CVE Published: 21/05/2024 |
CVE Updated: 04/11/2024 |
CVE Year: 2023 Source: Linux |
Vendor: Linux |
Product: Linux Status : PUBLISHED
CVE-2023-52767 Description
In the Linux kernel, the following vulnerability has been resolved:
tls: fix NULL deref on tls_sw_splice_eof() with empty record
syzkaller discovered that if tls_sw_splice_eof() is executed as part of
sendfile() when the plaintext/ciphertext sk_msg are empty, the send path
gets confused because the empty ciphertext buffer does not have enough
space for the encryption overhead. This causes tls_push_record() to go on
the `split = true` path (which is only supposed to be used when interacting
with an attached BPF program), and then get further confused and hit the
tls_merge_open_record() path, which then assumes that there must be at
least one populated buffer element, leading to a NULL deref.
It is possible to have empty plaintext/ciphertext buffers if we previously
bailed from tls_sw_sendmsg_locked() via the tls_trim_both_msgs() path.
tls_sw_push_pending_record() already handles this case correctly; let\'s do
the same check in tls_sw_splice_eof().