syzbot


KCSAN: data-race in do_madvise / do_madvise

Status: moderation: reported on 2024/05/19 13:28
Subsystems: mm
[Documentation on labels]
Reported-by: syzbot+cf5ad1c95534522a611b@syzkaller.appspotmail.com
First crash: 26d, last: 26d

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

write to 0xffff888103220630 of 8 bytes by task 17120 on cpu 0:
 update_hiwater_rss include/linux/mm.h:2657 [inline]
 madvise_free_single_vma mm/madvise.c:781 [inline]
 madvise_dontneed_free mm/madvise.c:899 [inline]
 madvise_vma_behavior mm/madvise.c:1023 [inline]
 madvise_walk_vmas mm/madvise.c:1248 [inline]
 do_madvise+0x155c/0x2600 mm/madvise.c:1428
 __do_sys_madvise mm/madvise.c:1441 [inline]
 __se_sys_madvise mm/madvise.c:1439 [inline]
 __x64_sys_madvise+0x61/0x70 mm/madvise.c:1439
 x64_sys_call+0x2825/0x2d30 arch/x86/include/generated/asm/syscalls_64.h:29
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xcd/0x1d0 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

read to 0xffff888103220630 of 8 bytes by task 17119 on cpu 1:
 update_hiwater_rss include/linux/mm.h:2656 [inline]
 madvise_free_single_vma mm/madvise.c:781 [inline]
 madvise_dontneed_free mm/madvise.c:899 [inline]
 madvise_vma_behavior mm/madvise.c:1023 [inline]
 madvise_walk_vmas mm/madvise.c:1248 [inline]
 do_madvise+0x1534/0x2600 mm/madvise.c:1428
 __do_sys_madvise mm/madvise.c:1441 [inline]
 __se_sys_madvise mm/madvise.c:1439 [inline]
 __x64_sys_madvise+0x61/0x70 mm/madvise.c:1439
 x64_sys_call+0x2825/0x2d30 arch/x86/include/generated/asm/syscalls_64.h:29
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xcd/0x1d0 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

value changed: 0x0000000000000850 -> 0x00000000000008f0

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 PID: 17119 Comm: syz-executor.4 Tainted: G        W          6.9.0-syzkaller-08995-g0450d2083be6 #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
2024/05/19 13:27 upstream 0450d2083be6 c0f1611a .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in do_madvise / do_madvise
* Struck through repros no longer work on HEAD.