WARNING in kcov_remote_start (6)

Status: upstream: reported on 2024/11/04 21:25
Subsystems: kernel
Labels: prio:low
[Documentation on labels]
Reported-by: syzbot+3f51ad7ac3ae57a6fdcc@syzkaller.appspotmail.com
Fix commit: 2eed77fdcb0c kcov: fix data corruption and race conditions on PREEMPT_RT
Patched on: [ci-qemu-gce-upstream-auto ci-qemu-upstream ci-qemu-upstream-386 ci-qemu2-arm64 ci-qemu2-arm64-compat ci-qemu2-arm64-mte ci-snapshot-upstream-root ci-upstream-gce-leak ci-upstream-kasan-badwrites-root ci-upstream-kasan-gce ci-upstream-kasan-gce-386 ci-upstream-kasan-gce-root ci-upstream-kasan-gce-selinux-root ci-upstream-kasan-gce-smack-root ci-upstream-linux-next-kasan-gce-root ci-upstream-net-kasan-gce ci-upstream-net-this-kasan-gce ci-upstream-rust-kasan-gce ci2-upstream-fs ci2-upstream-kcsan-gce ci2-upstream-usb], missing on: [ci-qemu-native-arm64-kvm ci-qemu2-arm32 ci-qemu2-riscv64 ci-upstream-bpf-kasan-gce ci-upstream-bpf-next-kasan-gce ci-upstream-gce-arm64 ci-upstream-kmsan-gce-386-root ci-upstream-kmsan-gce-root]
First crash: 668d, last: 3d02h
✨ AI Jobs (1)
ID Workflow Result Correct Bug Created Started Finished Revision
7c1201c5 assessment-security DenialOfService: ❌ Exploitable: ❌ FilesystemTrigger: ❌ NetworkTrigger: ❌ PeripheralTrigger: ❌ RemoteTrigger: ❌ Unprivileged: ❌ UserNamespace: ❌ VMGuestTrigger: ❌ VMHostTrigger: ❌ WARNING in kcov_remote_start (6) 2026/05/24 13:26 2026/05/24 13:26 2026/05/24 14:13 c69befb3
Discussions (14)
Title Replies (including bot) Last reply
[PATCH v6] kcov: fix data corruption and race conditions on PREEMPT_RT by moving saved remote state to task_struct 5 (5) 2026/07/16 09:12
Re: [PATCH v5] kcov: fix data corruption and race conditions on PREEMPT_RT by moving saved remote state to task_struct 2 (2) 2026/07/10 10:43
Re: Policy regarding linux-next only changes 2 (2) 2026/07/02 14:11
[PATCH] kcov: fix potential kcov_mode corruption under CONFIG_PREEMPT_RT 5 (5) 2026/05/21 08:38
[syzbot] [wireless?] WARNING in kcov_remote_start (6) 0 (2) 2026/05/07 11:10
[PATCH (draft)] kcov: fix potential kcov_mode corruption under CONFIG_PREEMPT_RT 2 (2) 2026/05/04 15:39
[syzbot] Monthly wireless report (May 2026) 0 (1) 2026/05/02 12:32
[syzbot] Monthly wireless report (Apr 2026) 0 (1) 2026/04/01 07:42
[syzbot] Monthly wireless report (Mar 2026) 0 (1) 2026/03/01 06:22
[syzbot] Monthly wireless report (Jan 2026) 0 (1) 2026/01/28 22:39
[syzbot] Monthly usb report (Dec 2025) 0 (1) 2025/12/29 08:12
[syzbot] Monthly wireless report (Dec 2025) 0 (1) 2025/12/29 08:12
[syzbot] Monthly wireless report (Nov 2025) 0 (1) 2025/11/27 07:44
[syzbot] Monthly wireless report (Oct 2025) 0 (1) 2025/10/27 08:42
Similar bugs (10)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
linux-5.15 WARNING in kcov_remote_start (2) -1 1 186d 186d 0/3 auto-obsoleted due to no activity on 2026/06/06 04:25
linux-5.15 WARNING in kcov_remote_start -1 4 598d 698d 0/3 auto-obsoleted due to no activity on 2025/04/19 19:40
linux-5.15 WARNING in kcov_remote_start (3) -1 1 51d 51d 0/3 upstream: reported on 2026/07/10 20:40
linux-6.6 WARNING in kcov_remote_start -1 1 101d 101d 0/2 auto-obsoleted due to no activity on 2026/08/30 01:58
upstream WARNING in kcov_remote_start (4) usb -1 107983 782d 813d 26/29 fixed on 2024/07/10 08:24
upstream WARNING in kcov_remote_start (2) usb -1 syz, C 1153 2553d 2553d 0/29 closed as invalid on 2019/09/04 14:27
upstream WARNING in kcov_remote_start (5) wireless -1 4243 678d 778d 28/29 fixed on 2024/10/22 14:56
upstream WARNING in kcov_remote_start (3) usb -1 265513 817d 886d 25/29 fixed on 2024/06/05 13:52
upstream WARNING in kcov_remote_start usb -1 syz, C 655 2553d 2554d 0/29 closed as invalid on 2019/09/03 16:37
linux-6.1 WARNING in kcov_remote_start -1 14 27d 428d 0/3 upstream: reported on 2025/06/28 15:34

