syzbot


KCSAN: data-race in init_file / prepare_creds (2)

Status: moderation: reported on 2025/07/27 03:30
Subsystems: fs
[Documentation on labels]
Reported-by: syzbot+0873b15fae924aab48d4@syzkaller.appspotmail.com
First crash: 229d, last: 1d08h
✨ AI Jobs (2)
ID Workflow Result Correct Bug Created Started Finished Revision Error
e38c6a5e-4c62-4641-80f1-21efe2c512ef repro KCSAN: data-race in init_file / prepare_creds (2) 2026/03/10 13:36 2026/03/10 22:35 2026/03/10 23:01 86914af9098a80da53c3c5d46be980c572ee29f8
44cc4b32-787f-4637-bbfc-95a656d71dc9 assessment-kcsan Benign: ✅  Confident: ✅  KCSAN: data-race in init_file / prepare_creds (2) 2026/01/14 18:13 2026/01/14 18:13 2026/01/14 18:17 a9d6a79219801d2130df3b1a792c57f0e5428e9f
Similar bugs (1)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream KCSAN: data-race in init_file / prepare_creds fs 6 1 287d 287d 0/29 auto-obsoleted due to no activity on 2025/07/25 02:49

Sample crash report:
==================================================================
BUG: KCSAN: data-race in init_file / prepare_creds

write to 0xffff888101cf78e8 of 4 bytes by task 8581 on cpu 0:
 get_cred_many include/linux/cred.h:218 [inline]
 get_cred include/linux/cred.h:234 [inline]
 init_file+0x2d/0x1b0 fs/file_table.c:158
 alloc_empty_file+0x8b/0x200 fs/file_table.c:241
 alloc_file fs/file_table.c:355 [inline]
 alloc_file_pseudo+0xf6/0x190 fs/file_table.c:384
 sock_alloc_file+0x9c/0x1e0 net/socket.c:483
 sock_map_fd net/socket.c:513 [inline]
 __sys_socket+0x115/0x180 net/socket.c:1756
 __do_sys_socket net/socket.c:1761 [inline]
 __se_sys_socket net/socket.c:1759 [inline]
 __x64_sys_socket+0x3f/0x50 net/socket.c:1759
 x64_sys_call+0x11fc/0x3020 arch/x86/include/generated/asm/syscalls_64.h:42
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0x12c/0x370 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

read to 0xffff888101cf7840 of 184 bytes by task 8578 on cpu 1:
 prepare_creds+0x6d/0x540 kernel/cred.c:192
 copy_creds+0x8f/0x340 kernel/cred.c:286
 copy_process+0x62f/0x20d0 kernel/fork.c:2084
 kernel_clone+0x16b/0x5d0 kernel/fork.c:2654
 __do_sys_clone3 kernel/fork.c:2956 [inline]
 __se_sys_clone3+0x1f5/0x230 kernel/fork.c:2935
 __x64_sys_clone3+0x31/0x40 kernel/fork.c:2935
 x64_sys_call+0x580/0x3020 arch/x86/include/generated/asm/syscalls_64.h:436
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0x12c/0x370 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 UID: 0 PID: 8578 Comm: syz.4.1121 Tainted: G        W           syzkaller #0 PREEMPT(full) 
Tainted: [W]=WARN
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026
==================================================================

Crashes (21):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2026/03/12 02:11 upstream b29fb8829bff 2d88ab01 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in init_file / prepare_creds
2026/02/02 07:41 upstream 9f2693489ef8 6b8752f2 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in init_file / prepare_creds
2026/01/28 20:11 upstream 8dfce8991b95 004c195c .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in init_file / prepare_creds
2026/01/24 20:50 upstream 62085877ae65 40acda8a .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in init_file / prepare_creds
2026/01/24 04:54 upstream 5bde837031a3 4f25b9b4 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in init_file / prepare_creds
2026/01/10 06:22 upstream 372800cb95a3 d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in init_file / prepare_creds
2026/01/08 10:18 upstream f0b9d8eb98df d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in init_file / prepare_creds
2026/01/04 06:56 upstream aacb0a6d604a d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in init_file / prepare_creds
2025/12/30 05:21 upstream 8640b74557fc d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in init_file / prepare_creds
2025/12/29 10:59 upstream 7839932417dd d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in init_file / prepare_creds
2025/12/07 02:08 upstream cc3ee4ba57b7 d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in init_file / prepare_creds
2025/12/01 14:15 upstream 7d0a66e4bb90 d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in init_file / prepare_creds
2025/11/22 16:25 upstream 2eba5e05d9bc 4fb8ef37 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in init_file / prepare_creds
2025/11/17 20:17 upstream e7c375b18160 ef766cd7 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in init_file / prepare_creds
2025/11/15 20:58 upstream 7a0892d2836e f7988ea4 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in init_file / prepare_creds
2025/11/03 03:32 upstream 6146a0f1dfae 2c50b6a9 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in init_file / prepare_creds
2025/10/06 20:58 upstream fd94619c4336 91305dbe .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in init_file / prepare_creds
2025/10/04 06:22 upstream 9b0d551bcc05 49379ee0 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in init_file / prepare_creds
2025/09/21 15:36 upstream f975f08c2e89 67c37560 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in init_file / prepare_creds
2025/08/03 17:26 upstream 186f3edfdd41 7368264b .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in init_file / prepare_creds
2025/07/27 03:29 upstream 302f88ff3584 fb8f743d .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in init_file / prepare_creds
* Struck through repros no longer work on HEAD.