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Accepting request 497385 from home:bfrogers:branches:Virtualization

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One more security fix.

OBS-URL: https://build.opensuse.org/request/show/497385
OBS-URL: https://build.opensuse.org/package/show/Virtualization/qemu?expand=0&rev=340
This commit is contained in:
Bruce Rogers 2017-05-22 20:33:55 +00:00 committed by Git OBS Bridge
parent 8868022634
commit 6489295f0d
7 changed files with 201 additions and 0 deletions
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174
0055-9pfs-local-forbid-client-access-to-.patch Normal file
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@ -0,0 +1,174 @@
From 385fd07f1627cb73ed2ad266e23923cb7eae30f7 Mon Sep 17 00:00:00 2001
From: Greg Kurz <groug@kaod.org>
Date: Fri, 5 May 2017 14:48:08 +0200
Subject: [PATCH] 9pfs: local: forbid client access to metadata (CVE-2017-7493)
When using the mapped-file security mode, we shouldn't let the client mess
with the metadata. The current code already tries to hide the metadata dir
from the client by skipping it in local_readdir(). But the client can still
access or modify it through several other operations. This can be used to
escalate privileges in the guest.
Affected backend operations are:
- local_mknod()
- local_mkdir()
- local_open2()
- local_symlink()
- local_link()
- local_unlinkat()
- local_renameat()
- local_rename()
- local_name_to_path()
Other operations are safe because they are only passed a fid path, which
is computed internally in local_name_to_path().
This patch converts all the functions listed above to fail and return
EINVAL when being passed the name of the metadata dir. This may look
like a poor choice for errno, but there's no such thing as an illegal
path name on Linux and I could not think of anything better.
This fixes CVE-2017-7493.
Reported-by: Leo Gaspard <leo@gaspard.io>
Signed-off-by: Greg Kurz <groug@kaod.org>
Reviewed-by: Eric Blake <eblake@redhat.com>
(cherry picked from commit 7a95434e0ca8a037fd8aa1a2e2461f92585eb77b)
[BR: BSC#1039495]
Signed-off-by: Bruce Rogers <brogers@suse.com>
---
hw/9pfs/9p-local.c | 58 ++++++++++++++++++++++++++++++++++++++++++++++++++++--
1 file changed, 56 insertions(+), 2 deletions(-)
diff --git a/hw/9pfs/9p-local.c b/hw/9pfs/9p-local.c
index f3ebca4f7a..a2486566af 100644
--- a/hw/9pfs/9p-local.c
+++ b/hw/9pfs/9p-local.c
@@ -452,6 +452,11 @@ static off_t local_telldir(FsContext *ctx, V9fsFidOpenState *fs)
return telldir(fs->dir.stream);
}
+static bool local_is_mapped_file_metadata(FsContext *fs_ctx, const char *name)
+{
+ return !strcmp(name, VIRTFS_META_DIR);
+}
+
static struct dirent *local_readdir(FsContext *ctx, V9fsFidOpenState *fs)
{
struct dirent *entry;
@@ -465,8 +470,8 @@ again:
if (ctx->export_flags & V9FS_SM_MAPPED) {
entry->d_type = DT_UNKNOWN;
} else if (ctx->export_flags & V9FS_SM_MAPPED_FILE) {
- if (!strcmp(entry->d_name, VIRTFS_META_DIR)) {
- /* skp the meta data directory */
+ if (local_is_mapped_file_metadata(ctx, entry->d_name)) {
+ /* skip the meta data directory */
goto again;
}
entry->d_type = DT_UNKNOWN;
@@ -559,6 +564,12 @@ static int local_mknod(FsContext *fs_ctx, V9fsPath *dir_path,
int err = -1;
int dirfd;
+ if (fs_ctx->export_flags & V9FS_SM_MAPPED_FILE &&
+ local_is_mapped_file_metadata(fs_ctx, name)) {
+ errno = EINVAL;
+ return -1;
+ }
+
dirfd = local_opendir_nofollow(fs_ctx, dir_path->data);
if (dirfd == -1) {
return -1;
@@ -605,6 +616,12 @@ static int local_mkdir(FsContext *fs_ctx, V9fsPath *dir_path,
int err = -1;
int dirfd;
+ if (fs_ctx->export_flags & V9FS_SM_MAPPED_FILE &&
+ local_is_mapped_file_metadata(fs_ctx, name)) {
+ errno = EINVAL;
+ return -1;
+ }
+
dirfd = local_opendir_nofollow(fs_ctx, dir_path->data);
if (dirfd == -1) {
return -1;
@@ -694,6 +711,12 @@ static int local_open2(FsContext *fs_ctx, V9fsPath *dir_path, const char *name,
int err = -1;
int dirfd;
+ if (fs_ctx->export_flags & V9FS_SM_MAPPED_FILE &&
+ local_is_mapped_file_metadata(fs_ctx, name)) {
+ errno = EINVAL;
+ return -1;
+ }
+
/*
* Mark all the open to not follow symlinks
*/
@@ -752,6 +775,12 @@ static int local_symlink(FsContext *fs_ctx, const char *oldpath,
int err = -1;
int dirfd;
+ if (fs_ctx->export_flags & V9FS_SM_MAPPED_FILE &&
+ local_is_mapped_file_metadata(fs_ctx, name)) {
+ errno = EINVAL;
+ return -1;
+ }
+
dirfd = local_opendir_nofollow(fs_ctx, dir_path->data);
if (dirfd == -1) {
return -1;
@@ -826,6 +855,12 @@ static int local_link(FsContext *ctx, V9fsPath *oldpath,
int ret = -1;
int odirfd, ndirfd;
+ if (ctx->export_flags & V9FS_SM_MAPPED_FILE &&
+ local_is_mapped_file_metadata(ctx, name)) {
+ errno = EINVAL;
+ return -1;
+ }
+
odirfd = local_opendir_nofollow(ctx, odirpath);
if (odirfd == -1) {
goto out;
@@ -1096,6 +1131,12 @@ static int local_lremovexattr(FsContext *ctx, V9fsPath *fs_path,
static int local_name_to_path(FsContext *ctx, V9fsPath *dir_path,
const char *name, V9fsPath *target)
{
+ if (ctx->export_flags & V9FS_SM_MAPPED_FILE &&
+ local_is_mapped_file_metadata(ctx, name)) {
+ errno = EINVAL;
+ return -1;
+ }
+
if (dir_path) {
v9fs_path_sprintf(target, "%s/%s", dir_path->data, name);
} else if (strcmp(name, "/")) {
@@ -1116,6 +1157,13 @@ static int local_renameat(FsContext *ctx, V9fsPath *olddir,
int ret;
int odirfd, ndirfd;
+ if (ctx->export_flags & V9FS_SM_MAPPED_FILE &&
+ (local_is_mapped_file_metadata(ctx, old_name) ||
+ local_is_mapped_file_metadata(ctx, new_name))) {
+ errno = EINVAL;
+ return -1;
+ }
+
odirfd = local_opendir_nofollow(ctx, olddir->data);
if (odirfd == -1) {
return -1;
@@ -1206,6 +1254,12 @@ static int local_unlinkat(FsContext *ctx, V9fsPath *dir,
int ret;
int dirfd;
+ if (ctx->export_flags & V9FS_SM_MAPPED_FILE &&
+ local_is_mapped_file_metadata(ctx, name)) {
+ errno = EINVAL;
+ return -1;
+ }
+
dirfd = local_opendir_nofollow(ctx, dir->data);
if (dirfd == -1) {
return -1;

