Commit cba9f33d authored Mar 24, 2006 by Bart Samwel Committed by Linus Torvalds Mar 24, 2006

[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?)

Signed-off-by: Bart Samwel <bart@samwel.tk>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

parent ed5b43f1

kernel/sysctl.c

+4 −0

Original line number	Diff line number	Diff line
		@@ -2053,6 +2053,8 @@ static int do_proc_dointvec_jiffies_conv(int negp, unsigned long lvalp,
		int write, void *data)
		{
		if (write) {
		if (*lvalp > LONG_MAX / HZ)
		return 1;
		valp = negp ? -(lvalpHZ) : (lvalpHZ);
		} else {
		int val = *valp;
		@@ -2074,6 +2076,8 @@ static int do_proc_dointvec_userhz_jiffies_conv(int negp, unsigned long lvalp,
		int write, void *data)
		{
		if (write) {
		if (USER_HZ < HZ && lvalp > (LONG_MAX / HZ) USER_HZ)
		return 1;
		valp = clock_t_to_jiffies(negp ? -lvalp : lvalp);
		} else {
		int val = *valp;