syzbot


KCSAN: data-race in _copy_from_iter / _copy_from_iter (4)

Status: moderation: reported on 2024/11/07 22:48
Subsystems: mm
[Documentation on labels]
Reported-by: syzbot+0fc60bb395892ced5ddf@syzkaller.appspotmail.com
First crash: 2d00h, last: 2d00h
Similar bugs (3)
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream KCSAN: data-race in _copy_from_iter / _copy_from_iter mm 8 478d 522d 0/28 auto-obsoleted due to no activity on 2023/08/24 22:03
upstream KCSAN: data-race in _copy_from_iter / _copy_from_iter (3) mm 12 81d 194d 0/28 auto-obsoleted due to no activity on 2024/09/24 07:08
upstream KCSAN: data-race in _copy_from_iter / _copy_from_iter (2) mm 18 254d 335d 0/28 auto-obsoleted due to no activity on 2024/04/04 01:00

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

write to 0xffff88814b576000 of 4096 bytes by task 32191 on cpu 0:
 instrument_copy_from_user_before include/linux/instrumented.h:130 [inline]
 copy_from_user_iter lib/iov_iter.c:54 [inline]
 iterate_ubuf include/linux/iov_iter.h:30 [inline]
 iterate_and_advance2 include/linux/iov_iter.h:300 [inline]
 iterate_and_advance include/linux/iov_iter.h:328 [inline]
 __copy_from_iter lib/iov_iter.c:249 [inline]
 _copy_from_iter+0x133/0xd00 lib/iov_iter.c:260
 copy_page_from_iter+0x14f/0x280 lib/iov_iter.c:422
 process_vm_rw_pages mm/process_vm_access.c:43 [inline]
 process_vm_rw_single_vec mm/process_vm_access.c:118 [inline]
 process_vm_rw_core mm/process_vm_access.c:216 [inline]
 process_vm_rw+0x5d6/0x8c0 mm/process_vm_access.c:284
 __do_sys_process_vm_writev mm/process_vm_access.c:304 [inline]
 __se_sys_process_vm_writev mm/process_vm_access.c:299 [inline]
 __x64_sys_process_vm_writev+0x7a/0x90 mm/process_vm_access.c:299
 x64_sys_call+0x1a4/0x2d60 arch/x86/include/generated/asm/syscalls_64.h:312
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xc9/0x1c0 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

write to 0xffff88814b576000 of 4096 bytes by task 32193 on cpu 1:
 instrument_copy_from_user_before include/linux/instrumented.h:130 [inline]
 copy_from_user_iter lib/iov_iter.c:54 [inline]
 iterate_ubuf include/linux/iov_iter.h:30 [inline]
 iterate_and_advance2 include/linux/iov_iter.h:300 [inline]
 iterate_and_advance include/linux/iov_iter.h:328 [inline]
 __copy_from_iter lib/iov_iter.c:249 [inline]
 _copy_from_iter+0x133/0xd00 lib/iov_iter.c:260
 copy_page_from_iter+0x14f/0x280 lib/iov_iter.c:422
 process_vm_rw_pages mm/process_vm_access.c:43 [inline]
 process_vm_rw_single_vec mm/process_vm_access.c:118 [inline]
 process_vm_rw_core mm/process_vm_access.c:216 [inline]
 process_vm_rw+0x5d6/0x8c0 mm/process_vm_access.c:284
 __do_sys_process_vm_writev mm/process_vm_access.c:304 [inline]
 __se_sys_process_vm_writev mm/process_vm_access.c:299 [inline]
 __x64_sys_process_vm_writev+0x7a/0x90 mm/process_vm_access.c:299
 x64_sys_call+0x1a4/0x2d60 arch/x86/include/generated/asm/syscalls_64.h:312
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xc9/0x1c0 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 UID: 0 PID: 32193 Comm: syz.8.10251 Not tainted 6.12.0-rc6-syzkaller-00110-gff7afaeca1a1 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024
==================================================================

Crashes (1):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2024/11/07 22:48 upstream ff7afaeca1a1 867e44df .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in _copy_from_iter / _copy_from_iter
* Struck through repros no longer work on HEAD.