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KCSAN: data-race in bprm_execve / copy_process

Status: auto-closed as invalid on 2020/10/29 15:12
Subsystems: fs mm
[Documentation on labels]
First crash: 1302d, last: 1302d
Similar bugs (3)
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream KCSAN: data-race in bprm_execve / copy_process (4) fs mm 1 930d 930d 0/26 auto-closed as invalid on 2021/11/06 00:03
upstream KCSAN: data-race in bprm_execve / copy_process (2) fs mm 2 1194d 1223d 0/26 auto-closed as invalid on 2021/02/14 15:47
upstream KCSAN: data-race in bprm_execve / copy_process (3) fs mm 1 976d 976d 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 0xffff88812b7cc050 of 4 bytes by task 21510 on cpu 0:
 bprm_execve+0x56a/0x610 fs/exec.c:1956
 do_execveat_common+0x605/0x6d0 fs/exec.c:2026
 do_execve fs/exec.c:2094 [inline]
 __do_sys_execve fs/exec.c:2170 [inline]
 __se_sys_execve fs/exec.c:2165 [inline]
 __x64_sys_execve+0x56/0x70 fs/exec.c:2165
 do_syscall_64+0x39/0x80 arch/x86/entry/common.c:46
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

read to 0xffff88812b7cc050 of 4 bytes by task 21501 on cpu 1:
 copy_fs kernel/fork.c:1429 [inline]
 copy_process+0xd0f/0x2dc0 kernel/fork.c:2060
 _do_fork+0x14a/0x6c0 kernel/fork.c:2428
 __do_sys_clone kernel/fork.c:2545 [inline]
 __se_sys_clone kernel/fork.c:2529 [inline]
 __x64_sys_clone+0xc8/0xf0 kernel/fork.c:2529
 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: 21501 Comm: syz-executor.1 Not tainted 5.9.0-rc6-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: 21501 Comm: syz-executor.1 Not tainted 5.9.0-rc6-syzkaller #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+0x10f/0x19d lib/dump_stack.c:118
 panic+0x207/0x64a kernel/panic.c:231
 kcsan_report+0x684/0x690 kernel/kcsan/report.c:630
 kcsan_setup_watchpoint+0x41e/0x4a0 kernel/kcsan/core.c:540
 copy_fs kernel/fork.c:1429 [inline]
 copy_process+0xd0f/0x2dc0 kernel/fork.c:2060
 _do_fork+0x14a/0x6c0 kernel/fork.c:2428
 __do_sys_clone kernel/fork.c:2545 [inline]
 __se_sys_clone kernel/fork.c:2529 [inline]
 __x64_sys_clone+0xc8/0xf0 kernel/fork.c:2529
 do_syscall_64+0x39/0x80 arch/x86/entry/common.c:46
 entry_SYSCALL_64_after_hwframe+0x44/0xa9
RIP: 0033:0x460b49
Code: ff 48 85 f6 0f 84 67 88 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 3e 88 fb ff 74 01 c3 31 ed 48 f7 c7 00 00 01 00 75
RSP: 002b:00007ffd94076678 EFLAGS: 00000202 ORIG_RAX: 0000000000000038
RAX: ffffffffffffffda RBX: 00007fcd9f865700 RCX: 0000000000460b49
RDX: 00007fcd9f8659d0 RSI: 00007fcd9f864db0 RDI: 00000000003d0f00
RBP: 00007ffd940768a0 R08: 00007fcd9f865700 R09: 00007fcd9f865700
R10: 00007fcd9f8659d0 R11: 0000000000000202 R12: 0000000000000000
R13: 00007ffd9407672f R14: 0000000000020000 R15: 0000000002613c90
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
2020/09/24 15:02 upstream c9c9e6a49f89 54289b08 .config console log report info ci2-upstream-kcsan-gce
* Struck through repros no longer work on HEAD.