The branch, master has been updated
via 294a1a8 CVE-2017-2619: s3: smbd: Use the new non_widelink_open()
function.
via 4301505 CVE-2017-2619: s3: smbd: Add the core functions to prevent
symlink open races.
via 592e7fa CVE-2017-2619: s3: smbd: Move special handling of symlink
errno's into a utility function.
via 6ff5f0a CVE-2017-2619: s3: smbd: Remove O_NOFOLLOW guards. We
insist on O_NOFOLLOW existing.
via 49ed0b0 CVE-2017-2619: s3: smbd: Correctly fallback to
open_dir_safely if FDOPENDIR not supported on system.
via f6dfdf7 CVE-2017-2619: s3: smbd: Move the reference counting and
destructor setup to just before retuning success.
via e68e73b CVE-2017-2619: s3: smbd: OpenDir_fsp() - Fix memory leak on
error.
via 86f1523 CVE-2017-2619: s3: smbd: OpenDir_fsp() use early returns.
via 05a9898 CVE-2017-2619: s3: smbd: Create and use open_dir_safely().
Use from OpenDir().
via 682d597 CVE-2017-2619: s3: smbd: Opendir_internal() early return if
SMB_VFS_OPENDIR failed.
via 3461518 CVE-2017-2619: s3: smbd: Create wrapper function for
OpenDir in preparation for making robust.
via 0a982be CVE-2017-2619: s4/torture: add SMB2_FIND tests with
SMB2_CONTINUE_FLAG_REOPEN flag
via 47b6b6f CVE-2017-2619: s3/smbd: re-open directory after
dptr_CloseDir()
from 1e0df57 libwbclient: add WBC_SID_NAME_LABEL
https://git.samba.org/?p=samba.git;a=shortlog;h=master
- Log -----------------------------------------------------------------
commit 294a1a8374d413d8af506e962c1d310d9ee79ae5
Author: Jeremy Allison <[email protected]>
Date: Thu Dec 15 13:06:31 2016 -0800
CVE-2017-2619: s3: smbd: Use the new non_widelink_open() function.
BUG: https://bugzilla.samba.org/show_bug.cgi?id=12496
Signed-off-by: Jeremy Allison <[email protected]>
Reviewed-by: Uri Simchoni <[email protected]>
Autobuild-User(master): Karolin Seeger <[email protected]>
Autobuild-Date(master): Thu Mar 23 22:55:04 CET 2017 on sn-devel-144
commit 4301505d977449d1995699010bb04682009aa105
Author: Jeremy Allison <[email protected]>
Date: Thu Dec 15 13:04:46 2016 -0800
CVE-2017-2619: s3: smbd: Add the core functions to prevent symlink open
races.
BUG: https://bugzilla.samba.org/show_bug.cgi?id=12496
Signed-off-by: Jeremy Allison <[email protected]>
Reviewed-by: Uri Simchoni <[email protected]>
commit 592e7fa67b137099b894759e8aa579eea0eb9c4c
Author: Jeremy Allison <[email protected]>
Date: Thu Dec 15 12:56:08 2016 -0800
CVE-2017-2619: s3: smbd: Move special handling of symlink errno's into a
utility function.
BUG: https://bugzilla.samba.org/show_bug.cgi?id=12496
Signed-off-by: Jeremy Allison <[email protected]>
Reviewed-by: Uri Simchoni <[email protected]>
commit 6ff5f0a75a9ec1aeccf50dff97d4c328fd65f219
Author: Jeremy Allison <[email protected]>
Date: Thu Dec 15 12:52:13 2016 -0800
CVE-2017-2619: s3: smbd: Remove O_NOFOLLOW guards. We insist on O_NOFOLLOW
existing.
BUG: https://bugzilla.samba.org/show_bug.cgi?id=12496
Signed-off-by: Jeremy Allison <[email protected]>
Reviewed-by: Uri Simchoni <[email protected]>
commit 49ed0b01d1310f09e321122effed571b8ba852cb
Author: Jeremy Allison <[email protected]>
Date: Mon Dec 19 12:35:32 2016 -0800
CVE-2017-2619: s3: smbd: Correctly fallback to open_dir_safely if FDOPENDIR
not supported on system.
