[PATCH] Range checking in do_proc_dointvec_(userhz_)jiffies_conv

When (integer) sysctl values are in either seconds or centiseconds, but represented internally as jiffies, the allowable value range is decreased. This patch adds range checks to the conversion routines. For values in seconds: maximum LONG_MAX / HZ. For values in centiseconds: maximum (LONG_MAX / HZ) * USER_HZ. (BTW, does anyone else feel that an interface in seconds should not be accepting negative values?)

Bart Samwel committed 20 years ago

Commit cba9f331 parent ed5b43f1 file · +4 −0Browse files

Unified · Split

kernel/sysctl.c+4−0

@@ -2053,6 +2053,8 @@ static int do_proc_dointvec_jiffies_conv(int negp, unsigned long lvalp, · 2052 unmodified lines
2053	2053	int write, void *data)
2054	2054	{
2055	2055	if (write) {
	2056	+ if (*lvalp > LONG_MAX / HZ)
	2057	+ return 1;
2056	2058	valp = negp ? -(lvalpHZ) : (lvalpHZ);
2057	2059	} else {
2058	2060	int val = *valp;
@@ -2074,6 +2076,8 @@ static int do_proc_dointvec_userhz_jiffies_conv(int negp, unsigned long lvalp, · 15 unmodified lines
2074	2076	int write, void *data)
2075	2077	{
2076	2078	if (write) {
	2079	+ if (USER_HZ < HZ && lvalp > (LONG_MAX / HZ) USER_HZ)
	2080	+ return 1;
2077	2081	valp = clock_t_to_jiffies(negp ? -lvalp : lvalp);
2078	2082	} else {
2079	2083	int val = *valp;