[OE-core] [PATCH] meta:recipes-extended: stat fix security gaps
Khem Raj
raj.khem at gmail.com
Mon May 16 22:20:51 UTC 2016
> On May 16, 2016, at 2:37 PM, Plauchu Edwin <edwin.plauchu.camacho at linux.intel.com> wrote:
>
>
>
> On 16/05/16 16:28, Khem Raj wrote:
>>> On May 16, 2016, at 1:19 PM, edwin.plauchu.camacho at linux.intel.com wrote:
>>>
>>> From: Edwin Plauchu <edwin.plauchu.camacho at intel.com>
>>>
>>> This patch avoids stat fails to compile with compiler flags which elevate common string formatting issues into an error (-Wformat -Wformat-security -Werror=format-security).
>>>
>>> [YOCTO #9550]
>>>
>>> Signed-off-by: Edwin Plauchu <edwin.plauchu.camacho at intel.com>
>>> ---
>>> meta/conf/distro/include/security_flags.inc | 1 -
>>> .../stat/stat-3.3/fix-security-format.patch | 77 ++++++++++++++++++++++
>>> meta/recipes-extended/stat/stat_3.3.bb | 1 +
>>> 3 files changed, 78 insertions(+), 1 deletion(-)
>>> create mode 100644 meta/recipes-extended/stat/stat-3.3/fix-security-format.patch
>>>
>>> diff --git a/meta/conf/distro/include/security_flags.inc b/meta/conf/distro/include/security_flags.inc
>>> index 7a91cec..5ae6dd8 100644
>>> --- a/meta/conf/distro/include/security_flags.inc
>>> +++ b/meta/conf/distro/include/security_flags.inc
>>> @@ -105,7 +105,6 @@ SECURITY_STRINGFORMAT_pn-gettext = ""
>>> SECURITY_STRINGFORMAT_pn-kexec-tools = ""
>>> SECURITY_STRINGFORMAT_pn-makedevs = ""
>>> SECURITY_STRINGFORMAT_pn-oh-puzzles = ""
>>> -SECURITY_STRINGFORMAT_pn-stat = ""
>>> SECURITY_STRINGFORMAT_pn-unzip = ""
>>> SECURITY_STRINGFORMAT_pn-zip = ""
>>>
>>> diff --git a/meta/recipes-extended/stat/stat-3.3/fix-security-format.patch b/meta/recipes-extended/stat/stat-3.3/fix-security-format.patch
>>> new file mode 100644
>>> index 0000000..7d9f8df
>>> --- /dev/null
>>> +++ b/meta/recipes-extended/stat/stat-3.3/fix-security-format.patch
>>> @@ -0,0 +1,77 @@
>>> +meta: recipes-extended: Fixing security formatting issues on stat
>>> +
>>> +Fix security formatting issues related to printf without NULL argument
>>> +
>>> +stat.c: In function 'print_human_access':
>>> +stat.c:292:13: error: format not a string literal and no format arguments [-Werror=format-security]
>>> + printf (access);
>>> + ^
>>> +stat.c: In function 'print_human_time':
>>> +stat.c:299:57: error: format not a string literal and no format arguments [-Werror=format-security]
>>> + if (strftime(str, 40, "%c", localtime(t)) > 0) printf(str);
>>> + ^
>>> +stat.c: In function 'print_it':
>>> +stat.c:613:6: error: format not a string literal and no format arguments [-Werror=format-security]
>>> + printf(b);
>>> + ^
>>> +stat.c:642:6: error: format not a string literal and no format arguments [-Werror=format-security]
>>> + printf(b);
>>> + ^
>>> +
>>> +[YOCTO #9550]
>>> +[https://bugzilla.yoctoproject.org/show_bug.cgi?id=9550]
>>> +
>>> +Upstream-Status: Pending
>>> +
>>> +Signed-off-by: Edwin Plauchu <edwin.plauchu.camacho at intel.com>
>>> +
>>> +diff --git a/stat.c b/stat.c
>>> +index 1ed07a9..351ab54 100644
>>> +--- a/stat.c
>>> ++++ b/stat.c
>>> +@@ -21,6 +21,8 @@
>>> +
>>> + #include "fs.h"
>>> +
>>> ++#define __PRINT(STR) printf (STR,NULL)
>>> ++
>> Can we use proper formatting string here something like
>> printf(“%s”, access );
>>
>> or use fputs() Call instead
> With fputs we need to specify stdout stream and
> the printf "%s" option needs a little bit more processing in formatting.
>
> The actual change covers the security considerations with minimal add of NULL if you
> know why the another ways will be better please tell me.
First of all macros here make code quite unreadable.
secondly, I am just recommending how printf
is supposed to be used here,
int printf(const char *format, ...);
someone just missed specifying a formatting string.
>
> Thanks in advance
> Edwin Plauchu
>>
>>> + void print_human_type(unsigned short mode)
>>> + {
>>> + switch (mode & S_IFMT)
>>> +@@ -289,15 +291,15 @@ void print_human_access(struct stat *statbuf)
>>> + default:
>>> + access[0] = '?';
>>> + }
>>> +- printf (access);
>>> ++ __PRINT(access);
>>> + }
>>> +
>>> + void print_human_time(time_t *t)
>>> + {
>>> + char str[40];
>>> +
>>> +- if (strftime(str, 40, "%c", localtime(t)) > 0) printf(str);
>>> +- else printf("Cannot calculate human readable time, sorry");
>>> ++ if (strftime(str, 40, "%c", localtime(t)) > 0) __PRINT(str);
>>> ++ else __PRINT("Cannot calculate human readable time, sorry");
>>> + }
>>> +
>>> + /* print statfs info */
>>> +@@ -610,7 +612,7 @@ void print_it(char *masterformat, char *filename,
>>> + {
>>> + strcpy (pformat, "%");
>>> + *m++ = '\0';
>>> +- printf(b);
>>> ++ __PRINT(b);
>>> +
>>> + /* copy all format specifiers to our format string */
>>> + while (isdigit(*m) || strchr("#0-+. I", *m))
>>> +@@ -639,7 +641,7 @@ void print_it(char *masterformat, char *filename,
>>> + }
>>> + else
>>> + {
>>> +- printf(b);
>>> ++ __PRINT(b);
>>> + b = NULL;
>>> + }
>>> + }
>>> diff --git a/meta/recipes-extended/stat/stat_3.3.bb b/meta/recipes-extended/stat/stat_3.3.bb
>>> index a5ece07..0697c73 100644
>>> --- a/meta/recipes-extended/stat/stat_3.3.bb
>>> +++ b/meta/recipes-extended/stat/stat_3.3.bb
>>> @@ -6,6 +6,7 @@ LIC_FILES_CHKSUM = "file://COPYRIGHT;md5=39886b077fd072e876e5c4c16310b631 \
>>> file://GPL;md5=94d55d512a9ba36caa9b7df079bae19f"
>>>
>>> SRC_URI = "http://www.ibiblio.org/pub/Linux/utils/file/${BP}.tar.gz \
>>> + file://fix-security-format.patch \
>>> file://fix-error-return.patch"
>>>
>>> SRC_URI[md5sum] = "37e247e8e400ad9205f1b0500b728fd3"
>>> --
>>> 1.9.1
>>>
>>> --
>>> _______________________________________________
>>> Openembedded-core mailing list
>>> Openembedded-core at lists.openembedded.org
>>> http://lists.openembedded.org/mailman/listinfo/openembedded-core
>
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