syzbot


KCSAN: data-race in acct_account_cputime / mmap_region (2)

Status: auto-closed as invalid on 2021/10/16 03:06
Reported-by: syzbot+@syzkaller.appspotmail.com
First crash: 462d, last: 452d
similar bugs (1):
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream KCSAN: data-race in acct_account_cputime / mmap_region 2 800d 820d 0/24 auto-closed as invalid on 2020/11/02 12:13

Sample crash report:
==================================================================
BUG: KCSAN: data-race in acct_account_cputime / mmap_region

write to 0xffff88813719ba40 of 8 bytes by task 23547 on cpu 1:
 vm_stat_account mm/mmap.c:3335 [inline]
 mmap_region+0x6f6/0x1260 mm/mmap.c:1849
 do_mmap+0x781/0xc20 mm/mmap.c:1575
 vm_mmap_pgoff+0x117/0x1f0 mm/util.c:519
 ksys_mmap_pgoff+0xcf/0x350 mm/mmap.c:1624
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x44/0xa0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x44/0xae

read to 0xffff88813719ba40 of 8 bytes by interrupt on cpu 0:
 __acct_update_integrals kernel/tsacct.c:140 [inline]
 acct_account_cputime+0x15a/0x1a0 kernel/tsacct.c:164
 update_process_times+0x5c/0x150 kernel/time/timer.c:1783
 tick_sched_handle kernel/time/tick-sched.c:226 [inline]
 tick_sched_timer+0x191/0x210 kernel/time/tick-sched.c:1421
 __run_hrtimer+0x160/0x480 kernel/time/hrtimer.c:1685
 __hrtimer_run_queues kernel/time/hrtimer.c:1749 [inline]
 hrtimer_interrupt+0x380/0xaf0 kernel/time/hrtimer.c:1811
 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1086 [inline]
 __sysvec_apic_timer_interrupt+0x6f/0x1c0 arch/x86/kernel/apic/apic.c:1103
 sysvec_apic_timer_interrupt+0x64/0x80 arch/x86/kernel/apic/apic.c:1097
 asm_sysvec_apic_timer_interrupt+0x12/0x20
 finish_task_switch+0xda/0x290 kernel/sched/core.c:4814
 context_switch kernel/sched/core.c:4943 [inline]
 __schedule+0x435/0x680 kernel/sched/core.c:6287
 schedule+0x67/0x90 kernel/sched/core.c:6366
 schedule_timeout+0x51/0x250 kernel/time/timer.c:1857
 unix_wait_for_peer+0x12e/0x1d0 net/unix/af_unix.c:1280
 unix_dgram_sendmsg+0xd3b/0x1650 net/unix/af_unix.c:1868
 sock_sendmsg_nosec net/socket.c:704 [inline]
 sock_sendmsg net/socket.c:724 [inline]
 ____sys_sendmsg+0x39a/0x510 net/socket.c:2409
 ___sys_sendmsg net/socket.c:2463 [inline]
 __sys_sendmmsg+0x388/0x520 net/socket.c:2549
 __do_sys_sendmmsg net/socket.c:2578 [inline]
 __se_sys_sendmmsg net/socket.c:2575 [inline]
 __x64_sys_sendmmsg+0x53/0x60 net/socket.c:2575
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x44/0xa0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x44/0xae

value changed: 0x0000000000005332 -> 0x0000000000005353

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 PID: 23552 Comm: syz-executor.0 Not tainted 5.14.0-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 2021/09/11 03:03 upstream e99f23c5bf59 3ce60af8 .config log report info KCSAN: data-race in acct_account_cputime / mmap_region
ci2-upstream-kcsan-gce 2021/09/01 19:54 upstream 835d31d319d9 7eb7e152 .config log report info KCSAN: data-race in acct_account_cputime / mmap_region
* Struck through repros no longer work on HEAD.