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().
OS | Version | Architecture | Package | Version | Filename |
---|---|---|---|---|---|
Debian | 12 | all | linux | < 6.1.82-1 | linux_6.1.82-1_all.deb |
Debian | 11 | all | linux | < 5.10.223-1 | linux_5.10.223-1_all.deb |
Debian | 999 | all | linux | < 6.6.8-1 | linux_6.6.8-1_all.deb |
Debian | 13 | all | linux | < 6.6.8-1 | linux_6.6.8-1_all.deb |