From b5495b4217d3fa64deac479db83dbede149af7d8 Mon Sep 17 00:00:00 2001 From: Tim Gardner Date: Thu, 14 Nov 2013 15:04:51 -0700 Subject: [PATCH] SELinux: security_load_policy: Silence frame-larger-than warning Dynamically allocate a couple of the larger stack variables in order to reduce the stack footprint below 1024. gcc-4.8 security/selinux/ss/services.c: In function 'security_load_policy': security/selinux/ss/services.c:1964:1: warning: the frame size of 1104 bytes is larger than 1024 bytes [-Wframe-larger-than=] } Also silence a couple of checkpatch warnings at the same time. WARNING: sizeof policydb should be sizeof(policydb) + memcpy(oldpolicydb, &policydb, sizeof policydb); WARNING: sizeof policydb should be sizeof(policydb) + memcpy(&policydb, newpolicydb, sizeof policydb); Cc: Stephen Smalley Cc: James Morris Cc: Eric Paris Signed-off-by: Tim Gardner Signed-off-by: Paul Moore --- security/selinux/ss/services.c | 54 ++++++++++++++++++++-------------- 1 file changed, 32 insertions(+), 22 deletions(-) diff --git a/security/selinux/ss/services.c b/security/selinux/ss/services.c index ee470a0b5c27..6db5546717eb 100644 --- a/security/selinux/ss/services.c +++ b/security/selinux/ss/services.c @@ -1831,7 +1831,7 @@ static int security_preserve_bools(struct policydb *p); */ int security_load_policy(void *data, size_t len) { - struct policydb oldpolicydb, newpolicydb; + struct policydb *oldpolicydb, *newpolicydb; struct sidtab oldsidtab, newsidtab; struct selinux_mapping *oldmap, *map = NULL; struct convert_context_args args; @@ -1840,12 +1840,19 @@ int security_load_policy(void *data, size_t len) int rc = 0; struct policy_file file = { data, len }, *fp = &file; + oldpolicydb = kzalloc(2 * sizeof(*oldpolicydb), GFP_KERNEL); + if (!oldpolicydb) { + rc = -ENOMEM; + goto out; + } + newpolicydb = oldpolicydb + 1; + if (!ss_initialized) { avtab_cache_init(); rc = policydb_read(&policydb, fp); if (rc) { avtab_cache_destroy(); - return rc; + goto out; } policydb.len = len; @@ -1855,14 +1862,14 @@ int security_load_policy(void *data, size_t len) if (rc) { policydb_destroy(&policydb); avtab_cache_destroy(); - return rc; + goto out; } rc = policydb_load_isids(&policydb, &sidtab); if (rc) { policydb_destroy(&policydb); avtab_cache_destroy(); - return rc; + goto out; } security_load_policycaps(); @@ -1874,36 +1881,36 @@ int security_load_policy(void *data, size_t len) selinux_status_update_policyload(seqno); selinux_netlbl_cache_invalidate(); selinux_xfrm_notify_policyload(); - return 0; + goto out; } #if 0 sidtab_hash_eval(&sidtab, "sids"); #endif - rc = policydb_read(&newpolicydb, fp); + rc = policydb_read(newpolicydb, fp); if (rc) - return rc; + goto out; - newpolicydb.len = len; + newpolicydb->len = len; /* If switching between different policy types, log MLS status */ - if (policydb.mls_enabled && !newpolicydb.mls_enabled) + if (policydb.mls_enabled && !newpolicydb->mls_enabled) printk(KERN_INFO "SELinux: Disabling MLS support...\n"); - else if (!policydb.mls_enabled && newpolicydb.mls_enabled) + else if (!policydb.mls_enabled && newpolicydb->mls_enabled) printk(KERN_INFO "SELinux: Enabling MLS support...\n"); - rc = policydb_load_isids(&newpolicydb, &newsidtab); + rc = policydb_load_isids(newpolicydb, &newsidtab); if (rc) { printk(KERN_ERR "SELinux: unable to load the initial SIDs\n"); - policydb_destroy(&newpolicydb); - return rc; + policydb_destroy(newpolicydb); + goto out; } - rc = selinux_set_mapping(&newpolicydb, secclass_map, &map, &map_size); + rc = selinux_set_mapping(newpolicydb, secclass_map, &map, &map_size); if (rc) goto err; - rc = security_preserve_bools(&newpolicydb); + rc = security_preserve_bools(newpolicydb); if (rc) { printk(KERN_ERR "SELinux: unable to preserve booleans\n"); goto err; @@ -1921,7 +1928,7 @@ int security_load_policy(void *data, size_t len) * in the new SID table. */ args.oldp = &policydb; - args.newp = &newpolicydb; + args.newp = newpolicydb; rc = sidtab_map(&newsidtab, convert_context, &args); if (rc) { printk(KERN_ERR "SELinux: unable to convert the internal" @@ -1931,12 +1938,12 @@ int security_load_policy(void *data, size_t len) } /* Save the old policydb and SID table to free later. */ - memcpy(&oldpolicydb, &policydb, sizeof policydb); + memcpy(oldpolicydb, &policydb, sizeof(policydb)); sidtab_set(&oldsidtab, &sidtab); /* Install the new policydb and SID table. */ write_lock_irq(&policy_rwlock); - memcpy(&policydb, &newpolicydb, sizeof policydb); + memcpy(&policydb, newpolicydb, sizeof(policydb)); sidtab_set(&sidtab, &newsidtab); security_load_policycaps(); oldmap = current_mapping; @@ -1946,7 +1953,7 @@ int security_load_policy(void *data, size_t len) write_unlock_irq(&policy_rwlock); /* Free the old policydb and SID table. */ - policydb_destroy(&oldpolicydb); + policydb_destroy(oldpolicydb); sidtab_destroy(&oldsidtab); kfree(oldmap); @@ -1956,14 +1963,17 @@ int security_load_policy(void *data, size_t len) selinux_netlbl_cache_invalidate(); selinux_xfrm_notify_policyload(); - return 0; + rc = 0; + goto out; err: kfree(map); sidtab_destroy(&newsidtab); - policydb_destroy(&newpolicydb); - return rc; + policydb_destroy(newpolicydb); +out: + kfree(oldpolicydb); + return rc; } size_t security_policydb_len(void) -- 2.34.1