From c6872c361190d4f1a559d23458f6cdffb154b0b0 Mon Sep 17 00:00:00 2001 From: V3n3RiX Date: Mon, 3 Jul 2023 04:04:58 +0100 Subject: gentoo auto-resync : 03:07:2023 - 04:04:58 --- .../qemu/files/qemu-7.2.3-CVE-2023-2861.patch | 162 ++++++++++++++++++++ .../qemu/files/qemu-8.0.2-CVE-2023-2861.patch | 167 +++++++++++++++++++++ 2 files changed, 329 insertions(+) create mode 100644 app-emulation/qemu/files/qemu-7.2.3-CVE-2023-2861.patch create mode 100644 app-emulation/qemu/files/qemu-8.0.2-CVE-2023-2861.patch (limited to 'app-emulation/qemu/files') diff --git a/app-emulation/qemu/files/qemu-7.2.3-CVE-2023-2861.patch b/app-emulation/qemu/files/qemu-7.2.3-CVE-2023-2861.patch new file mode 100644 index 000000000000..9a9c11a41d66 --- /dev/null +++ b/app-emulation/qemu/files/qemu-7.2.3-CVE-2023-2861.patch @@ -0,0 +1,162 @@ +https://bugs.gentoo.org/909542 +https://gitlab.com/qemu-project/qemu/-/commit/10fad73a2bf1c76c8aa9d6322755e5f877d83ce5 + +From 10fad73a2bf1c76c8aa9d6322755e5f877d83ce5 Mon Sep 17 00:00:00 2001 +From: Christian Schoenebeck +Date: Wed, 7 Jun 2023 18:29:33 +0200 +Subject: [PATCH] 9pfs: prevent opening special files (CVE-2023-2861) + +The 9p protocol does not specifically define how server shall behave when +client tries to open a special file, however from security POV it does +make sense for 9p server to prohibit opening any special file on host side +in general. A sane Linux 9p client for instance would never attempt to +open a special file on host side, it would always handle those exclusively +on its guest side. A malicious client however could potentially escape +from the exported 9p tree by creating and opening a device file on host +side. + +With QEMU this could only be exploited in the following unsafe setups: + + - Running QEMU binary as root AND 9p 'local' fs driver AND 'passthrough' + security model. + +or + + - Using 9p 'proxy' fs driver (which is running its helper daemon as + root). + +These setups were already discouraged for safety reasons before, +however for obvious reasons we are now tightening behaviour on this. + +Fixes: CVE-2023-2861 +Reported-by: Yanwu Shen +Reported-by: Jietao Xiao +Reported-by: Jinku Li +Reported-by: Wenbo Shen +Signed-off-by: Christian Schoenebeck +Reviewed-by: Greg Kurz +Reviewed-by: Michael Tokarev +Message-Id: +(cherry picked from commit f6b0de53fb87ddefed348a39284c8e2f28dc4eda) +Signed-off-by: Michael Tokarev +(Mjt: drop adding qemu_fstat wrapper for 7.2 where wrappers aren't used) +--- a/fsdev/virtfs-proxy-helper.c ++++ b/fsdev/virtfs-proxy-helper.c +@@ -26,6 +26,7 @@ + #include "qemu/xattr.h" + #include "9p-iov-marshal.h" + #include "hw/9pfs/9p-proxy.h" ++#include "hw/9pfs/9p-util.h" + #include "fsdev/9p-iov-marshal.h" + + #define PROGNAME "virtfs-proxy-helper" +@@ -338,6 +339,28 @@ static void resetugid(int suid, int sgid) + } + } + ++/* ++ * Open regular file or directory. Attempts to open any special file are ++ * rejected. ++ * ++ * returns file descriptor or -1 on error ++ */ ++static int open_regular(const char *pathname, int flags, mode_t mode) ++{ ++ int fd; ++ ++ fd = open(pathname, flags, mode); ++ if (fd < 0) { ++ return fd; ++ } ++ ++ if (close_if_special_file(fd) < 0) { ++ return -1; ++ } ++ ++ return fd; ++} ++ + /* + * send response in two parts + * 1) ProxyHeader +@@ -682,7 +705,7 @@ static int do_create(struct iovec *iovec) + if (ret < 0) { + goto unmarshal_err_out; + } +- ret = open(path.data, flags, mode); ++ ret = open_regular(path.data, flags, mode); + if (ret < 0) { + ret = -errno; + } +@@ -707,7 +730,7 @@ static int do_open(struct iovec *iovec) + if (ret < 0) { + goto err_out; + } +- ret = open(path.data, flags); ++ ret = open_regular(path.data, flags, 0); + if (ret < 0) { + ret = -errno; + } +--- a/hw/9pfs/9p-util.h ++++ b/hw/9pfs/9p-util.h +@@ -13,6 +13,8 @@ + #ifndef QEMU_9P_UTIL_H + #define QEMU_9P_UTIL_H + ++#include "qemu/error-report.h" ++ + #ifdef O_PATH + #define O_PATH_9P_UTIL O_PATH + #else +@@ -112,6 +114,38 @@ static inline void close_preserve_errno(int fd) + errno = serrno; + } + ++/** ++ * close_if_special_file() - Close @fd if neither regular file nor directory. ++ * ++ * @fd: file descriptor of open file ++ * Return: 0 on regular file or directory, -1 otherwise ++ * ++ * CVE-2023-2861: Prohibit opening any special file directly on host ++ * (especially device files), as a compromised client could potentially gain ++ * access outside exported tree under certain, unsafe setups. We expect ++ * client to handle I/O on special files exclusively on guest side. ++ */ ++static inline int close_if_special_file(int fd) ++{ ++ struct stat stbuf; ++ ++ if (fstat(fd, &stbuf) < 0) { ++ close_preserve_errno(fd); ++ return -1; ++ } ++ if (!S_ISREG(stbuf.st_mode) && !S_ISDIR(stbuf.st_mode)) { ++ error_report_once( ++ "9p: broken or compromised client detected; attempt to open " ++ "special file (i.e. neither regular file, nor directory)" ++ ); ++ close(fd); ++ errno = ENXIO; ++ return -1; ++ } ++ ++ return 0; ++} ++ + static inline int openat_dir(int dirfd, const char *name) + { + return openat(dirfd, name, +@@ -146,6 +180,10 @@ again: + return -1; + } + ++ if (close_if_special_file(fd) < 0) { ++ return -1; ++ } ++ + serrno = errno; + /* O_NONBLOCK was only needed to open the file. Let's drop it. We don't + * do that with O_PATH since fcntl(F_SETFL) isn't supported, and openat() +-- +GitLab diff --git a/app-emulation/qemu/files/qemu-8.0.2-CVE-2023-2861.patch b/app-emulation/qemu/files/qemu-8.0.2-CVE-2023-2861.patch new file mode 100644 index 000000000000..75fa534b4f1c --- /dev/null +++ b/app-emulation/qemu/files/qemu-8.0.2-CVE-2023-2861.patch @@ -0,0 +1,167 @@ +https://bugs.gentoo.org/909542 +https://gitlab.com/qemu-project/qemu/-/commit/b9d2887be4e616cdaeedd0b7456bfaa71ee798af + +From b9d2887be4e616cdaeedd0b7456bfaa71ee798af Mon Sep 17 00:00:00 2001 +From: Christian Schoenebeck +Date: Wed, 7 Jun 2023 18:29:33 +0200 +Subject: [PATCH] 9pfs: prevent opening special files (CVE-2023-2861) + +The 9p protocol does not specifically define how server shall behave when +client tries to open a special file, however from security POV it does +make sense for 9p server to prohibit opening any special file on host side +in general. A sane Linux 9p client for instance would never attempt to +open a special file on host side, it would always handle those exclusively +on its guest side. A malicious client however could potentially escape +from the exported 9p tree by creating and opening a device file on host +side. + +With QEMU this could only be exploited in the following unsafe setups: + + - Running QEMU binary as root AND 9p 'local' fs driver AND 'passthrough' + security model. + +or + + - Using 9p 'proxy' fs driver (which is running its helper daemon as + root). + +These setups were already discouraged for safety reasons before, +however for obvious reasons we are now tightening behaviour on this. + +Fixes: