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BUG: KMSAN: kernel-infoleak in instrument_copy_to_user include/linux/instrumented.h:114 [inline]
BUG: KMSAN: kernel-infoleak in copyout+0xb8/0x100 lib/iov_iter.c:169
 instrument_copy_to_user include/linux/instrumented.h:114 [inline]
 copyout+0xb8/0x100 lib/iov_iter.c:169
 _copy_to_iter+0x6d8/0x1d00 lib/iov_iter.c:536
 copy_to_iter include/linux/uio.h:206 [inline]
 simple_copy_to_iter+0x68/0xa0 net/core/datagram.c:513
 __skb_datagram_iter+0x123/0xdc0 net/core/datagram.c:419
 skb_copy_datagram_iter+0x5c/0x200 net/core/datagram.c:527
 skb_copy_datagram_msg include/linux/skbuff.h:3950 [inline]
 nr_recvmsg+0x3f3/0x6a0 net/netrom/af_netrom.c:1181
 sock_recvmsg_nosec+0x7a/0x120 net/socket.c:1019
 ____sys_recvmsg+0x664/0x7f0 net/socket.c:2720
 ___sys_recvmsg+0x223/0x840 net/socket.c:2764
 do_recvmmsg+0x624/0xfd0 net/socket.c:2850
 __sys_recvmmsg+0x10a/0x430 net/socket.c:2937
 __do_compat_sys_recvmmsg_time32 net/compat.c:418 [inline]
 __se_compat_sys_recvmmsg_time32 net/compat.c:414 [inline]
 __ia32_compat_sys_recvmmsg_time32+0xf5/0x180 net/compat.c:414
 do_syscall_32_irqs_on arch/x86/entry/common.c:112 [inline]
 __do_fast_syscall_32+0xa2/0x100 arch/x86/entry/common.c:178
 do_fast_syscall_32+0x37/0x80 arch/x86/entry/common.c:203
 do_SYSENTER_32+0x1f/0x30 arch/x86/entry/common.c:246
 entry_SYSENTER_compat_after_hwframe+0x70/0x82

Uninit was stored to memory at:
 skb_copy_from_linear_data include/linux/skbuff.h:4071 [inline]
 nr_loopback_queue+0x10d/0x310 net/netrom/nr_loopback.c:35
 nr_route_frame+0x1f1/0xfc0 net/netrom/nr_route.c:776
 nr_transmit_buffer+0x187/0x2a0 net/netrom/nr_out.c:209
 nr_write_internal+0x81e/0xe30 net/netrom/nr_subr.c:205
 nr_establish_data_link+0x4f/0x80 net/netrom/nr_out.c:227
 nr_connect+0xb1e/0x1490 net/netrom/af_netrom.c:718
 __sys_connect_file net/socket.c:2003 [inline]
 __sys_connect+0x5f6/0x680 net/socket.c:2020
 __do_sys_connect net/socket.c:2030 [inline]
 __se_sys_connect net/socket.c:2027 [inline]
 __ia32_sys_connect+0x90/0xe0 net/socket.c:2027
 do_syscall_32_irqs_on arch/x86/entry/common.c:112 [inline]
 __do_fast_syscall_32+0xa2/0x100 arch/x86/entry/common.c:178
 do_fast_syscall_32+0x37/0x80 arch/x86/entry/common.c:203
 do_SYSENTER_32+0x1f/0x30 arch/x86/entry/common.c:246
 entry_SYSENTER_compat_after_hwframe+0x70/0x82

Uninit was created at:
 slab_post_alloc_hook+0x12d/0xb60 mm/slab.h:716
 slab_alloc_node mm/slub.c:3451 [inline]
 kmem_cache_alloc_node+0x535/0xa30 mm/slub.c:3496
 kmalloc_reserve+0x148/0x470 net/core/skbuff.c:568
 __alloc_skb+0x318/0x740 net/core/skbuff.c:654
 alloc_skb include/linux/skbuff.h:1288 [inline]
 nr_write_internal+0x15f/0xe30 net/netrom/nr_subr.c:144
 nr_establish_data_link+0x4f/0x80 net/netrom/nr_out.c:227
 nr_connect+0xb1e/0x1490 net/netrom/af_netrom.c:718
 __sys_connect_file net/socket.c:2003 [inline]
 __sys_connect+0x5f6/0x680 net/socket.c:2020
 __do_sys_connect net/socket.c:2030 [inline]
 __se_sys_connect net/socket.c:2027 [inline]
 __ia32_sys_connect+0x90/0xe0 net/socket.c:2027
 do_syscall_32_irqs_on arch/x86/entry/common.c:112 [inline]
 __do_fast_syscall_32+0xa2/0x100 arch/x86/entry/common.c:178
 do_fast_syscall_32+0x37/0x80 arch/x86/entry/common.c:203
 do_SYSENTER_32+0x1f/0x30 arch/x86/entry/common.c:246
 entry_SYSENTER_compat_after_hwframe+0x70/0x82

Bytes 37-242 of 243 are uninitialized
Memory access of size 243 starts at ffff8880a22d7400
Data copied to user address 0000000020000340

CPU: 0 PID: 5298 Comm: syz-executor.3 Not tainted 6.4.0-rc3-syzkaller-gf93f2feda5d6 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/28/2023
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