Attachment 16805 Details for Bug 8773 – patch from master backported to 4.15

[patch] patch from master backported to 4.15

0001-Don-t-use-sysconf-_SC_NGROUPS_MAX-on-macOS-for-getgr.patch (text/plain), 6.12 KB, created by Andrew Bartlett on 2021-09-12 21:46:23 UTC

(hide)

Description:

Filename:

MIME Type:

Creator: Andrew Bartlett

Created: 2021-09-12 21:46:23 UTC

Size: 6.12 KB

patch

obsolete

>From 3d40975cf5249bdd75078a59d64ba31048fff645 Mon Sep 17 00:00:00 2001
>From: Alex Richardson <Alexander.Richardson@cl.cam.ac.uk>
>Date: Fri, 5 Oct 2018 09:35:40 +0100
>Subject: [PATCH] Don't use sysconf(_SC_NGROUPS_MAX) on macOS for getgroups()
>
>On MacOS sysconf(_SC_NGROUPS_MAX) always returns 16. However, this is not
>the value used by getgroups(2). MacOS uses nested groups but getgroups(2)
>will return the flattened list which can easily exceed 16 groups. In my
>testing getgroups() already returns 16 groups on a freshly installed
>system. And on a 10.14 system the root user is in more than 16 groups by
>default which makes it impossible to run smbd without this change.
>Setting _DARWIN_UNLIMITED_GETGROUPS allows getgroups() to return more than
>16 groups. This also changes set_unix_security_ctx() to only set up to
>16 groups since that is the limit for initgroups() according to the manpage.
>
>BUG: https://bugzilla.samba.org/show_bug.cgi?id=8773
>
>Signed-off-by: Alex Richardson <Alexander.Richardson@cl.cam.ac.uk>
>Reviewed-by: Andrew Bartlett <abartlet@samba.org>
>Reviewed-by: Jeremy Allison <jra@samba.org>
>
>Autobuild-User(master): Jeremy Allison <jra@samba.org>
>Autobuild-Date(master): Thu Sep  9 17:43:19 UTC 2021 on sn-devel-184
>
>(cherry picked from commit 2c18a982537ea1a62e4d802c9ae0ef06b36158dc)
>---
> buildtools/wafsamba/wscript    |  5 ++++-
> source3/include/proto.h        |  3 ++-
> source3/lib/system.c           | 24 +++++++++++++++++++++---
> source3/lib/system_smbd.c      |  2 +-
> source3/smbd/sec_ctx.c         |  2 +-
> testsuite/smbd/sec_ctx_utils.c |  2 +-
> 6 files changed, 30 insertions(+), 8 deletions(-)
>
>diff --git a/buildtools/wafsamba/wscript b/buildtools/wafsamba/wscript
>index 1aadb9570e1..def13f71c93 100644
>--- a/buildtools/wafsamba/wscript
>+++ b/buildtools/wafsamba/wscript
>@@ -542,7 +542,10 @@ struct foo bar = { .y = 'X', .x = 1 };
>     conf.CHECK_HEADERS('strings.h inttypes.h stdint.h unistd.h minix/config.h', add_headers=True)
>     conf.CHECK_HEADERS('ctype.h', add_headers=True)
> 
>-    if sys.platform != 'darwin':
>+    if sys.platform == 'darwin':
>+        conf.DEFINE('_DARWIN_C_SOURCE', 1, add_to_cflags=True)
>+        conf.DEFINE('_DARWIN_UNLIMITED_GETGROUPS', 1, add_to_cflags=True)
>+    else:
>         conf.CHECK_HEADERS('standards.h', add_headers=True)
> 
>     conf.CHECK_HEADERS('stdbool.h stdint.h stdarg.h vararg.h', add_headers=True)
>diff --git a/source3/include/proto.h b/source3/include/proto.h
>index 938a71e8083..eb45179aebb 100644
>--- a/source3/include/proto.h
>+++ b/source3/include/proto.h
>@@ -230,7 +230,8 @@ void set_effective_capability(enum smbd_capability capability);
> void drop_effective_capability(enum smbd_capability capability);
> long sys_random(void);
> void sys_srandom(unsigned int seed);
>-int groups_max(void);
>+int getgroups_max(void);
>+int setgroups_max(void);
> int sys_getgroups(int setlen, gid_t *gidset);
> int sys_setgroups(gid_t UNUSED(primary_gid), int setlen, gid_t *gidset);
> uint32_t unix_dev_major(SMB_DEV_T dev);
