[PATCH 10/46] selinux: Move some assignments for the variable "rc" in policydb_read()

SF Markus Elfring
2017-01-15T15:10:10Z

From: Markus Elfring <elfring@users.sourceforge.net>
Date: Sat, 14 Jan 2017 15:22:29 +0100

One local variable was set to an error code in some cases before
a concrete error situation was detected. Thus move the corresponding
assignments into if branches to indicate a software failure there.

Signed-off-by: Markus Elfring <elfring@users.sourceforge.net>
---
security/selinux/ss/policydb.c | 59 +++++++++++++++++++++++++-----------------
1 file changed, 35 insertions(+), 24 deletions(-)

diff --git a/security/selinux/ss/policydb.c b/security/selinux/ss/policydb.c
index 53e6d06e772a..506b0228d1f1 100644
--- a/security/selinux/ss/policydb.c
+++ b/security/selinux/ss/policydb.c
@@ -2250,15 +2250,14 @@ int policydb_read(struct policydb *p, void *fp)
if (rc)
goto bad;

- rc = -EINVAL;
if (le32_to_cpu(buf[0]) != POLICYDB_MAGIC) {
printk(KERN_ERR "SELinux: policydb magic number 0x%x does "
"not match expected magic number 0x%x\n",
le32_to_cpu(buf[0]), POLICYDB_MAGIC);
+ rc = -EINVAL;
goto bad;
}

- rc = -EINVAL;
len = le32_to_cpu(buf[1]);
if (len != strlen(POLICYDB_STRING)) {
printk(KERN_ERR "SELinux: policydb string length %d does not "
@@ -2265,11 +2265,13 @@ int policydb_read(struct policydb *p, void *fp)
len, strlen(POLICYDB_STRING));
+ rc = -EINVAL;
goto bad;
}

- rc = -ENOMEM;
policydb_str = kmalloc(len + 1, GFP_KERNEL);
- if (!policydb_str)
+ if (!policydb_str) {
+ rc = -ENOMEM;
goto bad;
+ }

rc = next_entry(policydb_str, fp, len);
if (rc) {
@@ -2279,12 +2280,12 @@ int policydb_read(struct policydb *p, void *fp)
goto bad;
}

- rc = -EINVAL;
policydb_str[len] = '\0';
if (strcmp(policydb_str, POLICYDB_STRING)) {
printk(KERN_ERR "SELinux: policydb string %s does not match "
"my string %s\n", policydb_str, POLICYDB_STRING);
kfree(policydb_str);
+ rc = -EINVAL;
goto bad;
}
/* Done with policydb_str. */
@@ -2296,24 +2297,24 @@ int policydb_read(struct policydb *p, void *fp)
if (rc)
goto bad;

- rc = -EINVAL;
p->policyvers = le32_to_cpu(buf[0]);
if (p->policyvers < POLICYDB_VERSION_MIN ||
p->policyvers > POLICYDB_VERSION_MAX) {
printk(KERN_ERR "SELinux: policydb version %d does not match "
"my version range %d-%d\n",
le32_to_cpu(buf[0]), POLICYDB_VERSION_MIN, POLICYDB_VERSION_MAX);
+ rc = -EINVAL;
goto bad;
}

if ((le32_to_cpu(buf[1]) & POLICYDB_CONFIG_MLS)) {
p->mls_enabled = 1;

- rc = -EINVAL;
if (p->policyvers < POLICYDB_VERSION_MLS) {
printk(KERN_ERR "SELinux: security policydb version %d "
"(MLS) not backwards compatible\n",
p->policyvers);
+ rc = -EINVAL;
goto bad;
}
}
@@ -2332,21 +2333,21 @@ int policydb_read(struct policydb *p, void *fp)
goto bad;
}

- rc = -EINVAL;
info = policydb_lookup_compat(p->policyvers);
if (!info) {
printk(KERN_ERR "SELinux: unable to find policy compat info "
"for version %d\n", p->policyvers);
+ rc = -EINVAL;
goto bad;
}

