:57 [inline]
 kasan_save_track+0x3e/0x80 mm/kasan/common.c:78
 poison_kmalloc_redzone mm/kasan/common.c:398 [inline]
 __kasan_kmalloc+0x93/0xb0 mm/kasan/common.c:415
 kasan_kmalloc include/linux/kasan.h:263 [inline]
 __kmalloc_cache_noprof+0x318/0x660 mm/slub.c:5451
 _kmalloc_noprof include/linux/slab.h:969 [inline]
 _kzalloc_noprof include/linux/slab.h:1286 [inline]
 alloc_sk_msg net/core/skmsg.c:526 [inline]
 sk_psock_skb_ingress_self+0x5e/0x320 net/core/skmsg.c:628
 sk_psock_verdict_apply net/core/skmsg.c:1028 [inline]
 sk_psock_verdict_recv+0xca9/0xeb0 net/core/skmsg.c:1222
 udp_read_skb+0x5f4/0x6d0 net/ipv4/udp.c:2022
 sk_psock_verdict_data_ready+0x25f/0x690 net/core/skmsg.c:1247
 __udp_enqueue_schedule_skb+0xc26/0x12d0 net/ipv4/udp.c:1745
 __udp_queue_rcv_skb net/ipv4/udp.c:2319 [inline]
 udp_queue_rcv_one_skb+0x750/0x10e0 net/ipv4/udp.c:2410
 __udp4_lib_mcast_deliver+0xace/0xb60 net/ipv4/udp.c:2522
 udp_rcv+0xd3e/0x1db0 net/ipv4/udp.c:2647
 ip_protocol_deliver_rcu+0x27e/0x440 net/ipv4/ip_input.c:207
 ip_local_deliver_finish+0x3bb/0x6f0 net/ipv4/ip_input.c:241
 NF_HOOK+0x336/0x3c0 include/linux/netfilter.h:318
 dst_input include/net/dst.h:481 [inline]
 ip_sublist_rcv_finish+0x1f0/0x240 net/ipv4/ip_input.c:623
 ip_list_rcv_finish net/ipv4/ip_input.c:667 [inline]
 ip_sublist_rcv+0x5cc/0xa70 net/ipv4/ip_input.c:683
 ip_list_rcv+0x3ec/0x440 net/ipv4/ip_input.c:717
 __netif_receive_skb_list_ptype net/core/dev.c:6250 [inline]
 __netif_receive_skb_list_core+0x804/0x830 net/core/dev.c:6296
 __netif_receive_skb_list net/core/dev.c:6348 [inline]
 netif_receive_skb_list_internal+0x995/0xcf0 net/core/dev.c:6439
 netif_receive_skb_list+0x55/0x450 net/core/dev.c:6491
 xdp_recv_frames net/bpf/test_run.c:268 [inline]
 xdp_test_run_batch net/bpf/test_run.c:349 [inline]
 bpf_test_run_xdp_live+0x1875/0x1c20 net/bpf/test_run.c:378
 bpf_prog_test_run_xdp+0x7d8/0x11d0 net/bpf/test_run.c:1429
 bpf_prog_test_run+0x2c5/0x340 kernel/bpf/syscall.c:4742
 __sys_bpf+0x643/0x950 kernel/bpf/syscall.c:6292
 __do_sys_bpf kernel/bpf/syscall.c:6387 [inline]
 __se_sys_bpf kernel/bpf/syscall.c:6385 [inline]
 __x64_sys_bpf+0x7c/0x90 kernel/bpf/syscall.c:6385
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0x174/0x580 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

Freed by task 5925:
 kasan_save_stack mm/kasan/common.c:57 [inline]
 kasan_save_track+0x3e/0x80 mm/kasan/common.c:78
 kasan_save_free_info+0x40/0x50 mm/kasan/generic.c:584
 poison_slab_object mm/kasan/common.c:253 [inline]
 __kasan_slab_free+0x5c/0x80 mm/kasan/common.c:285
 kasan_slab_free include/linux/kasan.h:235 [inline]
 slab_free_hook mm/slub.c:2700 [inline]
 slab_free mm/slub.c:6310 [inline]
 kfree+0x1c5/0x640 mm/slub.c:6625
 kfree_sk_msg include/linux/skmsg.h:425 [inline]
 __sk_msg_recvmsg+0xd2d/0xf30 net/core/skmsg.c:492
 udp_bpf_recvmsg+0x18b/0xa90 net/ipv4/udp_bpf.c:83
 sock_recvmsg_nosec net/socket.c:1128 [inline]
 sock_recvmsg+0x155/0x1b0 net/socket.c:1148
 ____sys_recvmsg+0x1e6/0x4a0 net/socket.c:2904
 ___sys_recvmsg+0x213/0x5a0 net/socket.c:2946
 __sys_recvmsg net/socket.c:2979 [inline]
 __do_sys_recvmsg net/socket.c:2985 [inline]
 __se_sys_recvmsg net/socket.c:2982 [inline]
 __x64_sys_recvmsg+0x1ae/0x290 net/socket.c:2982
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0x174/0x580 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

