* include/linux/ucopysize.h:45:4: error: call to '__bad_copy_from' declared with 'error' attribute: copy source size is too small
@ 2025-08-05 19:49 kernel test robot
2025-08-26 0:31 ` Kees Cook
0 siblings, 1 reply; 3+ messages in thread
From: kernel test robot @ 2025-08-05 19:49 UTC (permalink / raw)
To: Kees Cook; +Cc: llvm, oe-kbuild-all, linux-kernel
tree: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git master
head: 6bcdbd62bd56e6d7383f9e06d9d148935b3c9b73
commit: 808aac63e2bdf9bae08485e072bf3d317a18acbf uaccess: Introduce ucopysize.h
date: 5 months ago
config: um-randconfig-001-20250806 (https://download.01.org/0day-ci/archive/20250806/202508060351.OMeX2wGa-lkp@intel.com/config)
compiler: clang version 16.0.6 (https://github.com/llvm/llvm-project 7cbf1a2591520c2491aa35339f227775f4d3adf6)
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20250806/202508060351.OMeX2wGa-lkp@intel.com/reproduce)
If you fix the issue in a separate patch/commit (i.e. not just a new version of
the same patch/commit), kindly add following tags
| Reported-by: kernel test robot <lkp@intel.com>
| Closes: https://lore.kernel.org/oe-kbuild-all/202508060351.OMeX2wGa-lkp@intel.com/
All errors (new ones prefixed by >>):
In file included from net/sctp/socket.c:45:
In file included from include/linux/sched/signal.h:9:
In file included from include/linux/sched/task.h:13:
In file included from include/linux/uaccess.h:10:
>> include/linux/ucopysize.h:45:4: error: call to '__bad_copy_from' declared with 'error' attribute: copy source size is too small
__bad_copy_from();
^
1 error generated.
vim +45 include/linux/ucopysize.h
36
37 static __always_inline __must_check bool
38 check_copy_size(const void *addr, size_t bytes, bool is_source)
39 {
40 int sz = __builtin_object_size(addr, 0);
41 if (unlikely(sz >= 0 && sz < bytes)) {
42 if (!__builtin_constant_p(bytes))
43 copy_overflow(sz, bytes);
44 else if (is_source)
> 45 __bad_copy_from();
46 else
47 __bad_copy_to();
48 return false;
49 }
50 if (WARN_ON_ONCE(bytes > INT_MAX))
51 return false;
52 check_object_size(addr, bytes, is_source);
53 return true;
54 }
55
--
0-DAY CI Kernel Test Service
https://github.com/intel/lkp-tests/wiki
^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: include/linux/ucopysize.h:45:4: error: call to '__bad_copy_from' declared with 'error' attribute: copy source size is too small
2025-08-05 19:49 kernel test robot
@ 2025-08-26 0:31 ` Kees Cook
0 siblings, 0 replies; 3+ messages in thread
From: Kees Cook @ 2025-08-26 0:31 UTC (permalink / raw)
To: kernel test robot, Nathan Chancellor; +Cc: llvm, oe-kbuild-all, linux-kernel
On Wed, Aug 06, 2025 at 03:49:28AM +0800, kernel test robot wrote:
> tree: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git master
> head: 6bcdbd62bd56e6d7383f9e06d9d148935b3c9b73
> commit: 808aac63e2bdf9bae08485e072bf3d317a18acbf uaccess: Introduce ucopysize.h
> date: 5 months ago
> config: um-randconfig-001-20250806 (https://download.01.org/0day-ci/archive/20250806/202508060351.OMeX2wGa-lkp@intel.com/config)
The option inducing the miscompile (the "len" argument gets turned into
a compiler-constant value +1 from where it actually should be across the
inlinings of copy_to_user) is, *drum roll* -fsanitize=alignment
So, I think we need to ban CONFIG_UBSAN_ALIGNMENT on at least on x86...
-Kees
> compiler: clang version 16.0.6 (https://github.com/llvm/llvm-project 7cbf1a2591520c2491aa35339f227775f4d3adf6)
> reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20250806/202508060351.OMeX2wGa-lkp@intel.com/reproduce)
>
> If you fix the issue in a separate patch/commit (i.e. not just a new version of
> the same patch/commit), kindly add following tags
> | Reported-by: kernel test robot <lkp@intel.com>
> | Closes: https://lore.kernel.org/oe-kbuild-all/202508060351.OMeX2wGa-lkp@intel.com/
>
> All errors (new ones prefixed by >>):
>
> In file included from net/sctp/socket.c:45:
> In file included from include/linux/sched/signal.h:9:
> In file included from include/linux/sched/task.h:13:
> In file included from include/linux/uaccess.h:10:
> >> include/linux/ucopysize.h:45:4: error: call to '__bad_copy_from' declared with 'error' attribute: copy source size is too small
> __bad_copy_from();
> ^
> 1 error generated.