- rc = -EINVAL;
if (le32_to_cpu(buf[2]) != info->sym_num ||
le32_to_cpu(buf[3]) != info->ocon_num) {
printk(KERN_ERR "SELinux: policydb table sizes (%d,%d) do "
"not match mine (%d,%d)\n", le32_to_cpu(buf[2]),
le32_to_cpu(buf[3]),
info->sym_num, info->ocon_num);
+ rc = -EINVAL;
goto bad;
}

@@ -2365,10 +2366,11 @@ int policydb_read(struct policydb *p, void *fp)
p->symtab[i].nprim = nprim;
}

- rc = -EINVAL;
p->process_class = string_to_security_class(p, "process");
- if (!p->process_class)
+ if (!p->process_class) {
+ rc = -EINVAL;
goto bad;
+ }

rc = avtab_read(&p->te_avtab, fp, p);
if (rc)
@@ -2386,10 +2388,12 @@ int policydb_read(struct policydb *p, void *fp)
nel = le32_to_cpu(buf[0]);
ltr = NULL;
for (i = 0; i < nel; i++) {
- rc = -ENOMEM;
tr = kzalloc(sizeof(*tr), GFP_KERNEL);
- if (!tr)
+ if (!tr) {
+ rc = -ENOMEM;
goto bad;
+ }
+
if (ltr)
ltr->next = tr;
else
@@ -2398,7 +2402,6 @@ int policydb_read(struct policydb *p, void *fp)
if (rc)
goto bad;

- rc = -EINVAL;
tr->role = le32_to_cpu(buf[0]);
tr->type = le32_to_cpu(buf[1]);
tr->new_role = le32_to_cpu(buf[2]);
@@ -2410,12 +2413,14 @@ int policydb_read(struct policydb *p, void *fp)
} else
tr->tclass = p->process_class;

- rc = -EINVAL;
if (!policydb_role_isvalid(p, tr->role) ||
!policydb_type_isvalid(p, tr->type) ||
!policydb_class_isvalid(p, tr->tclass) ||
- !policydb_role_isvalid(p, tr->new_role))
+ !policydb_role_isvalid(p, tr->new_role)) {
+ rc = -EINVAL;
goto bad;
+ }
+
ltr = tr;
}

@@ -2425,10 +2430,12 @@ int policydb_read(struct policydb *p, void *fp)
nel = le32_to_cpu(buf[0]);
lra = NULL;
for (i = 0; i < nel; i++) {
- rc = -ENOMEM;
ra = kzalloc(sizeof(*ra), GFP_KERNEL);
- if (!ra)
+ if (!ra) {
+ rc = -ENOMEM;
goto bad;
+ }
+
if (lra)
lra->next = ra;
else
@@ -2437,12 +2444,14 @@ int policydb_read(struct policydb *p, void *fp)
if (rc)
goto bad;

- rc = -EINVAL;
ra->role = le32_to_cpu(buf[0]);
ra->new_role = le32_to_cpu(buf[1]);
if (!policydb_role_isvalid(p, ra->role) ||
- !policydb_role_isvalid(p, ra->new_role))
+ !policydb_role_isvalid(p, ra->new_role)) {
+ rc = -EINVAL;
goto bad;
+ }
+
lra = ra;
}

@@ -2454,11 +2463,12 @@ int policydb_read(struct policydb *p, void *fp)
if (rc)
goto bad;

- rc = -EINVAL;
p->process_trans_perms = string_to_av_perm(p, p->process_class, "transition");
p->process_trans_perms |= string_to_av_perm(p, p->process_class, "dyntransition");
- if (!p->process_trans_perms)
+ if (!p->process_trans_perms) {
+ rc = -EINVAL;
goto bad;
+ }

rc = ocontext_read(p, info, fp);
if (rc)
@@ -2472,12 +2482,13 @@ int policydb_read(struct policydb *p, void *fp)
if (rc)
goto bad;

- rc = -ENOMEM;
p->type_attr_map_array = flex_array_alloc(sizeof(struct ebitmap),
p->p_types.nprim,
GFP_KERNEL | __GFP_ZERO);
- if (!p->type_attr_map_array)
+ if (!p->type_attr_map_array) {
+ rc = -ENOMEM;
goto bad;
+ }

/* preallocate so we don't have to worry about the put ever failing */
rc = flex_array_prealloc(p->type_attr_map_array, 0, p->p_types.nprim,
--
2.11.0