>diff --git a/source3/lib/system.c b/source3/lib/system.c
>index 5d57ffadda1..a14fc51ca63 100644
>--- a/source3/lib/system.c
>+++ b/source3/lib/system.c
>@@ -756,7 +756,7 @@ void sys_srandom(unsigned int seed)
>  Returns equivalent to NGROUPS_MAX - using sysconf if needed.
> ****************************************************************************/
> 
>-int groups_max(void)
>+int setgroups_max(void)
> {
> #if defined(SYSCONF_SC_NGROUPS_MAX)
> 	int ret = sysconf(_SC_NGROUPS_MAX);
>@@ -766,6 +766,24 @@ int groups_max(void)
> #endif
> }
> 
>+int getgroups_max(void)
>+{
>+#if defined(DARWINOS)
>+	/*
>+	 * On MacOS sysconf(_SC_NGROUPS_MAX) returns 16 due to MacOS's group
>+	 * nesting. However, The initgroups() manpage states the following:
>+	 * "Note that OS X supports group membership in an unlimited number
>+	 * of groups. The OS X kernel uses the group list stored in the process
>+	 * credentials only as an initial cache.  Additional group memberships
>+	 * are determined by communication between the operating system and the
>+	 * opendirectoryd daemon."
>+	 */
>+	return INT_MAX;
>+#else
>+	return setgroups_max();
>+#endif
>+}
>+
> /**************************************************************************
>  Wrap setgroups and getgroups for systems that declare getgroups() as
>  returning an array of gid_t, but actuall return an array of int.
>@@ -831,7 +849,7 @@ static int sys_broken_setgroups(int setlen, gid_t *gidset)
> 	if (setlen == 0)
> 		return 0 ;
> 
>-	if (setlen < 0 || setlen > groups_max()) {
>+	if (setlen < 0 || setlen > setgroups_max()) {
> 		errno = EINVAL; 
> 		return -1;   
> 	}
>@@ -882,7 +900,7 @@ static int sys_bsd_setgroups(gid_t primary_gid, int setlen, const gid_t *gidset)
> 	int ret;
> 
> 	/* setgroups(2) will fail with EINVAL if we pass too many groups. */
>-	max = groups_max();
>+	max = setgroups_max();
> 
> 	/* No group list, just make sure we are setting the efective GID. */
> 	if (setlen == 0) {
>diff --git a/source3/lib/system_smbd.c b/source3/lib/system_smbd.c
>index 3b1ac9c1c2a..73bffe05f7a 100644
>--- a/source3/lib/system_smbd.c
>+++ b/source3/lib/system_smbd.c
>@@ -205,7 +205,7 @@ bool getgroups_unix_user(TALLOC_CTX *mem_ctx, const char *user,
> 			 gid_t primary_gid,
> 			 gid_t **ret_groups, uint32_t *p_ngroups)
> {
>-	int max_grp = MIN(128, groups_max());
>+	int max_grp = MIN(128, getgroups_max());
> 	gid_t stack_groups[max_grp];
> 	uint32_t ngrp;
> 	gid_t *temp_groups = stack_groups;
>diff --git a/source3/smbd/sec_ctx.c b/source3/smbd/sec_ctx.c
>index 5e0710e0ecb..d6fd11cd4a3 100644
>--- a/source3/smbd/sec_ctx.c
>+++ b/source3/smbd/sec_ctx.c
>@@ -282,7 +282,7 @@ static void set_unix_security_ctx(uid_t uid, gid_t gid, int ngroups, gid_t *grou
> 
> static void set_unix_security_ctx(uid_t uid, gid_t gid, int ngroups, gid_t *groups)
> {
>-	int max = groups_max();
>+	int max = NGROUPS_MAX;
> 
> 	/* Start context switch */
> 	gain_root();
>diff --git a/testsuite/smbd/sec_ctx_utils.c b/testsuite/smbd/sec_ctx_utils.c
>index e72292b9864..3834cfd4a16 100644
>--- a/testsuite/smbd/sec_ctx_utils.c
>+++ b/testsuite/smbd/sec_ctx_utils.c
>@@ -30,7 +30,7 @@ void get_random_grouplist(int *ngroups, gid_t **groups)
> {
> 	int i;
> 
>-	*ngroups = random() % groups_max();
>+	*ngroups = random() % setgroups_max();
> 	*groups = malloc(*ngroups * sizeof(gid_t));
> 
> 	if (!groups) {
>-- 
>2.25.1
>

Flags:

jra: review+

Actions: View

Attachments on bug 8773: 7340 | 7727 | 16805