From d212aca070267ee742f22aab891960da4f552089 Mon Sep 17 00:00:00 2001 From: Samanta Navarro Date: Mon, 26 Jul 2021 13:36:28 +0300 Subject: [PATCH] db: fix installed db writing with long names Packages containing files with path names longer than 1024 characters cannot fit into the buffer which is used to write "installed" database. This leads to bbuf being APK_BLOB_NULL in apk_db_write_fdb because apk_blob_push_blob notices the condition and correctly handles it. The problem occurs when arguments to apk_ostream_write are manually calculated by pointer arithmetics. Since bbuf.ptr is NULL in such a case, bbuf.ptr - buf leads to a huge size value while buf still points into the stack. fixes #10751 [TT: minor edit to commit and abbreviating the commit message] --- src/database.c | 15 ++++++++++----- 1 file changed, 10 insertions(+), 5 deletions(-) diff --git a/src/database.c b/src/database.c index 10e9776..1b281f7 100644 --- a/src/database.c +++ b/src/database.c @@ -928,7 +928,7 @@ static int apk_db_write_fdb(struct apk_database *db, struct apk_ostream *os) struct apk_db_dir_instance *diri; struct apk_db_file *file; struct hlist_node *c1, *c2; - char buf[1024]; + char buf[1024+PATH_MAX]; apk_blob_t bbuf = APK_BLOB_BUF(buf); int r; @@ -972,6 +972,12 @@ static int apk_db_write_fdb(struct apk_database *db, struct apk_ostream *os) if (diri->acl != apk_default_acl_dir) apk_blob_push_db_acl(&bbuf, 'M', diri->acl); + bbuf = apk_blob_pushed(APK_BLOB_BUF(buf), bbuf); + if (APK_BLOB_IS_NULL(bbuf)) return -ENOBUFS; + r = apk_ostream_write(os, bbuf.ptr, bbuf.len); + if (r < 0) return r; + bbuf = APK_BLOB_BUF(buf); + hlist_for_each_entry(file, c2, &diri->owned_files, diri_files_list) { apk_blob_push_blob(&bbuf, APK_BLOB_STR("R:")); apk_blob_push_blob(&bbuf, APK_BLOB_PTR_LEN(file->name, file->namelen)); @@ -986,13 +992,12 @@ static int apk_db_write_fdb(struct apk_database *db, struct apk_ostream *os) apk_blob_push_blob(&bbuf, APK_BLOB_STR("\n")); } - r = apk_ostream_write(os, buf, bbuf.ptr - buf); + bbuf = apk_blob_pushed(APK_BLOB_BUF(buf), bbuf); + if (APK_BLOB_IS_NULL(bbuf)) return -ENOBUFS; + r = apk_ostream_write(os, bbuf.ptr, bbuf.len); if (r < 0) return r; bbuf = APK_BLOB_BUF(buf); } - r = apk_ostream_write(os, buf, bbuf.ptr - buf); - if (r < 0) return r; - bbuf = APK_BLOB_BUF(buf); } r = apk_ostream_write(os, "\n", 1); if (r < 0) return r;