5.15-stable review patch. If anyone has any objections, please let me know.
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From: David Disseldorp ddiss@suse.de
[ Upstream commit af36c51e0e111de4e908328d49cba49de758f66e ]
build_compression_ctxt() is currently unreachable due to conn.compress_algorithm remaining zero (SMB3_COMPRESS_NONE).
It appears to have been broken in a couple of subtle ways over the years: - prior to d6c9ad23b421 ("ksmbd: use the common definitions for NEGOTIATE_PROTOCOL") smb2_compression_ctx.DataLength was set to 8, which didn't account for the single CompressionAlgorithms flexible array member. - post d6c9ad23b421 smb2_compression_capabilities_context CompressionAlgorithms is a three member array, while CompressionAlgorithmCount is set to indicate only one member. assemble_neg_contexts() ctxt_size is also incorrectly incremented by sizeof(struct smb2_compression_capabilities_context) + 2, which assumes one flexible array member.
Signed-off-by: David Disseldorp ddiss@suse.de Acked-by: Namjae Jeon linkinjeon@kernel.org Signed-off-by: Steve French stfrench@microsoft.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- fs/ksmbd/smb2pdu.c | 27 ++------------------------- 1 file changed, 2 insertions(+), 25 deletions(-)
--- a/fs/ksmbd/smb2pdu.c +++ b/fs/ksmbd/smb2pdu.c @@ -787,19 +787,6 @@ static void build_encrypt_ctxt(struct sm pneg_ctxt->Ciphers[0] = cipher_type; }
-static void build_compression_ctxt(struct smb2_compression_ctx *pneg_ctxt, - __le16 comp_algo) -{ - pneg_ctxt->ContextType = SMB2_COMPRESSION_CAPABILITIES; - pneg_ctxt->DataLength = - cpu_to_le16(sizeof(struct smb2_compression_ctx) - - sizeof(struct smb2_neg_context)); - pneg_ctxt->Reserved = cpu_to_le32(0); - pneg_ctxt->CompressionAlgorithmCount = cpu_to_le16(1); - pneg_ctxt->Reserved1 = cpu_to_le32(0); - pneg_ctxt->CompressionAlgorithms[0] = comp_algo; -} - static void build_sign_cap_ctxt(struct smb2_signing_capabilities *pneg_ctxt, __le16 sign_algo) { @@ -862,18 +849,8 @@ static void assemble_neg_contexts(struct neg_ctxt_cnt++; ctxt_size += sizeof(struct smb2_encryption_neg_context) + 2; } - - if (conn->compress_algorithm) { - ctxt_size = round_up(ctxt_size, 8); - ksmbd_debug(SMB, - "assemble SMB2_COMPRESSION_CAPABILITIES context\n"); - /* Temporarily set to SMB3_COMPRESS_NONE */ - build_compression_ctxt((struct smb2_compression_ctx *) - (pneg_ctxt + ctxt_size), - conn->compress_algorithm); - neg_ctxt_cnt++; - ctxt_size += sizeof(struct smb2_compression_ctx) + 2; - } + /* compression context not yet supported */ + WARN_ON(conn->compress_algorithm != SMB3_COMPRESS_NONE);
if (conn->posix_ext_supported) { ctxt_size = round_up(ctxt_size, 8);