From 662e9c04fbdf8e01036ab98783693051b0eb9c7e Mon Sep 17 00:00:00 2001 From: Jeremy Allison Date: Fri, 21 Oct 2011 14:12:41 -0700 Subject: Fix bug #8541 - readlink() on Linux clients fails if the symlink target is outside of the share. The key is to only allow the lookup to succeed if it's a UNIX level lookup or readlink, but disallow all other operations. Autobuild-User: Jeremy Allison Autobuild-Date: Sat Oct 22 01:37:41 CEST 2011 on sn-devel-104 --- source3/include/smb.h | 1 + source3/smbd/filename.c | 34 +++++++++++++++++++++++++++------- source3/smbd/proto.h | 1 + source3/smbd/trans2.c | 18 ++++++++++++++---- 4 files changed, 43 insertions(+), 11 deletions(-) diff --git a/source3/include/smb.h b/source3/include/smb.h index 8e0e8efa80..ace3c5efba 100644 --- a/source3/include/smb.h +++ b/source3/include/smb.h @@ -1603,6 +1603,7 @@ struct smb_file_time { #define UCF_ALWAYS_ALLOW_WCARD_LCOMP 0x00000002 #define UCF_COND_ALLOW_WCARD_LCOMP 0x00000004 #define UCF_POSIX_PATHNAMES 0x00000008 +#define UCF_UNIX_NAME_LOOKUP 0x00000010 /* * smb_filename diff --git a/source3/smbd/filename.c b/source3/smbd/filename.c index b7c7831008..722da31659 100644 --- a/source3/smbd/filename.c +++ b/source3/smbd/filename.c @@ -977,25 +977,39 @@ NTSTATUS unix_convert(TALLOC_CTX *ctx, } /**************************************************************************** - Check a filename - possibly calling check_reduced_name. - This is called by every routine before it allows an operation on a filename. - It does any final confirmation necessary to ensure that the filename is - a valid one for the user to access. + Ensure a path is not vetod. ****************************************************************************/ -NTSTATUS check_name(connection_struct *conn, const char *name) +NTSTATUS check_veto_path(connection_struct *conn, const char *name) { if (IS_VETO_PATH(conn, name)) { /* Is it not dot or dot dot. */ if (!(ISDOT(name) || ISDOTDOT(name))) { - DEBUG(5,("check_name: file path name %s vetoed\n", + DEBUG(5,("check_veto_path: file path name %s vetoed\n", name)); return map_nt_error_from_unix(ENOENT); } } + return NT_STATUS_OK; +} + +/**************************************************************************** + Check a filename - possibly calling check_reduced_name. + This is called by every routine before it allows an operation on a filename. + It does any final confirmation necessary to ensure that the filename is + a valid one for the user to access. +****************************************************************************/ + +NTSTATUS check_name(connection_struct *conn, const char *name) +{ + NTSTATUS status = check_veto_path(conn, name); + + if (!NT_STATUS_IS_OK(status)) { + return status; + } if (!lp_widelinks(SNUM(conn)) || !lp_symlinks(SNUM(conn))) { - NTSTATUS status = check_reduced_name(conn,name); + status = check_reduced_name(conn,name); if (!NT_STATUS_IS_OK(status)) { DEBUG(5,("check_name: name %s failed with %s\n",name, nt_errstr(status))); @@ -1313,6 +1327,12 @@ NTSTATUS filename_convert(TALLOC_CTX *ctx, return status; } + if ((ucf_flags & UCF_UNIX_NAME_LOOKUP) && + VALID_STAT((*pp_smb_fname)->st) && + S_ISLNK((*pp_smb_fname)->st.st_ex_mode)) { + return check_veto_path(conn, (*pp_smb_fname)->base_name); + } + status = check_name(conn, (*pp_smb_fname)->base_name); if (!NT_STATUS_IS_OK(status)) { DEBUG(3,("filename_convert: check_name failed " diff --git a/source3/smbd/proto.h b/source3/smbd/proto.h index 49bb911cbc..9891c1e403 100644 --- a/source3/smbd/proto.h +++ b/source3/smbd/proto.h @@ -342,6 +342,7 @@ NTSTATUS unix_convert(TALLOC_CTX *ctx, const char *orig_path, struct smb_filename **smb_fname, uint32_t ucf_flags); +NTSTATUS check_veto_path(connection_struct *conn, const char *name); NTSTATUS check_name(connection_struct *conn, const char *name); int get_real_filename(connection_struct *conn, const char *path, const char *name, TALLOC_CTX *mem_ctx, diff --git a/source3/smbd/trans2.c b/source3/smbd/trans2.c index 1a381950df..6ac95bde68 100644 --- a/source3/smbd/trans2.c +++ b/source3/smbd/trans2.c @@ -2270,6 +2270,7 @@ static void call_trans2findfirst(connection_struct *conn, TALLOC_CTX *ctx = talloc_tos(); struct dptr_struct *dirptr = NULL; struct smbd_server_connection *sconn = req->sconn; + uint32_t ucf_flags = (UCF_SAVE_LCOMP | UCF_ALWAYS_ALLOW_WCARD_LCOMP); if (total_params < 13) { reply_nterror(req, NT_STATUS_INVALID_PARAMETER); @@ -2313,6 +2314,7 @@ close_if_end = %d requires_resume_key = %d level = 0x%x, max_data_bytes = %d\n", reply_nterror(req, NT_STATUS_INVALID_LEVEL); goto out; } + ucf_flags |= UCF_UNIX_NAME_LOOKUP; break; default: reply_nterror(req, NT_STATUS_INVALID_LEVEL); @@ -5103,6 +5105,7 @@ static void call_trans2qfilepathinfo(connection_struct *conn, } else { uint32_t name_hash; char *fname = NULL; + uint32_t ucf_flags = 0; /* qpathinfo */ if (total_params < 7) { @@ -5114,9 +5117,16 @@ static void call_trans2qfilepathinfo(connection_struct *conn, DEBUG(3,("call_trans2qfilepathinfo: TRANSACT2_QPATHINFO: level = %d\n", info_level)); - if (INFO_LEVEL_IS_UNIX(info_level) && !lp_unix_extensions()) { - reply_nterror(req, NT_STATUS_INVALID_LEVEL); - return; + if (INFO_LEVEL_IS_UNIX(info_level)) { + if (!lp_unix_extensions()) { + reply_nterror(req, NT_STATUS_INVALID_LEVEL); + return; + } + if (info_level == SMB_QUERY_FILE_UNIX_BASIC || + info_level == SMB_QUERY_FILE_UNIX_INFO2 || + info_level == SMB_QUERY_FILE_UNIX_LINK) { + ucf_flags |= UCF_UNIX_NAME_LOOKUP; + } } srvstr_get_path(req, params, req->flags2, &fname, ¶ms[6], @@ -5131,7 +5141,7 @@ static void call_trans2qfilepathinfo(connection_struct *conn, conn, req->flags2 & FLAGS2_DFS_PATHNAMES, fname, - 0, + ucf_flags, NULL, &smb_fname); if (!NT_STATUS_IS_OK(status)) { -- cgit