syzbot


KCSAN: data-race in getrusage / try_to_unmap_one

Status: moderation: reported on 2024/04/04 07:56
Subsystems: mm
[Documentation on labels]
Reported-by: syzbot+e56458f60991622c35e8@syzkaller.appspotmail.com
First crash: 26d, last: 26d

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

write to 0xffff888129174630 of 8 bytes by task 28295 on cpu 0:
 update_hiwater_rss include/linux/mm.h:2655 [inline]
 try_to_unmap_one+0x7f8/0x15a0 mm/rmap.c:1774
 rmap_walk_anon+0x295/0x430 mm/rmap.c:2599
 try_to_unmap+0xe9/0x110
 shrink_folio_list+0xde0/0x2460 mm/vmscan.c:1260
 reclaim_folio_list+0x81/0x1e0 mm/vmscan.c:2108
 reclaim_pages+0x227/0x290 mm/vmscan.c:2145
 madvise_cold_or_pageout_pte_range+0xaa0/0xb30 mm/madvise.c:527
 walk_pmd_range mm/pagewalk.c:143 [inline]
 walk_pud_range mm/pagewalk.c:221 [inline]
 walk_p4d_range mm/pagewalk.c:256 [inline]
 walk_pgd_range+0x80d/0xef0 mm/pagewalk.c:293
 __walk_page_range+0xc5/0x330 mm/pagewalk.c:395
 walk_page_range+0x2c5/0x400 mm/pagewalk.c:521
 madvise_pageout_page_range mm/madvise.c:586 [inline]
 madvise_pageout mm/madvise.c:613 [inline]
 madvise_vma_behavior mm/madvise.c:1032 [inline]
 madvise_walk_vmas mm/madvise.c:1261 [inline]
 do_madvise+0x1a38/0x2620 mm/madvise.c:1441
 __do_sys_madvise mm/madvise.c:1454 [inline]
 __se_sys_madvise mm/madvise.c:1452 [inline]
 __x64_sys_madvise+0x61/0x70 mm/madvise.c:1452
 do_syscall_64+0xd3/0x1d0
 entry_SYSCALL_64_after_hwframe+0x72/0x7a

read to 0xffff888129174630 of 8 bytes by task 28296 on cpu 1:
 get_mm_hiwater_rss include/linux/mm.h:2642 [inline]
 setmax_mm_hiwater_rss include/linux/mm.h:2672 [inline]
 getrusage+0xa35/0xb90 kernel/sys.c:1861
 io_sq_thread+0x4d3/0xef0 io_uring/sqpoll.c:305
 ret_from_fork+0x4b/0x60 arch/x86/kernel/process.c:147
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:243

value changed: 0x0000000000000940 -> 0x0000000000001140

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 PID: 28296 Comm: iou-sqp-28295 Tainted: G        W          6.9.0-rc2-syzkaller-00080-gc85af715cac0 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/27/2024
==================================================================

Crashes (1):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2024/04/04 07:55 upstream c85af715cac0 51c4dcff .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in getrusage / try_to_unmap_one
* Struck through repros no longer work on HEAD.