Never use current user info or file ownership during build

There's no situation where rpmbuild should use uid/gid from either
the filesystem or current user. The former made sense in the
pre-historic times before Buildroot was a thing, but in the last 20+
years that's always the wrong thing to do. Always. The only user/group
info rpm can legitimately use is the one that is explicitly specified in
the packaging, and otherwise fallback to root/equivalent.

Besides fixing a long-standing annoyance with src.rpm file ownership,
this also fixes a regression in 4.19.0 where a non-local or otherwise
unresolvable user info could cause a segfault during rpmbuild (RhBug:2248763).

Fixes: #2604
(backported from commit a0553eb)

build/build.c

@@ -19,7 +19,6 @@
 #include <rpm/rpmfileutil.h>
 #include "rpmbuild_internal.h"
 #include "rpmbuild_misc.h"
-#include "rpmug.h"
 
 #include "debug.h"
 
@@ -496,7 +495,6 @@ static rpmRC buildSpec(rpmts ts, BTA_t buildArgs, rpmSpec spec, int what)
 	}
     }
 
-    rpmugFree();
     if (missing_buildreqs && !rc) {
 	rc = RPMRC_MISSINGBUILDREQUIRES;
     }

build/files.c

@@ -30,7 +30,6 @@
 #include "rpmio_internal.h"	/* XXX rpmioSlurp */
 #include "rpmfts.h"
 #include "rpmfi_internal.h"	/* XXX fi->apath */
-#include "rpmug.h"
 #include "rpmbuild_internal.h"
 #include "rpmbuild_misc.h"
 
@@ -96,8 +95,6 @@ typedef struct FileListRec_s {
 #define	fl_ino	fl_st.st_ino
 #define	fl_mode	fl_st.st_mode
 #define	fl_nlink fl_st.st_nlink
-#define	fl_uid	fl_st.st_uid
-#define	fl_gid	fl_st.st_gid
 #define	fl_rdev	fl_st.st_rdev
 #define	fl_size	fl_st.st_size
 #define	fl_mtime fl_st.st_mtime
@@ -1143,15 +1140,13 @@ static void genCpioListAndHeader(FileList fl, Package pkg, int isSrc)
 	    if ((flp[1].specdFlags & (SPECD_UID | SPECD_DEFUID)) <
 		(flp->specdFlags & (SPECD_UID | SPECD_DEFUID)))
 	    {
-		flp[1].fl_uid = flp->fl_uid;
 		flp[1].uname = flp->uname;
 	    }
 
 	    /* gid */
 	    if ((flp[1].specdFlags & (SPECD_GID | SPECD_DEFGID)) <
 		(flp->specdFlags & (SPECD_GID | SPECD_DEFGID)))
 	    {
-		flp[1].fl_gid = flp->fl_gid;
 		flp[1].gname = flp->gname;
 	    }
 
@@ -1402,8 +1397,6 @@ static rpmRC addFile(FileList fl, const char * diskPath,
     const char *cpioPath;
     struct stat statbuf;
     mode_t fileMode;
-    uid_t fileUid;
-    gid_t fileGid;
     const char *fileUname;
     const char *fileGname;
     rpmRC rc = RPMRC_FAIL; /* assume failure */
@@ -1492,8 +1485,6 @@ static rpmRC addFile(FileList fl, const char * diskPath,
     }
 
     fileMode = statp->st_mode;
-    fileUid = statp->st_uid;
-    fileGid = statp->st_gid;
 
     /* Explicit %attr() always wins */
     if (fl->cur.ar.ar_fmodestr) {
@@ -1522,22 +1513,16 @@ static rpmRC addFile(FileList fl, const char * diskPath,
     } else if (fl->def.ar.ar_user) {
 	fileUname = rpmstrPoolStr(fl->pool, fl->def.ar.ar_user);
     } else {
-	fileUname = rpmugUname(fileUid);
+	fileUname = UID_0_USER;
     }
     if (fl->cur.ar.ar_group) {
 	fileGname = rpmstrPoolStr(fl->pool, fl->cur.ar.ar_group);
     } else if (fl->def.ar.ar_group) {
 	fileGname = rpmstrPoolStr(fl->pool, fl->def.ar.ar_group);
     } else {
-	fileGname = rpmugGname(fileGid);
+	fileGname = GID_0_GROUP;
     }
 
