[syzbot] [bpf?] KMSAN: uninit-value in trie_lookup_elem (2)

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: 614da38e2f7a Merge tag 'hid-for-linus-2024051401' of git:/..
git tree: upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=14d2697e980000
kernel config: https://syzkaller.appspot.com/x/.config?x=f5d2cbf33633f507
dashboard link: https://syzkaller.appspot.com/bug?extid=3ac129054f077c7d7ca2
compiler: Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40

Unfortunately, I don't have any reproducer for this issue yet.

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/89eafb874b71/disk-614da38e.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/356000512ad9/vmlinux-614da38e.xz
kernel image: https://storage.googleapis.com/syzbot-assets/839c73939115/bzImage-614da38e.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+3ac129...@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_run128+0xb5/0xe0 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_kfree+0x29/0x40 include/trace/events/kmem.h:94
trace_kfree include/trace/events/kmem.h:94 [inline]
kfree+0x69e/0xa60 mm/slub.c:4450
prog_array_map_alloc+0x233/0x430 kernel/bpf/arraymap.c:1107
map_create+0x1185/0x1e10 kernel/bpf/syscall.c:1320
__sys_bpf+0xa65/0xd90 kernel/bpf/syscall.c:5642
__do_sys_bpf kernel/bpf/syscall.c:5767 [inline]
__se_sys_bpf kernel/bpf/syscall.c:5765 [inline]
__x64_sys_bpf+0xa0/0xe0 kernel/bpf/syscall.c:5765
x64_sys_call+0x96b/0x3b50 arch/x86/include/generated/asm/syscalls_64.h:322
do_syscall_x64 arch/x86/entry/common.c:52 [inline]
do_syscall_64+0xcf/0x1e0 arch/x86/entry/common.c:83
entry_SYSCALL_64_after_hwframe+0x77/0x7f

Local variable stack created at:
__bpf_prog_run128+0x45/0xe0 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: 8814 Comm: syz-executor.0 Not tainted 6.9.0-syzkaller-02707-g614da38e2f7a #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/02/2024
=====================================================


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