apparmor: Move path lookup to using preallocated buffers
Dynamically allocating buffers is problematic and is an extra layer
that is a potntial point of failure and can slow down mediation.
Change path lookup to use the preallocated per cpu buffers.
Signed-off-by: John Johansen <john.johansen@canonical.com>
diff --git a/security/apparmor/file.c b/security/apparmor/file.c
index 83d43ac..22be62f 100644
--- a/security/apparmor/file.c
+++ b/security/apparmor/file.c
@@ -285,7 +285,8 @@ int aa_path_perm(const char *op, struct aa_profile *profile,
int error;
flags |= profile->path_flags | (S_ISDIR(cond->mode) ? PATH_IS_DIR : 0);
- error = aa_path_name(path, flags, &buffer, &name, &info,
+ get_buffers(buffer);
+ error = aa_path_name(path, flags, buffer, &name, &info,
profile->disconnected);
if (error) {
if (error == -ENOENT && is_deleted(path->dentry)) {
@@ -304,7 +305,7 @@ int aa_path_perm(const char *op, struct aa_profile *profile,
}
error = aa_audit_file(profile, &perms, op, request, name, NULL,
cond->uid, info, error);
- kfree(buffer);
+ put_buffers(buffer);
return error;
}
@@ -363,16 +364,17 @@ int aa_path_link(struct aa_profile *profile, struct dentry *old_dentry,
unsigned int state;
int error;
+ get_buffers(buffer, buffer2);
lperms = nullperms;
/* buffer freed below, lname is pointer in buffer */
- error = aa_path_name(&link, profile->path_flags, &buffer, &lname,
+ error = aa_path_name(&link, profile->path_flags, buffer, &lname,
&info, profile->disconnected);
if (error)
goto audit;
/* buffer2 freed below, tname is pointer in buffer2 */
- error = aa_path_name(&target, profile->path_flags, &buffer2, &tname,
+ error = aa_path_name(&target, profile->path_flags, buffer2, &tname,
&info, profile->disconnected);
if (error)
goto audit;
@@ -432,8 +434,7 @@ int aa_path_link(struct aa_profile *profile, struct dentry *old_dentry,
audit:
error = aa_audit_file(profile, &lperms, OP_LINK, request,
lname, tname, cond.uid, info, error);
- kfree(buffer);
- kfree(buffer2);
+ put_buffers(buffer, buffer2);
return error;
}