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BUG: KMSAN: kernel-infoleak in instrument_copy_to_user include/linux/instrumented.h:114 [inline]
BUG: KMSAN: kernel-infoleak in _inline_copy_to_user include/linux/uaccess.h:196 [inline]
BUG: KMSAN: kernel-infoleak in _copy_to_user+0xcc/0x120 lib/usercopy.c:26
 instrument_copy_to_user include/linux/instrumented.h:114 [inline]
 _inline_copy_to_user include/linux/uaccess.h:196 [inline]
 _copy_to_user+0xcc/0x120 lib/usercopy.c:26
 copy_to_user include/linux/uaccess.h:225 [inline]
 move_addr_to_user+0x29c/0x410 net/socket.c:293
 ____sys_recvmsg+0x232/0x610 net/socket.c:2841
 ___sys_recvmsg+0x20b/0x850 net/socket.c:2876
 do_recvmmsg+0x40e/0xdf0 net/socket.c:2971
 __sys_recvmmsg net/socket.c:3045 [inline]
 __do_sys_recvmmsg net/socket.c:3068 [inline]
 __se_sys_recvmmsg net/socket.c:3061 [inline]
 __x64_sys_recvmmsg+0x383/0x500 net/socket.c:3061
 x64_sys_call+0x2f74/0x3e20 arch/x86/include/generated/asm/syscalls_64.h:300
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xd9/0x210 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

Uninit was stored to memory at:
 skb_copy_from_linear_data_offset include/linux/skbuff.h:4266 [inline]
 nr_recvmsg+0x59b/0x790 net/netrom/af_netrom.c:1196
 sock_recvmsg_nosec net/socket.c:1065 [inline]
 sock_recvmsg+0x2dc/0x390 net/socket.c:1087
 ____sys_recvmsg+0x193/0x610 net/socket.c:2834
 ___sys_recvmsg+0x20b/0x850 net/socket.c:2876
 do_recvmmsg+0x40e/0xdf0 net/socket.c:2971
 __sys_recvmmsg net/socket.c:3045 [inline]
 __do_sys_recvmmsg net/socket.c:3068 [inline]
 __se_sys_recvmmsg net/socket.c:3061 [inline]
 __x64_sys_recvmmsg+0x383/0x500 net/socket.c:3061
 x64_sys_call+0x2f74/0x3e20 arch/x86/include/generated/asm/syscalls_64.h:300
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xd9/0x210 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

Uninit was created at:
 slab_post_alloc_hook mm/slub.c:4186 [inline]
 slab_alloc_node mm/slub.c:4229 [inline]
 kmem_cache_alloc_node_noprof+0x818/0xf00 mm/slub.c:4281
 kmalloc_reserve+0x13c/0x4b0 net/core/skbuff.c:578
 __alloc_skb+0x347/0x7d0 net/core/skbuff.c:669
 alloc_skb include/linux/skbuff.h:1336 [inline]
 nr_loopback_queue+0x5f/0x400 net/netrom/nr_loopback.c:34
 nr_route_frame+0x264/0xff0 net/netrom/nr_route.c:777
 nr_transmit_buffer+0x1ab/0x2f0 net/netrom/nr_out.c:209
 nr_send_iframe net/netrom/nr_out.c:94 [inline]
 nr_kick+0x5b0/0x940 net/netrom/nr_out.c:166
 nr_output+0x7a0/0x7d0 net/netrom/nr_out.c:72
 nr_sendmsg+0xb10/0xe30 net/netrom/af_netrom.c:1143
 sock_sendmsg_nosec net/socket.c:714 [inline]
 __sock_sendmsg+0x333/0x3d0 net/socket.c:729
 ____sys_sendmsg+0x7e0/0xd80 net/socket.c:2614
 ___sys_sendmsg+0x271/0x3b0 net/socket.c:2668
 __sys_sendmsg net/socket.c:2700 [inline]
 __do_sys_sendmsg net/socket.c:2705 [inline]
 __se_sys_sendmsg net/socket.c:2703 [inline]
 __x64_sys_sendmsg+0x211/0x3e0 net/socket.c:2703
 x64_sys_call+0x1dfd/0x3e20 arch/x86/include/generated/asm/syscalls_64.h:47
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xd9/0x210 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

Bytes 2-8 of 16 are uninitialized
Memory access of size 16 starts at ffff88803b24ba38
Data copied to user address 0000200000000040

CPU: 1 UID: 0 PID: 11108 Comm: syz.0.1433 Not tainted 6.16.0-syzkaller-10499-g89748acdf226 #0 PREEMPT(none) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025
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