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

[Alex Hung]

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>