[syslinux] [PATCH] isohybrid: fix overflow on 32 bit system

[H. Peter Anvin]

No #if.

On May 12, 2014 6:26:18 PM PDT, Kang Kai <Kai.Kang at windriver.com> wrote:
>On 2014年05月12日 22:38, H. Peter Anvin wrote:
>> That is because it needs to use fseeko() and use off_t.
>
>Do you mean it does need a patch for isohybrid.c. And the patch looks
>like:
>
>#if _FILE_OFFSET_BITS == 64
>     fseeko(...)
>#else
>    fseek(...)
>
>
>Regards,
>Kai
>
>>
>> On May 11, 2014 11:53:17 PM PDT, Kang Kai <Kai.Kang at windriver.com>
>wrote:
>>> On 2014年05月12日 10:49, H. Peter Anvin wrote:
>>>> On 05/11/2014 06:56 PM, Kai Kang wrote:
>>>>> When call isohybrid with option '-u', it overflows on a 32 bits
>>> host. It
>>>>> seeks to 512 bytes before the end of the image to install gpt
>>> header. If
>>>>> the size of image is larger than LONG_MAX, it overflows fseek()
>and
>>>>> cause error:
>>>>>
>>>>> isohybrid: wrlinux-image-x86-64-20140505110100.iso: seek error -
>8:
>>> Invalid argument
>>>>> Check the offset and call fseek() multi-times if offset is too
>>> large.
>>>>> Signed-off-by: Kai Kang <kai.kang at windriver.com>
>>>> NAK.
>>>>
>>>> The right thing to do is compile it with #define _FILE_OFFSET_BITS
>64
>>>> and change fseek to fseeko with the appropriate type being off_t.
>>>>
>>>> 	-hpa
>>> Hi hpa,
>>>
>>> Thanks for your reply.
>>>
>>> In utils/Makefile, -D_FILE_OFFSET_BITS=64 is added to CFLAGS.
>isohybrid
>>>
>>> is compiled with -D_FILE_OFFSET_BITS=64 but it still fails to handle
>>> the
>>> large offset.
>>>
>>> make[3]: Entering directory
>>>
>`/home/neil/wrlinux/builds/install-x86-64/bitbake_build/tmp/work/i686-linux/syslinux-native/6.01-r0/syslinux-6.01/bios/utils'
>>> gcc
>>>
>-isystem/home/neil/wrlinux/builds/install-x86-64/bitbake_build/tmp/sysroots/i686-linux/usr/include
>>>
>>> -O2 -pipe -Wp,-MT,isohybrid.o,-MMD,./.isohybrid.o.d -W -Wall
>>> -Wstrict-prototypes -Os -fomit-frame-pointer
>*-D_FILE_OFFSET_BITS=64*
>>>
>-I/home/neil/wrlinux/builds/install-x86-64/bitbake_build/tmp/work/i686-linux/syslinux-native/6.01-r0/syslinux-6.01/utils
>>>
>>> -c -o isohybrid.o
>>>
>/home/neil/wrlinux/builds/install-x86-64/bitbake_build/tmp/work/i686-linux/syslinux-native/6.01-r0/syslinux-6.01/utils/isohybrid.c
>>>
>>> I build it on RedHat Enterprise Linux 6.2 with glibc 2.12.
>>>
>>> Regards,
>>> Kai
>>>

-- 
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