BUG: https://bugzilla.samba.org/show_bug.cgi?id=12496
Signed-off-by: Jeremy Allison <[email protected]>
Reviewed-by: Uri Simchoni <[email protected]>
commit f6dfdf7d31967076dbd51ceb35145d28381a6f92
Author: Jeremy Allison <[email protected]>
Date: Mon Dec 19 12:32:07 2016 -0800
CVE-2017-2619: s3: smbd: Move the reference counting and destructor setup
to just before retuning success.
BUG: https://bugzilla.samba.org/show_bug.cgi?id=12496
Signed-off-by: Jeremy Allison <[email protected]>
Reviewed-by: Uri Simchoni <[email protected]>
commit e68e73b8d3c164b882d3cc02685f99f2ea3d2880
Author: Jeremy Allison <[email protected]>
Date: Mon Dec 19 12:15:59 2016 -0800
CVE-2017-2619: s3: smbd: OpenDir_fsp() - Fix memory leak on error.
BUG: https://bugzilla.samba.org/show_bug.cgi?id=12496
Signed-off-by: Jeremy Allison <[email protected]>
Reviewed-by: Uri Simchoni <[email protected]>
commit 86f15237a13a4dd2bca7c9cd81a9e54029d0becc
Author: Jeremy Allison <[email protected]>
Date: Mon Dec 19 12:13:20 2016 -0800
CVE-2017-2619: s3: smbd: OpenDir_fsp() use early returns.
BUG: https://bugzilla.samba.org/show_bug.cgi?id=12496
Signed-off-by: Jeremy Allison <[email protected]>
Reviewed-by: Uri Simchoni <[email protected]>
commit 05a9898ddae5566884357f8f66e15e5ba102ef49
Author: Jeremy Allison <[email protected]>
Date: Mon Dec 19 16:35:00 2016 -0800
CVE-2017-2619: s3: smbd: Create and use open_dir_safely(). Use from
OpenDir().
Hardens OpenDir against TOC/TOU races.
BUG: https://bugzilla.samba.org/show_bug.cgi?id=12496
Signed-off-by: Jeremy Allison <[email protected]>
Reviewed-by: Uri Simchoni <[email protected]>
commit 682d597ee3b23e9f49e124e1e04e2b288c9a053f
Author: Jeremy Allison <[email protected]>
Date: Mon Dec 19 16:25:26 2016 -0800
CVE-2017-2619: s3: smbd: Opendir_internal() early return if SMB_VFS_OPENDIR
failed.
BUG: https://bugzilla.samba.org/show_bug.cgi?id=12496
Signed-off-by: Jeremy Allison <[email protected]>
Reviewed-by: Uri Simchoni <[email protected]>
commit 34615180279fdeeeb3e91cc3b9574af91c3db589
Author: Jeremy Allison <[email protected]>
Date: Mon Dec 19 11:55:56 2016 -0800
CVE-2017-2619: s3: smbd: Create wrapper function for OpenDir in preparation
for making robust.
BUG: https://bugzilla.samba.org/show_bug.cgi?id=12496
Signed-off-by: Jeremy Allison <[email protected]>
Reviewed-by: Uri Simchoni <[email protected]>
commit 0a982be89f81ea2448bcd2398358d0503e9adea1
Author: Ralph Boehme <[email protected]>
Date: Sun Mar 19 18:52:10 2017 +0100
CVE-2017-2619: s4/torture: add SMB2_FIND tests with
SMB2_CONTINUE_FLAG_REOPEN flag
Bug: https://bugzilla.samba.org/show_bug.cgi?id=12496
Signed-off-by: Ralph Boehme <[email protected]>
Reviewed-by: Uri Simchoni <[email protected]>
commit 47b6b6f8f58efbabd7e4610f51db61dca2bc157c
Author: Ralph Boehme <[email protected]>
Date: Sun Mar 19 15:58:17 2017 +0100
CVE-2017-2619: s3/smbd: re-open directory after dptr_CloseDir()
dptr_CloseDir() will close and invalidate the fsp's file descriptor, we
have to reopen it.
