* [PATCH] uaccess: Disallow > INT_MAX copy sizes
@ 2019-08-25 23:18 Kees Cook
2019-09-23 23:08 ` Kees Cook
0 siblings, 1 reply; 3+ messages in thread
From: Kees Cook @ 2019-08-25 23:18 UTC (permalink / raw)
To: Andrew Morton; +Cc: Alexander Viro, Dan Carpenter, linux-kernel
As we've done with VFS, string operations, etc, reject usercopy sizes
larger than INT_MAX, which would be nice to have for catching bugs
related to size calculation overflows[1].
This adds 10 bytes to x86_64 defconfig text and 1980 bytes to the data
section:
text data bss dec hex filename
19691167 5134320 1646664 26472151 193eed7 vmlinux.before
19691177 5136300 1646664 26474141 193f69d vmlinux.after
[1] https://marc.info/?l=linux-s390&m=156631939010493&w=2
Suggested-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Kees Cook <keescook@chromium.org>
---
include/linux/thread_info.h | 2 ++
1 file changed, 2 insertions(+)
diff --git a/include/linux/thread_info.h b/include/linux/thread_info.h
index 659a4400517b..e93e249a4e9b 100644
--- a/include/linux/thread_info.h
+++ b/include/linux/thread_info.h
@@ -147,6 +147,8 @@ check_copy_size(const void *addr, size_t bytes, bool is_source)
__bad_copy_to();
return false;
}
+ if (WARN_ON_ONCE(bytes > INT_MAX))
+ return false;
check_object_size(addr, bytes, is_source);
return true;
}
--
2.17.1
--
Kees Cook
^ permalink raw reply related [flat|nested] 3+ messages in thread
* Re: [PATCH] uaccess: Disallow > INT_MAX copy sizes
2019-08-25 23:18 [PATCH] uaccess: Disallow > INT_MAX copy sizes Kees Cook
@ 2019-09-23 23:08 ` Kees Cook
2019-09-24 23:29 ` Andrew Morton
0 siblings, 1 reply; 3+ messages in thread
From: Kees Cook @ 2019-09-23 23:08 UTC (permalink / raw)
To: Andrew Morton; +Cc: Alexander Viro, Dan Carpenter, linux-kernel
On Sun, Aug 25, 2019 at 04:18:56PM -0700, Kees Cook wrote:
> As we've done with VFS, string operations, etc, reject usercopy sizes
> larger than INT_MAX, which would be nice to have for catching bugs
> related to size calculation overflows[1].
>
> This adds 10 bytes to x86_64 defconfig text and 1980 bytes to the data
> section:
>
> text data bss dec hex filename
> 19691167 5134320 1646664 26472151 193eed7 vmlinux.before
> 19691177 5136300 1646664 26474141 193f69d vmlinux.after
>
> [1] https://marc.info/?l=linux-s390&m=156631939010493&w=2
>
> Suggested-by: Dan Carpenter <dan.carpenter@oracle.com>
> Signed-off-by: Kees Cook <keescook@chromium.org>
ping! Andrew, can you take this?
-Kees
> ---
> include/linux/thread_info.h | 2 ++
> 1 file changed, 2 insertions(+)
>
> diff --git a/include/linux/thread_info.h b/include/linux/thread_info.h
> index 659a4400517b..e93e249a4e9b 100644
> --- a/include/linux/thread_info.h
> +++ b/include/linux/thread_info.h
> @@ -147,6 +147,8 @@ check_copy_size(const void *addr, size_t bytes, bool is_source)
> __bad_copy_to();
> return false;
> }
> + if (WARN_ON_ONCE(bytes > INT_MAX))
> + return false;
> check_object_size(addr, bytes, is_source);
> return true;
> }
> --
> 2.17.1
>
>
> --
> Kees Cook
--
Kees Cook
^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: [PATCH] uaccess: Disallow > INT_MAX copy sizes
2019-09-23 23:08 ` Kees Cook
@ 2019-09-24 23:29 ` Andrew Morton
0 siblings, 0 replies; 3+ messages in thread
From: Andrew Morton @ 2019-09-24 23:29 UTC (permalink / raw)
To: Kees Cook; +Cc: Alexander Viro, Dan Carpenter, linux-kernel
On Mon, 23 Sep 2019 16:08:54 -0700 Kees Cook <keescook@chromium.org> wrote:
> On Sun, Aug 25, 2019 at 04:18:56PM -0700, Kees Cook wrote:
> > As we've done with VFS, string operations, etc, reject usercopy sizes
> > larger than INT_MAX, which would be nice to have for catching bugs
> > related to size calculation overflows[1].
> >
> > This adds 10 bytes to x86_64 defconfig text and 1980 bytes to the data
> > section:
> >
> > text data bss dec hex filename
> > 19691167 5134320 1646664 26472151 193eed7 vmlinux.before
> > 19691177 5136300 1646664 26474141 193f69d vmlinux.after
> >
> > [1] https://marc.info/?l=linux-s390&m=156631939010493&w=2
> >
> > Suggested-by: Dan Carpenter <dan.carpenter@oracle.com>
> > Signed-off-by: Kees Cook <keescook@chromium.org>
>
> ping! Andrew, can you take this?
It's in my post 5.4-rc1 pile.
^ permalink raw reply [flat|nested] 3+ messages in thread
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