The branch, v4-4-test has been updated
via 0839f6c s3: Test for CVE-2017-2619 regression with "follow symlinks
= no" - part 2
via ed694d0 s3: smbd: Fix "follow symlink = no" regression part 2.
via 8e3e969 s3: smbd: Fix "follow symlink = no" regression part 2.
via 9a5be8b s3: Fixup test for CVE-2017-2619 regression with "follow
symlinks = no"
via 161a078 s3: Test for CVE-2017-2619 regression with "follow symlinks
= no".
via 4a6d828e s3: smbd: Fix incorrect logic exposed by fix for the
security bug 12496 (CVE-2017-2619).
from 2e00feb s3: locking: Update oplock optimization for the leases era !
https://git.samba.org/?p=samba.git;a=shortlog;h=v4-4-test
- Log -----------------------------------------------------------------
commit 0839f6c6f4005f217475c70ba60b75bbd72e608e
Author: Jeremy Allison <j...@samba.org>
Date: Mon Mar 27 22:10:29 2017 -0700
s3: Test for CVE-2017-2619 regression with "follow symlinks = no" - part 2
Add tests for regular access.
BUG: https://bugzilla.samba.org/show_bug.cgi?id=12721
Signed-off-by: Jeremy Allison <j...@samba.org>
Reviewed-by: Ralph Boehme <s...@samba.org>
Autobuild-User(master): Ralph Böhme <s...@samba.org>
Autobuild-Date(master): Tue Mar 28 17:05:27 CEST 2017 on sn-devel-144
(cherry picked from commit 4e734fcd1bf82c08aa303ce44e9735acccffcf06)
Autobuild-User(v4-4-test): Karolin Seeger <ksee...@samba.org>
Autobuild-Date(v4-4-test): Wed Mar 29 13:57:56 CEST 2017 on sn-devel-144
commit ed694d068081d4849e558fabc0c42085c64ee3b5
Author: Jeremy Allison <j...@samba.org>
Date: Mon Mar 27 17:09:38 2017 -0700
s3: smbd: Fix "follow symlink = no" regression part 2.
Use the cwd_name parameter to reconstruct the original
client name for symlink testing.
BUG: https://bugzilla.samba.org/show_bug.cgi?id=12721
Signed-off-by: Jeremy Allison <j...@samba.org>
Reviewed-by: Ralph Boehme <s...@samba.org>
(cherry picked from commit e182a4d39e86c9694e255efdf6ee2ea3ccb9af4a)
commit 8e3e969eeddc542385d0ccee793f71c12e8fd4b6
Author: Jeremy Allison <j...@samba.org>
Date: Mon Mar 27 17:04:58 2017 -0700
s3: smbd: Fix "follow symlink = no" regression part 2.
Add an extra paramter to cwd_name to check_reduced_name().
If cwd_name == NULL then fname is a client given path relative
to the root path of the share.
If cwd_name != NULL then fname is a client given path relative
to cwd_name. cwd_name is relative to the root path of the share.
Not yet used, logic added in the next commit.
BUG: https://bugzilla.samba.org/show_bug.cgi?id=12721
Signed-off-by: Jeremy Allison <j...@samba.org>
Reviewed-by: Ralph Boehme <s...@samba.org>
(cherry picked from commit 83e30cb48859b412b76572b6a3ba84d8fde167af)
commit 9a5be8b68ba38e0d98329c44d0d5c6d4579c9bf5
Author: Jeremy Allison <j...@samba.org>
Date: Mon Mar 27 22:07:50 2017 -0700
s3: Fixup test for CVE-2017-2619 regression with "follow symlinks = no"
Use correct bash operators (not string operators).
Add missing "return".
BUG: https://bugzilla.samba.org/show_bug.cgi?id=12721
Signed-off-by: Jeremy Allison <j...@samba.org>
Reviewed-by: Ralph Boehme <s...@samba.org>
(cherry picked from commit 037297a1c50e90a0092e3b94f472623f41ccc015)
commit 161a078f550f4c9a50a8f42e29b1f27de689362b
Author: Jeremy Allison <j...@samba.org>
Date: Mon Mar 27 11:48:25 2017 -0700
s3: Test for CVE-2017-2619 regression with "follow symlinks = no".