>
>
> vim +45 include/linux/ucopysize.h
>
> 36
> 37 static __always_inline __must_check bool
> 38 check_copy_size(const void *addr, size_t bytes, bool is_source)
> 39 {
> 40 int sz = __builtin_object_size(addr, 0);
> 41 if (unlikely(sz >= 0 && sz < bytes)) {
> 42 if (!__builtin_constant_p(bytes))
> 43 copy_overflow(sz, bytes);
> 44 else if (is_source)
> > 45 __bad_copy_from();
> 46 else
> 47 __bad_copy_to();
> 48 return false;
> 49 }
> 50 if (WARN_ON_ONCE(bytes > INT_MAX))
> 51 return false;
> 52 check_object_size(addr, bytes, is_source);
> 53 return true;
> 54 }
> 55
>
> --
> 0-DAY CI Kernel Test Service
> https://github.com/intel/lkp-tests/wiki
--
Kees Cook
^ permalink raw reply [flat|nested] 3+ messages in thread
* include/linux/ucopysize.h:45:4: error: call to '__bad_copy_from' declared with 'error' attribute: copy source size is too small
@ 2026-04-03 8:44 kernel test robot
0 siblings, 0 replies; 3+ messages in thread
From: kernel test robot @ 2026-04-03 8:44 UTC (permalink / raw)
To: Kees Cook; +Cc: llvm, oe-kbuild-all, linux-kernel
Hi Kees,
FYI, the error/warning still remains.
tree: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git master
head: 5619b098e2fbf3a23bf13d91897056a1fe238c6d
commit: 808aac63e2bdf9bae08485e072bf3d317a18acbf uaccess: Introduce ucopysize.h
date: 1 year, 1 month ago
config: um-randconfig-001-20260403 (https://download.01.org/0day-ci/archive/20260403/202604030531.O6FveVgn-lkp@intel.com/config)
compiler: clang version 20.1.8 (https://github.com/llvm/llvm-project 87f0227cb60147a26a1eeb4fb06e3b505e9c7261)
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20260403/202604030531.O6FveVgn-lkp@intel.com/reproduce)
If you fix the issue in a separate patch/commit (i.e. not just a new version of
the same patch/commit), kindly add following tags
| Fixes: 808aac63e2bd ("uaccess: Introduce ucopysize.h")
| Reported-by: kernel test robot <lkp@intel.com>
| Closes: https://lore.kernel.org/oe-kbuild-all/202604030531.O6FveVgn-lkp@intel.com/
All errors (new ones prefixed by >>):
In file included from net/sctp/socket.c:45:
In file included from include/linux/sched/signal.h:9:
In file included from include/linux/sched/task.h:13:
In file included from include/linux/uaccess.h:10:
>> include/linux/ucopysize.h:45:4: error: call to '__bad_copy_from' declared with 'error' attribute: copy source size is too small
45 | __bad_copy_from();
| ^
1 error generated.
vim +45 include/linux/ucopysize.h
36
37 static __always_inline __must_check bool
38 check_copy_size(const void *addr, size_t bytes, bool is_source)
39 {
40 int sz = __builtin_object_size(addr, 0);
41 if (unlikely(sz >= 0 && sz < bytes)) {
42 if (!__builtin_constant_p(bytes))
43 copy_overflow(sz, bytes);
44 else if (is_source)
> 45 __bad_copy_from();
46 else
47 __bad_copy_to();
48 return false;
49 }
50 if (WARN_ON_ONCE(bytes > INT_MAX))
51 return false;
52 check_object_size(addr, bytes, is_source);
53 return true;
54 }
55
--
0-DAY CI Kernel Test Service
https://github.com/intel/lkp-tests/wiki
^ permalink raw reply [flat|nested] 3+ messages in thread
end of thread, other threads:[~2026-04-03 8:45 UTC | newest]
Thread overview: 3+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
2026-04-03 8:44 include/linux/ucopysize.h:45:4: error: call to '__bad_copy_from' declared with 'error' attribute: copy source size is too small kernel test robot
-- strict thread matches above, loose matches on Subject: below --
2025-08-05 19:49 kernel test robot
2025-08-26 0:31 ` Kees Cook
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox