syzbot


KCSAN: data-race in __should_fail_alloc_page / debugfs_write_file_bool

Status: moderation: reported on 2024/06/01 04:59
Subsystems: fs
[Documentation on labels]
Reported-by: syzbot+5eb7efe76f46bca6bd71@syzkaller.appspotmail.com
First crash: 21d, last: 21d

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

write to 0xffffffff86183ea8 of 1 bytes by task 3088 on cpu 0:
 debugfs_write_file_bool+0xbd/0x160 fs/debugfs/file.c:911
 vfs_write+0x28b/0x900 fs/read_write.c:588
 ksys_write+0xeb/0x1b0 fs/read_write.c:643
 __do_sys_write fs/read_write.c:655 [inline]
 __se_sys_write fs/read_write.c:652 [inline]
 __x64_sys_write+0x42/0x50 fs/read_write.c:652
 x64_sys_call+0x27ef/0x2d70 arch/x86/include/generated/asm/syscalls_64.h:2
 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

read to 0xffffffff86183ea8 of 1 bytes by task 3089 on cpu 1:
 __should_fail_alloc_page+0x57/0x110 mm/fail_page_alloc.c:32
 prepare_alloc_pages mm/page_alloc.c:4433 [inline]
 __alloc_pages_noprof+0x109/0x360 mm/page_alloc.c:4649
 alloc_pages_mpol_noprof+0xb1/0x1e0 mm/mempolicy.c:2265
 alloc_pages_noprof+0xe1/0x100 mm/mempolicy.c:2336
 get_free_pages_noprof+0xc/0x30 mm/page_alloc.c:4707
 _pgd_alloc arch/x86/mm/pgtable.c:423 [inline]
 pgd_alloc+0x22/0x170 arch/x86/mm/pgtable.c:439
 mm_alloc_pgd kernel/fork.c:796 [inline]
 mm_init+0x372/0x6f0 kernel/fork.c:1295
 mm_alloc+0x81/0xa0 kernel/fork.c:1335
 bprm_mm_init fs/exec.c:385 [inline]
 alloc_bprm+0x1c8/0x5e0 fs/exec.c:1599
 do_execveat_common+0x138/0x7d0 fs/exec.c:1949
 do_execve fs/exec.c:2072 [inline]
 __do_sys_execve fs/exec.c:2148 [inline]
 __se_sys_execve fs/exec.c:2143 [inline]
 __x64_sys_execve+0x5a/0x70 fs/exec.c:2143
 x64_sys_call+0x1378/0x2d70 arch/x86/include/generated/asm/syscalls_64.h:60
 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: 0x01 -> 0x00

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 PID: 3089 Comm: syz-fuzzer Not tainted 6.10.0-rc1-syzkaller-00104-gd8ec19857b09 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/02/2024
==================================================================

Crashes (1):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2024/06/01 04:58 upstream d8ec19857b09 3113787f .config console log report [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in __should_fail_alloc_page / debugfs_write_file_bool
* Struck through repros no longer work on HEAD.