[syzbot] [bpf?] KMSAN: uninit-value in trie_delete_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+strace: https://syzkaller.appspot.com/x/log.txt?x=104e0b1c980000
kernel config: https://syzkaller.appspot.com/x/.config?x=f5d2cbf33633f507
dashboard link: https://syzkaller.appspot.com/bug?extid=57c04b477de48032b4d4
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=13a6eb32980000
C reproducer: https://syzkaller.appspot.com/x/repro.c?x=11f3a364980000

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+57c04b...@syzkaller.appspotmail.com

=====================================================
BUG: KMSAN: uninit-value in trie_delete_elem+0xc0/0xbe0 kernel/bpf/lpm_trie.c:448
trie_delete_elem+0xc0/0xbe0 kernel/bpf/lpm_trie.c:448
____bpf_map_delete_elem kernel/bpf/helpers.c:77 [inline]
bpf_map_delete_elem+0x5c/0x80 kernel/bpf/helpers.c:73
___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_ext4_sync_file_exit+0x2c/0x40 include/trace/events/ext4.h:958
trace_ext4_sync_file_exit include/trace/events/ext4.h:958 [inline]
ext4_sync_file+0x121c/0x13a0 fs/ext4/fsync.c:179
vfs_fsync_range+0x20d/0x270 fs/sync.c:188
generic_write_sync include/linux/fs.h:2811 [inline]
iomap_dio_complete+0xb58/0xf00 fs/iomap/direct-io.c:126
iomap_dio_rw+0x134/0x170 fs/iomap/direct-io.c:753
ext4_dio_write_iter fs/ext4/file.c:577 [inline]
ext4_file_write_iter+0x26ee/0x3450 fs/ext4/file.c:696
call_write_iter include/linux/fs.h:2120 [inline]
new_sync_write fs/read_write.c:497 [inline]
vfs_write+0xb31/0x14d0 fs/read_write.c:590
ksys_write+0x20f/0x4c0 fs/read_write.c:643
__do_sys_write fs/read_write.c:655 [inline]
__se_sys_write fs/read_write.c:652 [inline]
__x64_sys_write+0x93/0xe0 fs/read_write.c:652
x64_sys_call+0x3062/0x3b50 arch/x86/include/generated/asm/syscalls_64.h:2
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_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: 1 PID: 5048 Comm: syz-executor240 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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