Bug: https://bugzilla.samba.org/show_bug.cgi?id=12496
Signed-off-by: Ralph Boehme <[email protected]>
Reviewed-by: Uri Simchoni <[email protected]>
-----------------------------------------------------------------------
Summary of changes:
source3/smbd/dir.c | 161 ++++++++++++++-----
source3/smbd/open.c | 310 +++++++++++++++++++++++++++++++++---
source3/smbd/smb2_query_directory.c | 17 ++
source4/torture/smb2/dir.c | 12 +-
4 files changed, 434 insertions(+), 66 deletions(-)
Changeset truncated at 500 lines:
diff --git a/source3/smbd/dir.c b/source3/smbd/dir.c
index 3c6f000..1348d12 100644
--- a/source3/smbd/dir.c
+++ b/source3/smbd/dir.c
@@ -1630,7 +1630,8 @@ static int smb_Dir_destructor(struct smb_Dir *dirp)
Open a directory.
********************************************************************/
-struct smb_Dir *OpenDir(TALLOC_CTX *mem_ctx, connection_struct *conn,
+static struct smb_Dir *OpenDir_internal(TALLOC_CTX *mem_ctx,
+ connection_struct *conn,
const struct smb_filename *smb_dname,
const char *mask,
uint32_t attr)
@@ -1642,29 +1643,23 @@ struct smb_Dir *OpenDir(TALLOC_CTX *mem_ctx,
connection_struct *conn,
return NULL;
}
- dirp->conn = conn;
- dirp->name_cache_size = lp_directory_name_cache_size(SNUM(conn));
+ dirp->dir = SMB_VFS_OPENDIR(conn, smb_dname, mask, attr);
- dirp->dir_smb_fname = cp_smb_filename(dirp, smb_dname);
- if (!dirp->dir_smb_fname) {
- errno = ENOMEM;
+ if (!dirp->dir) {
+ DEBUG(5,("OpenDir: Can't open %s. %s\n",
+ smb_dname->base_name,
+ strerror(errno) ));
goto fail;
}
+ dirp->conn = conn;
+ dirp->name_cache_size = lp_directory_name_cache_size(SNUM(conn));
+
if (sconn && !sconn->using_smb2) {
sconn->searches.dirhandles_open++;
}
talloc_set_destructor(dirp, smb_Dir_destructor);
- dirp->dir = SMB_VFS_OPENDIR(conn, dirp->dir_smb_fname, mask, attr);
-
- if (!dirp->dir) {
- DEBUG(5,("OpenDir: Can't open %s. %s\n",
- dirp->dir_smb_fname->base_name,
- strerror(errno) ));
- goto fail;
- }
-
return dirp;
fail:
@@ -1672,6 +1667,87 @@ struct smb_Dir *OpenDir(TALLOC_CTX *mem_ctx,
connection_struct *conn,
return NULL;
}
+/****************************************************************************
+ Open a directory handle by pathname, ensuring it's under the share path.
+****************************************************************************/
+
+static struct smb_Dir *open_dir_safely(TALLOC_CTX *ctx,
+ connection_struct *conn,
+ const struct smb_filename *smb_dname,
+ const char *wcard,
+ uint32_t attr)
+{
+ struct smb_Dir *dir_hnd = NULL;
+ struct smb_filename *smb_fname_cwd = NULL;
+ char *saved_dir = vfs_GetWd(ctx, conn);
+ NTSTATUS status;
+
+ if (saved_dir == NULL) {
+ return NULL;
+ }
+
+ if (vfs_ChDir(conn, smb_dname->base_name) == -1) {
+ goto out;
+ }
+
+ smb_fname_cwd = synthetic_smb_fname(talloc_tos(),
+ ".",
+ NULL,
+ NULL,
+ smb_dname->flags);
+ if (smb_fname_cwd == NULL) {
+ goto out;
+ }
+
+ /*
+ * Now the directory is pinned, use
+ * REALPATH to ensure we can access it.
