From 7e22b671a36cfffc2d0961aedeb33c51033c530b Mon Sep 17 00:00:00 2001 From: yu_boyun <1215979730@qq.com> Date: Sat, 19 Sep 2020 16:12:59 +0800 Subject: [PATCH] fix CVE-2020-14367 --- ...create-new-file-when-writing-pidfile.patch | 207 ++++++++++++++++++ chrony.spec | 7 +- 2 files changed, 213 insertions(+), 1 deletion(-) create mode 100644 0001-main-create-new-file-when-writing-pidfile.patch diff --git a/0001-main-create-new-file-when-writing-pidfile.patch b/0001-main-create-new-file-when-writing-pidfile.patch new file mode 100644 index 0000000..316d26c --- /dev/null +++ b/0001-main-create-new-file-when-writing-pidfile.patch @@ -0,0 +1,207 @@ +From f00fed20092b6a42283f29c6ee1f58244d74b545 Mon Sep 17 00:00:00 2001 +From: Miroslav Lichvar +Date: Thu, 6 Aug 2020 09:31:11 +0200 +Subject: [PATCH] main: create new file when writing pidfile + +When writing the pidfile, open the file with the O_CREAT|O_EXCL flags +to avoid following a symlink and writing the PID to an unexpected file, +when chronyd still has the root privileges. + +The Linux open(2) man page warns about O_EXCL not working as expected on +NFS versions before 3 and Linux versions before 2.6. Saving pidfiles on +a distributed filesystem like NFS is not generally expected, but if +there is a reason to do that, these old kernel and NFS versions are not +considered to be supported for saving files by chronyd. + +This is a minimal backport specific to this issue of the following +commits: +- commit 2fc8edacb810 ("use PATH_MAX") +- commit f4c6a00b2a11 ("logging: call exit() in LOG_Message()") +- commit 7a4c396bba8f ("util: add functions for common file operations") +- commit e18903a6b563 ("switch to new util file functions") + +Reported-by: Matthias Gerstner +--- + logging.c | 1 + + main.c | 10 ++----- + sysincl.h | 1 + + util.c | 95 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ + util.h | 11 ++++++++ + 5 files changed, 111 insertions(+), 7 deletions(-) + +diff --git a/logging.c b/logging.c +index d2296e0..fd7f900 100644 +--- a/logging.c ++++ b/logging.c +@@ -171,6 +171,7 @@ void LOG_Message(LOG_Severity severity, + system_log = 0; + log_message(1, severity, buf); + } ++ exit(1); + break; + default: + assert(0); +diff --git a/main.c b/main.c +index 6ccf32e..8edb2e1 100644 +--- a/main.c ++++ b/main.c +@@ -281,13 +281,9 @@ write_pidfile(void) + if (!pidfile[0]) + return; + +- out = fopen(pidfile, "w"); +- if (!out) { +- LOG_FATAL("Could not open %s : %s", pidfile, strerror(errno)); +- } else { +- fprintf(out, "%d\n", (int)getpid()); +- fclose(out); +- } ++ out = UTI_OpenFile(NULL, pidfile, NULL, 'W', 0644); ++ fprintf(out, "%d\n", (int)getpid()); ++ fclose(out); + } + + /* ================================================== */ +diff --git a/sysincl.h b/sysincl.h +index 296c5e6..873a3bd 100644 +--- a/sysincl.h ++++ b/sysincl.h +@@ -37,6 +37,7 @@ + #include + #include + #include ++#include + #include + #include + #include +diff --git a/util.c b/util.c +index e7e3442..83b3b20 100644 +--- a/util.c ++++ b/util.c +@@ -1179,6 +1179,101 @@ UTI_CheckDirPermissions(const char *path, mode_t perm, uid_t uid, gid_t gid) + + /* ================================================== */ + ++static int ++join_path(const char *basedir, const char *name, const char *suffix, ++ char *buffer, size_t length, LOG_Severity severity) ++{ ++ const char *sep; ++ ++ if (!basedir) { ++ basedir = ""; ++ sep = ""; ++ } else { ++ sep = "/"; ++ } ++ ++ if (!suffix) ++ suffix = ""; ++ ++ if (snprintf(buffer, length, "%s%s%s%s", basedir, sep, name, suffix) >= length) { ++ LOG(severity, "File path %s%s%s%s too long", basedir, sep, name, suffix); ++ return 0; ++ } ++ ++ return 1; ++} ++ ++/* ================================================== */ ++ ++FILE * ++UTI_OpenFile(const char *basedir, const char *name, const char *suffix, ++ char mode, mode_t perm) ++{ ++ const char *file_mode; ++ char path[PATH_MAX]; ++ LOG_Severity severity; ++ int fd, flags; ++ FILE *file; ++ ++ severity = mode >= 'A' && mode <= 'Z' ? LOGS_FATAL : LOGS_ERR; ++ ++ if (!join_path(basedir, name, suffix, path, sizeof (path), severity)) ++ return NULL; ++ ++ switch (mode) { ++ case 'r': ++ case 'R': ++ flags = O_RDONLY; ++ file_mode = "r"; ++ if (severity != LOGS_FATAL) ++ severity = LOGS_DEBUG; ++ break; ++ case 'w': ++ case 'W': ++ flags = O_WRONLY | O_CREAT | O_EXCL; ++ file_mode = "w"; ++ break; ++ case 'a': ++ case 'A': ++ flags = O_WRONLY | O_CREAT | O_APPEND; ++ file_mode = "a"; ++ break; ++ default: ++ assert(0); ++ return NULL; ++ } ++ ++try_again: ++ fd = open(path, flags, perm); ++ if (fd < 0) { ++ if (errno == EEXIST) { ++ if (unlink(path) < 0) { ++ LOG(severity, "Could not remove %s : %s", path, strerror(errno)); ++ return NULL; ++ } ++ DEBUG_LOG("Removed %s", path); ++ goto try_again; ++ } ++ LOG(severity, "Could not open %s : %s", path, strerror(errno)); ++ return NULL; ++ } ++ ++ UTI_FdSetCloexec(fd); ++ ++ file = fdopen(fd, file_mode); ++ if (!file) { ++ LOG(severity, "Could not open %s : %s", path, strerror(errno)); ++ close(fd); ++ return NULL; ++ } ++ ++ DEBUG_LOG("Opened %s fd=%d mode=%c", path, fd, mode); ++ ++ return file; ++} ++ ++/* ================================================== */ ++ + void + UTI_DropRoot(uid_t uid, gid_t gid) + { +diff --git a/util.h b/util.h +index e3d6767..a2481cc 100644 +--- a/util.h ++++ b/util.h +@@ -176,6 +176,17 @@ extern int UTI_CreateDirAndParents(const char *path, mode_t mode, uid_t uid, gid + permissions and its uid/gid must match the specified values. */ + extern int UTI_CheckDirPermissions(const char *path, mode_t perm, uid_t uid, gid_t gid); + ++/* Open a file. The full path of the file is constructed from the basedir ++ (may be NULL), '/' (if basedir is not NULL), name, and suffix (may be NULL). ++ Created files have specified permissions (umasked). Returns NULL on error. ++ The following modes are supported (if the mode is an uppercase character, ++ errors are fatal): ++ r/R - open an existing file for reading ++ w/W - open a new file for writing (remove existing file) ++ a/A - open an existing file for appending (create if does not exist) */ ++extern FILE *UTI_OpenFile(const char *basedir, const char *name, const char *suffix, ++ char mode, mode_t perm); ++ + /* Set process user/group IDs and drop supplementary groups */ + extern void UTI_DropRoot(uid_t uid, gid_t gid); + +-- +1.8.3.1 + diff --git a/chrony.spec b/chrony.spec index 394f3e6..dec2ee5 100644 --- a/chrony.spec +++ b/chrony.spec @@ -2,7 +2,7 @@ Name: chrony Version: 3.5 -Release: 1 +Release: 2 Summary: An NTP client/server License: GPLv2 URL: https://chrony.tuxfamily.org @@ -17,6 +17,7 @@ Source6: https://github.com/mlichvar/clknetsim/archive/%{clknetsim_ver}/clknet #patch0 form fedora Patch0: chrony-service-helper.patch Patch1: chrony-packettest.patch +Patch2: 0001-main-create-new-file-when-writing-pidfile.patch BuildRequires: gcc gcc-c++ bison systemd libcap-devel libedit-devel nettle-devel pps-tools-devel libseccomp-devel Requires: shadow-utils systemd timedatex @@ -35,6 +36,7 @@ service to other computers in the network. %setup -q -n %{name}-%{version} -a 6 %patch0 -p1 %patch1 -p1 +%patch2 -p1 mv clknetsim-%{clknetsim_ver}* test/simulation/clknetsim %build @@ -135,6 +137,9 @@ fi %{_mandir}/man[158]/%{name}*.[158]* %changelog +* Sat Sep 19 2020 yuboyun - 3.5-2 +- fix CVE-2020-14367 + * Sat Jun 28 2020 hanzhijun - 3.5-1 - update to 3.5-1 -- Gitee