syzbot


KCSAN: data-race in close_fd_get_file / do_select (2)

Status: auto-obsoleted due to no activity on 2023/12/13 06:44
Subsystems: fs
[Documentation on labels]
Reported-by: syzbot+fd4f1f5dbf7f6926a47f@syzkaller.appspotmail.com
First crash: 106d, last: 106d
Similar bugs (1)
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream KCSAN: data-race in close_fd_get_file / do_select fs 1 165d 165d 0/26 auto-obsoleted due to no activity on 2023/10/15 19:22

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

write to 0xffff88811d087600 of 8 bytes by task 14951 on cpu 0:
 instrument_write include/linux/instrumented.h:41 [inline]
 ___clear_bit include/asm-generic/bitops/instrumented-non-atomic.h:44 [inline]
 __clear_open_fd fs/file.c:270 [inline]
 __put_unused_fd fs/file.c:571 [inline]
 pick_file fs/file.c:652 [inline]
 close_fd_get_file+0xf3/0x1a0 fs/file.c:817
 __do_sys_close fs/open.c:1580 [inline]
 __se_sys_close+0x17/0x1a0 fs/open.c:1575
 __x64_sys_close+0x1f/0x30 fs/open.c:1575
 do_syscall_x64 arch/x86/entry/common.c:51 [inline]
 do_syscall_64+0x44/0x110 arch/x86/entry/common.c:82
 entry_SYSCALL_64_after_hwframe+0x63/0x6b

read to 0xffff88811d087600 of 8 bytes by task 14953 on cpu 1:
 max_select_fd fs/select.c:447 [inline]
 do_select+0x2a2/0xf90 fs/select.c:490
 core_sys_select+0x361/0x520 fs/select.c:681
 do_pselect fs/select.c:763 [inline]
 __do_sys_pselect6 fs/select.c:804 [inline]
 __se_sys_pselect6+0x213/0x280 fs/select.c:795
 __x64_sys_pselect6+0x78/0x90 fs/select.c:795
 do_syscall_x64 arch/x86/entry/common.c:51 [inline]
 do_syscall_64+0x44/0x110 arch/x86/entry/common.c:82
 entry_SYSCALL_64_after_hwframe+0x63/0x6b

value changed: 0xffffffffffff0007 -> 0xffffffffffe00007

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 PID: 14953 Comm: syz-executor.4 Not tainted 6.6.0-syzkaller-15156-g13d88ac54ddd #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/09/2023
==================================================================

Crashes (1):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2023/11/08 06:43 upstream 13d88ac54ddd 83211397 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in close_fd_get_file / do_select
* Struck through repros no longer work on HEAD.