usercopy: Kernel memory exposure attempt detected from SLUB object 'skbuff_fclone_cache' (offset 340, size 4)!
------------[ cut here ]------------
kernel BUG at mm/usercopy.c:101!
invalid opcode: 0000 [#1] PREEMPT SMP KASAN
CPU: 1 PID: 1885 Comm: syz.4.400 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/09/2026
RIP: 0010:usercopy_abort+0x85/0x90 mm/usercopy.c:101
Code: 89 cb 49 c7 c6 c0 34 b1 85 4c 0f 44 f6 48 c7 c7 60 33 b1 85 4c 89 de 4c 89 c9 4d 89 d1 50 53 41 56 e8 17 bc ff ff 48 83 c4 18 <0f> 0b 00 00 cc cc 00 00 cc cc 00 90 90 90 90 90 90 90 90 90 90 90
RSP: 0018:ffffc900089d7498 EFLAGS: 00010282
RAX: 000000000000006e RBX: 0000000000000154 RCX: 1df4fdad3d06af00
RDX: 0000000000000000 RSI: 0000000080000000 RDI: 0000000000000000
RBP: ffffc900089d74a8 R08: ffffc900089d7187 R09: 1ffff9200113ae30
R10: dffffc0000000000 R11: fffff5200113ae31 R12: ffff8881001f0c00
R13: 0000000000000004 R14: ffffffff85b134c0 R15: 0000000000000154
FS: 00007f37fc3de6c0(0000) GS:ffff8881f6f00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f37fb5ea540 CR3: 000000013148f000 CR4: 00000000003506a0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
<TASK>
__check_heap_object+0xbe/0x110 mm/slub.c:4629
check_heap_object mm/usercopy.c:195 [inline]
__check_object_size+0x264/0x600 mm/usercopy.c:250
check_object_size include/linux/thread_info.h:199 [inline]
put_cmsg+0x1c4/0x5d0 net/core/scm.c:251
sock_recv_drops net/socket.c:989 [inline]
__sock_recv_cmsgs+0x459/0x5f0 net/socket.c:1008
sock_recv_cmsgs include/net/sock.h:2867 [inline]
udp_recvmsg+0x925/0x1210 net/ipv4/udp.c:1889
inet_recvmsg+0x141/0x480 net/ipv4/af_inet.c:875
____sys_recvmsg+0x2d6/0x5c0 net/socket.c:-1
___sys_recvmsg+0x210/0x590 net/socket.c:2769
do_recvmmsg+0x370/0x7e0 net/socket.c:2863
__sys_recvmmsg net/socket.c:2942 [inline]
__do_sys_recvmmsg net/socket.c:2965 [inline]
__se_sys_recvmmsg net/socket.c:2958 [inline]
__x64_sys_recvmmsg+0x195/0x250 net/socket.c:2958
x64_sys_call+0x3e7/0x9a0 arch/x86/include/generated/asm/syscalls_64.h:300
do_syscall_x64 arch/x86/entry/common.c:46 [inline]
do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:76
entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7f37fb59ce59
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:00007f37fc3de028 EFLAGS: 00000246
ORIG_RAX: 000000000000012b
RAX: ffffffffffffffda RBX: 00007f37fb816090 RCX: 00007f37fb59ce59
RDX: 0000000000000001 RSI: 0000200000009680 RDI: 0000000000000004
RBP: 00007f37fb632e6f R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000010103 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f37fb816128 R14: 00007f37fb816090 R15: 00007ffceb4e0ad8
</TASK>
Modules linked in:
---[ end trace 0000000000000000 ]---
RIP: 0010:usercopy_abort+0x85/0x90 mm/usercopy.c:101
Code: 89 cb 49 c7 c6 c0 34 b1 85 4c 0f 44 f6 48 c7 c7 60 33 b1 85 4c 89 de 4c 89 c9 4d 89 d1 50 53 41 56 e8 17 bc ff ff 48 83 c4 18 <0f> 0b 00 00 cc cc 00 00 cc cc 00 90 90 90 90 90 90 90 90 90 90 90
RSP: 0018:ffffc900089d7498 EFLAGS: 00010282
RAX: 000000000000006e RBX: 0000000000000154 RCX: 1df4fdad3d06af00
RDX: 0000000000000000 RSI: 0000000080000000 RDI: 0000000000000000
RBP: ffffc900089d74a8 R08: ffffc900089d7187 R09: 1ffff9200113ae30
R10: dffffc0000000000 R11: fffff5200113ae31 R12: ffff8881001f0c00
R13: 0000000000000004 R14: ffffffff85b134c0 R15: 0000000000000154
FS: 00007f37fc3de6c0(0000) GS:ffff8881f6e00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f5410fea540 CR3: 000000013148f000 CR4: 00000000003506b0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400