diff --git a/meta/recipes-devtools/rpm/files/CVE-2021-35939.patch b/meta/recipes-devtools/rpm/files/CVE-2021-35939.patch new file mode 100644 index 0000000000..b60cc0e5ce --- /dev/null +++ b/meta/recipes-devtools/rpm/files/CVE-2021-35939.patch @@ -0,0 +1,378 @@ +From 96ec957e281220f8e137a2d5eb23b83a6377d556 Mon Sep 17 00:00:00 2001 +From: Panu Matilainen +Date: Thu, 10 Feb 2022 14:32:43 +0200 +Subject: [PATCH] Validate intermediate symlinks during installation, + CVE-2021-35939 + +Whenever directory changes during unpacking, walk the entire tree from +starting from / and validate any symlinks crossed, fail the install +on invalid links. + +This is the first of step of many towards securing our file operations +against local tamperers and besides plugging that one CVE, paves the way +for the next step by adding the necessary directory fd tracking. +This also bumps the rpm OS requirements to a whole new level by requiring +the *at() family of calls from POSIX-1.2008. + +This necessarily does a whole lot of huffing and puffing we previously +did not do. It should be possible to cache secure (ie root-owned) +directory structures to avoid validating everything a million times +but for now, just keeping things simple. + +Upstream-Status: Backport [https://github.com/rpm-software-management/rpm/commit/96ec957e281220f8e137a2d5eb23b83a6377d556] +CVE: CVE-2021-35939 +Signed-off-by: Vivek Kumbhar +--- + INSTALL | 2 + + configure.ac | 3 +- + lib/fsm.c | 144 +++++++++++++++++++++++++++++++++++++++++-- + lib/rpmfi.c | 27 +++++++- + lib/rpmfi_internal.h | 17 +++++ + 5 files changed, 183 insertions(+), 10 deletions(-) + +diff --git a/INSTALL b/INSTALL +index 358e5ae0d..9a9c7b0d0 100644 +--- a/INSTALL ++++ b/INSTALL +@@ -103,6 +103,8 @@ option to configure). For GCC, OpenMP 4.5 is fully supported since GCC 6.1, + which is available from + http://www.gnu.org/ + ++Rpm requires a POSIX.1-2008 level operating system. ++ + To compile RPM: + -------------- + +diff --git a/configure.ac b/configure.ac +index 78c555f90..4ddacdfe2 100644 +--- a/configure.ac ++++ b/configure.ac +@@ -570,7 +570,8 @@ AC_CHECK_FUNCS([secure_getenv __secure_getenv]) + + AC_CHECK_FUNCS( + [mkstemp getcwd basename dirname realpath setenv unsetenv regcomp lchown \ +- utimes getline localtime_r statvfs getaddrinfo ], ++ utimes getline localtime_r statvfs getaddrinfo \ ++ openat mkdirat fstatat ], + [], [AC_MSG_ERROR([function required by rpm])]) + + AC_LIBOBJ(fnmatch) +diff --git a/lib/fsm.c b/lib/fsm.c +index 935a0a5c6..0b29284e8 100644 +--- a/lib/fsm.c ++++ b/lib/fsm.c +@@ -8,6 +8,7 @@ + #include + #include + #include ++#include + #if WITH_CAP + #include + #endif +@@ -20,6 +21,7 @@ + #include "rpmio/rpmio_internal.h" /* fdInit/FiniDigest */ + #include "lib/fsm.h" + #include "lib/rpmte_internal.h" /* XXX rpmfs */ ++#include "lib/rpmfi_internal.h" /* rpmfiSetOnChdir */ + #include "lib/rpmplugins.h" /* rpm plugins hooks */ + #include "lib/rpmug.h" + +@@ -406,17 +408,118 @@ static int fsmRmdir(const char *path) + return rc; + } + +-static int fsmMkdir(const char *path, mode_t mode) ++static int fsmMkdir(int dirfd, const char *path, mode_t mode) + { +- int rc = mkdir(path, (mode & 07777)); ++ int rc = mkdirat(dirfd, path, (mode & 07777)); + if (_fsm_debug) +- rpmlog(RPMLOG_DEBUG, " %8s (%s, 0%04o) %s\n", __func__, +- path, (unsigned)(mode & 07777), ++ rpmlog(RPMLOG_DEBUG, " %8s (%d %s, 0%04o) %s\n", __func__, ++ dirfd, path, (unsigned)(mode & 07777), + (rc < 0 ? strerror(errno) : "")); + if (rc < 0) rc = RPMERR_MKDIR_FAILED; + return rc; + } + ++static int fsmOpenat(int dirfd, const char *path, int flags) ++{ ++ struct stat lsb, sb; ++ int sflags = flags | O_NOFOLLOW; ++ int fd = openat(dirfd, path, sflags); ++ ++ /* ++ * Only ever follow symlinks by root or target owner. Since we can't ++ * open the symlink itself, the order matters: we stat the link *after* ++ * opening the target, and if the link ownership changed between the calls ++ * it could've only been the link owner or root. ++ */ ++ if (fd < 0 && errno == ELOOP && flags != sflags) { ++ int ffd = openat(dirfd, path, flags); ++ if (ffd >= 0 && fstatat(dirfd, path, &lsb, AT_SYMLINK_NOFOLLOW) == 0) { ++ if (fstat(ffd, &sb) == 0) { ++ if (lsb.st_uid == 0 || lsb.st_uid == sb.st_uid) { ++ fd = ffd; ++ } else { ++ close(ffd); ++ } ++ } ++ } ++ } ++ return fd; ++} ++ ++static int fsmDoMkDir(rpmPlugins plugins, int dirfd, const char *dn, ++ int owned, mode_t mode) ++{ ++ int rc; ++ rpmFsmOp op = (FA_CREATE); ++ if (!owned) ++ op |= FAF_UNOWNED; ++ ++ /* Run fsm file pre hook for all plugins */ ++ rc = rpmpluginsCallFsmFilePre(plugins, NULL, dn, mode, op); ++ ++ if (!rc) ++ rc = fsmMkdir(dirfd, dn, mode); ++ ++ if (!rc) { ++ rc = rpmpluginsCallFsmFilePrepare(plugins, NULL, dn, dn, mode, op); ++ } ++ ++ /* Run fsm file post hook for all plugins */ ++ rpmpluginsCallFsmFilePost(plugins, NULL, dn, mode, op, rc); ++ ++ if (!rc) { ++ rpmlog(RPMLOG_DEBUG, ++ "%s directory created with perms %04o\n", ++ dn, (unsigned)(mode & 07777)); ++ } ++ ++ return rc; ++} ++ ++static int ensureDir(rpmPlugins plugins, const char *p, int owned, int create) ++{ ++ char *path = xstrdup(p); ++ char *dp = path; ++ char *sp = NULL, *bn; ++ int oflags = O_RDONLY; ++ ++ int dirfd = fsmOpenat(-1, "/", oflags); ++ int fd = dirfd; /* special case of "/" */ ++ ++ while ((bn = strtok_r(dp, "/", &sp)) != NULL) { ++ struct stat sb; ++ fd = fsmOpenat(dirfd, bn, oflags); ++ ++ if (fd < 0 && errno == ENOENT && create) { ++ mode_t mode = S_IFDIR | (_dirPerms & 07777); ++ if (fsmDoMkDir(plugins, dirfd, bn, owned, mode) == 0) { ++ fd = fsmOpenat(dirfd, bn, oflags|O_NOFOLLOW); ++ } ++ } ++ ++ if (fd >= 0 && fstat(fd, &sb) == 0 && !S_ISDIR(sb.st_mode)) { ++ close(fd); ++ errno = ENOTDIR; ++ fd = -1; ++ } ++ ++ close(dirfd); ++ if (fd >= 0) { ++ dirfd = fd; ++ } else { ++ dirfd = -1; ++ rpmlog(RPMLOG_ERR, _("failed to open dir %s of %s: %s\n"), ++ bn, p, strerror(errno)); ++ break; ++ } ++ ++ dp = NULL; ++ } ++ ++ free(path); ++ return dirfd; ++} ++ + static int fsmMkfifo(const char *path, mode_t mode) + { + int rc = mkfifo(path, (mode & 07777)); +@@ -507,7 +610,7 @@ static int fsmMkdirs(rpmfiles files, rpmfs fs, rpmPlugins plugins) + rc = rpmpluginsCallFsmFilePre(plugins, NULL, dn, mode, op); + + if (!rc) +- rc = fsmMkdir(dn, mode); ++ rc = fsmMkdir(-1, dn, mode); + + if (!rc) { + rc = rpmpluginsCallFsmFilePrepare(plugins, NULL, dn, dn, +@@ -874,6 +977,21 @@ static void setFileState(rpmfs fs, int i) + } + } + ++struct diriter_s { ++ int dirfd; ++}; ++ ++static int onChdir(rpmfi fi, void *data) ++{ ++ struct diriter_s *di = data; ++ ++ if (di->dirfd >= 0) { ++ close(di->dirfd); ++ di->dirfd = -1; ++ } ++ return 0; ++} ++ + int rpmPackageFilesInstall(rpmts ts, rpmte te, rpmfiles files, + rpmpsm psm, char ** failedFile) + { +@@ -890,6 +1008,7 @@ int rpmPackageFilesInstall(rpmts ts, rpmte te, rpmfiles files, + char *tid = NULL; + struct filedata_s *fdata = xcalloc(fc, sizeof(*fdata)); + struct filedata_s *firstlink = NULL; ++ struct diriter_s di = { -1 }; + + /* transaction id used for temporary path suffix while installing */ + rasprintf(&tid, ";%08x", (unsigned)rpmtsGetTid(ts)); +@@ -929,6 +1048,7 @@ int rpmPackageFilesInstall(rpmts ts, rpmte te, rpmfiles files, + rc = RPMERR_BAD_MAGIC; + goto exit; + } ++ rpmfiSetOnChdir(fi, onChdir, &di); + + /* Detect and create directories not explicitly in package. */ + if (!rc) +@@ -943,6 +1063,16 @@ int rpmPackageFilesInstall(rpmts ts, rpmte te, rpmfiles files, + if (!fp->suffix) { + rc = fsmBackup(fi, fp->action); + } ++ ++ if (di.dirfd == -1) { ++ di.dirfd = ensureDir(plugins, rpmfiDN(fi), 0, ++ (fp->action == FA_CREATE)); ++ if (di.dirfd == -1) { ++ rc = RPMERR_OPEN_FAILED; ++ break; ++ } ++ } ++ + /* Assume file does't exist when tmp suffix is in use */ + if (!fp->suffix) { + if (fp->action == FA_TOUCH) { +@@ -977,7 +1107,7 @@ int rpmPackageFilesInstall(rpmts ts, rpmte te, rpmfiles files, + mode_t mode = fp->sb.st_mode; + mode &= ~07777; + mode |= 00700; +- rc = fsmMkdir(fp->fpath, mode); ++ rc = fsmMkdir(di.dirfd, fp->fpath, mode); + } + } else if (S_ISLNK(fp->sb.st_mode)) { + if (rc == RPMERR_ENOENT) { +@@ -1019,6 +1149,8 @@ int rpmPackageFilesInstall(rpmts ts, rpmte te, rpmfiles files, + fp->stage = FILE_UNPACK; + } + fi = rpmfiFree(fi); ++ close(di.dirfd); ++ di.dirfd = -1; + + if (!rc && fx < 0 && fx != RPMERR_ITER_END) + rc = fx; +diff --git a/lib/rpmfi.c b/lib/rpmfi.c +index 33b657aa2..740e257fe 100644 +--- a/lib/rpmfi.c ++++ b/lib/rpmfi.c +@@ -55,6 +55,9 @@ struct rpmfi_s { + int intervalStart; /*!< Start of iterating interval. */ + int intervalEnd; /*!