Re: kern/58051: ccd(4) sysctl()s abused the api

["Paul Goyette via gnats" <gnats-admin%NetBSD.org@localhost>]

The following reply was made to PR kern/58051; it has been noted by GNATS.

From: Paul Goyette <paul%whooppee.com@localhost>
To: gnats-bugs%netbsd.org@localhost
Cc: 
Subject: Re: kern/58051: ccd(4) sysctl()s abused the api
Date: Sat, 26 Apr 2025 07:24:48 -0700 (PDT)

 Any reason to keep this PR open?  At the least, can we commit
 the proposed work-around, and then lower the priority?
 
 >> Fix:
 > 	The following works around the problem.  The correct solution
 > 	would need a rewrite of ccd(4)'s sysctl() code.
 >
 > Index: ccd.c
 > ===================================================================
 > RCS file: /cvsroot/src/sys/dev/ccd.c,v
 > retrieving revision 1.189
 > diff -u -p -r1.189 ccd.c
 > --- ccd.c     28 Mar 2022 12:48:35 -0000      1.189
 > +++ ccd.c     5 Mar 2024 20:17:50 -0000
 > @@ -1772,13 +1772,14 @@ ccd_info_sysctl(SYSCTLFN_ARGS)
 > 	struct sysctlnode node;
 > 	struct ccddiskinfo ccd;
 > 	struct ccd_softc *sc;
 > -	int unit;
 > +	int unit, error;
 >
 > 	if (newp == NULL || newlen != sizeof(int))
 > 		return EINVAL;
 >
 > -	unit = *(const int *)newp;
 > -	newp = NULL;
 > +	error = sysctl_copyin(l, newp, &unit, sizeof unit);
 > +	if (error)
 > +		return error;
 > 	newlen = 0;
 > 	ccd.ccd_ndisks = ~0;
 > 	mutex_enter(&ccd_lock);
 > @@ -1816,8 +1817,9 @@ ccd_components_sysctl(SYSCTLFN_ARGS)
 > 		return EINVAL;
 >
 > 	size = 0;
 > -	unit = *(const int *)newp;
 > -	newp = NULL;
 > +	error = sysctl_copyin(l, newp, &unit, sizeof unit);
 > +	if (error)
 > +		return error;
 > 	newlen = 0;
 > 	mutex_enter(&ccd_lock);
 > 	LIST_FOREACH(sc, &ccds, sc_link)
 
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