KCSAN: data-race in alloc_pid / copy_process (2)

Status: moderation: reported C repro on 2020/06/09 14:58
Subsystems: kernel
Labels: prio:low
[Documentation on labels]
Reported-by: syzbot+0718f65353d72efaac1e@syzkaller.appspotmail.com
First crash: 2520d, last: 1d21h
▶ ▼ ✨ AI Jobs (5)
ID Workflow Result Correct Bug Created Started Finished Revision
04c23478 repro-c Reproduced: ✅ ❓ KCSAN: data-race in alloc_pid / copy_process (2) 2026/10/02 20:32 2026/10/02 20:32 2026/10/02 21:01 57bbd979
f5f3590f assessment-security DenialOfService: ❌ Exploitable: ❌ FilesystemTrigger: ❌ NetworkTrigger: ❌ PeripheralTrigger: ❌ RemoteTrigger: ❌ Unprivileged: ✅ UserNamespace: ✅ VMGuestTrigger: ❌ VMHostTrigger: ❌ ❓ KCSAN: data-race in alloc_pid / copy_process (2) 2026/05/16 15:14 2026/05/16 15:40 2026/05/16 16:05 de5aae85
f1fb5761 repro ❓ KCSAN: data-race in alloc_pid / copy_process (2) 2026/03/07 22:22 2026/03/07 22:22 2026/03/07 22:24 31e9c887
321d819b assessment-kcsan Benign: ✅ Confident: ✅ ❓ KCSAN: data-race in alloc_pid / copy_process (2) 2026/02/24 21:06 2026/02/24 21:06 2026/02/24 21:08 305c0ec5
3400e0bb assessment-kcsan 💥 KCSAN: data-race in alloc_pid / copy_process (2) 2026/01/10 03:12 2026/01/10 03:12 2026/01/10 03:13 75199160
▶ ▼ Discussions (2)
Title Replies (including bot) Last reply
[PATCH v2] pid: annotate data-races around pid_ns->pid_allocated 4 (4) 2025/04/28 08:30
[PATCH v1] pid: annotate data-races around pid_ns->pid_allocated 7 (7) 2025/04/25 05:37
▶ ▼ Similar bugs (1)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream KCSAN: data-race in alloc_pid / copy_process kernel 6 5 2538d 2549d 0/29 closed as invalid on 2019/11/19 13:24
▶ ▼ Last patch testing requests (1)
Created Duration User Patch Repo Result
2026/10/02 21:45 9m retest repro git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git 5e0f8396d4805a3e7f753fa58c8c55f1f3cc2160 report job log log

Sample crash report:
==================================================================
BUG: KCSAN: data-race in alloc_pid / copy_process

read-write to 0xffffffff86e5c368 of 4 bytes by task 17397 on cpu 1:
 alloc_pid+0x6da/0x960 kernel/pid.c:334
 copy_process+0x11a8/0x2360 kernel/fork.c:2327
 kernel_clone+0x1c0/0x5f0 kernel/fork.c:2771
 __do_sys_clone kernel/fork.c:2913 [inline]
 __se_sys_clone kernel/fork.c:2897 [inline]
 __x64_sys_clone+0x143/0x180 kernel/fork.c:2897
 x64_sys_call+0x2479/0x2550 arch/x86/include/generated/asm/syscalls_64.h:57
 do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
 do_syscall_64+0x112/0x360 arch/x86/entry/syscall_64.c:84
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

read to 0xffffffff86e5c368 of 4 bytes by task 10201 on cpu 0:
 copy_process+0x1ae8/0x2360 kernel/fork.c:2490
 kernel_clone+0x1c0/0x5f0 kernel/fork.c:2771
 __do_sys_clone kernel/fork.c:2913 [inline]
 __se_sys_clone kernel/fork.c:2897 [inline]
 __x64_sys_clone+0x143/0x180 kernel/fork.c:2897
 x64_sys_call+0x2479/0x2550 arch/x86/include/generated/asm/syscalls_64.h:57
 do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
 do_syscall_64+0x112/0x360 arch/x86/entry/syscall_64.c:84
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

value changed: 0x80000383 -> 0x80000384

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 UID: 0 PID: 10201 Comm: syz-executor362 Not tainted syzkaller #0 PREEMPT(lazy) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/16/2026
==================================================================

