From 2e94b6ec10f1d15e24867bab3063bb85f173406a Mon Sep 17 00:00:00 2001 From: Jeremy Allison <jra@samba.org> Date: Thu, 9 Jul 2015 10:58:11 -0700 Subject: [PATCH] CVE-2015-5252: s3: smbd: Fix symlink verification (file access outside the share). Ensure matching component ends in '/' or '\0'. BUG: https://bugzilla.samba.org/show_bug.cgi?id=11395 Signed-off-by: Jeremy Allison <jra@samba.org> Reviewed-by: Volker Lendecke <vl@samba.org> --- source3/smbd/vfs.c | 7 +++++-- 1 file changed, 5 insertions(+), 2 deletions(-) --- a/source3/smbd/vfs.c +++ b/source3/smbd/vfs.c @@ -982,6 +982,7 @@ NTSTATUS check_reduced_name(connection_s if (!allow_widelinks || !allow_symlinks) { const char *conn_rootdir; size_t rootdir_len; + bool matched; conn_rootdir = SMB_VFS_CONNECTPATH(conn, fname); if (conn_rootdir == NULL) { @@ -992,8 +993,10 @@ NTSTATUS check_reduced_name(connection_s } rootdir_len = strlen(conn_rootdir); - if (strncmp(conn_rootdir, resolved_name, - rootdir_len) != 0) { + matched = (strncmp(conn_rootdir, resolved_name, + rootdir_len) == 0); + if (!matched || (resolved_name[rootdir_len] != '/' && + resolved_name[rootdir_len] != '\0')) { DEBUG(2, ("check_reduced_name: Bad access " "attempt: %s is a symlink outside the " "share path\n", fname));