7
qemu-linux-user.changes
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@ -1,3 +1,10 @@
-------------------------------------------------------------------
Mon May 22 19:06:25 UTC 2017 - brogers@suse.com
- Patch queue updated from git://github.com/openSUSE/qemu.git opensuse-2.9
* Patches added:
0055-9pfs-local-forbid-client-access-to-.patch
-------------------------------------------------------------------
Thu May 11 20:55:59 UTC 2017 - brogers@suse.com

2
qemu-linux-user.spec
View File

@ -80,6 +80,7 @@ Patch0051: 0051-input-limit-kbd-queue-depth.patch
Patch0052: 0052-audio-release-capture-buffers.patch
Patch0053: 0053-scsi-avoid-an-off-by-one-error-in-m.patch
Patch0054: 0054-vmw_pvscsi-check-message-ring-page-.patch
Patch0055: 0055-9pfs-local-forbid-client-access-to-.patch
# Please do not add QEMU patches manually here.
# Run update_git.sh to regenerate this queue.
Source400: update_git.sh
@ -187,6 +188,7 @@ run cross-architecture builds.
%patch0052 -p1
%patch0053 -p1
%patch0054 -p1
%patch0055 -p1
%build
./configure \

7
qemu-testsuite.changes
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@ -1,3 +1,10 @@
-------------------------------------------------------------------
Mon May 22 19:06:22 UTC 2017 - brogers@suse.com
- Protect access to metadata in virtio-9pfs (CVE-2017-7493 bsc#1039495)
0055-9pfs-local-forbid-client-access-to-.patch
- Patch queue updated from git://github.com/openSUSE/qemu.git opensuse-2.9
-------------------------------------------------------------------
Thu May 11 20:55:57 UTC 2017 - brogers@suse.com

2
qemu-testsuite.spec
View File

@ -184,6 +184,7 @@ Patch0051: 0051-input-limit-kbd-queue-depth.patch
Patch0052: 0052-audio-release-capture-buffers.patch
Patch0053: 0053-scsi-avoid-an-off-by-one-error-in-m.patch
Patch0054: 0054-vmw_pvscsi-check-message-ring-page-.patch
Patch0055: 0055-9pfs-local-forbid-client-access-to-.patch
# Please do not add QEMU patches manually here.
# Run update_git.sh to regenerate this queue.
@ -884,6 +885,7 @@ This package provides a service file for starting and stopping KSM.
%patch0052 -p1
%patch0053 -p1
%patch0054 -p1
%patch0055 -p1
pushd roms/ipxe
%patch1100 -p1

7
qemu.changes
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@ -1,3 +1,10 @@
-------------------------------------------------------------------
Mon May 22 19:06:22 UTC 2017 - brogers@suse.com
- Protect access to metadata in virtio-9pfs (CVE-2017-7493 bsc#1039495)
0055-9pfs-local-forbid-client-access-to-.patch
- Patch queue updated from git://github.com/openSUSE/qemu.git opensuse-2.9
-------------------------------------------------------------------
Thu May 11 20:55:57 UTC 2017 - brogers@suse.com

2
qemu.spec
View File

@ -184,6 +184,7 @@ Patch0051: 0051-input-limit-kbd-queue-depth.patch
Patch0052: 0052-audio-release-capture-buffers.patch
Patch0053: 0053-scsi-avoid-an-off-by-one-error-in-m.patch
Patch0054: 0054-vmw_pvscsi-check-message-ring-page-.patch
Patch0055: 0055-9pfs-local-forbid-client-access-to-.patch
# Please do not add QEMU patches manually here.
# Run update_git.sh to regenerate this queue.
@ -884,6 +885,7 @@ This package provides a service file for starting and stopping KSM.
%patch0052 -p1
%patch0053 -p1
%patch0054 -p1
%patch0055 -p1
pushd roms/ipxe
%patch1100 -p1