syzbot


KMSAN: uninit-value in htab_lru_percpu_map_lookup_elem

Status: closed as dup on 2024/04/08 22:12
Subsystems: bpf
[Documentation on labels]
Reported-by: syzbot+b8d77b9bb107fa1bd641@syzkaller.appspotmail.com
First crash: 35d, last: 10d
Duplicate of
Title Repro Cause bisect Fix bisect Count Last Reported
KMSAN: uninit-value in dev_map_lookup_elem bpf net C 3 37d 43d
Discussions (1)
Title Replies (including bot) Last reply
[syzbot] [bpf?] KMSAN: uninit-value in htab_lru_percpu_map_lookup_elem 1 (2) 2024/04/08 22:12

Sample crash report:
=====================================================
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_elem+0x39a/0x580 kernel/bpf/hashtab.c:2326
 __htab_map_lookup_elem kernel/bpf/hashtab.c:691 [inline]
 htab_lru_percpu_map_lookup_elem+0x39a/0x580 kernel/bpf/hashtab.c:2326
 ____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_run64+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+0x6a5/0xa30 mm/slub.c:4377
 kvfree+0x69/0x80 mm/util.c:680
 __bpf_prog_put_rcu+0x37/0xf0 kernel/bpf/syscall.c:2232
 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
 __preempt_count_dec_and_test arch/x86/include/asm/preempt.h:94 [inline]
 flush_tlb_mm_range+0x294/0x320 arch/x86/mm/tlb.c:1036
 flush_tlb_page arch/x86/include/asm/tlbflush.h:254 [inline]
 ptep_clear_flush+0x166/0x1c0 mm/pgtable-generic.c:101
 wp_page_copy mm/memory.c:3329 [inline]
 do_wp_page+0x419d/0x66e0 mm/memory.c:3660
 handle_pte_fault mm/memory.c:5316 [inline]
 __handle_mm_fault mm/memory.c:5441 [inline]
 handle_mm_fault+0x5b76/0xce00 mm/memory.c:5606
 do_user_addr_fault arch/x86/mm/fault.c:1362 [inline]
 handle_page_fault arch/x86/mm/fault.c:1505 [inline]
 exc_page_fault+0x419/0x730 arch/x86/mm/fault.c:1563
 asm_exc_page_fault+0x2b/0x30 arch/x86/include/asm/idtentry.h:623

Local variable stack created at:
 __bpf_prog_run64+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: 1 PID: 5015 Comm: syz-executor232 Not tainted 6.9.0-rc2-syzkaller-00002-g026e680b0a08 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/27/2024
=====================================================

Crashes (6):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2024/04/02 18:53 upstream 026e680b0a08 6baf5069 .config strace log report syz C [disk image] [vmlinux] [kernel image] ci-upstream-kmsan-gce-root KMSAN: uninit-value in htab_lru_percpu_map_lookup_elem
2024/04/27 09:40 upstream 5eb4573ea63d 07b455f9 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kmsan-gce-root KMSAN: uninit-value in htab_lru_percpu_map_lookup_elem
2024/04/08 18:03 upstream fec50db7033e 53df08b6 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kmsan-gce-root KMSAN: uninit-value in htab_lru_percpu_map_lookup_elem
2024/04/07 02:27 upstream f2f80ac80987 ca620dd8 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kmsan-gce-root KMSAN: uninit-value in htab_lru_percpu_map_lookup_elem
2024/04/02 16:48 upstream 026e680b0a08 6baf5069 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kmsan-gce-root KMSAN: uninit-value in htab_lru_percpu_map_lookup_elem
2024/04/09 05:31 upstream fec50db7033e 53df08b6 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kmsan-gce-386-root KMSAN: uninit-value in htab_lru_percpu_map_lookup_elem
* Struck through repros no longer work on HEAD.