syzbot


KCSAN: data-race in exec_mmap / mm_update_next_owner (5)

Status: moderation: reported on 2024/07/08 23:05
Subsystems: fs mm
[Documentation on labels]
Reported-by: syzbot+a34e05bc2c7066e437bc@syzkaller.appspotmail.com
First crash: 10d, last: 10d
Similar bugs (4)
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream KCSAN: data-race in exec_mmap / mm_update_next_owner (4) fs mm 1 152d 152d 0/27 auto-obsoleted due to no activity on 2024/03/24 16:03
upstream KCSAN: data-race in exec_mmap / mm_update_next_owner (2) fs mm 13 283d 415d 0/27 auto-obsoleted due to no activity on 2023/11/14 07:06
upstream KCSAN: data-race in exec_mmap / mm_update_next_owner (3) mm fs 1 247d 221d 0/27 auto-obsoleted due to no activity on 2023/12/25 00:09
upstream KCSAN: data-race in exec_mmap / mm_update_next_owner fs mm 36 466d 769d 0/27 auto-obsoleted due to no activity on 2023/05/15 19:34

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

write to 0xffff88810a963680 of 8 bytes by task 24880 on cpu 1:
 exec_mmap+0x14f/0x430 fs/exec.c:1041
 begin_new_exec+0xac9/0x1080 fs/exec.c:1329
 load_elf_binary+0x641/0x1870 fs/binfmt_elf.c:996
 search_binary_handler fs/exec.c:1797 [inline]
 exec_binprm fs/exec.c:1839 [inline]
 bprm_execve+0x4e6/0xc60 fs/exec.c:1891
 kernel_execve+0x60f/0x670 fs/exec.c:2058
 call_usermodehelper_exec_async+0x19d/0x250 kernel/umh.c:110
 ret_from_fork+0x4b/0x60 arch/x86/kernel/process.c:147
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244

read to 0xffff88810a963680 of 8 bytes by task 24881 on cpu 0:
 mm_update_next_owner+0x1c9/0x450 kernel/exit.c:492
 exit_mm+0xdc/0x190 kernel/exit.c:566
 do_exit+0x556/0x1710 kernel/exit.c:863
 do_group_exit+0x142/0x150 kernel/exit.c:1025
 __do_sys_exit_group kernel/exit.c:1036 [inline]
 __se_sys_exit_group kernel/exit.c:1034 [inline]
 __x64_sys_exit_group+0x1f/0x20 kernel/exit.c:1034
 x64_sys_call+0x27f9/0x2d70 arch/x86/include/generated/asm/syscalls_64.h:232
 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 -> 0xffff888112a78540

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 PID: 24881 Comm: syz.3.7502 Tainted: G        W          6.10.0-rc7-syzkaller-00003-g4376e966ecb7 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/07/2024
==================================================================

Crashes (1):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2024/07/08 23:04 upstream 4376e966ecb7 cde64f7d .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in exec_mmap / mm_update_next_owner
* Struck through repros no longer work on HEAD.