+ */
+ status = check_name(conn, ".");
+ if (!NT_STATUS_IS_OK(status)) {
+ goto out;
+ }
+
+ dir_hnd = OpenDir_internal(ctx,
+ conn,
+ smb_fname_cwd,
+ wcard,
+ attr);
+
+ if (dir_hnd == NULL) {
+ goto out;
+ }
+
+ /*
+ * OpenDir_internal only gets "." as the dir name.
+ * Store the real dir name here.
+ */
+
+ dir_hnd->dir_smb_fname = cp_smb_filename(dir_hnd, smb_dname);
+ if (!dir_hnd->dir_smb_fname) {
+ TALLOC_FREE(dir_hnd);
+ errno = ENOMEM;
+ }
+
+ out:
+
+ vfs_ChDir(conn, saved_dir);
+ TALLOC_FREE(saved_dir);
+ return dir_hnd;
+}
+
+struct smb_Dir *OpenDir(TALLOC_CTX *mem_ctx, connection_struct *conn,
+ const struct smb_filename *smb_dname,
+ const char *mask,
+ uint32_t attr)
+{
+ return open_dir_safely(mem_ctx,
+ conn,
+ smb_dname,
+ mask,
+ attr);
+}
+
/*******************************************************************
Open a directory from an fsp.
********************************************************************/
@@ -1685,7 +1761,17 @@ static struct smb_Dir *OpenDir_fsp(TALLOC_CTX *mem_ctx,
connection_struct *conn,
struct smbd_server_connection *sconn = conn->sconn;
if (!dirp) {
- return NULL;
+ goto fail;
+ }
+
+ if (!fsp->is_directory) {
+ errno = EBADF;
+ goto fail;
+ }
+
+ if (fsp->fh->fd == -1) {
+ errno = EBADF;
+ goto fail;
}
dirp->conn = conn;
@@ -1697,40 +1783,33 @@ static struct smb_Dir *OpenDir_fsp(TALLOC_CTX *mem_ctx,
connection_struct *conn,
goto fail;
}
- if (sconn && !sconn->using_smb2) {
- sconn->searches.dirhandles_open++;
- }
- talloc_set_destructor(dirp, smb_Dir_destructor);
-
- if (fsp->is_directory && fsp->fh->fd != -1) {
- dirp->dir = SMB_VFS_FDOPENDIR(fsp, mask, attr);
- if (dirp->dir != NULL) {
- dirp->fsp = fsp;
- } else {
- DEBUG(10,("OpenDir_fsp: SMB_VFS_FDOPENDIR on %s
returned "
- "NULL (%s)\n",
- dirp->dir_smb_fname->base_name,
- strerror(errno)));
- if (errno != ENOSYS) {
- return NULL;
- }
+ dirp->dir = SMB_VFS_FDOPENDIR(fsp, mask, attr);
+ if (dirp->dir != NULL) {
+ dirp->fsp = fsp;
+ } else {
+ DEBUG(10,("OpenDir_fsp: SMB_VFS_FDOPENDIR on %s returned "
+ "NULL (%s)\n",
+ dirp->dir_smb_fname->base_name,
+ strerror(errno)));
+ if (errno != ENOSYS) {
+ goto fail;
}
}
if (dirp->dir == NULL) {
- /* FDOPENDIR didn't work. Use OPENDIR instead. */
- dirp->dir = SMB_VFS_OPENDIR(conn,
- dirp->dir_smb_fname,
+ /* FDOPENDIR is not supported. Use OPENDIR instead. */
+ TALLOC_FREE(dirp);
+ return open_dir_safely(mem_ctx,
+ conn,
+ fsp->fsp_name,
mask,
attr);
}
- if (!dirp->dir) {
- DEBUG(5,("OpenDir_fsp: Can't open %s. %s\n",
- dirp->dir_smb_fname->base_name,
- strerror(errno) ));
- goto fail;
+ if (sconn && !sconn->using_smb2) {
+ sconn->searches.dirhandles_open++;
}
+ talloc_set_destructor(dirp, smb_Dir_destructor);
return dirp;
diff --git a/source3/smbd/open.c b/source3/smbd/open.c
index 603a01d..a6e61e7 100644
--- a/source3/smbd/open.c
+++ b/source3/smbd/open.c
@@ -364,6 +364,269 @@ static NTSTATUS check_base_file_access(struct
connection_struct *conn,
}
/****************************************************************************
+ Handle differing symlink errno's
+****************************************************************************/
+
+static int link_errno_convert(int err)
+{
+#if defined(ENOTSUP) && defined(OSF1)
+ /* handle special Tru64 errno */
+ if (err == ENOTSUP) {
+ err = ELOOP;
+ }
+#endif /* ENOTSUP */
+#ifdef EFTYPE
+ /* fix broken NetBSD errno */
+ if (err == EFTYPE) {
+ err = ELOOP;
+ }
+#endif /* EFTYPE */
+ /* fix broken FreeBSD errno */
+ if (err == EMLINK) {
+ err = ELOOP;
+ }
+ return err;
+}
+
+static int non_widelink_open(struct connection_struct *conn,
+ const char *conn_rootdir,
+ files_struct *fsp,
+ struct smb_filename *smb_fname,
+ int flags,
+ mode_t mode,
+ unsigned int link_depth);
+
+/****************************************************************************
+ Follow a symlink in userspace.
