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Re: [PATCH] locale: don't crash if locale-archive is an empty file
- From: "Carlos O'Donell" <carlos at redhat dot com>
- To: Aurelien Jarno <aurelien at aurel32 dot net>, libc-alpha at sourceware dot org
- Date: Fri, 29 Nov 2013 11:36:35 -0500
- Subject: Re: [PATCH] locale: don't crash if locale-archive is an empty file
- Authentication-results: sourceware.org; auth=none
- References: <1385739561-27038-1-git-send-email-aurelien at aurel32 dot net>
On 11/29/2013 10:39 AM, Aurelien Jarno wrote:
> In case of power failure followed by filesystem issues locale-archive
> can end-up containing all zeros. In that case all calls to setlocale()
> generate a SIGFPE. This renders a system with a default non-C locale
> unbootable.
>
> Avoid this by ignoring the locale instead of generating a SIGFPE.
> ---
> locale/loadarchive.c | 4 ++++
> 1 file changed, 4 insertions(+)
>
> 2013-11-29 Aurelien Jarno <aurelien@aurel32.net>
>
> * locale/loadarchive.c (_nl_load_locale_from_archive): Avoid
> division by 0.
>
> diff --git a/locale/loadarchive.c b/locale/loadarchive.c
> index 70136dc..7cfc498 100644
> --- a/locale/loadarchive.c
> +++ b/locale/loadarchive.c
> @@ -274,6 +274,10 @@ _nl_load_locale_from_archive (int category, const char **namep)
> namehashtab = (struct namehashent *) ((char *) head
> + head->namehash_offset);
>
> + /* Avoid division by 0 if the file is corrupted. */
> + if (__builtin_expect (head->namehash_size == 0, 0))
> + goto close_and_out;
> +
> idx = hval % head->namehash_size;
> incr = 1 + hval % (head->namehash_size - 2);
>
>
How did you test this?
OK to checkin if you did a reasonable amount of testing.
e.g.
* Created locale full of zeros (at least enough zeroes to cover header).
- Tested calling setlocale with a non-builtin locale and it fails.
- Tested calling setlocale with a builtin locale and it works.
Cheers,
Carlos.