Sample crash report:
------------[ cut here ]------------
in_task() && kcov_mode_enabled(mode)
WARNING: kernel/kcov.c:894 at kcov_remote_start+0x5d6/0x710 kernel/kcov.c:894, CPU#0: kworker/u8:13/1191
Modules linked in:
CPU: 0 UID: 0 PID: 1191 Comm: kworker/u8:13 Not tainted syzkaller #0 PREEMPT_{RT,(full)} 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026
Workqueue: events_unbound cfg80211_wiphy_work
RIP: 0010:kcov_remote_start+0x5d6/0x710 kernel/kcov.c:894
Code: 03 00 00 00 5b 41 5c 41 5d 41 5e 41 5f 5d e9 11 f7 02 03 90 0f 0b 90 eb d1 90 0f 0b 90 0f b7 83 c0 04 00 00 e9 ab fa ff ff 90 <0f> 0b 90 eb 04 90 0f 0b 90 e8 0c b8 8a 09 89 c0 48 c7 c7 c0 52 a3
RSP: 0018:ffffc900062cf9d8 EFLAGS: 00010202
RAX: 0000000000000000 RBX: ffff888028ce0000 RCX: 8000000000000001
RDX: 0000000000000000 RSI: ffffffff8bcbc060 RDI: ffffffff8bcbc020
RBP: ffff88803eb0a780 R08: ffffffff8b52ee52 R09: 0000000000000000
R10: 0000000000000000 R11: ffffffff8e1c3740 R12: dffffc0000000000
R13: ffff888021fa5ef8 R14: 0000000000000000 R15: ffff888062931180
FS:  0000000000000000(0000) GS:ffff888125bf4000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007ffe645aa80c CR3: 000000005f61e000 CR4: 00000000003526f0
Call Trace:
 <TASK>
 kcov_remote_start_common include/linux/kcov.h:48 [inline]
 ieee80211_iface_work+0x20c/0x1010 net/mac80211/iface.c:1818
 cfg80211_wiphy_work+0x29e/0x420 net/wireless/core.c:541
 process_one_work kernel/workqueue.c:3387 [inline]
 process_scheduled_works+0xc3d/0x1630 kernel/workqueue.c:3470
 worker_thread+0xa47/0xfb0 kernel/workqueue.c:3551
 kthread+0x38b/0x470 kernel/kthread.c:436
 ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>

Crashes (43237):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2026/08/23 21:35 upstream 2709dd5ae32f 1e72964b .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-smack-root WARNING in kcov_remote_start
2026/08/23 20:29 upstream 2709dd5ae32f 1e72964b .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-smack-root WARNING in kcov_remote_start
2026/08/23 19:27 upstream 2709dd5ae32f 1e72964b .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-smack-root WARNING in kcov_remote_start
2026/08/23 19:21 upstream 2709dd5ae32f 1e72964b .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-smack-root WARNING in kcov_remote_start
2026/08/23 18:18 upstream 2709dd5ae32f 1e72964b .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-smack-root WARNING in kcov_remote_start
2026/08/23 17:13 upstream 2709dd5ae32f 1e72964b .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-smack-root WARNING in kcov_remote_start
2026/08/23 16:02 upstream 2709dd5ae32f 1e72964b .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-smack-root WARNING in kcov_remote_start
2026/08/23 13:31 upstream 2709dd5ae32f 1e72964b .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-smack-root WARNING in kcov_remote_start
2026/08/23 12:54 upstream 2709dd5ae32f 1e72964b .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-smack-root WARNING in kcov_remote_start
2026/08/23 11:53 upstream 2709dd5ae32f 1e72964b .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-smack-root WARNING in kcov_remote_start
2026/08/23 11:07 upstream 2709dd5ae32f 1e72964b .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-smack-root WARNING in kcov_remote_start
2026/08/23 10:01 upstream 2709dd5ae32f 1e72964b .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-smack-root WARNING in kcov_remote_start
2026/08/23 09:26 upstream 2709dd5ae32f 1e72964b .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-smack-root WARNING in kcov_remote_start
2026/08/23 08:15 upstream 2709dd5ae32f 1e72964b .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-smack-root WARNING in kcov_remote_start
