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BUG: KASAN: use-after-free in skb_headlen include/linux/skbuff.h:2395 [inline]
BUG: KASAN: use-after-free in __skb_datagram_iter+0x703/0x780 net/core/datagram.c:411
Read of size 4 at addr ffff888112155a70 by task syz-executor.0/450

CPU: 1 PID: 450 Comm: syz-executor.0 Not tainted 6.1.57-syzkaller-1150540-g401a2769d990 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 11/17/2023
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0x151/0x1b7 lib/dump_stack.c:106
 print_address_description mm/kasan/report.c:316 [inline]
 print_report+0x158/0x4e0 mm/kasan/report.c:427
 kasan_report+0x13c/0x170 mm/kasan/report.c:531
 __asan_report_load4_noabort+0x14/0x20 mm/kasan/report_generic.c:350
 skb_headlen include/linux/skbuff.h:2395 [inline]
 __skb_datagram_iter+0x703/0x780 net/core/datagram.c:411
 skb_copy_datagram_iter+0x43/0x180 net/core/datagram.c:527
 skb_copy_datagram_msg include/linux/skbuff.h:3931 [inline]
 unix_stream_read_actor+0x70/0xb0 net/unix/af_unix.c:2920
 unix_stream_recv_urg+0x1b4/0x300 net/unix/af_unix.c:2647
 unix_stream_read_generic+0x2140/0x2220 net/unix/af_unix.c:2726
 unix_stream_recvmsg+0x222/0x2b0 net/unix/af_unix.c:2957
 ____sys_recvmsg+0x285/0x530
 ___sys_recvmsg net/socket.c:2760 [inline]
 __sys_recvmsg+0x2e9/0x3d0 net/socket.c:2790
 __do_sys_recvmsg net/socket.c:2800 [inline]
 __se_sys_recvmsg net/socket.c:2797 [inline]
 __x64_sys_recvmsg+0x7f/0x90 net/socket.c:2797
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x3d/0xb0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x63/0xcd
RIP: 0033:0x7ff4e047cae9
Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 e1 20 00 00 90 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 b0 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007ff4e118c0c8 EFLAGS: 00000246 ORIG_RAX: 000000000000002f
RAX: ffffffffffffffda RBX: 00007ff4e059c120 RCX: 00007ff4e047cae9
RDX: 0000000040010083 RSI: 0000000020000140 RDI: 0000000000000004
RBP: 00007ff4e04c847a R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 000000000000006e R14: 00007ff4e059c120 R15: 00007ffc7d2c5648
 </TASK>

Allocated by task 449:
 kasan_save_stack mm/kasan/common.c:45 [inline]
 kasan_set_track+0x4b/0x70 mm/kasan/common.c:52
 kasan_save_alloc_info+0x1f/0x30 mm/kasan/generic.c:505
 __kasan_slab_alloc+0x6c/0x80 mm/kasan/common.c:333
 kasan_slab_alloc include/linux/kasan.h:202 [inline]
 slab_post_alloc_hook+0x53/0x2c0 mm/slab.h:768
 slab_alloc_node mm/slub.c:3421 [inline]
 kmem_cache_alloc_node+0x18a/0x2d0 mm/slub.c:3466
 __alloc_skb+0xcc/0x2d0 net/core/skbuff.c:505
 alloc_skb include/linux/skbuff.h:1283 [inline]
 alloc_skb_with_frags+0xa6/0x680 net/core/skbuff.c:6153
 sock_alloc_send_pskb+0x915/0xa50 net/core/sock.c:2744
 sock_alloc_send_skb include/net/sock.h:1921 [inline]
 queue_oob+0x102/0x8e0 net/unix/af_unix.c:2114
 unix_stream_sendmsg+0xe10/0x1070 net/unix/af_unix.c:2251
 sock_sendmsg_nosec net/socket.c:716 [inline]
 __sock_sendmsg net/socket.c:728 [inline]
 ____sys_sendmsg+0x5dc/0x9d0 net/socket.c:2499
 ___sys_sendmsg net/socket.c:2553 [inline]
 __sys_sendmsg+0x2a9/0x390 net/socket.c:2582
 __do_sys_sendmsg net/socket.c:2591 [inline]
 __se_sys_sendmsg net/socket.c:2589 [inline]
 __x64_sys_sendmsg+0x7f/0x90 net/socket.c:2589
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x3d/0xb0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x63/0xcd

