Attachment 15001 Details for Bug 13851 – patch for 4.5 (v2)

[patch] patch for 4.5 (v2)

CVE-2019-3880-v4-5-02.patch (text/plain), 4.42 KB, created by Andrew Bartlett on 2019-03-27 04:01:30 UTC

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Creator: Andrew Bartlett

Created: 2019-03-27 04:01:30 UTC

Size: 4.42 KB

patch

obsolete

>From 278d169c1078608ef41702bcd5b0dbfed62c3886 Mon Sep 17 00:00:00 2001
>From: Jeremy Allison <jra@samba.org>
>Date: Thu, 21 Mar 2019 14:51:30 -0700
>Subject: [PATCH] CVE-2019-3880 s3: rpc: winreg: Remove implementations of
> SaveKey/RestoreKey.
>
>The were not using VFS backend calls and could only work
>locally, and were unsafe against symlink races and other
>security issues.
>
>If the incoming handle is valid, return WERR_BAD_PATHNAME.
>
>[MS-RRP] states "The format of the file name is implementation-specific"
>so ensure we don't allow this.
>
>As reported by Michael Hanselmann.
>
>BUG: https://bugzilla.samba.org/show_bug.cgi?id=13851
>
>Signed-off-by: Jeremy Allison <jra@samba.org>
>Reviewed-by: Andrew Bartlett <abartlet@samba.org>
>
>(backported to Samba 4.5 by Andrew Bartlett)
>---
> source3/rpc_server/winreg/srv_winreg_nt.c | 96 ++-----------------------------
> 1 file changed, 6 insertions(+), 90 deletions(-)
>
>diff --git a/source3/rpc_server/winreg/srv_winreg_nt.c b/source3/rpc_server/winreg/srv_winreg_nt.c
>index f45c3b9ff9d..cbe7834264d 100644
>--- a/source3/rpc_server/winreg/srv_winreg_nt.c
>+++ b/source3/rpc_server/winreg/srv_winreg_nt.c
>@@ -640,46 +640,6 @@ WERROR _winreg_AbortSystemShutdown(struct pipes_struct *p,
> }
> 
> /*******************************************************************
>- ********************************************************************/
>-
>-static int validate_reg_filename(TALLOC_CTX *ctx, char **pp_fname )
>-{
>-	char *p = NULL;
>-	int num_services = lp_numservices();
>-	int snum = -1;
>-	const char *share_path = NULL;
>-	char *fname = *pp_fname;
>-
>-	/* convert to a unix path, stripping the C:\ along the way */
>-
>-	if (!(p = valid_share_pathname(ctx, fname))) {
>-		return -1;
>-	}
>-
>-	/* has to exist within a valid file share */
>-
>-	for (snum=0; snum<num_services; snum++) {
>-		if (!lp_snum_ok(snum) || lp_printable(snum)) {
>-			continue;
>-		}
>-
>-		share_path = lp_path(talloc_tos(), snum);
>-
>-		/* make sure we have a path (e.g. [homes] ) */
>-		if (strlen(share_path) == 0) {
>-			continue;
>-		}
>-
>-		if (strncmp(share_path, p, strlen(share_path)) == 0) {
>-			break;
>-		}
>-	}
>-
>-	*pp_fname = p;
>-	return (snum < num_services) ? snum : -1;
>-}
>-
>-/*******************************************************************
>  _winreg_RestoreKey
>  ********************************************************************/
> 
>@@ -687,36 +647,11 @@ WERROR _winreg_RestoreKey(struct pipes_struct *p,
> 			  struct winreg_RestoreKey *r)
> {
> 	struct registry_key *regkey = find_regkey_by_hnd( p, r->in.handle );
>-	char *fname = NULL;
>-	int snum = -1;
> 
>-	if ( !regkey )
>-		return WERR_BADFID;
>-
>-	if ( !r->in.filename || !r->in.filename->name )
>-		return WERR_INVALID_PARAM;
>-
>-	fname = talloc_strdup(p->mem_ctx, r->in.filename->name);
>-	if (!fname) {
>-		return WERR_NOMEM;
>-	}
>-
>-	DEBUG(8,("_winreg_RestoreKey: verifying restore of key [%s] from "
>-		 "\"%s\"\n", regkey->key->name, fname));
>-
>-	if ((snum = validate_reg_filename(p->mem_ctx, &fname)) == -1)
>-		return WERR_OBJECT_PATH_INVALID;
>-
>-	/* user must posses SeRestorePrivilege for this this proceed */
>-
>-	if ( !security_token_has_privilege(p->session_info->security_token, SEC_PRIV_RESTORE)) {
>-		return WERR_ACCESS_DENIED;
>+	if ( !regkey ) {
>+		return WERR_INVALID_HANDLE;
> 	}
>-
>-	DEBUG(2,("_winreg_RestoreKey: Restoring [%s] from %s in share %s\n",
>-		 regkey->key->name, fname, lp_servicename(talloc_tos(), snum) ));
>-
>-	return reg_restorekey(regkey, fname);
>+	return WERR_BAD_PATHNAME;
> }
> 
> /*******************************************************************
>@@ -727,30 +662,11 @@ WERROR _winreg_SaveKey(struct pipes_struct *p,
> 		       struct winreg_SaveKey *r)
> {
> 	struct registry_key *regkey = find_regkey_by_hnd( p, r->in.handle );
>-	char *fname = NULL;
>-	int snum = -1;
> 
>-	if ( !regkey )
>-		return WERR_BADFID;
>-
>-	if ( !r->in.filename || !r->in.filename->name )
>-		return WERR_INVALID_PARAM;
>-
>-	fname = talloc_strdup(p->mem_ctx, r->in.filename->name);
>-	if (!fname) {
>-		return WERR_NOMEM;
>+	if ( !regkey ) {
>+		return WERR_INVALID_HANDLE;
> 	}
>-
>-	DEBUG(8,("_winreg_SaveKey: verifying backup of key [%s] to \"%s\"\n",
>-		 regkey->key->name, fname));
>-
>-	if ((snum = validate_reg_filename(p->mem_ctx, &fname)) == -1 )
>-		return WERR_OBJECT_PATH_INVALID;
>-
>-	DEBUG(2,("_winreg_SaveKey: Saving [%s] to %s in share %s\n",
>-		 regkey->key->name, fname, lp_servicename(talloc_tos(), snum) ));
>-
>-	return reg_savekey(regkey, fname);
>+	return WERR_BAD_PATHNAME;
> }
> 
> /*******************************************************************
>-- 
>2.11.0
>

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