syzbot


KCSAN: data-race in dequeue_signal / ptrace_check_attach (11)

Status: moderation: reported on 2024/11/15 16:28
Subsystems: kernel
[Documentation on labels]
Reported-by: syzbot+33a9f8bebf79b4b8fe84@syzkaller.appspotmail.com
First crash: 91d, last: 18d
Similar bugs (10)
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream KCSAN: data-race in dequeue_signal / ptrace_check_attach (6) kernel 1 491d 491d 0/28 auto-obsoleted due to no activity on 2023/11/16 03:30
upstream KCSAN: data-race in dequeue_signal / ptrace_check_attach (10) kernel 1 127d 127d 0/28 auto-obsoleted due to no activity on 2024/11/13 22:28
upstream KCSAN: data-race in dequeue_signal / ptrace_check_attach (7) kernel 13 327d 430d 0/28 auto-obsoleted due to no activity on 2024/04/27 21:52
upstream KCSAN: data-race in dequeue_signal / ptrace_check_attach (5) kernel 3 530d 593d 0/28 auto-obsoleted due to no activity on 2023/10/08 11:58
upstream KCSAN: data-race in dequeue_signal / ptrace_check_attach (3) kernel 3 715d 740d 0/28 auto-obsoleted due to no activity on 2023/04/16 11:35
upstream KCSAN: data-race in dequeue_signal / ptrace_check_attach (2) kernel 1 785d 785d 0/28 auto-obsoleted due to no activity on 2023/02/02 07:54
upstream KCSAN: data-race in dequeue_signal / ptrace_check_attach (9) kernel 1 193d 193d 0/28 auto-obsoleted due to no activity on 2024/09/09 07:15
upstream KCSAN: data-race in dequeue_signal / ptrace_check_attach kernel 1 888d 888d 0/28 auto-obsoleted due to no activity on 2022/10/15 10:03
upstream KCSAN: data-race in dequeue_signal / ptrace_check_attach (4) kernel 2 654d 663d 0/28 auto-obsoleted due to no activity on 2023/06/06 04:16
upstream KCSAN: data-race in dequeue_signal / ptrace_check_attach (8) kernel 2 272d 292d 0/28 auto-obsoleted due to no activity on 2024/06/22 14:38

Sample crash report:
netlink: 168 bytes leftover after parsing attributes in process `syz.2.1219'.
==================================================================
BUG: KCSAN: data-race in dequeue_signal / ptrace_check_attach

read-write to 0xffff8881086e2638 of 8 bytes by task 6582 on cpu 1:
 dequeue_signal+0x2e3/0x370 kernel/signal.c:655
 get_signal+0x376/0x1000 kernel/signal.c:2916
 arch_do_signal_or_restart+0x95/0x4b0 arch/x86/kernel/signal.c:337
 exit_to_user_mode_loop kernel/entry/common.c:111 [inline]
 exit_to_user_mode_prepare include/linux/entry-common.h:329 [inline]
 irqentry_exit_to_user_mode+0xa7/0x120 kernel/entry/common.c:231
 irqentry_exit+0x12/0x50 kernel/entry/common.c:334
 asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:623

read to 0xffff8881086e2638 of 8 bytes by task 6579 on cpu 0:
 ptrace_freeze_traced kernel/ptrace.c:189 [inline]
 ptrace_check_attach+0x7f/0x290 kernel/ptrace.c:256
 __do_sys_ptrace kernel/ptrace.c:1280 [inline]
 __se_sys_ptrace+0xd4/0x2b0 kernel/ptrace.c:1258
 __x64_sys_ptrace+0x55/0x70 kernel/ptrace.c:1258
 x64_sys_call+0x2225/0x2dc0 arch/x86/include/generated/asm/syscalls_64.h:102
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xc9/0x1c0 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

value changed: 0x0000000000000000 -> 0x0000000008010000

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 UID: 0 PID: 6579 Comm: syz.2.1219 Not tainted 6.13.0-syzkaller-08265-g9c5968db9e62 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 12/27/2024
==================================================================

Crashes (10):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2025/01/27 17:47 upstream 9c5968db9e62 d99a33ad .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in dequeue_signal / ptrace_check_attach
2025/01/24 08:53 upstream bc8198dc7ebc 521b0ce3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in dequeue_signal / ptrace_check_attach
2025/01/22 11:55 upstream c4b9570cfb63 da72ac06 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in dequeue_signal / ptrace_check_attach
2025/01/13 22:03 upstream 5bc55a333a2f 249ceea9 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in dequeue_signal / ptrace_check_attach
2025/01/10 13:09 upstream 643e2e259c2b 67d7ec0a .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in dequeue_signal / ptrace_check_attach
2025/01/06 20:13 upstream 9d89551994a4 f3558dbf .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in dequeue_signal / ptrace_check_attach
2024/12/29 16:50 upstream 059dd502b263 d3ccff63 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in dequeue_signal / ptrace_check_attach
2024/12/17 21:17 upstream 59dbb9d81adf a0626d3a .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in dequeue_signal / ptrace_check_attach
2024/11/24 11:54 upstream 9f16d5e6f220 68da6d95 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in dequeue_signal / ptrace_check_attach
2024/11/15 16:28 upstream cfaaa7d010d1 f6ede3a3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in dequeue_signal / ptrace_check_attach
* Struck through repros no longer work on HEAD.