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KCSAN: data-race in copy_process / copy_process

Status: closed as invalid on 2019/10/18 14:11
Subsystems: kasan
[Documentation on labels]
First crash: 1593d, last: 1593d
Similar bugs (1)
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream KCSAN: data-race in copy_process / copy_process (2) kernel 294 1332d 1509d 15/26 fixed on 2020/08/01 00:48

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

read to 0xffffffff85ff6558 of 4 bytes by task 7533 on cpu 1:
 copy_process+0x91e/0x37f0 kernel/fork.c:1899
 _do_fork+0xfe/0x6e0 kernel/fork.c:2371
 __do_sys_clone kernel/fork.c:2526 [inline]
 __se_sys_clone kernel/fork.c:2507 [inline]
 __x64_sys_clone+0x12b/0x160 kernel/fork.c:2507
 do_syscall_64+0xcf/0x2f0 arch/x86/entry/common.c:296
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

write to 0xffffffff85ff6558 of 4 bytes by task 7566 on cpu 0:
 copy_process+0x2ade/0x37f0 kernel/fork.c:2223
 _do_fork+0xfe/0x6e0 kernel/fork.c:2371
 __do_sys_clone kernel/fork.c:2526 [inline]
 __se_sys_clone kernel/fork.c:2507 [inline]
 __x64_sys_clone+0x12b/0x160 kernel/fork.c:2507
 do_syscall_64+0xcf/0x2f0 arch/x86/entry/common.c:296
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 PID: 7566 Comm: syz-executor.5 Not tainted 5.3.0+ #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
==================================================================
Kernel panic - not syncing: panic_on_warn set ...
CPU: 0 PID: 7566 Comm: syz-executor.5 Not tainted 5.3.0+ #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 __dump_stack lib/dump_stack.c:77 [inline]
 dump_stack+0xf5/0x159 lib/dump_stack.c:113
 panic+0x209/0x639 kernel/panic.c:219
 kcsan_report.cold+0xc/0x1b kernel/kcsan/report.c:303
 __kcsan_setup_watchpoint+0x3ee/0x510 kernel/kcsan/core.c:440
 __tsan_write4 kernel/kcsan/kcsan.c:30 [inline]
 __tsan_write4+0x32/0x40 kernel/kcsan/kcsan.c:30
 copy_process+0x2ade/0x37f0 kernel/fork.c:2223
 _do_fork+0xfe/0x6e0 kernel/fork.c:2371
 __do_sys_clone kernel/fork.c:2526 [inline]
 __se_sys_clone kernel/fork.c:2507 [inline]
 __x64_sys_clone+0x12b/0x160 kernel/fork.c:2507
 do_syscall_64+0xcf/0x2f0 arch/x86/entry/common.c:296
 entry_SYSCALL_64_after_hwframe+0x44/0xa9
RIP: 0033:0x45c429
Code: ff 48 85 f6 0f 84 27 8e fb ff 48 83 ee 10 48 89 4e 08 48 89 3e 48 89 d7 4c 89 c2 4d 89 c8 4c 8b 54 24 08 b8 38 00 00 00 0f 05 <48> 85 c0 0f 8c fe 8d fb ff 74 01 c3 31 ed 48 f7 c7 00 00 01 00 75
RSP: 002b:00007ffcff20d2b8 EFLAGS: 00000202 ORIG_RAX: 0000000000000038
RAX: ffffffffffffffda RBX: 00007f4d6a4c3700 RCX: 000000000045c429
RDX: 00007f4d6a4c39d0 RSI: 00007f4d6a4c2db0 RDI: 00000000003d0f00
RBP: 00007ffcff20d4d0 R08: 00007f4d6a4c3700 R09: 00007f4d6a4c3700
R10: 00007f4d6a4c39d0 R11: 0000000000000202 R12: 0000000000000000
R13: 00007ffcff20d36f R14: 00007f4d6a4c39c0 R15: 000000000075bfd4
Shutting down cpus with NMI
Kernel Offset: disabled
Rebooting in 86400 seconds..

Crashes (1):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2019/10/15 16:28 https://github.com/google/ktsan.git kcsan 81f95ec7998e b5268b89 .config console log report ci2-upstream-kcsan-gce
* Struck through repros no longer work on HEAD.