[PATCH 5.3 092/197] LSM: SafeSetID: Stop releasing uninitialized ruleset

From: Greg Kroah-Hartman
Date: Sun Oct 27 2019 - 17:23:21 EST


From: Micah Morton <mortonm@xxxxxxxxxxxx>

[ Upstream commit 21ab8580b383f27b7f59b84ac1699cb26d6c3d69 ]

The first time a rule set is configured for SafeSetID, we shouldn't be
trying to release the previously configured ruleset, since there isn't
one. Currently, the pointer that would point to a previously configured
ruleset is uninitialized on first rule set configuration, leading to a
crash when we try to call release_ruleset with that pointer.

Acked-by: Jann Horn <jannh@xxxxxxxxxx>
Signed-off-by: Micah Morton <mortonm@xxxxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
security/safesetid/securityfs.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/security/safesetid/securityfs.c b/security/safesetid/securityfs.c
index d568e17dd7739..74a13d432ed80 100644
--- a/security/safesetid/securityfs.c
+++ b/security/safesetid/securityfs.c
@@ -187,7 +187,8 @@ static ssize_t handle_policy_update(struct file *file,
out_free_buf:
kfree(buf);
out_free_pol:
- release_ruleset(pol);
+ if (pol)
+ release_ruleset(pol);
return err;
}

--
2.20.1