syzbot


KCSAN: data-race in do_sync_mmap_readahead / ondemand_readahead (3)

Status: auto-closed as invalid on 2022/01/09 16:13
Reported-by: syzbot+@syzkaller.appspotmail.com
First crash: 362d, last: 362d
similar bugs (3):
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream KCSAN: data-race in do_sync_mmap_readahead / ondemand_readahead (4) 1 290d 290d 0/24 auto-closed as invalid on 2022/03/22 07:37
upstream KCSAN: data-race in do_sync_mmap_readahead / ondemand_readahead (2) 1 531d 531d 0/24 auto-closed as invalid on 2021/07/24 19:56
upstream KCSAN: data-race in do_sync_mmap_readahead / ondemand_readahead 1 613d 613d 0/24 auto-closed as invalid on 2021/05/17 09:41

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

write to 0xffff888104d7d398 of 8 bytes by task 1808 on cpu 1:
 do_sync_mmap_readahead+0x2cf/0x370 mm/filemap.c:2992
 filemap_fault+0x267/0xa10 mm/filemap.c:3089
 __do_fault mm/memory.c:3849 [inline]
 do_read_fault mm/memory.c:4164 [inline]
 do_fault mm/memory.c:4293 [inline]
 handle_pte_fault mm/memory.c:4551 [inline]
 __handle_mm_fault mm/memory.c:4686 [inline]
 handle_mm_fault+0xba6/0x1590 mm/memory.c:4784
 do_user_addr_fault+0x609/0xbe0 arch/x86/mm/fault.c:1397
 handle_page_fault arch/x86/mm/fault.c:1485 [inline]
 exc_page_fault+0x91/0x290 arch/x86/mm/fault.c:1541
 asm_exc_page_fault+0x1e/0x30

read to 0xffff888104d7d398 of 8 bytes by task 1797 on cpu 0:
 ondemand_readahead+0x110/0x700 mm/readahead.c:464
 page_cache_async_ra+0xed/0x120 mm/readahead.c:608
 page_cache_async_readahead include/linux/pagemap.h:1052 [inline]
 do_async_mmap_readahead+0x211/0x250 mm/filemap.c:3023
 filemap_fault+0x101/0xa10 mm/filemap.c:3079
 __do_fault mm/memory.c:3849 [inline]
 do_read_fault mm/memory.c:4164 [inline]
 do_fault mm/memory.c:4293 [inline]
 handle_pte_fault mm/memory.c:4551 [inline]
 __handle_mm_fault mm/memory.c:4686 [inline]
 handle_mm_fault+0xba6/0x1590 mm/memory.c:4784
 do_user_addr_fault+0x609/0xbe0 arch/x86/mm/fault.c:1397
 handle_page_fault arch/x86/mm/fault.c:1485 [inline]
 exc_page_fault+0x91/0x290 arch/x86/mm/fault.c:1541
 asm_exc_page_fault+0x1e/0x30

value changed: 0x000000000000039e -> 0x000000000000036e

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 PID: 1797 Comm: syz-fuzzer Tainted: G        W         5.16.0-rc3-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
==================================================================

Crashes (1):
Manager Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Title
ci2-upstream-kcsan-gce 2021/12/05 16:08 upstream 79a72162048e a617004c .config log report info KCSAN: data-race in do_sync_mmap_readahead / ondemand_readahead
* Struck through repros no longer work on HEAD.