syzbot


KCSAN: data-race in getrusage / try_to_unmap_one (2)

Status: upstream: reported on 2025/04/03 07:05
Subsystems: mm
[Documentation on labels]
Reported-by: syzbot+988c9343ca9f2c49b9c4@syzkaller.appspotmail.com
First crash: 23d, last: 20h09m
Discussions (1)
Title Replies (including bot) Last reply
[syzbot] [mm?] KCSAN: data-race in getrusage / try_to_unmap_one (2) 0 (1) 2025/04/03 07:05
Similar bugs (1)
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream KCSAN: data-race in getrusage / try_to_unmap_one mm 1 387d 387d 0/28 auto-obsoleted due to no activity on 2024/05/09 07:56

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

write to 0xffff88810005fa00 of 8 bytes by task 3586 on cpu 0:
 update_hiwater_rss include/linux/mm.h:2771 [inline]
 try_to_unmap_one+0xf0e/0x2140 mm/rmap.c:2061
 __rmap_walk_file+0x1e9/0x2b0 mm/rmap.c:2897
 try_to_unmap+0x1ae/0x1e0 mm/rmap.c:-1
 shrink_folio_list+0x121a/0x2670 mm/vmscan.c:1373
 reclaim_folio_list+0x80/0x2b0 mm/vmscan.c:2217
 reclaim_pages+0x215/0x270 mm/vmscan.c:2254
 madvise_cold_or_pageout_pte_range+0xd61/0xdd0 mm/madvise.c:558
 walk_pmd_range mm/pagewalk.c:130 [inline]
 walk_pud_range mm/pagewalk.c:226 [inline]
 walk_p4d_range mm/pagewalk.c:264 [inline]
 walk_pgd_range+0x86b/0x11b0 mm/pagewalk.c:305
 __walk_page_range+0xdd/0x340 mm/pagewalk.c:412
 walk_page_range_mm+0x352/0x4a0 mm/pagewalk.c:505
 walk_page_range+0x56/0x70 mm/pagewalk.c:584
 madvise_pageout_page_range mm/madvise.c:617 [inline]
 madvise_pageout mm/madvise.c:644 [inline]
 madvise_vma_behavior mm/madvise.c:1269 [inline]
 madvise_walk_vmas mm/madvise.c:1530 [inline]
 madvise_do_behavior+0x1bea/0x24a0 mm/madvise.c:1695
 do_madvise mm/madvise.c:1782 [inline]
 __do_sys_madvise mm/madvise.c:1790 [inline]
 __se_sys_madvise mm/madvise.c:1788 [inline]
 __x64_sys_madvise+0xc9/0x100 mm/madvise.c:1788
 x64_sys_call+0x2455/0x2fb0 arch/x86/include/generated/asm/syscalls_64.h:29
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xd0/0x1a0 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

read to 0xffff88810005fa00 of 8 bytes by task 3600 on cpu 1:
 get_mm_hiwater_rss include/linux/mm.h:2758 [inline]
 setmax_mm_hiwater_rss include/linux/mm.h:2788 [inline]
 getrusage+0xa52/0xbb0 kernel/sys.c:1876
 io_sq_thread+0x5dd/0x1110 io_uring/sqpoll.c:310
 ret_from_fork+0x4b/0x60 arch/x86/kernel/process.c:153
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245

value changed: 0x00000000000016f4 -> 0x0000000000001721

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 UID: 0 PID: 3600 Comm: iou-sqp-3586 Not tainted 6.15.0-rc3-syzkaller-00094-g02ddfb981de8 #0 PREEMPT(voluntary) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025
==================================================================

Crashes (3):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2025/04/25 13:03 upstream 02ddfb981de8 e3715315 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in getrusage / try_to_unmap_one
2025/04/03 17:41 upstream a1b5bd45d4ee 996a9618 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in getrusage / try_to_unmap_one
2025/04/03 03:34 upstream 92b71befc349 c799dfdd .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.