On Wed, Apr 26, 2017 at 10:16:22PM -0700, Dillon Jay Pena wrote:
> In solisten, if somaxconn and backlog (both ints) are greater than
> SHRT_MAX, then there is overflow when setting so->so_qlimit = backlog
This can only happen if the admin sets silly sysctl values. backlog
is already checked against somaxconn and sominconn. Default range
is between 80 and 128 which is a valid short.
> It seems to me there are two ways to fix the problem.
A third way would be to prevent wrong values when the admin tries
to configure them. But I don't know wether this would be overkill,
we have a bunch of other sysctls where an admin can shoot himself
in the foot.
This prevents the missconfig where it happens with an error message.
# sysctl kern.somaxconn=32768
sysctl: kern.somaxconn: Invalid argument
Do we want the check?
bluhm
Index: kern/kern_sysctl.c
===================================================================
RCS file: /data/mirror/openbsd/cvs/src/sys/kern/kern_sysctl.c,v
retrieving revision 1.324
diff -u -p -r1.324 kern_sysctl.c
--- kern/kern_sysctl.c 5 Apr 2017 04:15:44 -0000 1.324
+++ kern/kern_sysctl.c 27 Apr 2017 11:47:38 -0000
@@ -431,10 +431,26 @@ kern_sysctl(int *name, u_int namelen, vo
return (sysctl_int(oldp, oldlenp, newp, newlen, &maxthread));
case KERN_NTHREADS:
return (sysctl_rdint(oldp, oldlenp, newp, nthreads));
- case KERN_SOMAXCONN:
- return (sysctl_int(oldp, oldlenp, newp, newlen, &somaxconn));
- case KERN_SOMINCONN:
- return (sysctl_int(oldp, oldlenp, newp, newlen, &sominconn));
+ case KERN_SOMAXCONN: {
+ int val = somaxconn;
+ error = sysctl_int(oldp, oldlenp, newp, newlen, &val);
+ if (error)
+ return error;
+ if (val < 0 || val > SHRT_MAX)
+ return EINVAL;
+ somaxconn = val;
+ return 0;
+ }
+ case KERN_SOMINCONN: {
+ int val = sominconn;
+ error = sysctl_int(oldp, oldlenp, newp, newlen, &val);
+ if (error)
+ return error;
+ if (val < 0 || val > SHRT_MAX)
+ return EINVAL;
+ sominconn = val;
+ return 0;
+ }
case KERN_NOSUIDCOREDUMP:
return (sysctl_int(oldp, oldlenp, newp, newlen,
&nosuidcoredump));
case KERN_FSYNC:
