[PATCH] pci: aspm: fix memory read outside buffer

[Keng-Yu Lin]

On Wed, May 16, 2012 at 10:37 AM, Alex Hung <alex.hung at canonical.com> wrote:
> On 05/16/2012 02:03 AM, Colin King wrote:
>>
>> From: Colin Ian King<colin.king at canonical.com>
>>
>> valgrind picked up the following bug:
>>
>> ==32563== Invalid read of size 1
>> ==32563==    at 0x41DB6C: pcie_check_aspm_registers (aspm.c:247)
>> ==32563==    by 0x534131C: fwts_framework_args (fwts_framework.c:608)
>> ==32563==    by 0x403C68: main (main.c:27)
>> ==32563==  Address 0x62e9ba3 is 2 bytes after a block of size 1 alloc'd
>> ==32563==    at 0x4C29DB4: calloc (in
>> /usr/lib/valgrind/vgpreload_memcheck-amd64-linux.so)
>> ==32563==    by 0x5346F20: fwts_list_from_text (fwts_text_list.c:109)
>> ==32563==    by 0x5345E94: fwts_pipe_exec (fwts_pipeio.c:149)
>> ==32563==    by 0x41DB38: pcie_check_aspm_registers (aspm.c:236)
>> ==32563==    by 0x534131C: fwts_framework_args (fwts_framework.c:608)
>> ==32563==    by 0x403C68: main (main.c:27)
>>
>> this occurs when parsing the output from lspci - the code is reading
>> outside the
>> returned string and we need to check for short strings before parsing the
>> line.
>>
>> Signed-off-by: Colin Ian King<colin.king at canonical.com>
>> ---
>>  src/pci/aspm/aspm.c |    2 +-
>>  1 file changed, 1 insertion(+), 1 deletion(-)
>>
>> diff --git a/src/pci/aspm/aspm.c b/src/pci/aspm/aspm.c
>> index c3c1c71..c461ce8 100644
>> --- a/src/pci/aspm/aspm.c
>> +++ b/src/pci/aspm/aspm.c
>> @@ -244,7 +244,7 @@ int pcie_check_aspm_registers(fwts_framework *fw,
>>                        char *line = fwts_text_list_text(item);
>>                        char *pEnd;
>>
>> -                       if (line[3] == ' ') {
>> +                       if (strlen(line)>= 3&&  line[3] == ' ') {
>>                                reg_val = strtol(line,&pEnd, 16);
>>                                for (i = 0; reg_loc<  256&&  i<  16; i++) {
>>
>>                                        reg_val = strtol(pEnd + 1,&pEnd,
>> 16);
>
>
> Thanks for catching that.
>
> Acked-by: Alex Hung <alex.hung at canonical.com>
>
Acked-by: Keng-Yu Lin <kengyu at canonical.com>