This patch addresses an issue of type confusion in tls_is_tx_ready(), as a check for NULL of list_first_entry() return value is wrong. This issue has been given a CVE entry CVE-2023-1075 [1] and is still present in several stable branches. As the flawed function tls_is_tx_ready() is named is_tx_ready() and is situated in another file (specifically, include/net/tls.h) in older kernel versions, fix the error there instead. This adapted backport can be cleanly applied to 5.4, 5.10 and 5.15 branches. [PATCH 5.4/5.10/5.15 1/1] net/tls: tls_is_tx_ready() checked list_entry Use list_first_entry_or_null() instead of list_entry() to properly check for empty lists. Fixes [1]. [1] https://nvd.nist.gov/vuln/detail/cve-2023-1075 [2] https://github.com/torvalds/linux/commit/ffe2a22562444720b05bdfeb999c03e810d84cbb
