syzbot


KCSAN: data-race in ext4_setattr / filemap_fault

Status: auto-closed as invalid on 2021/10/27 08:46
Reported-by: syzbot+@syzkaller.appspotmail.com
First crash: 453d, last: 436d
similar bugs (2):
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream KCSAN: data-race in ext4_setattr / filemap_fault (3) 1 303d 303d 0/24 auto-closed as invalid on 2022/03/09 21:42
upstream KCSAN: data-race in ext4_setattr / filemap_fault (2) 2 395d 395d 0/24 auto-closed as invalid on 2021/12/08 02:58

Sample crash report:
==================================================================
BUG: KCSAN: data-race in ext4_setattr / filemap_fault

write to 0xffff8881340bf2a8 of 8 bytes by task 13403 on cpu 1:
 i_size_write include/linux/fs.h:916 [inline]
 ext4_setattr+0xd7f/0xef0 fs/ext4/inode.c:5498
 notify_change+0x8a3/0xac0 fs/attr.c:410
 do_truncate fs/open.c:64 [inline]
 do_sys_ftruncate+0x2ea/0x3a0 fs/open.c:192
 __do_sys_ftruncate fs/open.c:203 [inline]
 __se_sys_ftruncate fs/open.c:201 [inline]
 __x64_sys_ftruncate+0x2f/0x40 fs/open.c:201
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x44/0xa0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x44/0xae

read to 0xffff8881340bf2a8 of 8 bytes by task 13401 on cpu 0:
 i_size_read include/linux/fs.h:894 [inline]
 filemap_fault+0x8b/0x9f0 mm/filemap.c:3050
 __do_fault mm/memory.c:3858 [inline]
 do_shared_fault mm/memory.c:4227 [inline]
 do_fault mm/memory.c:4305 [inline]
 handle_pte_fault mm/memory.c:4559 [inline]
 __handle_mm_fault mm/memory.c:4694 [inline]
 handle_mm_fault+0xc81/0x1580 mm/memory.c:4792
 do_user_addr_fault+0x609/0xbe0 arch/x86/mm/fault.c:1390
 handle_page_fault arch/x86/mm/fault.c:1475 [inline]
 exc_page_fault+0x91/0x220 arch/x86/mm/fault.c:1531
 asm_exc_page_fault+0x1e/0x30

value changed: 0x0000000000000000 -> 0x0000000000000009

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 PID: 13401 Comm: syz-executor.4 Not tainted 5.15.0-rc2-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
==================================================================

Crashes (2):
Manager Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Title
ci2-upstream-kcsan-gce 2021/09/22 08:46 upstream 92477dd1faa6 169724fe .config log report info KCSAN: data-race in ext4_setattr / filemap_fault
ci2-upstream-kcsan-gce 2021/09/05 08:03 upstream a9c9a6f741cd d236a457 .config log report info KCSAN: data-race in ext4_setattr / filemap_fault
* Struck through repros no longer work on HEAD.