2026/08/23 06:37 upstream 66fb95a52111 1e72964b .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-smack-root WARNING in kcov_remote_start
2026/08/23 05:25 upstream 66fb95a52111 1e72964b .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-smack-root WARNING in kcov_remote_start
2026/08/23 04:24 upstream 66fb95a52111 1e72964b .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-smack-root WARNING in kcov_remote_start
2026/08/23 02:36 upstream 66fb95a52111 1e72964b .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-smack-root WARNING in kcov_remote_start
2026/08/23 02:35 upstream 66fb95a52111 1e72964b .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-smack-root WARNING in kcov_remote_start
2026/08/23 01:32 upstream 66fb95a52111 1e72964b .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-smack-root WARNING in kcov_remote_start
2026/08/23 00:25 upstream 66fb95a52111 1e72964b .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-smack-root WARNING in kcov_remote_start
2026/08/22 23:08 upstream 66fb95a52111 1e72964b .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-smack-root WARNING in kcov_remote_start
2026/08/22 22:23 upstream 66fb95a52111 1e72964b .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-smack-root WARNING in kcov_remote_start
2026/08/22 21:18 upstream 66fb95a52111 1e72964b .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-smack-root WARNING in kcov_remote_start
2026/08/22 20:07 upstream 66fb95a52111 1e72964b .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-smack-root WARNING in kcov_remote_start
2026/08/22 19:06 upstream 66fb95a52111 1e72964b .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-smack-root WARNING in kcov_remote_start
2026/08/22 18:44 upstream 66fb95a52111 1e72964b .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-smack-root WARNING in kcov_remote_start
2026/08/22 17:14 upstream 26260251022f 1e72964b .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-smack-root WARNING in kcov_remote_start
2026/08/22 16:11 upstream 26260251022f 1e72964b .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-smack-root WARNING in kcov_remote_start
2026/08/22 14:59 upstream 26260251022f 1e72964b .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-smack-root WARNING in kcov_remote_start
2026/08/22 13:28 upstream 26260251022f 1e72964b .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-smack-root WARNING in kcov_remote_start
2026/08/22 11:10 upstream 26260251022f 1e72964b .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-smack-root WARNING in kcov_remote_start
2026/08/22 09:17 upstream 26260251022f 1e72964b .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-smack-root WARNING in kcov_remote_start
2026/08/22 08:12 upstream 26260251022f 1e72964b .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-smack-root WARNING in kcov_remote_start
2026/08/22 07:11 upstream 26260251022f 1e72964b .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-smack-root WARNING in kcov_remote_start
2026/08/22 06:01 upstream 26260251022f 1e72964b .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-smack-root WARNING in kcov_remote_start
2026/08/22 04:55 upstream 26260251022f 1e72964b .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-smack-root WARNING in kcov_remote_start
2026/08/22 03:17 upstream 818bebeb63dd 1e72964b .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-smack-root WARNING in kcov_remote_start
2026/08/22 02:14 upstream 818bebeb63dd 1e72964b .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-smack-root WARNING in kcov_remote_start
2026/08/22 01:07 upstream 818bebeb63dd 1e72964b .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-smack-root WARNING in kcov_remote_start
2026/08/21 23:46 upstream 818bebeb63dd 1e72964b .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-smack-root WARNING in kcov_remote_start