BUG: https://bugzilla.samba.org/show_bug.cgi?id=12721
Signed-off-by: Jeremy Allison <j...@samba.org>
Reviewed-by: Uri Simchoni <u...@samba.org>
Back-ported from commit 782172a9bef0040981d20e49519b13dd744df6a0
commit 4a6d828e8f230ab6578c73bba7eec06ece6f7fac
Author: Jeremy Allison <j...@samba.org>
Date: Mon Mar 27 10:46:47 2017 -0700
s3: smbd: Fix incorrect logic exposed by fix for the security bug 12496
(CVE-2017-2619).
In a UNIX filesystem, the names "." and ".." by definition can *never*
be symlinks - they are already reserved names.
BUG: https://bugzilla.samba.org/show_bug.cgi?id=12721
Signed-off-by: Jeremy Allison <j...@samba.org>
Reviewed-by: Uri Simchoni <u...@samba.org>
(cherry picked from commit ae17bebd250bdde5614b2ac17e53512f19fe9b68)
-----------------------------------------------------------------------
Summary of changes:
selftest/target/Samba3.pm | 7 ++
source3/script/tests/test_smbclient_s3.sh | 111 ++++++++++++++++++++++++++++++
source3/smbd/filename.c | 2 +-
source3/smbd/open.c | 2 +-
source3/smbd/proto.h | 4 +-
source3/smbd/vfs.c | 40 ++++++++++-
6 files changed, 160 insertions(+), 6 deletions(-)
Changeset truncated at 500 lines:
diff --git a/selftest/target/Samba3.pm b/selftest/target/Samba3.pm
index 619ae1e..938c459 100755
--- a/selftest/target/Samba3.pm
+++ b/selftest/target/Samba3.pm
@@ -1191,6 +1191,9 @@ sub provision($$$$$$$$)
my $shadow_shrdir="$shadow_basedir/share";
push(@dirs,$shadow_shrdir);
+ my $nosymlinks_shrdir="$shrdir/nosymlinks";
+ push(@dirs,$nosymlinks_shrdir);
+
# this gets autocreated by winbindd
my $wbsockdir="$prefix_abs/winbindd";
my $wbsockprivdir="$lockdir/winbindd_privileged";
@@ -1717,6 +1720,10 @@ sub provision($$$$$$$$)
copy = tmp
acl_xattr:ignore system acls = yes
acl_xattr:default acl style = windows
+[nosymlinks]
+ copy = tmp
+ path = $nosymlinks_shrdir
+ follow symlinks = no
[kernel_oplocks]
copy = tmp
kernel oplocks = yes
diff --git a/source3/script/tests/test_smbclient_s3.sh
b/source3/script/tests/test_smbclient_s3.sh
index 5e3db5d..0694e1b 100755
--- a/source3/script/tests/test_smbclient_s3.sh
+++ b/source3/script/tests/test_smbclient_s3.sh
@@ -1071,6 +1071,113 @@ done
LOGDIR=$(mktemp -d ${PREFIX}/${LOGDIR_PREFIX}_XXXXXX)
+# Test follow symlinks can't access symlinks
+test_nosymlinks()
+{
+# Setup test dirs.
+ slink_name="$LOCAL_PATH/nosymlinks/source"
+ slink_target="$LOCAL_PATH/nosymlinks/target"
+ mkdir_target="$LOCAL_PATH/nosymlinks/a"
+ dir1="$LOCAL_PATH/nosymlinks/foo"
+ dir2="$LOCAL_PATH/nosymlinks/foo/bar"
+ get_target="$LOCAL_PATH/nosymlinks/foo/bar/testfile"
+
+ rm -f $slink_target
+ rm -f $slink_name
+ rm -rf $mkdir_target
+ rm -rf $dir1
+
+ touch $slink_target
+ ln -s $slink_target $slink_name
+
+ mkdir $dir1
+ mkdir $dir2
+ touch $get_target
+
+# Getting a file through a symlink name should fail.
+ tmpfile=$PREFIX/smbclient_interactive_prompt_commands
+ cat > $tmpfile <<EOF
+get source
+quit
+EOF
+ cmd='CLI_FORCE_INTERACTIVE=yes $SMBCLIENT "$@" -U$USERNAME%$PASSWORD
//$SERVER/nosymlinks -I $SERVER_IP $ADDARGS < $tmpfile 2>&1'
+ eval echo "$cmd"
+ out=`eval $cmd`
+ ret=$?
