syzbot


KCSAN: data-race in do_nanosleep / proc_cgroup_show

Status: auto-closed as invalid on 2020/08/26 19:07
Reported-by: syzbot+@syzkaller.appspotmail.com
First crash: 809d, last: 797d

Sample crash report:
==================================================================
BUG: KCSAN: data-race in do_nanosleep / proc_cgroup_show

write to 0xffff8880ae705024 of 4 bytes by task 12298 on cpu 1:
 freezer_count include/linux/freezer.h:121 [inline]
 freezable_schedule include/linux/freezer.h:173 [inline]
 do_nanosleep+0x121/0x3a0 kernel/time/hrtimer.c:1879
 hrtimer_nanosleep kernel/time/hrtimer.c:1932 [inline]
 __do_sys_nanosleep kernel/time/hrtimer.c:1966 [inline]
 __se_sys_nanosleep+0x20b/0x2a0 kernel/time/hrtimer.c:1953
 __x64_sys_nanosleep+0x2d/0x40 kernel/time/hrtimer.c:1953
 do_syscall_64+0x51/0xb0 arch/x86/entry/common.c:384
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

read to 0xffff8880ae705024 of 4 bytes by task 12303 on cpu 0:
 proc_cgroup_show+0x3b3/0x6a0 kernel/cgroup/cgroup.c:5856
 proc_single_show+0x84/0x100 fs/proc/base.c:766
 seq_read+0x2ee/0x900 fs/seq_file.c:208
 do_loop_readv_writev fs/read_write.c:734 [inline]
 do_iter_read+0x3f5/0x480 fs/read_write.c:955
 vfs_readv fs/read_write.c:1073 [inline]
 do_preadv+0x13b/0x230 fs/read_write.c:1165
 __do_sys_preadv fs/read_write.c:1215 [inline]
 __se_sys_preadv fs/read_write.c:1210 [inline]
 __x64_sys_preadv+0x54/0x60 fs/read_write.c:1210
 do_syscall_64+0x51/0xb0 arch/x86/entry/common.c:384
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 PID: 12303 Comm: syz-executor.4 Not tainted 5.8.0-rc6-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
==================================================================

Crashes (2):
Manager Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Title
ci2-upstream-kcsan-gce 2020/07/22 19:05 upstream 8c26c87b0532 128cd85f .config log report
ci2-upstream-kcsan-gce 2020/07/10 09:46 upstream 42f82040ee66 56d01184 .config log report
* Struck through repros no longer work on HEAD.