[PATCH 5.4 34/58] audit: fix possible null-pointer dereference in audit_filter_rules

[Greg Kroah-Hartman]

From: Gaosheng Cui <cuigaosheng1@xxxxxxxxxx>

commit 6e3ee990c90494561921c756481d0e2125d8b895 upstream.

Fix  possible null-pointer dereference in audit_filter_rules.

audit_filter_rules() error: we previously assumed 'ctx' could be null

Cc: stable@xxxxxxxxxxxxxxx
Fixes: bf361231c295 ("audit: add saddr_fam filter field")
Reported-by: kernel test robot <lkp@xxxxxxxxx>
Reported-by: Dan Carpenter <dan.carpenter@xxxxxxxxxx>
Signed-off-by: Gaosheng Cui <cuigaosheng1@xxxxxxxxxx>
Signed-off-by: Paul Moore <paul@xxxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
 kernel/auditsc.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

--- a/kernel/auditsc.c
+++ b/kernel/auditsc.c
@@ -624,7 +624,7 @@ static int audit_filter_rules(struct tas
 			result = audit_comparator(audit_loginuid_set(tsk), f->op, f->val);
 			break;
 		case AUDIT_SADDR_FAM:
-			if (ctx->sockaddr)
+			if (ctx && ctx->sockaddr)
 				result = audit_comparator(ctx->sockaddr->ss_family,
 							  f->op, f->val);
 			break;