+****************************************************************************/
+
+static int process_symlink_open(struct connection_struct *conn,
+ const char *conn_rootdir,
+ files_struct *fsp,
+ struct smb_filename *smb_fname,
+ int flags,
+ mode_t mode,
+ unsigned int link_depth)
+{
+ int fd = -1;
+ char *link_target = NULL;
+ int link_len = -1;
+ char *oldwd = NULL;
+ size_t rootdir_len = 0;
+ char *resolved_name = NULL;
+ bool matched = false;
+ int saved_errno = 0;
+
+ /*
+ * Ensure we don't get stuck in a symlink loop.
+ */
+ link_depth++;
+ if (link_depth >= 20) {
+ errno = ELOOP;
+ goto out;
+ }
+
+ /* Allocate space for the link target. */
+ link_target = talloc_array(talloc_tos(), char, PATH_MAX);
+ if (link_target == NULL) {
+ errno = ENOMEM;
+ goto out;
+ }
+
+ /* Read the link target. */
+ link_len = SMB_VFS_READLINK(conn,
+ smb_fname->base_name,
+ link_target,
+ PATH_MAX - 1);
+ if (link_len == -1) {
+ goto out;
+ }
+
+ /* Ensure it's at least null terminated. */
+ link_target[link_len] = '\0';
+
+ /* Convert to an absolute path. */
+ resolved_name = SMB_VFS_REALPATH(conn, link_target);
+ if (resolved_name == NULL) {
+ goto out;
+ }
+
+ /*
+ * We know conn_rootdir starts with '/' and
+ * does not end in '/'. FIXME ! Should we
+ * smb_assert this ?
+ */
+ rootdir_len = strlen(conn_rootdir);
+
+ matched = (strncmp(conn_rootdir, resolved_name, rootdir_len) == 0);
+ if (!matched) {
+ errno = EACCES;
+ goto out;
+ }
+
+ /*
+ * Turn into a path relative to the share root.
+ */
+ if (resolved_name[rootdir_len] == '\0') {
+ /* Link to the root of the share. */
+ smb_fname->base_name = talloc_strdup(talloc_tos(), ".");
+ if (smb_fname->base_name == NULL) {
+ errno = ENOMEM;
+ goto out;
+ }
+ } else if (resolved_name[rootdir_len] == '/') {
+ smb_fname->base_name = &resolved_name[rootdir_len+1];
+ } else {
+ errno = EACCES;
+ goto out;
+ }
+
+ oldwd = vfs_GetWd(talloc_tos(), conn);
+ if (oldwd == NULL) {
+ goto out;
+ }
+
+ /* Ensure we operate from the root of the share. */
+ if (vfs_ChDir(conn, conn_rootdir) == -1) {
+ goto out;
+ }
+
+ /* And do it all again.. */
+ fd = non_widelink_open(conn,
+ conn_rootdir,
+ fsp,
+ smb_fname,
+ flags,
+ mode,
+ link_depth);
+ if (fd == -1) {
+ saved_errno = errno;
+ }
+
+ out:
+
+ SAFE_FREE(resolved_name);
+ TALLOC_FREE(link_target);
+ if (oldwd != NULL) {
+ int ret = vfs_ChDir(conn, oldwd);
+ if (ret == -1) {
+ smb_panic("unable to get back to old directory\n");
+ }
+ TALLOC_FREE(oldwd);
+ }
+ if (saved_errno != 0) {
+ errno = saved_errno;
+ }
+ return fd;
+}
+
+/****************************************************************************
+ Non-widelink open.
