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

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: 7efd0a74039f Merge tag 'ata-6.9-rc4' of git://git.kernel.o..
git tree: upstream
console+strace: https://syzkaller.appspot.com/x/log.txt?x=1492cb93180000
kernel config: https://syzkaller.appspot.com/x/.config?x=b5bc506ebba90cbf
dashboard link: https://syzkaller.appspot.com/bug?extid=1971e47e5210c718db3c
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=11ce7393180000
C reproducer: https://syzkaller.appspot.com/x/repro.c?x=155451eb180000

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/9fd81e15f087/disk-7efd0a74.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/2e4915d51565/vmlinux-7efd0a74.xz
kernel image: https://storage.googleapis.com/syzbot-assets/110eeae33f94/bzImage-7efd0a74.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+1971e4...@syzkaller.appspotmail.com

=====================================================
BUG: KMSAN: uninit-value in __htab_map_lookup_elem kernel/bpf/hashtab.c:691 [inline]
BUG: KMSAN: uninit-value in htab_lru_percpu_map_lookup_percpu_elem+0x3f8/0x630 kernel/bpf/hashtab.c:2343
__htab_map_lookup_elem kernel/bpf/hashtab.c:691 [inline]
htab_lru_percpu_map_lookup_percpu_elem+0x3f8/0x630 kernel/bpf/hashtab.c:2343
____bpf_map_lookup_percpu_elem kernel/bpf/helpers.c:133 [inline]
bpf_map_lookup_percpu_elem+0x67/0x90 kernel/bpf/helpers.c:130
___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_kfree+0x29/0x40 include/trace/events/kmem.h:94
trace_kfree include/trace/events/kmem.h:94 [inline]
kfree+0x6a5/0xa30 mm/slub.c:4377
security_task_free+0x115/0x150 security/security.c:3032
__put_task_struct+0x17f/0x730 kernel/fork.c:976
put_task_struct include/linux/sched/task.h:138 [inline]
delayed_put_task_struct+0x8a/0x280 kernel/exit.c:229
rcu_do_batch kernel/rcu/tree.c:2196 [inline]
rcu_core+0xa59/0x1e70 kernel/rcu/tree.c:2471
rcu_core_si+0x12/0x20 kernel/rcu/tree.c:2488
__do_softirq+0x1c0/0x7d7 kernel/softirq.c:554
invoke_softirq kernel/softirq.c:428 [inline]
__irq_exit_rcu kernel/softirq.c:633 [inline]
irq_exit_rcu+0x6a/0x130 kernel/softirq.c:645
instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1043 [inline]
sysvec_apic_timer_interrupt+0x83/0x90 arch/x86/kernel/apic/apic.c:1043
asm_sysvec_apic_timer_interrupt+0x1f/0x30 arch/x86/include/asm/idtentry.h:702
__msan_metadata_ptr_for_load_8+0x31/0x40 mm/kmsan/instrumentation.c:92
filter_irq_stacks+0x60/0x1a0 kernel/stacktrace.c:397
stack_depot_save_flags+0x2c/0x6e0 lib/stackdepot.c:609
stack_depot_save+0x12/0x20 lib/stackdepot.c:685
__msan_poison_alloca+0x106/0x1b0 mm/kmsan/instrumentation.c:285
arch_local_save_flags arch/x86/include/asm/irqflags.h:67 [inline]
arch_local_irq_save arch/x86/include/asm/irqflags.h:103 [inline]
__raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:108 [inline]
_raw_spin_lock_irqsave+0x35/0xc0 kernel/locking/spinlock.c:162
remove_wait_queue+0x36/0x270 kernel/sched/wait.c:54
do_wait+0x34a/0x530 kernel/exit.c:1640
kernel_wait4+0x2ab/0x480 kernel/exit.c:1790
__do_sys_wait4 kernel/exit.c:1818 [inline]
__se_sys_wait4 kernel/exit.c:1814 [inline]
__x64_sys_wait4+0x14e/0x310 kernel/exit.c:1814
x64_sys_call+0x6e6/0x3b50 arch/x86/include/generated/asm/syscalls_64.h:62
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: 0 PID: 5018 Comm: strace-static-x Not tainted 6.9.0-rc3-syzkaller-00355-g7efd0a74039f #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/27/2024
=====================================================


---
This report is generated by a bot. It may contain errors.
See https://goo.gl/tpsmEJ for more information about syzbot.
syzbot engineers can be reached at syzk...@googlegroups.com.

syzbot will keep track of this issue. See:
https://goo.gl/tpsmEJ#status for how to communicate with syzbot.

If the report is already addressed, let syzbot know by replying with:
#syz fix: exact-commit-title

If you want syzbot to run the reproducer, reply with:
#syz test: git://repo/address.git branch-or-commit-hash
If you attach or paste a git patch, syzbot will apply it before testing.

If you want to overwrite report's subsystems, reply with:
#syz set subsystems: new-subsystem
(See the list of subsystem names on the web dashboard)

If the report is a duplicate of another one, reply with:
#syz dup: exact-subject-of-another-report

If you want to undo deduplication, reply with:
#syz undup