2026/08/21 22:23 upstream 818bebeb63dd 1e72964b .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-smack-root WARNING in kcov_remote_start
2026/08/21 22:13 upstream 818bebeb63dd 1e72964b .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-smack-root WARNING in kcov_remote_start
2026/08/21 21:10 upstream 818bebeb63dd 1e72964b .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-smack-root WARNING in kcov_remote_start
2026/05/24 12:17 upstream 4cbfe4502e3d c69befb3 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-smack-root WARNING in kcov_remote_start
2026/04/03 00:19 upstream 5619b098e2fb 8b15d4ae .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-root WARNING in kcov_remote_start
2026/03/10 13:57 upstream 1f318b96cc84 4683d576 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-smack-root WARNING in kcov_remote_start
2026/03/06 16:42 upstream 5ee8dbf54602 41d8037d .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce WARNING in kcov_remote_start
2026/03/01 08:48 upstream 42eb01783091 43249bac .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-selinux-root WARNING in kcov_remote_start
2026/01/29 08:52 upstream 8dfce8991b95 b78a7341 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-badwrites-root WARNING in kcov_remote_start
2025/08/30 22:55 upstream 11e7861d680c 807a3b61 .config console log report info [disk image] [vmlinux] [kernel image] ci-qemu-gce-upstream-auto WARNING in kcov_remote_start
2024/11/03 07:56 upstream 3e5e6c9900c3 f00eed24 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-smack-root WARNING in kcov_remote_start
2026/02/24 08:18 upstream 7dff99b35460 41d2fa6a .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-386 WARNING in kcov_remote_start
2026/01/18 12:58 upstream d12453c7e281 d1b870e1 .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream WARNING in kcov_remote_start
2025/09/02 13:14 upstream b320789d6883 96a211bc .config console log report [disk image (non-bootable)] [vmlinux] [kernel image] ci-snapshot-upstream-root WARNING in kcov_remote_start
2025/12/28 12:00 upstream d26143bb38e2 d1b870e1 .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream-386 WARNING in kcov_remote_start
2026/08/28 12:18 net 1b78070aaef6 e2fa417d .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-net-this-kasan-gce WARNING in kcov_remote_start
2026/08/27 12:32 net 991c2be78257 a2b77b9e .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-net-this-kasan-gce WARNING in kcov_remote_start
2026/07/20 12:14 bpf 94515f3a7d42 de6a700d .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-bpf-kasan-gce WARNING in kcov_remote_start
2025/10/12 09:27 net f3426ac54c42 ff1712fe .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-net-this-kasan-gce WARNING in kcov_remote_start
2026/05/07 17:37 bpf-next 2ca6723a5f7b e358bca5 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-bpf-next-kasan-gce WARNING in kcov_remote_start
2025/08/18 08:17 net-next bab3ce404553 1804e95e .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-net-kasan-gce WARNING in kcov_remote_start
2026/07/08 14:17 linux-next 5c73cd9f0819 ab40da58 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-rust-kasan-gce WARNING in kcov_remote_start
2026/07/08 11:07 linux-next 5c73cd9f0819 ab40da58 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root WARNING in kcov_remote_start
2024/10/31 21:14 linux-next f9f24ca362a4 96eb609f .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root WARNING in kcov_remote_start
2025/04/28 17:47 git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git for-kernelci c72692105976 c6b4fb39 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-gce-arm64 WARNING in kcov_remote_start
* Struck through repros no longer work on HEAD.