[PATCH 4.4 14/57] sysctl: dont print negative flag for proc_douintvec

From: Greg Kroah-Hartman
Date: Thu Jul 13 2017 - 11:44:21 EST

4.4-stable review patch. If anyone has any objections, please let me know.


From: Liping Zhang <zlpnobody@xxxxxxxxx>

commit 5380e5644afbba9e3d229c36771134976f05c91e upstream.

I saw some very confusing sysctl output on my system:
# cat /proc/sys/net/core/xfrm_aevent_rseqth
# cat /proc/sys/net/core/xfrm_aevent_etime
# cat /proc/sys/net/ipv4/tcp_notsent_lowat

Because we forget to set the *negp flag in proc_douintvec, so it will
become a garbage value.

Since the value related to proc_douintvec is always an unsigned integer,
so we can set *negp to false explictily to fix this issue.

Fixes: e7d316a02f68 ("sysctl: handle error writing UINT_MAX to u32 fields")
Signed-off-by: Liping Zhang <zlpnobody@xxxxxxxxx>
Cc: Subash Abhinov Kasiviswanathan <subashab@xxxxxxxxxxxxxx>
Cc: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
Signed-off-by: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

kernel/sysctl.c | 1 +
1 file changed, 1 insertion(+)

--- a/kernel/sysctl.c
+++ b/kernel/sysctl.c
@@ -2070,6 +2070,7 @@ static int do_proc_douintvec_conv(bool *
*valp = *lvalp;
} else {
unsigned int val = *valp;
+ *negp = false;
*lvalp = (unsigned long)val;
return 0;