qemu: fix CVE-2020-29443 CVE-2020-35517

(From OE-Core rev: 3640c0095d13cf9e9b5160920d3f834c417e9f41)

Signed-off-by: Lee Chee Yang <chee.yang.lee@intel.com>
Signed-off-by: Anuj Mittal <anuj.mittal@intel.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>
This commit is contained in:
Lee Chee Yang
2021-02-10 20:50:47 +08:00
committed by Richard Purdie
parent 764b0f9f5e
commit 7bec49614c
3 changed files with 174 additions and 0 deletions

View File

@@ -37,6 +37,8 @@ SRC_URI = "https://download.qemu.org/${BPN}-${PV}.tar.xz \
file://CVE-2020-25624.patch \
file://CVE-2020-25723.patch \
file://CVE-2020-28916.patch \
file://CVE-2020-35517.patch \
file://CVE-2020-29443.patch \
"
UPSTREAM_CHECK_REGEX = "qemu-(?P<pver>\d+(\.\d+)+)\.tar"

View File

@@ -0,0 +1,46 @@
m 813212288970c39b1800f63e83ac6e96588095c6 Mon Sep 17 00:00:00 2001
From: Paolo Bonzini <pbonzini@redhat.com>
Date: Tue, 1 Dec 2020 13:09:26 +0100
Subject: [PATCH] ide: atapi: assert that the buffer pointer is in range
A case was reported where s->io_buffer_index can be out of range.
The report skimped on the details but it seems to be triggered
by s->lba == -1 on the READ/READ CD paths (e.g. by sending an
ATAPI command with LBA = 0xFFFFFFFF). For now paper over it
with assertions. The first one ensures that there is no overflow
when incrementing s->io_buffer_index, the second checks for the
buffer overrun.
Note that the buffer overrun is only a read, so I am not sure
if the assertion failure is actually less harmful than the overrun.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Message-id: 20201201120926.56559-1-pbonzini@redhat.com
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Upstream-Status: Backport [https://git.qemu.org/?p=qemu.git;a=patch;h=813212288970c39b1800f63e83ac6e96588095c6]
CVE: CVE-2020-29443
Signed-off-by: Chee Yang Lee <chee.yang.lee@intel.com>
---
hw/ide/atapi.c | 2 ++
1 file changed, 2 insertions(+)
diff --git a/hw/ide/atapi.c b/hw/ide/atapi.c
index 14a2b0b..e791578 100644
--- a/hw/ide/atapi.c
+++ b/hw/ide/atapi.c
@@ -276,6 +276,8 @@ void ide_atapi_cmd_reply_end(IDEState *s)
s->packet_transfer_size -= size;
s->elementary_transfer_size -= size;
s->io_buffer_index += size;
+ assert(size <= s->io_buffer_total_len);
+ assert(s->io_buffer_index <= s->io_buffer_total_len);
/* Some adapters process PIO data right away. In that case, we need
* to avoid mutual recursion between ide_transfer_start
--
1.8.3.1

