svn commit: r360031 - head/sys/security/audit

[Kyle Evans]

Author: kevans
Date: Fri Apr 17 02:09:31 2020
New Revision: 360031
URL: https://svnweb.freebsd.org/changeset/base/360031

Log:
  audit_canon_path_vp: don't panic if cdir == NULL
  
  cdir may have simply failed to resolve (e.g. fget_cap failure in namei
  leading to NULL dp passed to AUDIT_ARG_UPATH*_VP); restore the pre-rS358191
  behavior of setting cpath[0] = '\0' and bailing out instead of panicking.
  
  This was found by inadvertently running the libc/c063 tests with auditing
  enabled, resulting in a panic.
  
  Reviewed by:	mjg (committed version actually his)
  Differential Revision:	https://reviews.freebsd.org/D24445

Modified:
  head/sys/security/audit/audit_bsm_klib.c

Modified: head/sys/security/audit/audit_bsm_klib.c
==============================================================================
--- head/sys/security/audit/audit_bsm_klib.c	Fri Apr 17 01:52:27 2020	(r360030)
+++ head/sys/security/audit/audit_bsm_klib.c	Fri Apr 17 02:09:31 2020	(r360031)
@@ -433,10 +433,15 @@ audit_canon_path_vp(struct thread *td, struct vnode *r
 	    __func__,  __FILE__, __LINE__);
 
 	copy = path;
-	if (*path == '/')
+	if (*path == '/') {
 		vp = rdir;
-	else
+	} else {
+		if (cdir == NULL) {
+			cpath[0] = '\0';
+			return;
+		}
 		vp = cdir;
+	}
 	MPASS(vp != NULL);
 	/*
 	 * NB: We require that the supplied array be at least MAXPATHLEN bytes