< End of iterating interval. */ + ++ rpmfiChdirCb onChdir; /*!< Callback for directory changes */ ++ void *onChdirData; /*!< Caller private callback data */ ++ + rpmfiles files; /*!< File info set */ + rpmcpio_t archive; /*!< Archive with payload */ + unsigned char * found; /*!< Bit field of files found in the archive */ +@@ -309,6 +312,17 @@ int rpmfiDI(rpmfi fi) + } + #endif + ++int rpmfiSetOnChdir(rpmfi fi, rpmfiChdirCb cb, void *data) ++{ ++ int rc = -1; ++ if (fi != NULL) { ++ fi->onChdir = cb; ++ fi->onChdirData = data; ++ rc = 0; ++ } ++ return rc; ++} ++ + int rpmfiFX(rpmfi fi) + { + return (fi != NULL ? fi->i : -1); +@@ -319,9 +333,17 @@ int rpmfiSetFX(rpmfi fi, int fx) + int i = -1; + + if (fi != NULL && fx >= 0 && fx < rpmfilesFC(fi->files)) { +- i = fi->i; ++ int dx = fi->j; ++ i = fi->i; + fi->i = fx; + fi->j = rpmfilesDI(fi->files, fi->i); ++ i = fi->i; ++ ++ if (fi->j != dx && fi->onChdir) { ++ int chrc = fi->onChdir(fi, fi->onChdirData); ++ if (chrc < 0) ++ i = chrc; ++ } + } + return i; + } +@@ -1816,10 +1838,9 @@ static rpmfi initIter(rpmfiles files, int itype, int link) + + if (files && itype>=0 && itype<=RPMFILEITERMAX) { + fi = xcalloc(1, sizeof(*fi)); +- fi->i = -1; ++ fi->j = -1; + fi->files = link ? rpmfilesLink(files) : files; + fi->next = nextfuncs[itype]; +- fi->i = -1; + if (itype == RPMFI_ITER_BACK) { + fi->i = rpmfilesFC(fi->files); + } else if (itype >=RPMFI_ITER_READ_ARCHIVE +diff --git a/lib/rpmfi_internal.h b/lib/rpmfi_internal.h +index dccc6ccbe..37f1d45f5 100644 +--- a/lib/rpmfi_internal.h ++++ b/lib/rpmfi_internal.h +@@ -13,6 +13,23 @@ + extern "C" { + #endif + ++/** \ingroup rpmfi ++ * Callback on file iterator directory changes ++ * @param fi file info ++ * @param data caller private callback data ++ * @return 0 on success, < 0 on error (to stop iteration) ++ */ ++typedef int (*rpmfiChdirCb)(rpmfi fi, void *data); ++ ++/** \ingroup rpmfi ++ * Set a callback for directory changes during iteration. ++ * @param fi file info ++ * @param cb callback function ++ * @param data caller private callback data ++ * @return string pool handle (weak reference) ++ */ ++int rpmfiSetOnChdir(rpmfi fi, rpmfiChdirCb cb, void *data); ++ + /** \ingroup rpmfi + * Return file info set string pool handle + * @param fi file info +-- +2.39.3 + diff --git a/meta/recipes-devtools/rpm/rpm_4.17.1.bb b/meta/recipes-devtools/rpm/rpm_4.17.1.bb index 9b6446f265..aad8f2468f 100644 --- a/meta/recipes-devtools/rpm/rpm_4.17.1.bb +++ b/meta/recipes-devtools/rpm/rpm_4.17.1.bb @@ -40,6 +40,7 @@ SRC_URI = "git://github.com/rpm-software-management/rpm;branch=rpm-4.17.x;protoc file://0001-docs-do-not-build-manpages-requires-pandoc.patch \ file://0001-build-pack.c-do-not-insert-payloadflags-into-.rpm-me.patch \ file://0001-configure.ac-add-linux-gnux32-variant-to-triplet-han.patch \ + file://CVE-2021-35939.patch \ " PE = "1"