svn commit: r366017 - in head/sys: kern sys

[Konstantin Belousov]

Author: kib
Date: Tue Sep 22 22:06:20 2020
New Revision: 366017
URL: https://svnweb.freebsd.org/changeset/base/366017

Log:
  Add NIRES_STRICTREL.
  
  Stop abusing internal namei flag NI_LCF_STRICTRELATIVE as indicator of
  cap-restricted lookup.  Add designated returned flag NIRES_STRICTREL
  to inform kern_openat() that lookup was restricted.
  
  Reviewed by:	markj
  Tested by:	pho
  Sponsored by:	The FreeBSD Foundation
  MFC after:	1 week
  Differential revision:	https://reviews.freebsd.org/D25886

Modified:
  head/sys/kern/vfs_lookup.c
  head/sys/kern/vfs_syscalls.c
  head/sys/sys/namei.h

Modified: head/sys/kern/vfs_lookup.c
==============================================================================
--- head/sys/kern/vfs_lookup.c	Tue Sep 22 21:59:18 2020	(r366016)
+++ head/sys/kern/vfs_lookup.c	Tue Sep 22 22:06:20 2020	(r366017)
@@ -322,6 +322,7 @@ namei_setup(struct nameidata *ndp, struct vnode **dpp,
 	 */
 	if (IN_CAPABILITY_MODE(td) && (cnp->cn_flags & NOCAPCHECK) == 0) {
 		ndp->ni_lcf |= NI_LCF_STRICTRELATIVE;
+		ndp->ni_resflags |= NIRES_STRICTREL;
 		if (ndp->ni_dirfd == AT_FDCWD) {
 #ifdef KTRACE
 			if (KTRPOINT(td, KTR_CAPFAIL))
@@ -400,6 +401,7 @@ namei_setup(struct nameidata *ndp, struct vnode **dpp,
 			    ndp->ni_filecaps.fc_fcntls != CAP_FCNTL_ALL ||
 			    ndp->ni_filecaps.fc_nioctls != -1) {
 				ndp->ni_lcf |= NI_LCF_STRICTRELATIVE;
+				ndp->ni_resflags |= NIRES_STRICTREL;
 			}
 #endif
 		}

Modified: head/sys/kern/vfs_syscalls.c
==============================================================================
--- head/sys/kern/vfs_syscalls.c	Tue Sep 22 21:59:18 2020	(r366016)
+++ head/sys/kern/vfs_syscalls.c	Tue Sep 22 22:06:20 2020	(r366017)
@@ -1136,7 +1136,7 @@ kern_openat(struct thread *td, int fd, const char *pat
 		 * understand exactly what would happen, and we don't think
 		 * that it ever should.
 		 */
-		if ((nd.ni_lcf & NI_LCF_STRICTRELATIVE) == 0 &&
+		if ((nd.ni_resflags & NIRES_STRICTREL) == 0 &&
 		    (error == ENODEV || error == ENXIO) &&
 		    td->td_dupfd >= 0) {
 			error = dupfdopen(td, fdp, td->td_dupfd, flags, error,
@@ -1180,7 +1180,7 @@ success:
 		struct filecaps *fcaps;
 
 #ifdef CAPABILITIES
-		if ((nd.ni_lcf & NI_LCF_STRICTRELATIVE) != 0)
+		if ((nd.ni_resflags & NIRES_STRICTREL) != 0)
 			fcaps = &nd.ni_filecaps;
 		else
 #endif

Modified: head/sys/sys/namei.h
==============================================================================
--- head/sys/sys/namei.h	Tue Sep 22 21:59:18 2020	(r366016)
+++ head/sys/sys/namei.h	Tue Sep 22 22:06:20 2020	(r366017)
@@ -183,6 +183,7 @@ int	cache_fplookup(struct nameidata *ndp, enum cache_f
  * Namei results flags
  */
 #define	NIRES_ABS	0x00000001 /* Path was absolute */
+#define	NIRES_STRICTREL	0x00000002 /* Restricted lookup result */
 
 /*
  * Flags in ni_lcf, valid for the duration of the namei call.