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authorBart Samwel <bart@samwel.tk>2006-03-24 03:15:50 -0800
committerLinus Torvalds <torvalds@g5.osdl.org>2006-03-24 07:33:20 -0800
commitcba9f33d13a8ca3125b2a30abe2425ce562d8a83 (patch)
treee93e3da369be7e9f55d15d02908606a43cecfbb9 /kernel/sysctl.c
parented5b43f15a8e86e3ae939b98bc161ee973ecedf2 (diff)
downloadlwn-cba9f33d13a8ca3125b2a30abe2425ce562d8a83.tar.gz
lwn-cba9f33d13a8ca3125b2a30abe2425ce562d8a83.zip
[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>
Diffstat (limited to 'kernel/sysctl.c')
-rw-r--r--kernel/sysctl.c4
1 files changed, 4 insertions, 0 deletions
diff --git a/kernel/sysctl.c b/kernel/sysctl.c
index d13426680d10..e82726faeeff 100644
--- a/kernel/sysctl.c
+++ b/kernel/sysctl.c
@@ -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 ? -(*lvalp*HZ) : (*lvalp*HZ);
} 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;