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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 lib/iov_iter.c:169 [inline]
BUG: KMSAN: kernel-infoleak in _copy_to_iter+0x420/0x1d00 lib/iov_iter.c:536
 instrument_copy_to_user include/linux/instrumented.h:114 [inline]
 copyout lib/iov_iter.c:169 [inline]
 _copy_to_iter+0x420/0x1d00 lib/iov_iter.c:536
 copy_to_iter include/linux/uio.h:206 [inline]
 memcpy_to_msg include/linux/skbuff.h:4024 [inline]
 raw_recvmsg+0x2b8/0x9e0 net/can/raw.c:918
 sock_recvmsg_nosec net/socket.c:1019 [inline]
 sock_recvmsg net/socket.c:1040 [inline]
 ____sys_recvmsg+0x283/0x7f0 net/socket.c:2722
 ___sys_recvmsg+0x223/0x840 net/socket.c:2764
 __sys_recvmsg net/socket.c:2794 [inline]
 __do_sys_recvmsg net/socket.c:2804 [inline]
 __se_sys_recvmsg net/socket.c:2801 [inline]
 __x64_sys_recvmsg+0x301/0x490 net/socket.c:2801
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x41/0xc0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x63/0xcd

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]
 alloc_skb_with_frags+0xbd/0xbb0 net/core/skbuff.c:6380
 sock_alloc_send_pskb+0xa80/0xbf0 net/core/sock.c:2729
 sock_alloc_send_skb include/net/sock.h:1860 [inline]
 j1939_sk_alloc_skb net/can/j1939/socket.c:864 [inline]
 j1939_sk_send_loop net/can/j1939/socket.c:1121 [inline]
 j1939_sk_sendmsg+0xd18/0x2570 net/can/j1939/socket.c:1256
 sock_sendmsg_nosec net/socket.c:724 [inline]
 sock_sendmsg net/socket.c:747 [inline]
 ____sys_sendmsg+0x999/0xd50 net/socket.c:2503
 ___sys_sendmsg+0x28d/0x3c0 net/socket.c:2557
 __sys_sendmsg net/socket.c:2586 [inline]
 __do_sys_sendmsg net/socket.c:2595 [inline]
 __se_sys_sendmsg net/socket.c:2593 [inline]
 __x64_sys_sendmsg+0x304/0x490 net/socket.c:2593
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x41/0xc0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x63/0xcd

Bytes 12-15 of 16 are uninitialized
Memory access of size 16 starts at ffff88807e344790
Data copied to user address 0000000020000340

CPU: 0 PID: 3082 Comm: syz-executor.2 Not tainted 6.4.0-rc4-syzkaller-g2741f1b02117 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/25/2023
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