From: Rohith Surabattula rohiths@microsoft.com
commit 62593011247c8a8cfeb0c86aff84688b196727c2 upstream.
TCP server info field server->total_read is modified in parallel by demultiplex thread and decrypt offload worker thread. server->total_read is used in calculation to discard the remaining data of PDU which is not read into memory.
Because of parallel modification, server->total_read can get corrupted and can result in discarding the valid data of next PDU.
Signed-off-by: Rohith Surabattula rohiths@microsoft.com Reviewed-by: Aurelien Aptel aaptel@suse.com Reviewed-by: Pavel Shilovsky pshilov@microsoft.com CC: Stable stable@vger.kernel.org #5.4+ Signed-off-by: Steve French stfrench@microsoft.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org
--- fs/cifs/smb2ops.c | 12 +++++++----- 1 file changed, 7 insertions(+), 5 deletions(-)
--- a/fs/cifs/smb2ops.c +++ b/fs/cifs/smb2ops.c @@ -4103,7 +4103,8 @@ smb3_is_transform_hdr(void *buf) static int decrypt_raw_data(struct TCP_Server_Info *server, char *buf, unsigned int buf_data_size, struct page **pages, - unsigned int npages, unsigned int page_data_size) + unsigned int npages, unsigned int page_data_size, + bool is_offloaded) { struct kvec iov[2]; struct smb_rqst rqst = {NULL}; @@ -4129,7 +4130,8 @@ decrypt_raw_data(struct TCP_Server_Info
memmove(buf, iov[1].iov_base, buf_data_size);
- server->total_read = buf_data_size + page_data_size; + if (!is_offloaded) + server->total_read = buf_data_size + page_data_size;
return rc; } @@ -4342,7 +4344,7 @@ static void smb2_decrypt_offload(struct struct mid_q_entry *mid;
rc = decrypt_raw_data(dw->server, dw->buf, dw->server->vals->read_rsp_size, - dw->ppages, dw->npages, dw->len); + dw->ppages, dw->npages, dw->len, true); if (rc) { cifs_dbg(VFS, "error decrypting rc=%d\n", rc); goto free_pages; @@ -4448,7 +4450,7 @@ receive_encrypted_read(struct TCP_Server
non_offloaded_decrypt: rc = decrypt_raw_data(server, buf, server->vals->read_rsp_size, - pages, npages, len); + pages, npages, len, false); if (rc) goto free_pages;
@@ -4504,7 +4506,7 @@ receive_encrypted_standard(struct TCP_Se server->total_read += length;
buf_size = pdu_length - sizeof(struct smb2_transform_hdr); - length = decrypt_raw_data(server, buf, buf_size, NULL, 0, 0); + length = decrypt_raw_data(server, buf, buf_size, NULL, 0, 0, false); if (length) return length;