This is a note to let you know that I've just added the patch titled ksmbd: fix slab-out-of-bounds read in smb2_handle_negotiate to the 6.3-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: ksmbd-fix-slab-out-of-bounds-read-in-smb2_handle_negotiate.patch and it can be found in the queue-6.3 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. >From d738950f112c8f40f0515fe967db998e8235a175 Mon Sep 17 00:00:00 2001 From: Kuan-Ting Chen <h3xrabbit@xxxxxxxxx> Date: Fri, 19 May 2023 22:59:28 +0900 Subject: ksmbd: fix slab-out-of-bounds read in smb2_handle_negotiate From: Kuan-Ting Chen <h3xrabbit@xxxxxxxxx> commit d738950f112c8f40f0515fe967db998e8235a175 upstream. Check request_buf length first to avoid out-of-bounds read by req->DialectCount. [ 3350.990282] BUG: KASAN: slab-out-of-bounds in smb2_handle_negotiate+0x35d7/0x3e60 [ 3350.990282] Read of size 2 at addr ffff88810ad61346 by task kworker/5:0/276 [ 3351.000406] Workqueue: ksmbd-io handle_ksmbd_work [ 3351.003499] Call Trace: [ 3351.006473] <TASK> [ 3351.006473] dump_stack_lvl+0x8d/0xe0 [ 3351.006473] print_report+0xcc/0x620 [ 3351.006473] kasan_report+0x92/0xc0 [ 3351.006473] smb2_handle_negotiate+0x35d7/0x3e60 [ 3351.014760] ksmbd_smb_negotiate_common+0x7a7/0xf00 [ 3351.014760] handle_ksmbd_work+0x3f7/0x12d0 [ 3351.014760] process_one_work+0xa85/0x1780 Cc: stable@xxxxxxxxxxxxxxx Signed-off-by: Kuan-Ting Chen <h3xrabbit@xxxxxxxxx> Acked-by: Namjae Jeon <linkinjeon@xxxxxxxxxx> Signed-off-by: Steve French <stfrench@xxxxxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- fs/ksmbd/smb2pdu.c | 10 +++++----- 1 file changed, 5 insertions(+), 5 deletions(-) --- a/fs/ksmbd/smb2pdu.c +++ b/fs/ksmbd/smb2pdu.c @@ -1081,16 +1081,16 @@ int smb2_handle_negotiate(struct ksmbd_w return rc; } - if (req->DialectCount == 0) { - pr_err("malformed packet\n"); + smb2_buf_len = get_rfc1002_len(work->request_buf); + smb2_neg_size = offsetof(struct smb2_negotiate_req, Dialects); + if (smb2_neg_size > smb2_buf_len) { rsp->hdr.Status = STATUS_INVALID_PARAMETER; rc = -EINVAL; goto err_out; } - smb2_buf_len = get_rfc1002_len(work->request_buf); - smb2_neg_size = offsetof(struct smb2_negotiate_req, Dialects); - if (smb2_neg_size > smb2_buf_len) { + if (req->DialectCount == 0) { + pr_err("malformed packet\n"); rsp->hdr.Status = STATUS_INVALID_PARAMETER; rc = -EINVAL; goto err_out; Patches currently in stable-queue which might be from h3xrabbit@xxxxxxxxx are queue-6.3/ksmbd-fix-slab-out-of-bounds-read-in-smb2_handle_negotiate.patch queue-6.3/ksmbd-fix-multiple-out-of-bounds-read-during-context-decoding.patch