+ rm -f $tmpfile
+
+ if [ $ret -ne 0 ] ; then
+ echo "$out"
+ echo "failed accessing nosymlinks with error $ret"
+ false
+ return
+ fi
+
+ echo "$out" | grep 'NT_STATUS_ACCESS_DENIED'
+ ret=$?
+ if [ $ret -ne 0 ] ; then
+ echo "$out"
+ echo "failed - should get NT_STATUS_ACCESS_DENIED getting
\\nosymlinks\\source"
+ false
+ return
+ fi
+
+# But we should be able to create and delete directories.
+ cat > $tmpfile <<EOF
+mkdir a
+mkdir a\\b
+quit
+EOF
+ cmd='CLI_FORCE_INTERACTIVE=yes $SMBCLIENT "$@" -U$USERNAME%$PASSWORD
//$SERVER/nosymlinks -I $SERVER_IP $ADDARGS < $tmpfile 2>&1'
+ eval echo "$cmd"
+ out=`eval $cmd`
+ ret=$?
+ rm -f $tmpfile
+
+ if [ $ret -ne 0 ] ; then
+ echo "$out"
+ echo "failed accessing nosymlinks with error $ret"
+ false
+ return
+ fi
+
+ echo "$out" | grep 'NT_STATUS'
+ ret=$?
+ if [ $ret -eq 0 ] ; then
+ echo "$out"
+ echo "failed - NT_STATUS_XXXX doing mkdir a; mkdir a\\b on \\nosymlinks"
+ false
+ fi
+
+# Ensure regular file/directory access also works.
+ cat > $tmpfile <<EOF
+cd foo\\bar
+ls
+get testfile -
+quit
+EOF
+ cmd='CLI_FORCE_INTERACTIVE=yes $SMBCLIENT "$@" -U$USERNAME%$PASSWORD
//$SERVER/nosymlinks -I $SERVER_IP $ADDARGS < $tmpfile 2>&1'
+ eval echo "$cmd"
+ out=`eval $cmd`
+ ret=$?
+ rm -f $tmpfile
+
+ if [ $ret -ne 0 ] ; then
+ echo "$out"
+ echo "failed accessing nosymlinks with error $ret"
+ false
+ return
+ fi
+
+ echo "$out" | grep 'NT_STATUS'
+ ret=$?
+ if [ $ret -eq 0 ] ; then
+ echo "$out"
+ echo "failed - NT_STATUS_XXXX doing cd foo\\bar; get testfile on
\\nosymlinks"
+ false
+ return
+ fi
+}
testit "smbclient -L $SERVER_IP" $SMBCLIENT -L $SERVER_IP -N -p 139 ||
failed=`expr $failed + 1`
testit "smbclient -L $SERVER -I $SERVER_IP" $SMBCLIENT -L $SERVER -I
$SERVER_IP -N -p 139 -c quit || failed=`expr $failed + 1`
@@ -1155,6 +1262,10 @@ testit "Ensure widelinks are restricted" \
test_widelinks || \
failed=`expr $failed + 1`
+testit "follow symlinks = no" \
+ test_nosymlinks || \
+ failed=`expr $failed + 1`
+
testit "rm -rf $LOGDIR" \
rm -rf $LOGDIR || \
failed=`expr $failed + 1`
diff --git a/source3/smbd/filename.c b/source3/smbd/filename.c
index 046ce9c..9f72f99 100644
--- a/source3/smbd/filename.c
+++ b/source3/smbd/filename.c
@@ -1240,7 +1240,7 @@ NTSTATUS check_name(connection_struct *conn, const char
*name)
}
if (!lp_widelinks(SNUM(conn)) || !lp_follow_symlinks(SNUM(conn))) {
- status = check_reduced_name(conn,name);
+ status = check_reduced_name(conn, NULL, name);
if (!NT_STATUS_IS_OK(status)) {
DEBUG(5,("check_name: name %s failed with %s\n",name,
nt_errstr(status)));
diff --git a/source3/smbd/open.c b/source3/smbd/open.c
index 0b66487..f19af87 100644
--- a/source3/smbd/open.c
+++ b/source3/smbd/open.c
@@ -546,7 +546,7 @@ static int non_widelink_open(struct connection_struct *conn,
}
/* Ensure the relative path is below the share. */
- status = check_reduced_name(conn, final_component);
+ status = check_reduced_name(conn, parent_dir, final_component);
if (!NT_STATUS_IS_OK(status)) {
saved_errno = map_errno_from_nt_status(status);
goto out;