The buggy address belongs to the object at ffff88807ca99800
 which belongs to the cache kmalloc-1k of size 1024
The buggy address is located 688 bytes inside of
 freed 1024-byte region [ffff88807ca99800, ffff88807ca99c00)

The buggy address belongs to the physical page:
page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x7ca98
head: order:3 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0
flags: 0xfff00000000040(head|node=0|zone=1|lastcpupid=0x7ff)
page_type: f5(slab)
raw: 00fff00000000040 ffff88813fe1bdc0 dead000000000100 dead000000000122
raw: 0000000000000000 0000000800100010 00000000f5000000 0000000000000000
head: 00fff00000000040 ffff88813fe1bdc0 dead000000000100 dead000000000122
head: 0000000000000000 0000000800100010 00000000f5000000 0000000000000000
head: 00fff00000000003 fffffffffffffe01 00000000ffffffff 00000000ffffffff
head: ffffffffffffffff 0000000000000000 00000000ffffffff 0000000000000008
page dumped because: kasan: bad access detected
page_owner tracks the page as allocated
page last allocated via order 3, migratetype Unmovable, gfp_mask 0xd2820(GFP_ATOMIC|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 5924, tgid 5923 (syz.0.35), ts 78627258310, free_ts 78624233321
 set_page_owner include/linux/page_owner.h:32 [inline]
 post_alloc_hook+0x22d/0x280 mm/page_alloc.c:1853
 prep_new_page mm/page_alloc.c:1861 [inline]
 get_page_from_freelist+0x24ae/0x2530 mm/page_alloc.c:3941
 __alloc_frozen_pages_noprof+0x18d/0x380 mm/page_alloc.c:5221
 alloc_slab_page mm/slub.c:3289 [inline]
 allocate_slab+0x74/0x5d0 mm/slub.c:3404
 new_slab mm/slub.c:3447 [inline]
 refill_objects+0x328/0x3c0 mm/slub.c:7241
 refill_sheaf mm/slub.c:2827 [inline]
 __pcs_replace_empty_main+0x2e0/0x6b0 mm/slub.c:4692
 alloc_from_pcs mm/slub.c:4790 [inline]
 slab_alloc_node mm/slub.c:4924 [inline]
 __kmalloc_cache_noprof+0x388/0x660 mm/slub.c:5446
 _kmalloc_noprof include/linux/slab.h:969 [inline]
 _kzalloc_noprof include/linux/slab.h:1286 [inline]
 alloc_sk_msg net/core/skmsg.c:526 [inline]
 sk_psock_skb_ingress_self+0x5e/0x320 net/core/skmsg.c:628
 sk_psock_verdict_apply net/core/skmsg.c:1028 [inline]
 sk_psock_verdict_recv+0xca9/0xeb0 net/core/skmsg.c:1222
 udp_read_skb+0x5f4/0x6d0 net/ipv4/udp.c:2022
 sk_psock_verdict_data_ready+0x25f/0x690 net/core/skmsg.c:1247
 __udp_enqueue_schedule_skb+0xc26/0x12d0 net/ipv4/udp.c:1745
 __udp_queue_rcv_skb net/ipv4/udp.c:2319 [inline]
 udp_queue_rcv_one_skb+0x750/0x10e0 net/ipv4/udp.c:2410
 __udp4_lib_mcast_deliver+0xace/0xb60 net/ipv4/udp.c:2522
 udp_rcv+0xd3e/0x1db0 net/ipv4/udp.c:2647
 ip_protocol_deliver_rcu+0x27e/0x440 net/ipv4/ip_input.c:207
page last free pid 5924 tgid 5923 stack trace:
 reset_page_owner include/linux/page_owner.h:25 [inline]
 __free_pages_prepare mm/page_alloc.c:1397 [inline]
 __free_frozen_pages+0xc0d/0xd20 mm/page_alloc.c:2938
 bpf_check+0x39e1/0x4c30 kernel/bpf/verifier.c:20216
 bpf_prog_load+0x1419/0x1a10 kernel/bpf/syscall.c:3082
 __sys_bpf+0x618/0x950 kernel/bpf/syscall.c:6274
 __do_sys_bpf kernel/bpf/syscall.c:6387 [inline]
 __se_sys_bpf kernel/bpf/syscall.c:6385 [inline]
 __x64_sys_bpf+0x7c/0x90 kernel/bpf/syscall.c:6385
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0x174/0x580 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

Memory state around the buggy address:
 ffff88807ca99980: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff88807ca99a00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>ffff88807ca99a80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                                     ^
 ffff88807ca99b00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff88807ca99b80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
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