syzbot


KCSAN: data-race in ext4_setattr / filemap_fault (2)

Status: auto-closed as invalid on 2021/12/08 02:58
Reported-by: syzbot+@syzkaller.appspotmail.com
First crash: 391d, last: 391d
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 299d 299d 0/24 auto-closed as invalid on 2022/03/09 21:42
upstream KCSAN: data-race in ext4_setattr / filemap_fault 2 433d 450d 0/24 auto-closed as invalid on 2021/10/27 08:46

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

write to 0xffff888104ac4328 of 8 bytes by task 25036 on cpu 0:
 i_size_write include/linux/fs.h:913 [inline]
 ext4_setattr+0xd7e/0xf20 fs/ext4/inode.c:5440
 notify_change+0x8a3/0xac0 fs/attr.c:410
 do_truncate fs/open.c:64 [inline]
 do_sys_ftruncate+0x323/0x430 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 0xffff888104ac4328 of 8 bytes by task 25041 on cpu 1:
 i_size_read include/linux/fs.h:891 [inline]
 filemap_fault+0x88/0xa10 mm/filemap.c:3048
 __do_fault mm/memory.c:3859 [inline]
 do_read_fault mm/memory.c:4183 [inline]
 do_fault mm/memory.c:4312 [inline]
 handle_pte_fault mm/memory.c:4570 [inline]
 __handle_mm_fault mm/memory.c:4705 [inline]
 handle_mm_fault+0xba6/0x1590 mm/memory.c:4803
 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
 __get_user_8+0x18/0x30
 __do_sys_io_submit fs/aio.c:1933 [inline]
 __se_sys_io_submit+0xdd/0x280 fs/aio.c:1908
 __x64_sys_io_submit+0x3f/0x50 fs/aio.c:1908
 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

value changed: 0x0000000000000000 -> 0x0000000000048280

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 PID: 25041 Comm: syz-executor.5 Tainted: G        W         5.15.0-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 2021/11/03 02:51 upstream bfc484fe6abb 17f3edd2 .config log report info KCSAN: data-race in ext4_setattr / filemap_fault
ci2-upstream-kcsan-gce 2021/11/02 14:10 upstream bfc484fe6abb 098b5d53 .config log report info KCSAN: data-race in ext4_setattr / filemap_fault
* Struck through repros no longer work on HEAD.