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KCSAN: data-race in _copy_from_iter / _copy_from_iter (3)

Status: moderation: reported on 2024/04/29 10:31
Subsystems: mm
[Documentation on labels]
Reported-by: syzbot+4327174be96f5f7e66f9@syzkaller.appspotmail.com
First crash: 50d, last: 19d
Similar bugs (2)
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 333d 378d 0/27 auto-obsoleted due to no activity on 2023/08/24 22:03
upstream KCSAN: data-race in _copy_from_iter / _copy_from_iter (2) mm 18 110d 191d 0/27 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 0xffff888104db8000 of 4096 bytes by task 28123 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:29 [inline]
 iterate_and_advance2 include/linux/iov_iter.h:245 [inline]
 iterate_and_advance include/linux/iov_iter.h:271 [inline]
 __copy_from_iter lib/iov_iter.c:249 [inline]
 _copy_from_iter+0x129/0xb00 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+0x206/0x2d70 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 0xffff888104db8000 of 4096 bytes by task 28124 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:29 [inline]
 iterate_and_advance2 include/linux/iov_iter.h:245 [inline]
 iterate_and_advance include/linux/iov_iter.h:271 [inline]
 __copy_from_iter lib/iov_iter.c:249 [inline]
 _copy_from_iter+0x129/0xb00 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+0x206/0x2d70 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 PID: 28124 Comm: syz-executor.1 Tainted: G        W          6.10.0-rc1-syzkaller-00027-g4a4be1ad3a6e #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/02/2024
==================================================================

Crashes (3):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2024/05/30 04:09 upstream 4a4be1ad3a6e 34889ee3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in _copy_from_iter / _copy_from_iter
2024/05/28 22:33 upstream e0cce98fe279 34889ee3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in _copy_from_iter / _copy_from_iter
2024/04/29 10:30 upstream e67572cd2204 27e33c58 .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.