syzbot


KMSAN: uninit-value in trie_lookup_elem (2)

Status: upstream: reported on 2024/06/16 00:31
Subsystems: bpf
[Documentation on labels]
Reported-by: syzbot+3ac129054f077c7d7ca2@syzkaller.appspotmail.com
First crash: 31d, last: 31d
Discussions (1)
Title Replies (including bot) Last reply
[syzbot] [bpf?] KMSAN: uninit-value in trie_lookup_elem (2) 0 (1) 2024/06/16 00:31
Similar bugs (1)
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream KMSAN: uninit-value in trie_lookup_elem bpf C 12 95d 113d 26/27 fixed on 2024/06/05 13:52

Sample crash report:
=====================================================
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
=====================================================

Crashes (1):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2024/06/12 00:19 upstream 614da38e2f7a c7d7d815 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kmsan-gce-root KMSAN: uninit-value in trie_lookup_elem
* Struck through repros no longer work on HEAD.