syzbot


KMSAN: uninit-value in strnchr (2)

Status: upstream: reported C repro on 2024/06/10 04:33
Subsystems: bpf
[Documentation on labels]
Reported-by: syzbot+33bce7b14333572224b2@syzkaller.appspotmail.com
First crash: 12d, last: 6d05h
Discussions (1)
Title Replies (including bot) Last reply
[syzbot] [bpf?] KMSAN: uninit-value in strnchr (2) 0 (1) 2024/06/10 04:33
Similar bugs (2)
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream KMSAN: uninit-value in strnchr bpf C 173 13d 103d 0/27 closed as dup on 2024/04/09 05:30
upstream KMSAN: uninit-value in ieee802154_subif_start_xmit bpf C done 119 320d 316d 23/27 fixed on 2023/10/12 12:47

Sample crash report:
=====================================================
BUG: KMSAN: uninit-value in strnchr+0x90/0xd0 lib/string.c:387
 strnchr+0x90/0xd0 lib/string.c:387
 bpf_bprintf_prepare+0x1c2/0x23c0 kernel/bpf/helpers.c:829
 ____bpf_trace_printk kernel/trace/bpf_trace.c:385 [inline]
 bpf_trace_printk+0xec/0x3e0 kernel/trace/bpf_trace.c:375
 ___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_tlb_flush+0x2c/0x40 include/trace/events/tlb.h:38
 trace_tlb_flush include/trace/events/tlb.h:38 [inline]
 switch_mm_irqs_off+0x9d2/0x1010 arch/x86/mm/tlb.c:642
 unuse_temporary_mm arch/x86/kernel/alternative.c:1815 [inline]
 __text_poke+0xb4e/0xfb0 arch/x86/kernel/alternative.c:1925
 text_poke arch/x86/kernel/alternative.c:1968 [inline]
 text_poke_bp_batch+0x17f/0x960 arch/x86/kernel/alternative.c:2276
 text_poke_flush arch/x86/kernel/alternative.c:2470 [inline]
 text_poke_finish+0x7d/0xd0 arch/x86/kernel/alternative.c:2477
 arch_jump_label_transform_apply+0x23/0x40 arch/x86/kernel/jump_label.c:146
 __jump_label_update+0x6af/0x6d0 kernel/jump_label.c:483
 jump_label_update+0x6a0/0x7a0 kernel/jump_label.c:882
 static_key_enable_cpuslocked+0x229/0x260 kernel/jump_label.c:205
 static_key_enable+0x23/0x30 kernel/jump_label.c:218
 tracepoint_add_func+0x1084/0x1280 kernel/tracepoint.c:361
 tracepoint_probe_register_prio_may_exist+0xa8/0xf0 kernel/tracepoint.c:482
 tracepoint_probe_register_may_exist include/linux/tracepoint.h:52 [inline]
 __bpf_probe_register kernel/trace/bpf_trace.c:2446 [inline]
 bpf_probe_register+0x201/0x250 kernel/trace/bpf_trace.c:2452
 bpf_raw_tp_link_attach+0x627/0x8a0 kernel/bpf/syscall.c:3865
 bpf_raw_tracepoint_open+0x485/0x8a0 kernel/bpf/syscall.c:3892
 __sys_bpf+0x5a6/0xd90 kernel/bpf/syscall.c:5702
 __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_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-executor406 Not tainted 6.9.0-syzkaller-02707-g614da38e2f7a #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/02/2024
=====================================================

