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

Status: auto-closed as invalid on 2021/02/14 15:47
Subsystems: fs mm
[Documentation on labels]
First crash: 1166d, last: 1138d
Similar bugs (3)
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream KCSAN: data-race in bprm_execve / copy_process mm fs 1 1246d 1246d 0/26 auto-closed as invalid on 2020/10/29 15:12
upstream KCSAN: data-race in bprm_execve / copy_process (4) fs mm 1 873d 873d 0/26 auto-closed as invalid on 2021/11/06 00:03
upstream KCSAN: data-race in bprm_execve / copy_process (3) fs mm 1 920d 920d 0/26 auto-closed as invalid on 2021/09/20 14:52

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

write to 0xffff888101646a90 of 4 bytes by task 20117 on cpu 0:
 bprm_execve+0x495/0x4f0 fs/exec.c:1849
 do_execveat_common+0x60c/0x6c0 fs/exec.c:1915
 do_execve fs/exec.c:1983 [inline]
 __do_sys_execve fs/exec.c:2059 [inline]
 __se_sys_execve fs/exec.c:2054 [inline]
 __x64_sys_execve+0x56/0x70 fs/exec.c:2054
 do_syscall_64+0x39/0x80 arch/x86/entry/common.c:46
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

read to 0xffff888101646a90 of 4 bytes by task 20111 on cpu 1:
 copy_fs kernel/fork.c:1436 [inline]
 copy_process+0xd3a/0x2da0 kernel/fork.c:2090
 kernel_clone+0x14b/0x680 kernel/fork.c:2464
 __do_sys_clone kernel/fork.c:2581 [inline]
 __se_sys_clone kernel/fork.c:2565 [inline]
 __x64_sys_clone+0xc8/0xf0 kernel/fork.c:2565
 do_syscall_64+0x39/0x80 arch/x86/entry/common.c:46
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 PID: 20111 Comm: syz-executor.4 Not tainted 5.11.0-rc2-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
==================================================================
Kernel panic - not syncing: panic_on_warn set ...
CPU: 1 PID: 20111 Comm: syz-executor.4 Not tainted 5.11.0-rc2-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 __dump_stack lib/dump_stack.c:79 [inline]
 dump_stack+0x116/0x15d lib/dump_stack.c:120
 panic+0x1e7/0x5fa kernel/panic.c:231
 kcsan_report+0x67b/0x680 kernel/kcsan/report.c:634
 kcsan_setup_watchpoint+0x47b/0x4e0 kernel/kcsan/core.c:568
 copy_fs kernel/fork.c:1436 [inline]
 copy_process+0xd3a/0x2da0 kernel/fork.c:2090
 kernel_clone+0x14b/0x680 kernel/fork.c:2464
 __do_sys_clone kernel/fork.c:2581 [inline]
 __se_sys_clone kernel/fork.c:2565 [inline]
 __x64_sys_clone+0xc8/0xf0 kernel/fork.c:2565
 do_syscall_64+0x39/0x80 arch/x86/entry/common.c:46
 entry_SYSCALL_64_after_hwframe+0x44/0xa9
RIP: 0033:0x460be9
Code: ff 48 85 f6 0f 84 37 8a 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 0e 8a fb ff 74 01 c3 31 ed 48 f7 c7 00 00 01 00 75
RSP: 002b:00007fffa39ea2c8 EFLAGS: 00000202 ORIG_RAX: 0000000000000038
RAX: ffffffffffffffda RBX: 00007f9ad8ac8700 RCX: 0000000000460be9
RDX: 00007f9ad8ac89d0 RSI: 00007f9ad8ac7db0 RDI: 00000000003d0f00
RBP: 00007fffa39ea4e0 R08: 00007f9ad8ac8700 R09: 00007f9ad8ac8700
R10: 00007f9ad8ac89d0 R11: 0000000000000202 R12: 0000000000000000
R13: 00007fffa39ea37f R14: 0000000000020000 R15: 00000000018fcc90
Kernel Offset: disabled
Rebooting in 86400 seconds..

Crashes (2):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2021/01/10 15:38 upstream 2ff90100ace8 2c1f2513 .config console log report info ci2-upstream-kcsan-gce
2020/12/13 05:19 upstream 7b1b868e1d91 bca53db9 .config console log report info ci2-upstream-kcsan-gce
* Struck through repros no longer work on HEAD.