Crashes (3612):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2026/10/05 00:36 git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git a90ee4305c4a 853b104b .config console log report C ci2-upstream-kcsan-gce KCSAN: data-race in alloc_pid / copy_process
2026/10/13 14:16 upstream 24a19b953e2a 5a1eeac4 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in alloc_pid / copy_process
2026/10/11 19:42 upstream b88c841d1164 4f92358f .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in alloc_pid / copy_process
2026/10/11 01:17 upstream 3857c2fe5449 4f92358f .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in alloc_pid / copy_process
2026/10/09 23:58 upstream fc1c25014ff8 4f92358f .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in alloc_pid / copy_process
2026/10/08 22:34 upstream 6c377d19d4a5 b2734a59 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in alloc_pid / copy_process
2026/10/08 13:56 upstream 7b63ef2d55f2 4f6a9fcf .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in alloc_pid / copy_process
2026/10/08 03:02 upstream 7b63ef2d55f2 6520ecdb .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in alloc_pid / copy_process
2026/10/06 15:05 upstream 2c3418fffa9d f7710056 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in alloc_pid / copy_process
2026/10/05 17:09 upstream 67f0943b394d af63e995 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in alloc_pid / copy_process
2026/10/05 11:06 upstream a90ee4305c4a 57bbd979 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in alloc_pid / copy_process
2026/10/03 12:39 upstream e767a4ea70a3 57bbd979 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in alloc_pid / copy_process
2026/09/30 22:44 upstream 551c722f4080 38f7f0d1 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in alloc_pid / copy_process
2026/09/26 19:50 upstream fddfc3ec3179 a3c7249d .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in alloc_pid / copy_process
2026/09/25 12:12 upstream f49a343b305c f281d9d2 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in alloc_pid / copy_process
2026/09/25 00:59 upstream f49a343b305c 3c3cdf19 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in alloc_pid / copy_process
2026/09/21 05:53 upstream 93f51579e7df 853b104b .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in alloc_pid / copy_process
2026/09/20 20:05 upstream 518e5b794c06 853b104b .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in alloc_pid / copy_process
2026/09/19 11:27 upstream 40288c9206c1 853b104b .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in alloc_pid / copy_process
2026/09/16 07:44 upstream 9b87fdc9af2f 12a0a44a .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in alloc_pid / copy_process
2026/09/16 00:32 upstream f6e7b42bf05b 2daa4bb5 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in alloc_pid / copy_process
2026/09/15 14:40 upstream 587858367581 2daa4bb5 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in alloc_pid / copy_process
2026/09/15 05:30 upstream 587858367581 81a27d1a .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in alloc_pid / copy_process
2026/09/15 02:50 upstream 704340f1cd0d 81a27d1a .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in alloc_pid / copy_process
2026/09/14 11:04 upstream 704340f1cd0d 70a60e12 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in alloc_pid / copy_process
2026/09/08 18:02 upstream 28924df2a08f 243b72f1 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in alloc_pid / copy_process
2026/09/08 05:42 upstream 28924df2a08f 680aa3e1 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in alloc_pid / copy_process
2026/09/07 11:36 upstream df2908090cda 680aa3e1 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in alloc_pid / copy_process
2026/09/05 16:16 upstream bc35965f6940 4f7b22a0 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in alloc_pid / copy_process
2026/09/01 08:13 upstream bf1079577a11 316d9396 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in alloc_pid / copy_process
2026/08/31 14:03 upstream cee9395acd80 2f52988a .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in alloc_pid / copy_process
2026/08/29 13:04 upstream c20313e98b04 2f52988a .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in alloc_pid / copy_process
2026/08/27 21:03 upstream 73e3f0710014 69a01293 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in alloc_pid / copy_process
2026/08/27 03:50 upstream 502d45774af0 a2b77b9e .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in alloc_pid / copy_process
2026/08/24 10:56 upstream 0a0d1d55dad5 b55bd4c3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in alloc_pid / copy_process
2026/08/22 16:52 upstream 66fb95a52111 1e72964b .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in alloc_pid / copy_process
2026/08/21 13:34 upstream 818bebeb63dd 1e72964b .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in alloc_pid / copy_process
2026/08/20 03:27 upstream e8bf40d15402 1e72964b .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in alloc_pid / copy_process
2026/08/17 10:50 upstream 8d3ae59288f1 905244d6 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in alloc_pid / copy_process
2026/08/13 19:54 upstream 3aa1dcaa4f6f b13552fe .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in alloc_pid / copy_process
2026/08/11 01:48 upstream d58772d8520c 508909ea .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in alloc_pid / copy_process
2026/08/09 16:34 upstream 06cf61899d64 5d63f80b .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in alloc_pid / copy_process
2026/08/06 17:49 upstream fcaeecb8b0cd c38879ea .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in alloc_pid / copy_process
2026/08/05 04:25 upstream c21bb4193868 52aa2820 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in alloc_pid / copy_process
2026/08/03 21:05 upstream 075b74841bd0 6b7c9f71 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in alloc_pid / copy_process
2026/05/15 20:17 upstream 70eda68668d1 9cd3beaa .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in alloc_pid / copy_process
2026/03/07 10:09 upstream 651690480a96 5cb44a80 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in alloc_pid / copy_process
2026/02/24 10:45 upstream 7dff99b35460 96b1aa46 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in alloc_pid / copy_process
2026/01/08 23:00 upstream 79b95d74470d d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in alloc_pid / copy_process
2021/01/17 10:24 upstream 0da0a8a0a0e1 813be542 .config console log report info ci2-upstream-kcsan-gce
2020/06/08 23:26 https://github.com/google/ktsan.git kcsan 7c3cd68e5d38 0d60b78a .config console log report ci2-upstream-kcsan-gce
2020/06/05 14:51 https://github.com/google/ktsan.git kcsan 7c3cd68e5d38 d36418e9 .config console log report ci2-upstream-kcsan-gce
2019/11/20 23:46 https://github.com/google/ktsan.git kcsan 5863cc791e4c 8098ea0f .config console log report ci2-upstream-kcsan-gce
* Struck through repros no longer work on HEAD.