View File

@@ -0,0 +1,126 @@
From ebf101955ce8f8d72fba103b5151115a4335de2c Mon Sep 17 00:00:00 2001
From: Stefan Hajnoczi <stefanha@redhat.com>
Date: Tue, 6 Oct 2020 10:58:26 +0100
Subject: [PATCH] virtiofsd: avoid /proc/self/fd tempdir
In order to prevent /proc/self/fd escapes a temporary directory is
created where /proc/self/fd is bind-mounted. This doesn't work on
read-only file systems.
Avoid the temporary directory by bind-mounting /proc/self/fd over /proc.
This does not affect other processes since we remounted / with MS_REC |
MS_SLAVE. /proc must exist and virtiofsd does not use it so it's safe to
do this.
Path traversal can be tested with the following function:
static void test_proc_fd_escape(struct lo_data *lo)
{
int fd;
int level = 0;
ino_t last_ino = 0;
fd = lo->proc_self_fd;
for (;;) {
struct stat st;
if (fstat(fd, &st) != 0) {
perror("fstat");
return;
}
if (last_ino && st.st_ino == last_ino) {
fprintf(stderr, "inode number unchanged, stopping\n");
return;
}
last_ino = st.st_ino;
fprintf(stderr, "Level %d dev %lu ino %lu\n", level,
(unsigned long)st.st_dev,
(unsigned long)last_ino);
fd = openat(fd, "..", O_PATH | O_DIRECTORY | O_NOFOLLOW);
level++;
}
}
Before and after this patch only Level 0 is displayed. Without
/proc/self/fd bind-mount protection it is possible to traverse parent
directories.
Fixes: 397ae982f4df4 ("virtiofsd: jail lo->proc_self_fd")
Cc: Miklos Szeredi <mszeredi@redhat.com>
Cc: Jens Freimann <jfreimann@redhat.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Message-Id: <20201006095826.59813-1-stefanha@redhat.com>
Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Tested-by: Jens Freimann <jfreimann@redhat.com>
Reviewed-by: Jens Freimann <jfreimann@redhat.com>
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Upstream-Status: Backport
[https://github.com/qemu/qemu/commit/ebf101955ce8f8d72fba103b5151115a4335de2c]
CVE: CVE-2020-35517
Signed-off-by: Chee Yang Lee <chee.yang.lee@intel.com>
---
tools/virtiofsd/passthrough_ll.c | 34 +++++++++++---------------------
1 file changed, 11 insertions(+), 23 deletions(-)
diff --git a/tools/virtiofsd/passthrough_ll.c b/tools/virtiofsd/passthrough_ll.c
index 477e6ee0b53..ff53df44510 100644
--- a/tools/virtiofsd/passthrough_ll.c
+++ b/tools/virtiofsd/passthrough_ll.c
@@ -2393,8 +2393,6 @@ static void setup_wait_parent_capabilities(void)
static void setup_namespaces(struct lo_data *lo, struct fuse_session *se)
{
pid_t child;
- char template[] = "virtiofsd-XXXXXX";
- char *tmpdir;
/*
* Create a new pid namespace for *child* processes. We'll have to
@@ -2458,33 +2456,23 @@ static void setup_namespaces(struct lo_data *lo, struct fuse_session *se)
exit(1);
}
- tmpdir = mkdtemp(template);
- if (!tmpdir) {
- fuse_log(FUSE_LOG_ERR, "tmpdir(%s): %m\n", template);
- exit(1);
- }
-
- if (mount("/proc/self/fd", tmpdir, NULL, MS_BIND, NULL) < 0) {
- fuse_log(FUSE_LOG_ERR, "mount(/proc/self/fd, %s, MS_BIND): %m\n",
- tmpdir);
+ /*
+ * We only need /proc/self/fd. Prevent ".." from accessing parent
+ * directories of /proc/self/fd by bind-mounting it over /proc. Since / was
+ * previously remounted with MS_REC | MS_SLAVE this mount change only
+ * affects our process.
+ */
+ if (mount("/proc/self/fd", "/proc", NULL, MS_BIND, NULL) < 0) {
+ fuse_log(FUSE_LOG_ERR, "mount(/proc/self/fd, MS_BIND): %m\n");
exit(1);
}
- /* Now we can get our /proc/self/fd directory file descriptor */
- lo->proc_self_fd = open(tmpdir, O_PATH);
+ /* Get the /proc (actually /proc/self/fd, see above) file descriptor */
+ lo->proc_self_fd = open("/proc", O_PATH);
if (lo->proc_self_fd == -1) {
- fuse_log(FUSE_LOG_ERR, "open(%s, O_PATH): %m\n", tmpdir);
+ fuse_log(FUSE_LOG_ERR, "open(/proc, O_PATH): %m\n");
exit(1);
}
-
- if (umount2(tmpdir, MNT_DETACH) < 0) {
- fuse_log(FUSE_LOG_ERR, "umount2(%s, MNT_DETACH): %m\n", tmpdir);
- exit(1);
- }
-
- if (rmdir(tmpdir) < 0) {
- fuse_log(FUSE_LOG_ERR, "rmdir(%s): %m\n", tmpdir);
- }
}
/*