Crashes (80):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2024/06/06 13:48 upstream 614da38e2f7a 121701b6 .config strace log report syz / log C [disk image] [vmlinux] [kernel image] ci-upstream-kmsan-gce-root KMSAN: uninit-value in strnchr
2024/06/12 08:33 upstream 614da38e2f7a 4d75f4f7 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kmsan-gce-root KMSAN: uninit-value in strnchr
2024/06/11 16:10 upstream 614da38e2f7a c7d7d815 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kmsan-gce-root KMSAN: uninit-value in strnchr
2024/06/11 08:47 upstream 614da38e2f7a 048c640a .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kmsan-gce-root KMSAN: uninit-value in strnchr
2024/06/11 01:39 upstream 614da38e2f7a 048c640a .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kmsan-gce-root KMSAN: uninit-value in strnchr
2024/06/10 22:13 upstream 614da38e2f7a 048c640a .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kmsan-gce-root KMSAN: uninit-value in strnchr
2024/06/10 06:15 upstream 614da38e2f7a 82c05ab8 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kmsan-gce-root KMSAN: uninit-value in strnchr
2024/06/10 05:11 upstream 614da38e2f7a 82c05ab8 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kmsan-gce-root KMSAN: uninit-value in strnchr
2024/06/09 08:58 upstream 614da38e2f7a 82c05ab8 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kmsan-gce-root KMSAN: uninit-value in strnchr
2024/06/08 08:02 upstream 614da38e2f7a 82c05ab8 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kmsan-gce-root KMSAN: uninit-value in strnchr
2024/06/08 08:02 upstream 614da38e2f7a 82c05ab8 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kmsan-gce-root KMSAN: uninit-value in strnchr
2024/06/08 07:44 upstream 614da38e2f7a 82c05ab8 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kmsan-gce-root KMSAN: uninit-value in strnchr
2024/06/08 07:44 upstream 614da38e2f7a 82c05ab8 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kmsan-gce-root KMSAN: uninit-value in strnchr
2024/06/08 06:15 upstream 614da38e2f7a 82c05ab8 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kmsan-gce-root KMSAN: uninit-value in strnchr
2024/06/08 06:15 upstream 614da38e2f7a 82c05ab8 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kmsan-gce-root KMSAN: uninit-value in strnchr
2024/06/08 04:32 upstream 614da38e2f7a 82c05ab8 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kmsan-gce-root KMSAN: uninit-value in strnchr
2024/06/08 04:31 upstream 614da38e2f7a 82c05ab8 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kmsan-gce-root KMSAN: uninit-value in strnchr
2024/06/08 02:13 upstream 614da38e2f7a 82c05ab8 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kmsan-gce-root KMSAN: uninit-value in strnchr
2024/06/08 02:13 upstream 614da38e2f7a 82c05ab8 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kmsan-gce-root KMSAN: uninit-value in strnchr
2024/06/08 01:27 upstream 614da38e2f7a 82c05ab8 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kmsan-gce-root KMSAN: uninit-value in strnchr
2024/06/08 01:26 upstream 614da38e2f7a 82c05ab8 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kmsan-gce-root KMSAN: uninit-value in strnchr
2024/06/07 17:56 upstream 614da38e2f7a 121701b6 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kmsan-gce-root KMSAN: uninit-value in strnchr
2024/06/07 17:36 upstream 614da38e2f7a 121701b6 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kmsan-gce-root KMSAN: uninit-value in strnchr
2024/06/07 17:36 upstream 614da38e2f7a 121701b6 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kmsan-gce-root KMSAN: uninit-value in strnchr
2024/06/07 03:45 upstream 614da38e2f7a 121701b6 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kmsan-gce-root KMSAN: uninit-value in strnchr
2024/06/07 03:45 upstream 614da38e2f7a 121701b6 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kmsan-gce-root KMSAN: uninit-value in strnchr
2024/06/06 16:30 upstream 614da38e2f7a 121701b6 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kmsan-gce-root KMSAN: uninit-value in strnchr
2024/06/06 16:30 upstream 614da38e2f7a 121701b6 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kmsan-gce-root KMSAN: uninit-value in strnchr
2024/06/06 04:26 upstream 614da38e2f7a 121701b6 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kmsan-gce-root KMSAN: uninit-value in strnchr
2024/06/06 04:26 upstream 614da38e2f7a 121701b6 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kmsan-gce-root KMSAN: uninit-value in strnchr
2024/06/11 21:15 upstream 101b7a97143a c7d7d815 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kmsan-gce-386-root KMSAN: uninit-value in strnchr
2024/06/11 19:25 upstream 101b7a97143a c7d7d815 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kmsan-gce-386-root KMSAN: uninit-value in strnchr
2024/06/11 17:46 upstream 101b7a97143a c7d7d815 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kmsan-gce-386-root KMSAN: uninit-value in strnchr
2024/06/11 09:30 upstream 101b7a97143a 048c640a .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kmsan-gce-386-root KMSAN: uninit-value in strnchr
2024/06/11 03:13 upstream 101b7a97143a 048c640a .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kmsan-gce-386-root KMSAN: uninit-value in strnchr
2024/06/10 09:33 upstream 101b7a97143a 82c05ab8 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kmsan-gce-386-root KMSAN: uninit-value in strnchr
2024/06/09 09:58 upstream 101b7a97143a 82c05ab8 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kmsan-gce-386-root KMSAN: uninit-value in strnchr
2024/06/08 12:17 upstream 101b7a97143a 82c05ab8 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kmsan-gce-386-root KMSAN: uninit-value in strnchr
2024/06/08 12:17 upstream 101b7a97143a 82c05ab8 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kmsan-gce-386-root KMSAN: uninit-value in strnchr
2024/06/08 11:37 upstream 101b7a97143a 82c05ab8 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kmsan-gce-386-root KMSAN: uninit-value in strnchr
2024/06/08 11:36 upstream 101b7a97143a 82c05ab8 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kmsan-gce-386-root KMSAN: uninit-value in strnchr
2024/06/08 09:56 upstream 101b7a97143a 82c05ab8 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kmsan-gce-386-root KMSAN: uninit-value in strnchr
2024/06/08 09:56 upstream 101b7a97143a 82c05ab8 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kmsan-gce-386-root KMSAN: uninit-value in strnchr
2024/06/08 08:16 upstream 101b7a97143a 82c05ab8 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kmsan-gce-386-root KMSAN: uninit-value in strnchr
2024/06/08 08:16 upstream 101b7a97143a 82c05ab8 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kmsan-gce-386-root KMSAN: uninit-value in strnchr
2024/06/08 05:53 upstream 101b7a97143a 82c05ab8 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kmsan-gce-386-root KMSAN: uninit-value in strnchr
2024/06/08 05:53 upstream 101b7a97143a 82c05ab8 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kmsan-gce-386-root KMSAN: uninit-value in strnchr
2024/06/08 04:26 upstream 101b7a97143a 82c05ab8 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kmsan-gce-386-root KMSAN: uninit-value in strnchr
2024/06/08 04:26 upstream 101b7a97143a 82c05ab8 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kmsan-gce-386-root KMSAN: uninit-value in strnchr
2024/06/07 04:33 upstream 101b7a97143a 121701b6 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kmsan-gce-386-root KMSAN: uninit-value in strnchr
2024/06/07 04:32 upstream 101b7a97143a 121701b6 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kmsan-gce-386-root KMSAN: uninit-value in strnchr
2024/06/06 18:37 upstream 101b7a97143a 121701b6 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kmsan-gce-386-root KMSAN: uninit-value in strnchr
2024/06/06 18:36 upstream 101b7a97143a 121701b6 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kmsan-gce-386-root KMSAN: uninit-value in strnchr
2024/06/06 09:38 upstream 101b7a97143a 121701b6 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kmsan-gce-386-root KMSAN: uninit-value in strnchr
2024/06/06 09:38 upstream 101b7a97143a 121701b6 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kmsan-gce-386-root KMSAN: uninit-value in strnchr
* Struck through repros no longer work on HEAD.