[pacman-dev] [PATCH v2] Do not add root prefix twice when checking database files

[Allan McRae]

When checking .INSTALL and .CHANGELOG files in the mtree file, we need to find
the path they are stored in the local database. This was appending the root
prefix twice as alpm_option_get_dbpath already includes the root path.

While fixing that issue I added checks that the paths for the database files
were not longer than PATH_MAX.

Fixes FS#48563.

Signed-off-by: Allan McRae <allan at archlinux.org>
---

v2: Improve generation of paths for local db files

 src/pacman/check.c | 54 ++++++++++++++++++++++++++++++------------------------
 1 file changed, 30 insertions(+), 24 deletions(-)

diff --git a/src/pacman/check.c b/src/pacman/check.c
index 0fe74e8..d282cc2 100644
--- a/src/pacman/check.c
+++ b/src/pacman/check.c
@@ -254,7 +254,6 @@ int check_pkg_full(alpm_pkg_t *pkg)
 	const char *root, *pkgname;
 	size_t errors = 0;
 	size_t rootlen;
-	char filepath[PATH_MAX];
 	struct archive *mtree;
 	struct archive_entry *entry = NULL;
 	size_t file_count = 0;
@@ -267,7 +266,6 @@ int check_pkg_full(alpm_pkg_t *pkg)
 		pm_printf(ALPM_LOG_ERROR, _("path too long: %s%s\n"), root, "");
 		return 1;
 	}
-	strcpy(filepath, root);
 
 	pkgname = alpm_pkg_get_name(pkg);
 	mtree = alpm_pkg_mtree_open(pkg);
@@ -282,6 +280,8 @@ int check_pkg_full(alpm_pkg_t *pkg)
 	while(alpm_pkg_mtree_next(pkg, mtree, &entry) == ARCHIVE_OK) {
 		struct stat st;
 		const char *path = archive_entry_pathname(entry);
+		char filepath[PATH_MAX];
+		int filepath_len;
 		mode_t type;
 		size_t file_errors = 0;
 		int backup = 0;
@@ -292,31 +292,37 @@ int check_pkg_full(alpm_pkg_t *pkg)
 			path += 2;
 		}
 
-		if(strcmp(path, ".INSTALL") == 0) {
-			char filename[PATH_MAX];
-			snprintf(filename, PATH_MAX, "%slocal/%s-%s/install",
-					alpm_option_get_dbpath(config->handle) + 1,
-					pkgname, alpm_pkg_get_version(pkg));
-			archive_entry_set_pathname(entry, filename);
-			path = archive_entry_pathname(entry);
-		} else if(strcmp(path, ".CHANGELOG") == 0) {
-			char filename[PATH_MAX];
-			snprintf(filename, PATH_MAX, "%slocal/%s-%s/changelog",
-					alpm_option_get_dbpath(config->handle) + 1,
-					pkgname, alpm_pkg_get_version(pkg));
-			archive_entry_set_pathname(entry, filename);
-			path = archive_entry_pathname(entry);
-		} else if(*path == '.') {
-			continue;
-		}
+		if(*path == '.') {
+			const char *dbfile = NULL;
 
-		file_count++;
+			if(strcmp(path, ".INSTALL") == 0) {
+				dbfile = "install";
+			} else if(strcmp(path, ".CHANGELOG") == 0) {
+				dbfile = "changelog";
+			} else {
+				continue;
+			}
 
-		if(rootlen + 1 + strlen(path) > PATH_MAX) {
-			pm_printf(ALPM_LOG_WARNING, _("path too long: %s%s\n"), root, path);
-			continue;
+			/* Do not append root directory as alpm_option_get_dbpath is already
+			 * an absoute path */
+			filepath_len = snprintf(filepath, PATH_MAX, "%slocal/%s-%s/%s",
+					alpm_option_get_dbpath(config->handle),
+					pkgname, alpm_pkg_get_version(pkg), dbfile);
+			if(filepath_len >= PATH_MAX) {
+				pm_printf(ALPM_LOG_WARNING, _("path too long: %slocal/%s-%s/%s\n"),
+						alpm_option_get_dbpath(config->handle),
+						pkgname, alpm_pkg_get_version(pkg), dbfile);
+				continue;
+			}
+		} else {
+			filepath_len = snprintf(filepath, PATH_MAX, "%s%s", root, path);
+			if(filepath_len >= PATH_MAX) {
+				pm_printf(ALPM_LOG_WARNING, _("path too long: %s%s\n"), root, path);
+				continue;
+			}
 		}
-		strcpy(filepath + rootlen, path);
+
+		file_count++;
 
 		exists = check_file_exists(pkgname, filepath, rootlen, &st);
 		if(exists == 1) {
-- 
2.7.4