syzbot


KCSAN: data-race in next_uptodate_page / truncate_setsize

Status: auto-closed as invalid on 2022/02/15 03:51
Reported-by: syzbot+@syzkaller.appspotmail.com
First crash: 330d, last: 330d

Sample crash report:
loop4: detected capacity change from 0 to 16
==================================================================
BUG: KCSAN: data-race in next_uptodate_page / truncate_setsize

write to 0xffff888134ff5198 of 8 bytes by task 13633 on cpu 1:
 i_size_write include/linux/fs.h:913 [inline]
 truncate_setsize+0x2a/0xc0 mm/truncate.c:772
 fat_setattr+0x69a/0x7d0 fs/fat/file.c:538
 notify_change+0x8a3/0xac0 fs/attr.c:410
 do_truncate+0xf7/0x140 fs/open.c:64
 handle_truncate fs/namei.c:3082 [inline]
 do_open fs/namei.c:3430 [inline]
 path_openat+0x191f/0x1eb0 fs/namei.c:3559
 do_filp_open+0x105/0x220 fs/namei.c:3586
 do_sys_openat2+0xb5/0x2b0 fs/open.c:1212
 do_sys_open fs/open.c:1228 [inline]
 __do_sys_creat fs/open.c:1304 [inline]
 __se_sys_creat fs/open.c:1298 [inline]
 __x64_sys_creat+0x62/0x80 fs/open.c:1298
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x44/0xd0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x44/0xae

read to 0xffff888134ff5198 of 8 bytes by task 13521 on cpu 0:
 i_size_read include/linux/fs.h:891 [inline]
 next_uptodate_page+0x334/0x630 mm/filemap.c:3262
 next_map_page mm/filemap.c:3287 [inline]
 filemap_map_pages+0x531/0x5f0 mm/filemap.c:3343
 do_fault_around mm/memory.c:4143 [inline]
 do_read_fault mm/memory.c:4158 [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+0xaf7/0x1590 mm/memory.c:4784
 faultin_page mm/gup.c:939 [inline]
 __get_user_pages+0x388/0xc80 mm/gup.c:1160
 populate_vma_page_range mm/gup.c:1492 [inline]
 __mm_populate+0x24d/0x370 mm/gup.c:1601
 mm_populate include/linux/mm.h:2734 [inline]
 vm_mmap_pgoff+0x160/0x1f0 mm/util.c:524
 ksys_mmap_pgoff+0x265/0x320 mm/mmap.c:1623
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x44/0xd0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x44/0xae

value changed: 0x000000000000f000 -> 0x0000000000000000

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 PID: 13521 Comm: syz-executor.4 Not tainted 5.16.0-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 2022/01/11 03:48 upstream 133d9c53c9dc ddb0ab8c .config log report info KCSAN: data-race in next_uptodate_page / truncate_setsize
* Struck through repros no longer work on HEAD.