diff --git a/source3/smbd/proto.h b/source3/smbd/proto.h
index ebccdb9..9103e6e 100644
--- a/source3/smbd/proto.h
+++ b/source3/smbd/proto.h
@@ -1197,7 +1197,9 @@ const char *vfs_readdirname(connection_struct *conn, void
*p,
SMB_STRUCT_STAT *sbuf, char **talloced);
int vfs_ChDir(connection_struct *conn, const char *path);
char *vfs_GetWd(TALLOC_CTX *ctx, connection_struct *conn);
-NTSTATUS check_reduced_name(connection_struct *conn, const char *fname);
+NTSTATUS check_reduced_name(connection_struct *conn,
+ const char *cwd_name,
+ const char *fname);
NTSTATUS check_reduced_name_with_privilege(connection_struct *conn,
const char *fname,
struct smb_request *smbreq);
diff --git a/source3/smbd/vfs.c b/source3/smbd/vfs.c
index 93726bd..254337f 100644
--- a/source3/smbd/vfs.c
+++ b/source3/smbd/vfs.c
@@ -1149,11 +1149,20 @@ NTSTATUS
check_reduced_name_with_privilege(connection_struct *conn,
/*******************************************************************
Reduce a file name, removing .. elements and checking that
it is below dir in the heirachy. This uses realpath.
+
+ If cwd_name == NULL then fname is a client given path relative
+ to the root path of the share.
+
+ If cwd_name != NULL then fname is a client given path relative
+ to cwd_name. cwd_name is relative to the root path of the share.
********************************************************************/
-NTSTATUS check_reduced_name(connection_struct *conn, const char *fname)
+NTSTATUS check_reduced_name(connection_struct *conn,
+ const char *cwd_name,
+ const char *fname)
{
char *resolved_name = NULL;
+ char *new_fname = NULL;
bool allow_symlinks = true;
bool allow_widelinks = false;
@@ -1277,8 +1286,11 @@ NTSTATUS check_reduced_name(connection_struct *conn,
const char *fname)
/* fname can't have changed in resolved_path. */
const char *p = &resolved_name[rootdir_len];
- /* *p can be '\0' if fname was "." */
- if (*p == '\0' && ISDOT(fname)) {
+ /*
+ * UNIX filesystem semantics, names consisting
+ * only of "." or ".." CANNOT be symlinks.
+ */
+ if (ISDOT(fname) || ISDOTDOT(fname)) {
goto out;
}
@@ -1292,11 +1304,32 @@ NTSTATUS check_reduced_name(connection_struct *conn,
const char *fname)
}
p++;
+
+ /*
+ * If cwd_name is present and not ".",
+ * then fname is relative to that, not
+ * the root of the share. Make sure the
+ * path we check is the one the client
+ * sent (cwd_name+fname).
+ */
+ if (cwd_name != NULL && !ISDOT(cwd_name)) {
+ new_fname = talloc_asprintf(talloc_tos(),
+ "%s/%s",
+ cwd_name,
+ fname);
+ if (new_fname == NULL) {
+ SAFE_FREE(resolved_name);
+ return NT_STATUS_NO_MEMORY;
+ }
+ fname = new_fname;
+ }
+
if (strcmp(fname, p)!=0) {
DEBUG(2, ("check_reduced_name: Bad access "
"attempt: %s is a symlink to %s\n",
fname, p));
SAFE_FREE(resolved_name);
+ TALLOC_FREE(new_fname);
return NT_STATUS_ACCESS_DENIED;
}
}
@@ -1306,6 +1339,7 @@ NTSTATUS check_reduced_name(connection_struct *conn,
const char *fname)
DBG_INFO("%s reduced to %s\n", fname, resolved_name);
SAFE_FREE(resolved_name);
+ TALLOC_FREE(new_fname);
return NT_STATUS_OK;
}
--
Samba Shared Repository
