+ procfs-replace-all-non-returning-strlcpy-with-strscpy.patch added to mm-nonmm-unstable branch

+ procfs-replace-all-non-returning-strlcpy-with-strscpy.patch added to mm-nonmm-unstable branch

[Andrew Morton]

The patch titled
     Subject: procfs: replace all non-returning strlcpy with strscpy
has been added to the -mm mm-nonmm-unstable branch.  Its filename is
     procfs-replace-all-non-returning-strlcpy-with-strscpy.patch

This patch will shortly appear at
     https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/procfs-replace-all-non-returning-strlcpy-with-strscpy.patch

This patch will later appear in the mm-nonmm-unstable branch at
    git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

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------------------------------------------------------
From: Azeem Shaikh <azeemshaikh38@gmail.com>
Subject: procfs: replace all non-returning strlcpy with strscpy
Date: Wed, 10 May 2023 21:24:57 +0000

strlcpy() reads the entire source buffer first.  This read may exceed the
destination size limit.  This is both inefficient and can lead to linear
read overflows if a source string is not NUL-terminated [1].  In an effort
to remove strlcpy() completely [2], replace strlcpy() here with strscpy().
No return values were used, so direct replacement is safe.

[1] https://www.kernel.org/doc/html/latest/process/deprecated.html#strlcpy
[2] https://github.com/KSPP/linux/issues/89

Link: https://lkml.kernel.org/r/20230510212457.3491385-1-azeemshaikh38@gmail.com
Signed-off-by: Azeem Shaikh <azeemshaikh38@gmail.com>
Cc: Baoquan He <bhe@redhat.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Kefeng Wang <wangkefeng.wang@huawei.com>
Cc: Liu Shixin <liushixin2@huawei.com>
Cc: Lorenzo Stoakes <lstoakes@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

 fs/proc/kcore.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

--- a/fs/proc/kcore.c~procfs-replace-all-non-returning-strlcpy-with-strscpy
+++ a/fs/proc/kcore.c
@@ -419,7 +419,7 @@ static ssize_t read_kcore_iter(struct ki
 		char *notes;
 		size_t i = 0;
 
-		strlcpy(prpsinfo.pr_psargs, saved_command_line,
+		strscpy(prpsinfo.pr_psargs, saved_command_line,
 			sizeof(prpsinfo.pr_psargs));
 
 		notes = kzalloc(notes_len, GFP_KERNEL);
_

Patches currently in -mm which might be from azeemshaikh38@gmail.com are

procfs-replace-all-non-returning-strlcpy-with-strscpy.patch

Re: + procfs-replace-all-non-returning-strlcpy-with-strscpy.patch added to mm-nonmm-unstable branch

[Alexey Dobriyan]

On Wed, May 10, 2023 at 09:34:49PM -0700, Andrew Morton wrote:
> Subject: procfs: replace all non-returning strlcpy with strscpy
> strlcpy() reads the entire source buffer first.  This read may exceed the
> destination size limit.

> This is both inefficient and can lead to linear read overflows if a source string is not NUL-terminated [1].

This is funny. C strings are always NUL-terminated by definition.

Reviewed-by: Alexey Dobriyan <adobriyan@gmail.com>

> --- a/fs/proc/kcore.c~procfs-replace-all-non-returning-strlcpy-with-strscpy
> +++ a/fs/proc/kcore.c
> @@ -419,7 +419,7 @@ static ssize_t read_kcore_iter(struct ki
>  		char *notes;
>  		size_t i = 0;
>  
> -		strlcpy(prpsinfo.pr_psargs, saved_command_line,
> +		strscpy(prpsinfo.pr_psargs, saved_command_line,
>  			sizeof(prpsinfo.pr_psargs));
>  
>  		notes = kzalloc(notes_len, GFP_KERNEL);