syzbot


KCSAN: data-race in handle_mm_fault / loop_configure

Status: auto-closed as invalid on 2022/06/18 04:50
Reported-by: syzbot+@syzkaller.appspotmail.com
First crash: 196d, last: 196d
similar bugs (1):
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream KCSAN: data-race in handle_mm_fault / loop_configure (2) 1 91d 91d 0/24 auto-closed as invalid on 2022/10/01 14:20

Sample crash report:
==================================================================
BUG: KCSAN: data-race in handle_mm_fault / loop_configure

write to 0xffff8881062aa460 of 4 bytes by task 19262 on cpu 1:
 mapping_set_gfp_mask include/linux/pagemap.h:290 [inline]
 loop_configure+0x83c/0xc90 drivers/block/loop.c:1036
 lo_ioctl+0x617/0x11b0
 blkdev_ioctl+0x20e/0x440 block/ioctl.c:588
 vfs_ioctl fs/ioctl.c:51 [inline]
 __do_sys_ioctl fs/ioctl.c:870 [inline]
 __se_sys_ioctl+0xcb/0x140 fs/ioctl.c:856
 __x64_sys_ioctl+0x3f/0x50 fs/ioctl.c:856
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x2b/0x70 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x44/0xae

read to 0xffff8881062aa460 of 4 bytes by task 19250 on cpu 0:
 mapping_gfp_mask include/linux/pagemap.h:274 [inline]
 __get_fault_gfp_mask mm/memory.c:2858 [inline]
 __handle_mm_fault mm/memory.c:4685 [inline]
 handle_mm_fault+0x24f/0xa40 mm/memory.c:4861
 do_user_addr_fault+0x4cd/0x940 arch/x86/mm/fault.c:1397
 handle_page_fault arch/x86/mm/fault.c:1484 [inline]
 exc_page_fault+0x60/0x160 arch/x86/mm/fault.c:1540
 asm_exc_page_fault+0x1e/0x30

value changed: 0x00100cca -> 0x00100c0a

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 PID: 19250 Comm: syz-executor.0 Not tainted 5.18.0-rc6-syzkaller-00123-gf2dd007445b1-dirty #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 2022/05/14 04:47 upstream f2dd007445b1 107f6434 .config log report info KCSAN: data-race in handle_mm_fault / loop_configure
* Struck through repros no longer work on HEAD.