[syzbot] [bpf?] KMSAN: uninit-value in trie_lookup_elem

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: 741e9d668aa5 Merge tag 'scsi-misc' of git://git.kernel.org..
git tree: upstream
console+strace: https://syzkaller.appspot.com/x/log.txt?x=13ec5ac9180000
kernel config: https://syzkaller.appspot.com/x/.config?x=48bb382b96e7eda7
dashboard link: https://syzkaller.appspot.com/bug?extid=d2b113dc9fea5e1d2848
compiler: Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40
syz repro: https://syzkaller.appspot.com/x/repro.syz?x=129b7946180000
C reproducer: https://syzkaller.appspot.com/x/repro.c?x=17be1546180000

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/20ec6fc7fdfe/disk-741e9d66.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/81cd64abe7a8/vmlinux-741e9d66.xz
kernel image: https://storage.googleapis.com/syzbot-assets/180340ffa1c7/bzImage-741e9d66.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+d2b113...@syzkaller.appspotmail.com

=====================================================
BUG: KMSAN: uninit-value in trie_lookup_elem+0x4b9/0x510 kernel/bpf/lpm_trie.c:234
trie_lookup_elem+0x4b9/0x510 kernel/bpf/lpm_trie.c:234
____bpf_map_lookup_elem kernel/bpf/helpers.c:42 [inline]
bpf_map_lookup_elem+0x5c/0x80 kernel/bpf/helpers.c:38
___bpf_prog_run+0x13fe/0xe0f0 kernel/bpf/core.c:1997
__bpf_prog_run32+0xb2/0xe0 kernel/bpf/core.c:2236
bpf_dispatcher_nop_func include/linux/bpf.h:1234 [inline]
__bpf_prog_run include/linux/filter.h:657 [inline]
bpf_prog_run include/linux/filter.h:664 [inline]
__bpf_trace_run kernel/trace/bpf_trace.c:2381 [inline]
bpf_trace_run2+0x116/0x300 kernel/trace/bpf_trace.c:2420
__bpf_trace_skb_copy_datagram_iovec+0x2c/0x40 include/trace/events/skb.h:73
trace_skb_copy_datagram_iovec include/trace/events/skb.h:73 [inline]
skb_copy_datagram_iter+0x15e/0x200 net/core/datagram.c:545
skb_copy_datagram_msg include/linux/skbuff.h:4045 [inline]
tcp_recvmsg_locked+0xcf6/0x3680 net/ipv4/tcp.c:2500
tcp_recvmsg+0x279/0xad0 net/ipv4/tcp.c:2578
inet_recvmsg+0x167/0x6a0 net/ipv4/af_inet.c:883
sock_recvmsg_nosec net/socket.c:1046 [inline]
sock_recvmsg+0x235/0x340 net/socket.c:1068
sock_read_iter+0x333/0x3c0 net/socket.c:1138
call_read_iter include/linux/fs.h:2102 [inline]
new_sync_read fs/read_write.c:395 [inline]
vfs_read+0xda3/0xef0 fs/read_write.c:476
ksys_read+0x20f/0x4c0 fs/read_write.c:619
__do_sys_read fs/read_write.c:629 [inline]
__se_sys_read fs/read_write.c:627 [inline]
__x64_sys_read+0x93/0xe0 fs/read_write.c:627
do_syscall_64+0xd5/0x1f0
entry_SYSCALL_64_after_hwframe+0x6d/0x75

Local variable stack created at:
__bpf_prog_run32+0x43/0xe0 kernel/bpf/core.c:2236
bpf_dispatcher_nop_func include/linux/bpf.h:1234 [inline]
__bpf_prog_run include/linux/filter.h:657 [inline]
bpf_prog_run include/linux/filter.h:664 [inline]
__bpf_trace_run kernel/trace/bpf_trace.c:2381 [inline]
bpf_trace_run2+0x116/0x300 kernel/trace/bpf_trace.c:2420

CPU: 0 PID: 5010 Comm: sshd Not tainted 6.8.0-syzkaller-11339-g741e9d668aa5 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/29/2024
=====================================================


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