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

[Colin King]

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);
-- 
1.7.9.5