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BUG: KMSAN: kernel-infoleak in instrument_copy_to_user include/linux/instrumented.h:131 [inline]
BUG: KMSAN: kernel-infoleak in _inline_copy_to_user include/linux/uaccess.h:205 [inline]
BUG: KMSAN: kernel-infoleak in _copy_to_user+0xcc/0x120 lib/usercopy.c:26
 instrument_copy_to_user include/linux/instrumented.h:131 [inline]
 _inline_copy_to_user include/linux/uaccess.h:205 [inline]
 _copy_to_user+0xcc/0x120 lib/usercopy.c:26
 copy_to_user include/linux/uaccess.h:236 [inline]
 move_addr_to_user+0x299/0x3f0 net/socket.c:306
 ____sys_recvmsg+0x232/0x620 net/socket.c:2819
 ___sys_recvmsg+0x20b/0x850 net/socket.c:2854
 do_recvmmsg+0x40e/0xdf0 net/socket.c:2949
 __sys_recvmmsg net/socket.c:3023 [inline]
 __do_sys_recvmmsg net/socket.c:3046 [inline]
 __se_sys_recvmmsg net/socket.c:3039 [inline]
 __x64_sys_recvmmsg+0x383/0x500 net/socket.c:3039
 x64_sys_call+0x96d/0x3ea0 arch/x86/include/generated/asm/syscalls_64.h:300
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0x134/0xf80 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:4354 [inline]
 nr_recvmsg+0x59b/0x790 net/netrom/af_netrom.c:1196
 sock_recvmsg_nosec net/socket.c:1078 [inline]
 sock_recvmsg+0x27b/0x310 net/socket.c:1100
 ____sys_recvmsg+0x193/0x620 net/socket.c:2812
 ___sys_recvmsg+0x20b/0x850 net/socket.c:2854
 do_recvmmsg+0x40e/0xdf0 net/socket.c:2949
 __sys_recvmmsg net/socket.c:3023 [inline]
 __do_sys_recvmmsg net/socket.c:3046 [inline]
 __se_sys_recvmmsg net/socket.c:3039 [inline]
 __x64_sys_recvmmsg+0x383/0x500 net/socket.c:3039
 x64_sys_call+0x96d/0x3ea0 arch/x86/include/generated/asm/syscalls_64.h:300
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0x134/0xf80 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:4545 [inline]
 slab_alloc_node mm/slub.c:4866 [inline]
 kmem_cache_alloc_node_noprof+0x3cd/0x12d0 mm/slub.c:4918
 kmalloc_reserve net/core/skbuff.c:613 [inline]
 __alloc_skb+0x855/0x1190 net/core/skbuff.c:713
 alloc_skb include/linux/skbuff.h:1383 [inline]
 nr_loopback_queue+0x5f/0x400 net/netrom/nr_loopback.c:34
 nr_route_frame+0x273/0x1450 net/netrom/nr_route.c:777
 nr_transmit_buffer+0x1ab/0x2f0 net/netrom/nr_out.c:211
 nr_send_iframe net/netrom/nr_out.c:96 [inline]
 nr_kick+0x5aa/0x940 net/netrom/nr_out.c:168
 nr_output+0x7b3/0x7e0 net/netrom/nr_out.c:74
 nr_sendmsg+0xa64/0xc80 net/netrom/af_netrom.c:1143
 sock_sendmsg_nosec net/socket.c:727 [inline]
 __sock_sendmsg net/socket.c:742 [inline]
 ____sys_sendmsg+0xf37/0xfd0 net/socket.c:2592
 ___sys_sendmsg+0x271/0x3b0 net/socket.c:2646
 __sys_sendmsg net/socket.c:2678 [inline]
 __do_sys_sendmsg net/socket.c:2683 [inline]
 __se_sys_sendmsg net/socket.c:2681 [inline]
 __x64_sys_sendmsg+0x211/0x3e0 net/socket.c:2681
 x64_sys_call+0x1e20/0x3ea0 arch/x86/include/generated/asm/syscalls_64.h:47
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0x134/0xf80 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 ffff88805499fa38
Data copied to user address 00002000000002c0

CPU: 1 UID: 0 PID: 9718 Comm: syz.4.551 Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026
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