+****************************************************************************/
+
+static int non_widelink_open(struct connection_struct *conn,
+ const char *conn_rootdir,
+ files_struct *fsp,
+ struct smb_filename *smb_fname,
+ int flags,
+ mode_t mode,
+ unsigned int link_depth)
+{
+ NTSTATUS status;
+ int fd = -1;
+ struct smb_filename *smb_fname_rel = NULL;
+ int saved_errno = 0;
+ char *oldwd = NULL;
+ char *parent_dir = NULL;
+ const char *final_component = NULL;
+
+ if (!parent_dirname(talloc_tos(),
+ smb_fname->base_name,
+ &parent_dir,
+ &final_component)) {
+ goto out;
+ }
+
+ oldwd = vfs_GetWd(talloc_tos(), conn);
+ if (oldwd == NULL) {
+ goto out;
+ }
+
+ /* Pin parent directory in place. */
+ if (vfs_ChDir(conn, parent_dir) == -1) {
+ goto out;
+ }
+
+ /* Ensure the relative path is below the share. */
+ status = check_reduced_name(conn, final_component);
+ if (!NT_STATUS_IS_OK(status)) {
+ saved_errno = map_errno_from_nt_status(status);
+ goto out;
+ }
+
+ smb_fname_rel = synthetic_smb_fname(talloc_tos(),
+ final_component,
+ smb_fname->stream_name,
+ &smb_fname->st,
+ smb_fname->flags);
+
+ flags |= O_NOFOLLOW;
+
+ {
+ struct smb_filename *tmp_name = fsp->fsp_name;
+ fsp->fsp_name = smb_fname_rel;
+ fd = SMB_VFS_OPEN(conn, smb_fname_rel, fsp, flags, mode);
+ fsp->fsp_name = tmp_name;
+ }
+
+ if (fd == -1) {
+ saved_errno = link_errno_convert(errno);
+ if (saved_errno == ELOOP) {
+ if (fsp->posix_flags & FSP_POSIX_FLAGS_OPEN) {
+ /* Never follow symlinks on posix open. */
+ goto out;
+ }
+ if (!lp_follow_symlinks(SNUM(conn))) {
+ /* Explicitly no symlinks. */
+ goto out;
+ }
+ /*
+ * We have a symlink. Follow in userspace
+ * to ensure it's under the share definition.
+ */
+ fd = process_symlink_open(conn,
+ conn_rootdir,
+ fsp,
+ smb_fname_rel,
+ flags,
+ mode,
+ link_depth);
+ if (fd == -1) {
+ saved_errno =
+ link_errno_convert(errno);
+ }
+ }
+ }
+
+ out:
+
+ TALLOC_FREE(parent_dir);
+ TALLOC_FREE(smb_fname_rel);
+
+ if (oldwd != NULL) {
+ int ret = vfs_ChDir(conn, oldwd);
+ if (ret == -1) {
+ smb_panic("unable to get back to old directory\n");
+ }
+ TALLOC_FREE(oldwd);
+ }
+ if (saved_errno != 0) {
+ errno = saved_errno;
+ }
+ return fd;
+}
+
+/****************************************************************************
fd support routines - attempt to do a dos_open.
****************************************************************************/
@@ -375,8 +638,7 @@ NTSTATUS fd_open(struct connection_struct *conn,
struct smb_filename *smb_fname = fsp->fsp_name;
NTSTATUS status = NT_STATUS_OK;
-#ifdef O_NOFOLLOW
- /*
+ /*
* Never follow symlinks on a POSIX client. The
--
Samba Shared Repository