CVE-2023-2861 +Reported-by: Yanwu Shen +Reported-by: Jietao Xiao +Reported-by: Jinku Li +Reported-by: Wenbo Shen +Signed-off-by: Christian Schoenebeck +Reviewed-by: Greg Kurz +Reviewed-by: Michael Tokarev +Message-Id: +(cherry picked from commit f6b0de53fb87ddefed348a39284c8e2f28dc4eda) +Signed-off-by: Michael Tokarev +--- a/fsdev/virtfs-proxy-helper.c ++++ b/fsdev/virtfs-proxy-helper.c +@@ -26,6 +26,7 @@ + #include "qemu/xattr.h" + #include "9p-iov-marshal.h" + #include "hw/9pfs/9p-proxy.h" ++#include "hw/9pfs/9p-util.h" + #include "fsdev/9p-iov-marshal.h" + + #define PROGNAME "virtfs-proxy-helper" +@@ -338,6 +339,28 @@ static void resetugid(int suid, int sgid) + } + } + ++/* ++ * Open regular file or directory. Attempts to open any special file are ++ * rejected. ++ * ++ * returns file descriptor or -1 on error ++ */ ++static int open_regular(const char *pathname, int flags, mode_t mode) ++{ ++ int fd; ++ ++ fd = open(pathname, flags, mode); ++ if (fd < 0) { ++ return fd; ++ } ++ ++ if (close_if_special_file(fd) < 0) { ++ return -1; ++ } ++ ++ return fd; ++} ++ + /* + * send response in two parts + * 1) ProxyHeader +@@ -682,7 +705,7 @@ static int do_create(struct iovec *iovec) + if (ret < 0) { + goto unmarshal_err_out; + } +- ret = open(path.data, flags, mode); ++ ret = open_regular(path.data, flags, mode); + if (ret < 0) { + ret = -errno; + } +@@ -707,7 +730,7 @@ static int do_open(struct iovec *iovec) + if (ret < 0) { + goto err_out; + } +- ret = open(path.data, flags); ++ ret = open_regular(path.data, flags, 0); + if (ret < 0) { + ret = -errno; + } +--- a/hw/9pfs/9p-util.h ++++ b/hw/9pfs/9p-util.h +@@ -13,6 +13,8 @@ + #ifndef QEMU_9P_UTIL_H + #define QEMU_9P_UTIL_H + ++#include "qemu/error-report.h" ++ + #ifdef O_PATH + #define O_PATH_9P_UTIL O_PATH + #else +@@ -95,6 +97,7 @@ static inline int errno_to_dotl(int err) { + #endif + + #define qemu_openat openat ++#define qemu_fstat fstat + #define qemu_fstatat fstatat + #define qemu_mkdirat mkdirat + #define qemu_renameat renameat +@@ -108,6 +111,38 @@ static inline void close_preserve_errno(int fd) + errno = serrno; + } + ++/** ++ * close_if_special_file() - Close @fd if neither regular file nor directory. ++ * ++ * @fd: file descriptor of open file ++ * Return: 0 on regular file or directory, -1 otherwise ++ * ++ * CVE-2023-2861: Prohibit opening any special file directly on host ++ * (especially device files), as a compromised client could potentially gain ++ * access outside exported tree under certain, unsafe setups. We expect ++ * client to handle I/O on special files exclusively on guest side. ++ */ ++static inline int close_if_special_file(int fd) ++{ ++ struct stat stbuf; ++ ++ if (qemu_fstat(fd, &stbuf) < 0) { ++ close_preserve_errno(fd); ++ return -1; ++ } ++ if (!S_ISREG(stbuf.st_mode) && !S_ISDIR(stbuf.st_mode)) { ++ error_report_once( ++ "9p: broken or compromised client detected; attempt to open " ++ "special file (i.e. neither regular file, nor directory)" ++ ); ++ close(fd); ++ errno = ENXIO; ++ return -1; ++ } ++ ++ return 0; ++} ++ + static inline int openat_dir(int dirfd, const char *name) + { + return qemu_openat(dirfd, name, +@@ -142,6 +177,10 @@ again: + return -1; + } + ++ if (close_if_special_file(fd) < 0) { ++ return -1; ++ } ++ + serrno = errno; + /* O_NONBLOCK was only needed to open the file. Let's drop it. We don't + * do that with O_PATH since fcntl(F_SETFL) isn't supported, and openat() -- cgit v1.2.3