diff --git a/include/linux/security.h b/include/linux/security.h
index 334f75aa728991b1405a2f4daa13b8d7d27d176b..750130a7b9dd2ffb8248914b53c6a2a5d0774cd1 100644
--- a/include/linux/security.h
+++ b/include/linux/security.h
@@ -492,8 +492,8 @@ int security_inode_notifysecctx(struct inode *inode, void *ctx, u32 ctxlen);
int security_inode_setsecctx(struct dentry *dentry, void *ctx, u32 ctxlen);
int security_inode_getsecctx(struct inode *inode, void **ctx, u32 *ctxlen);
int security_locked_down(enum lockdown_reason what);
-int lsm_fill_user_ctx(struct lsm_ctx __user *ctx, void *context,
- size_t context_size, u64 id, u64 flags);
+int lsm_fill_user_ctx(struct lsm_ctx __user *uctx, size_t *uctx_len,
+ void *val, size_t val_len, u64 id, u64 flags);
#else /* CONFIG_SECURITY */
static inline int call_blocking_lsm_notifier(enum lsm_event event, void *data)
@@ -1424,8 +1424,9 @@ static inline int security_locked_down(enum lockdown_reason what)
{
return 0;
}
-static inline int lsm_fill_user_ctx(struct lsm_ctx __user *ctx, void *context,
- size_t context_size, u64 id, u64 flags)
+static inline int lsm_fill_user_ctx(struct lsm_ctx __user *uctx,
+ size_t *uctx_len, void *val, size_t val_len,
+ u64 id, u64 flags)
{
return -EOPNOTSUPP;
}
diff --git a/security/apparmor/lsm.c b/security/apparmor/lsm.c
index 8165f80c10ffcc4f9939ac1df6d8ad897b23f70c..332198e0a017ce62b2cd259612ed67f71bde1788 100644
--- a/security/apparmor/lsm.c
+++ b/security/apparmor/lsm.c
@@ -782,7 +782,6 @@ static int apparmor_getselfattr(unsigned int attr, struct lsm_ctx __user *lx,
int error = -ENOENT;
struct aa_task_ctx *ctx = task_ctx(current);
struct aa_label *label = NULL;
- size_t total_len = 0;
char *value;
switch (attr) {
@@ -804,22 +803,14 @@ static int apparmor_getselfattr(unsigned int attr, struct lsm_ctx __user *lx,
if (label) {
error = aa_getprocattr(label, &value, false);
- if (error > 0) {
- total_len = ALIGN(struct_size(lx, ctx, error), 8);
- if (total_len > *size)
- error = -E2BIG;
- else if (lx)
- error = lsm_fill_user_ctx(lx, value, error,
- LSM_ID_APPARMOR, 0);
- else
- error = 1;
- }
+ if (error > 0)
+ error = lsm_fill_user_ctx(lx, size, value, error,
+ LSM_ID_APPARMOR, 0);
kfree(value);
}
aa_put_label(label);
- *size = total_len;
if (error < 0)
return error;
return 1;
diff --git a/security/security.c b/security/security.c
index 78e7ffcc9f6cd3aa63e8056e531efd60fc4f9fed..86f7a19959910d4d455f8eb7744ae2467e015150 100644
--- a/security/security.c
+++ b/security/security.c
@@ -772,42 +772,49 @@ static int lsm_superblock_alloc(struct super_block *sb)
/**
* lsm_fill_user_ctx - Fill a user space lsm_ctx structure
- * @ctx: an LSM context to be filled
- * @context: the new context value
- * @context_size: the size of the new context value
+ * @uctx: a userspace LSM context to be filled
+ * @uctx_len: available uctx size (input), used uctx size (output)
+ * @val: the new LSM context value
+ * @val_len: the size of the new LSM context value
* @id: LSM id
* @flags: LSM defined flags
*
- * Fill all of the fields in a user space lsm_ctx structure.
- * Caller is assumed to have verified that @ctx has enough space
- * for @context.
+ * Fill all of the fields in a userspace lsm_ctx structure.
*
- * Returns 0 on success, -EFAULT on a copyout error, -ENOMEM
- * if memory can't be allocated.
+ * Returns 0 on success, -E2BIG if userspace buffer is not large enough,
+ * -EFAULT on a copyout error, -ENOMEM if memory can't be allocated.
