From: Raphael Zimmer Date: Tue, 28 Apr 2026 12:15:46 +0000 (+0200) Subject: libceph: Fix potential out-of-bounds access in __ceph_x_decrypt() X-Git-Tag: ceph-for-7.1-rc4~5 X-Git-Url: http://git-server-git.apps.pok.os.sepia.ceph.com/?a=commitdiff_plain;h=821365487aa58d06bda65c676ba215d506ba9768;p=ceph-client.git libceph: Fix potential out-of-bounds access in __ceph_x_decrypt() In __ceph_x_decrypt(), a part of the buffer p is interpreted as a ceph_x_encrypt_header, and the magic field of this struct is accessed. This happens without any guarantee that the buffer is large enough to hold this struct. The function parameter ciphertext_len represents the length of the ciphertext to decrypt and is guaranteed to be at most the remaining size of the allocated buffer p. However, this value is not necessarily greater than sizeof(ceph_x_encrypt_header). E.g., a message frame of type FRAME_TAG_AUTH_REPLY_MORE, that is just as long to hold the ciphertext at its end with a ciphertext_len of 8 or less, can trigger an out-of-bounds memory access when accessing hdr->magic. This patch fixes the issue by adding a check to ensure that the decrypted plaintext in the buffer is large enough to represent at least the ceph_x_encrypt_header. Cc: stable@vger.kernel.org Signed-off-by: Raphael Zimmer Reviewed-by: Ilya Dryomov Signed-off-by: Ilya Dryomov --- diff --git a/net/ceph/auth_x.c b/net/ceph/auth_x.c index 692e0b868822..9e64e82d0b63 100644 --- a/net/ceph/auth_x.c +++ b/net/ceph/auth_x.c @@ -115,6 +115,11 @@ static int __ceph_x_decrypt(const struct ceph_crypto_key *key, int usage_slot, if (ret) return ret; + if (plaintext_len < sizeof(*hdr)) { + pr_err("%s plaintext too small %d\n", __func__, plaintext_len); + return -EINVAL; + } + hdr = p + ceph_crypt_data_offset(key); if (le64_to_cpu(hdr->magic) != CEPHX_ENC_MAGIC) { pr_err("%s bad magic\n", __func__);