From: Pietro Borrello <borrello@diag.uniroma1.it>
Date: Sat, 28 Jan 2023 16:29:17 +0000
Subject: net/tls: tls_is_tx_ready() checked list_entry
Git-commit: ffe2a22562444720b05bdfeb999c03e810d84cbb
Patch-mainline: v6.2-rc7
References: CVE-2023-1075 bsc#1208598

tls_is_tx_ready() checks that list_first_entry() does not return NULL.
This condition can never happen. For empty lists, list_first_entry()
returns the list_entry() of the head, which is a type confusion.
Use list_first_entry_or_null() which returns NULL in case of empty
lists.

Fixes: a42055e8d2c3 ("net/tls: Add support for async encryption of records for performance")
Signed-off-by: Pietro Borrello <borrello@diag.uniroma1.it>
Link: https://lore.kernel.org/r/20230128-list-entry-null-check-tls-v1-1-525bbfe6f0d0@diag.uniroma1.it
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Miroslav Franc <mfranc@suse.cz>
---
 include/net/tls.h | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/include/net/tls.h b/include/net/tls.h
index 64217c9873c9..599a2a72a002 100644
--- a/include/net/tls.h
+++ b/include/net/tls.h
@@ -425,7 +425,7 @@ static inline bool is_tx_ready(struct tls_sw_context_tx *ctx)
 {
 	struct tls_rec *rec;
 
-	rec = list_first_entry(&ctx->tx_list, struct tls_rec, list);
+	rec = list_first_entry_or_null(&ctx->tx_list, struct tls_rec, list);
 	if (!rec)
 		return false;