*/
-int lsm_fill_user_ctx(struct lsm_ctx __user *ctx, void *context,
- size_t context_size, u64 id, u64 flags)
+int lsm_fill_user_ctx(struct lsm_ctx __user *uctx, size_t *uctx_len,
+ void *val, size_t val_len,
+ u64 id, u64 flags)
{
- struct lsm_ctx *lctx;
- size_t locallen = struct_size(lctx, ctx, context_size);
+ struct lsm_ctx *nctx = NULL;
+ size_t nctx_len;
int rc = 0;
- lctx = kzalloc(locallen, GFP_KERNEL);
- if (lctx == NULL)
- return -ENOMEM;
-
- lctx->id = id;
- lctx->flags = flags;
- lctx->ctx_len = context_size;
- lctx->len = locallen;
+ nctx_len = ALIGN(struct_size(nctx, ctx, val_len), BITS_PER_LONG / 8);
+ if (nctx_len > *uctx_len) {
+ rc = -E2BIG;
+ goto out;
+ }
- memcpy(lctx->ctx, context, context_size);
+ nctx = kzalloc(nctx_len, GFP_KERNEL);
+ if (nctx == NULL) {
+ rc = -ENOMEM;
+ goto out;
+ }
+ nctx->id = id;
+ nctx->flags = flags;
+ nctx->len = nctx_len;
+ nctx->ctx_len = val_len;
+ memcpy(nctx->ctx, val, val_len);
- if (copy_to_user(ctx, lctx, locallen))
+ if (copy_to_user(uctx, nctx, nctx_len))
rc = -EFAULT;
- kfree(lctx);
-
+out:
+ kfree(nctx);
+ *uctx_len = nctx_len;
return rc;
}
diff --git a/security/selinux/hooks.c b/security/selinux/hooks.c
index b6c7930a3ab29cb01df39fb2d9919d82247b050d..942f2b8c4ebb2f0136491f31d63c81138ad4fba5 100644
--- a/security/selinux/hooks.c
+++ b/security/selinux/hooks.c
@@ -6486,30 +6486,32 @@ static int selinux_lsm_setattr(u64 attr, void *value, size_t size)
return error;
}
+/**
+ * selinux_getselfattr - Get SELinux current task attributes
+ * @attr: the requested attribute
+ * @ctx: buffer to receive the result
+ * @size: buffer size (input), buffer size used (output)
+ * @flags: unused
+ *
+ * Fill the passed user space @ctx with the details of the requested
+ * attribute.
+ *
+ * Returns the number of attributes on success, an error code otherwise.
+ * There will only ever be one attribute.
+ */
static int selinux_getselfattr(unsigned int attr, struct lsm_ctx __user *ctx,
size_t *size, u32 flags)
{
- char *value;
- size_t total_len;
- int len;
- int rc = 0;
-
- len = selinux_lsm_getattr(attr, current, &value);
- if (len < 0)
- return len;
-
- total_len = ALIGN(struct_size(ctx, ctx, len), 8);
-
- if (total_len > *size)
- rc = -E2BIG;
- else if (ctx)
- rc = lsm_fill_user_ctx(ctx, value, len, LSM_ID_SELINUX, 0);
-
- kfree(value);
- *size = total_len;
- if (rc < 0)
- return rc;
- return 1;
+ int rc;
+ char *val;
+ int val_len;
+
+ val_len = selinux_lsm_getattr(attr, current, &val);
+ if (val_len < 0)
+ return val_len;
+ rc = lsm_fill_user_ctx(ctx, size, val, val_len, LSM_ID_SELINUX, 0);
+ kfree(val);
+ return (!rc ? 1 : rc);
}
static int selinux_setselfattr(unsigned int attr, struct lsm_ctx *ctx,
diff --git a/security/smack/smack_lsm.c b/security/smack/smack_lsm.c
index 12160d060cc133b1ede3f08a5f73bb76975e15d5..99664c8cf86759cfd856a2ba566ab77f1dbba5b0 100644
--- a/security/smack/smack_lsm.c
+++ b/security/smack/smack_lsm.c
@@ -3642,28 +3642,17 @@ static void smack_d_instantiate(struct dentry *opt_dentry, struct inode *inode)
static int smack_getselfattr(unsigned int attr, struct lsm_ctx __user *ctx,
size_t *size, u32 flags)
{
- struct smack_known *skp = smk_of_current();
- int total;
- int slen;
int rc;
+ struct smack_known *skp;
if (attr != LSM_ATTR_CURRENT)
return -EOPNOTSUPP;
- slen = strlen(skp->smk_known) + 1;
- total = ALIGN(slen + sizeof(*ctx), 8);
- if (total > *size)
- rc = -E2BIG;
- else if (ctx)
- rc = lsm_fill_user_ctx(ctx, skp->smk_known, slen, LSM_ID_SMACK,
- 0);
- else
- rc = 1;
-
- *size = total;
- if (rc >= 0)
- return 1;
- return rc;
+ skp = smk_of_current();
+ rc = lsm_fill_user_ctx(ctx, size,
+ skp->smk_known, strlen(skp->smk_known) + 1,
+ LSM_ID_SMACK, 0);
+ return (!rc ? 1 : rc);
}
/**