Freed by task 449:
 kasan_save_stack mm/kasan/common.c:45 [inline]
 kasan_set_track+0x4b/0x70 mm/kasan/common.c:52
 kasan_save_free_info+0x2b/0x40 mm/kasan/generic.c:516
 ____kasan_slab_free+0x131/0x180 mm/kasan/common.c:241
 __kasan_slab_free+0x11/0x20 mm/kasan/common.c:249
 kasan_slab_free include/linux/kasan.h:178 [inline]
 slab_free_hook mm/slub.c:1745 [inline]
 slab_free_freelist_hook mm/slub.c:1771 [inline]
 slab_free mm/slub.c:3684 [inline]
 kmem_cache_free+0x291/0x510 mm/slub.c:3706
 kfree_skbmem+0x104/0x170
 __kfree_skb net/core/skbuff.c:871 [inline]
 consume_skb+0xb4/0x250 net/core/skbuff.c:1035
 queue_oob+0x52c/0x8e0 net/unix/af_unix.c:2145
 unix_stream_sendmsg+0xe10/0x1070 net/unix/af_unix.c:2251
 sock_sendmsg_nosec net/socket.c:716 [inline]
 __sock_sendmsg net/socket.c:728 [inline]
 ____sys_sendmsg+0x5dc/0x9d0 net/socket.c:2499
 ___sys_sendmsg net/socket.c:2553 [inline]
 __sys_sendmsg+0x2a9/0x390 net/socket.c:2582
 __do_sys_sendmsg net/socket.c:2591 [inline]
 __se_sys_sendmsg net/socket.c:2589 [inline]
 __x64_sys_sendmsg+0x7f/0x90 net/socket.c:2589
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x3d/0xb0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x63/0xcd

The buggy address belongs to the object at ffff888112155a00
 which belongs to the cache skbuff_head_cache of size 256
The buggy address is located 112 bytes inside of
 256-byte region [ffff888112155a00, ffff888112155b00)

The buggy address belongs to the physical page:
page:ffffea0004485540 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x112155
flags: 0x4000000000000200(slab|zone=1)
raw: 4000000000000200 ffffea0004485580 dead000000000003 ffff88810025ac00
raw: 0000000000000000 00000000000c000c 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 0x12cc0(GFP_KERNEL|__GFP_NOWARN|__GFP_NORETRY), pid 110, tgid 110 (udevd), ts 4168519816, free_ts 0
 set_page_owner include/linux/page_owner.h:33 [inline]
 post_alloc_hook+0x213/0x220 mm/page_alloc.c:2566
 prep_new_page+0x1b/0x110 mm/page_alloc.c:2573
 get_page_from_freelist+0x27ea/0x2870 mm/page_alloc.c:4397
 __alloc_pages+0x3a1/0x780 mm/page_alloc.c:5684
 alloc_slab_page+0x6c/0xf0
 allocate_slab mm/slub.c:1962 [inline]
 new_slab+0x90/0x3e0 mm/slub.c:2015
 ___slab_alloc+0x6f9/0xb80 mm/slub.c:3203
 __slab_alloc+0x5d/0xa0 mm/slub.c:3302
 slab_alloc_node mm/slub.c:3387 [inline]
 kmem_cache_alloc_node+0x1c9/0x2d0 mm/slub.c:3466
 __alloc_skb+0xcc/0x2d0 net/core/skbuff.c:505
 alloc_skb include/linux/skbuff.h:1283 [inline]
 netlink_alloc_large_skb net/netlink/af_netlink.c:1199 [inline]
 netlink_sendmsg+0x7a6/0xd30 net/netlink/af_netlink.c:1850
 sock_sendmsg_nosec net/socket.c:716 [inline]
 __sock_sendmsg net/socket.c:728 [inline]
 ____sys_sendmsg+0x5dc/0x9d0 net/socket.c:2499
 ___sys_sendmsg net/socket.c:2553 [inline]
 __sys_sendmsg+0x2a9/0x390 net/socket.c:2582
 __do_sys_sendmsg net/socket.c:2591 [inline]
 __se_sys_sendmsg net/socket.c:2589 [inline]
 __x64_sys_sendmsg+0x7f/0x90 net/socket.c:2589
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x3d/0xb0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x63/0xcd
page_owner free stack trace missing

Memory state around the buggy address:
 ffff888112155900: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
 ffff888112155980: 00 00 00 00 00 00 00 00 fc fc fc fc fc fc fc fc
>ffff888112155a00: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                                                             ^
 ffff888112155a80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff888112155b00: fc fc fc fc fc fc fc fc 00 00 00 00 00 00 00 00
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