[apparmor] [PATCH] apparmor: return -ENOMEM in unpack_perms_table upon alloc failure

[Ryan Lee]

In policy_unpack.c:unpack_perms_table, the perms struct is allocated via
kcalloc, with the position being reset if the allocation fails. However,
the error path results in -EPROTO being retured instead of -ENOMEM. Fix
this to return the correct error code.

Reported-by: Zygmunt Krynicki <zygmunt.krynicki at canonical.com>
Fixes: fd1b2b95a2117 ("apparmor: add the ability for policy to specify a permission table")
Signed-off-by: Ryan Lee <ryan.lee at canonical.com>
---
 security/apparmor/policy_unpack.c | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/security/apparmor/policy_unpack.c b/security/apparmor/policy_unpack.c
index 019430225e4a..2280a8f7a843 100644
--- a/security/apparmor/policy_unpack.c
+++ b/security/apparmor/policy_unpack.c
@@ -700,8 +700,10 @@ static ssize_t unpack_perms_table(struct aa_ext *e, struct aa_perms **perms)
 		if (!aa_unpack_array(e, NULL, &size))
 			goto fail_reset;
 		*perms = kcalloc(size, sizeof(struct aa_perms), GFP_KERNEL);
-		if (!*perms)
-			goto fail_reset;
+		if (!*perms) {
+			e->pos = pos;
+			return -ENOMEM;
+		}
 		for (i = 0; i < size; i++) {
 			if (!unpack_perm(e, version, &(*perms)[i]))
 				goto fail;
-- 
2.43.0