Re: [HPDD-discuss] [PATCH] staging: lustre: lustre: obdclass: lprocfs_status.c: Fix for possible null pointer dereference
On Sun, 2014-12-14 at 23:52 +0100, Rickard Strandqvist wrote:
There is otherwise a risk of a possible null pointer dereference.
Was largely found by using a static code analysis program called cppcheck.
Perhaps the tool could use a little work.
It's not possible for end to be NULL no?
unsigned long long simple_strtoull(const char *cp, char **endp, unsigned int base)
{
unsigned long long result;
unsigned int rv;
cp = _parse_integer_fixup_radix(cp, &base);
rv = _parse_integer(cp, base, &result);
/* FIXME */
cp += (rv & ~KSTRTOX_OVERFLOW);
if (endp)
*endp = (char *)cp;
return result;
}
EXPORT_SYMBOL(simple_strtoull);
diff --git a/drivers/staging/lustre/lustre/obdclass/lprocfs_status.c
b/drivers/staging/lustre/lustre/obdclass/lprocfs_status.c
[]
Above this:
whole = simple_strtoull(pbuf, &end, 10);
+++ b/drivers/staging/lustre/lustre/obdclass/lprocfs_status.c
@@ -1897,17 +1897,19 @@ int lprocfs_write_frac_u64_helper(const char *buffer, unsigned
long count,
}
units = 1;
- switch (*end) {
- case 'p': case 'P':
- units <<= 10;
- case 't': case 'T':
- units <<= 10;
- case 'g': case 'G':
- units <<= 10;
- case 'm': case 'M':
- units <<= 10;
- case 'k': case 'K':
- units <<= 10;
+ if (end) {
+ switch (*end) {
+ case 'p': case 'P':
+ units <<= 10;
+ case 't': case 'T':
+ units <<= 10;
+ case 'g': case 'G':
+ units <<= 10;
+ case 'm': case 'M':
+ units <<= 10;
+ case 'k': case 'K':
+ units <<= 10;
+ }
The only thing I might do is
switch (tolower(*end)) {
and remove the second case entry for each line