From: Adhemerval Zanella <adhemerval.zanella@linaro.org>
To: libc-alpha@sourceware.org, Florian Weimer <fw@deneb.enyo.de>,
Szabolcs Nagy <szabolcs.nagy@arm.com>
Subject: Re: [PATCH] Fix aliasing violation in __vfscanf_internal [BZ #26690]
Date: Wed, 7 Oct 2020 15:10:24 -0300 [thread overview]
Message-ID: <6a8269f0-e514-22e4-d64e-b93986298577@linaro.org> (raw)
In-Reply-To: <87lfgh52pm.fsf@mid.deneb.enyo.de>
On 07/10/2020 15:08, Florian Weimer wrote:
> * Szabolcs Nagy via Libc-alpha:
>
>> diff --git a/stdio-common/vfscanf-internal.c b/stdio-common/vfscanf-internal.c
>> index 95b46dcbeb..d832493623 100644
>> --- a/stdio-common/vfscanf-internal.c
>> +++ b/stdio-common/vfscanf-internal.c
>> @@ -135,6 +135,16 @@
>>
>> #include "printf-parse.h" /* Use read_int. */
>>
>> +/* Same as read_int, but for CHAR_T * instead of UCHAR_T * string. */
>> +static int
>> +read_int_char (const CHAR_T * *pstr)
>> +{
>> + const UCHAR_T *ustr = (const UCHAR_T *) *pstr;
>> + int retval = read_int (&ustr);
>> + *pstr = (const CHAR_T *) ustr;
>> + return retval;
>> +}
>> +
>> #define encode_error() do { \
>> __set_errno (EILSEQ); \
>> goto errout; \
>> @@ -486,7 +496,7 @@ __vfscanf_internal (FILE *s, const char *format, va_list argptr,
>> /* Check for a positional parameter specification. */
>> if (ISDIGIT ((UCHAR_T) *f))
>> {
>> - argpos = read_int ((const UCHAR_T **) &f);
>> + argpos = read_int_char (&f);
>> if (*f == L_('$'))
>> ++f;
>> else
>> @@ -522,7 +532,7 @@ __vfscanf_internal (FILE *s, const char *format, va_list argptr,
>> /* Find the maximum field width. */
>> width = 0;
>> if (ISDIGIT ((UCHAR_T) *f))
>> - width = read_int ((const UCHAR_T **) &f);
>> + width = read_int_char (&f);
>> got_width:
>> if (width == 0)
>> width = -1;
>
> Patch and commit message look reasonable to me. Thanks.
>
Andreas has sent a similar fix for the same issue [1]. Is it something
wrong with his fix? It seems to cover more aliasing violation
[1] https://sourceware.org/pipermail/libc-alpha/2020-October/118149.html
next prev parent reply other threads:[~2020-10-07 18:10 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-10-07 17:50 Szabolcs Nagy
2020-10-07 18:08 ` Florian Weimer
2020-10-07 18:10 ` Adhemerval Zanella [this message]
2020-10-07 18:16 ` Florian Weimer
2020-10-08 7:27 ` Szabolcs Nagy
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