From 63259457a2eea54cc3b3a284b4bc7da52398a19a Mon Sep 17 00:00:00 2001
From: Gao Feng <fgao@ikuai8.com>
Date: Mon, 8 May 2017 15:54:58 -0700
Subject: [PATCH] proc/sysctl: fix the int overflow for jiffies conversion
do_proc_dointvec_jiffies_conv() uses LONG_MAX/HZ as the max value to
avoid overflow. But actually the *valp is int type, so it still causes
overflow.
For example,
echo 2147483647 > ./sys/net/ipv4/tcp_keepalive_time
Then,
cat ./sys/net/ipv4/tcp_keepalive_time
The output is "-1", it is not expected.
Now use INT_MAX/HZ as the max value instead LONG_MAX/HZ to fix it.
Link: http://lkml.kernel.org/r/1490109532-9228-1-git-send-email-fgao@ikuai8.com
Signed-off-by: Gao Feng <fgao@ikuai8.com>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Cc: Eric Dumazet <edumazet@google.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
---
kernel/sysctl.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/kernel/sysctl.c b/kernel/sysctl.c
index 21343d110296..4dfba1a76cc3 100644
--- a/kernel/sysctl.c
+++ b/kernel/sysctl.c
@@ -2576,7 +2576,7 @@ static int do_proc_dointvec_jiffies_conv(bool *negp, unsigned long *lvalp,
int write, void *data)
{
if (write) {
- if (*lvalp > LONG_MAX / HZ)
+ if (*lvalp > INT_MAX / HZ)
return 1;
*valp = *negp ? -(*lvalp*HZ) : (*lvalp*HZ);
} else {
--
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