-    /* Default user/group to builder's user/group */
-    if (fileUname == NULL)
-	fileUname = rpmugUname(getuid());
-    if (fileGname == NULL)
-	fileGname = rpmugGname(getgid());
-
     /* S_XXX macro must be consistent with type in find call at check-files script */
     if (check_fileList && (S_ISREG(fileMode) || S_ISLNK(fileMode))) {
 	appendStringBuf(check_fileList, diskPath);
@@ -1555,8 +1540,6 @@ static rpmRC addFile(FileList fl, const char * diskPath,
 
 	flp->fl_st = *statp;	/* structure assignment */
 	flp->fl_mode = fileMode;
-	flp->fl_uid = fileUid;
-	flp->fl_gid = fileGid;
 	if (S_ISDIR(fileMode))
 	    flp->fl_size = 0;
 
@@ -2780,23 +2763,13 @@ rpmRC processSourceFiles(rpmSpec spec, rpmBuildPkgFlags pkgFlags)
 
 	if (fl.def.ar.ar_user) {
 	    flp->uname = fl.def.ar.ar_user;
-	} else {
-	    flp->uname = rpmstrPoolId(fl.pool, rpmugUname(flp->fl_uid), 1);
-	}
-	if (! flp->uname) {
-	    flp->uname = rpmstrPoolId(fl.pool, rpmugUname(getuid()), 1);
 	}
 	if (! flp->uname) {
 	    flp->uname = rpmstrPoolId(fl.pool, UID_0_USER, 1);
 	}
 
 	if (fl.def.ar.ar_group) {
 	    flp->gname = fl.def.ar.ar_group;
-	} else {
-	    flp->gname = rpmstrPoolId(fl.pool, rpmugGname(flp->fl_gid), 1);
-	}
-	if (! flp->gname) {
-	    flp->gname = rpmstrPoolId(fl.pool, rpmugGname(getgid()), 1);
 	}
 	if (! flp->gname) {
 	    flp->gname = rpmstrPoolId(fl.pool, GID_0_GROUP, 1);

build/parsePrep.c

@@ -13,7 +13,6 @@
 #include <rpm/rpmfileutil.h>
 #include "rpmbuild_internal.h"
 #include "rpmbuild_misc.h"
-#include "rpmug.h"
 #include "debug.h"
 
 static void appendBuf(rpmSpec spec, const char *s, int nl)

build/rpmfc.c

@@ -21,7 +21,6 @@
 #include <rpm/rpmfi.h>
 #include <rpm/rpmstrpool.h>
 
-#include "rpmug.h"
 #include "rpmfi_internal.h"		/* rpmfiles stuff for now */
 #include "rpmbuild_internal.h"
 
@@ -1626,16 +1625,14 @@ rpmRC rpmfcGenerateDepends(const rpmSpec spec, Package pkg)
 	    if (rpmExpandNumeric("%{?_use_weak_usergroup_deps}"))
 		deptag = RPMTAG_RECOMMENDNAME;
 
-	    /* filter out root and current user/group */
-	    if (user && !rstreq(user, UID_0_USER) &&
-			!rstreq(user, rpmugUname(getuid()))) {
+	    /* filter out root user/group */
+	    if (user && !rstreq(user, UID_0_USER)) {
 		rpmds ds = rpmdsSingleNS(fc->pool, deptag, "user",
 					user, NULL, ugfl);
 		rpmdsMerge(packageDependencies(pkg, deptag), ds);
 		rpmdsFree(ds);
 	    }
-	    if (group && !rstreq(group, GID_0_GROUP) &&
-			 !rstreq(group, rpmugGname(getgid()))) {
+	    if (group && !rstreq(group, GID_0_GROUP)) {
 		rpmds ds = rpmdsSingleNS(fc->pool, deptag, "group",
 					group, NULL, ugfl);
 		rpmdsMerge(packageDependencies(pkg, deptag), ds);