From 9588c4950c9b3dd6c16b899156e6d985c7b43187 Mon Sep 17 00:00:00 2001 From: Jeremy Allison Date: Fri, 23 Oct 2015 14:54:31 -0700 Subject: [PATCH] CVE-2015-5299: s3-shadow-copy2: fix missing access check on snapdir Fix originally from https://bugzilla.samba.org/show_bug.cgi?id=11529 Signed-off-by: Jeremy Allison Reviewed-by: David Disseldorp --- source3/modules/vfs_shadow_copy2.c | 45 ++++++++++++++++++++++++++++++++++++++ 1 file changed, 45 insertions(+) diff --git a/source3/modules/vfs_shadow_copy2.c b/source3/modules/vfs_shadow_copy2.c index 439df5d..c5c2015 100644 --- a/source3/modules/vfs_shadow_copy2.c +++ b/source3/modules/vfs_shadow_copy2.c @@ -30,6 +30,7 @@ */ #include "includes.h" +#include "smbd/smbd.h" #include "system/filesys.h" #include "include/ntioctl.h" #include @@ -1179,6 +1180,42 @@ static char *have_snapdir(struct vfs_handle_struct *handle, return NULL; } +static bool check_access_snapdir(struct vfs_handle_struct *handle, + const char *path) +{ + struct smb_filename smb_fname; + int ret; + NTSTATUS status; + + ZERO_STRUCT(smb_fname); + smb_fname.base_name = talloc_asprintf(talloc_tos(), + "%s", + path); + if (smb_fname.base_name == NULL) { + return false; + } + + ret = SMB_VFS_NEXT_STAT(handle, &smb_fname); + if (ret != 0 || !S_ISDIR(smb_fname.st.st_ex_mode)) { + TALLOC_FREE(smb_fname.base_name); + return false; + } + + status = smbd_check_access_rights(handle->conn, + &smb_fname, + false, + SEC_DIR_LIST); + if (!NT_STATUS_IS_OK(status)) { + DEBUG(0,("user does not have list permission " + "on snapdir %s\n", + smb_fname.base_name)); + TALLOC_FREE(smb_fname.base_name); + return false; + } + TALLOC_FREE(smb_fname.base_name); + return true; +} + /** * Find the snapshot directory (if any) for the given * filename (which is relative to the share). @@ -1328,6 +1365,7 @@ static int shadow_copy2_get_shadow_copy_data( const char *snapdir; struct dirent *d; TALLOC_CTX *tmp_ctx = talloc_stackframe(); + bool ret; snapdir = shadow_copy2_find_snapdir(tmp_ctx, handle, fsp->fsp_name); if (snapdir == NULL) { @@ -1337,6 +1375,13 @@ static int shadow_copy2_get_shadow_copy_data( talloc_free(tmp_ctx); return -1; } + ret = check_access_snapdir(handle, snapdir); + if (!ret) { + DEBUG(0,("access denied on listing snapdir %s\n", snapdir)); + errno = EACCES; + talloc_free(tmp_ctx); + return -1; + } p = SMB_VFS_NEXT_OPENDIR(handle, snapdir, NULL, 0); -- 2.5.0