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authorHeinrich Schuchardt <xypron.glpk@gmx.de>2015-04-16 12:48:07 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2015-04-17 09:04:08 -0400
commit230633d109e35b0a24277498e773edeb79b4a331 (patch)
treea9619a1bca9f70f5fb0f87b47bdb5493a6e72a8f /kernel/sysctl.c
parent534b483a86e6b96f1b5cc03bbe4b696f3daead6d (diff)
downloadlinux-sh-230633d109e35b0a24277498e773edeb79b4a331.tar.gz
kernel/sysctl.c: detect overflows when converting to int
When converting unsigned long to int overflows may occur. These currently are not detected when writing to the sysctl file system. E.g. on a system where int has 32 bits and long has 64 bits echo 0x800001234 > /proc/sys/kernel/threads-max has the same effect as echo 0x1234 > /proc/sys/kernel/threads-max The patch adds the missing check in do_proc_dointvec_conv. With the patch an overflow will result in an error EINVAL when writing to the the sysctl file system. Signed-off-by: Heinrich Schuchardt <xypron.glpk@gmx.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'kernel/sysctl.c')
-rw-r--r--kernel/sysctl.c10
1 files changed, 9 insertions, 1 deletions
diff --git a/kernel/sysctl.c b/kernel/sysctl.c
index 3c0998426b57..2082b1a88fb9 100644
--- a/kernel/sysctl.c
+++ b/kernel/sysctl.c
@@ -1981,7 +1981,15 @@ static int do_proc_dointvec_conv(bool *negp, unsigned long *lvalp,
int write, void *data)
{
if (write) {
- *valp = *negp ? -*lvalp : *lvalp;
+ if (*negp) {
+ if (*lvalp > (unsigned long) INT_MAX + 1)
+ return -EINVAL;
+ *valp = -*lvalp;
+ } else {
+ if (*lvalp > (unsigned long) INT_MAX)
+ return -EINVAL;
+ *valp = *lvalp;
+ }
} else {
int val = *valp;
if (val < 0) {