From 90f7c100d2dd99d5cd5be950d553edd2647e6cc8 Mon Sep 17 00:00:00 2001 From: Paulo Alcantara Date: Sat, 6 Sep 2025 21:19:29 -0300 Subject: [PATCH] smb: client: fix compound alignment with encryption The encryption layer can't handle the padding iovs, so flatten the compound request into a single buffer with required padding to prevent the server from dropping the connection when finding unaligned compound requests. Fixes: bc925c1216f0 ("smb: client: improve compound padding in encryption") Signed-off-by: Paulo Alcantara (Red Hat) Reviewed-by: David Howells Cc: linux-cifs@vger.kernel.org Cc: stable@vger.kernel.org Signed-off-by: Steve French --- fs/smb/client/smb2ops.c | 28 +++++++++++++++++++++++++--- 1 file changed, 25 insertions(+), 3 deletions(-) diff --git a/fs/smb/client/smb2ops.c b/fs/smb/client/smb2ops.c index 94b1d7a395d50..9f9955d274cf6 100644 --- a/fs/smb/client/smb2ops.c +++ b/fs/smb/client/smb2ops.c @@ -2640,13 +2640,35 @@ smb2_set_next_command(struct cifs_tcon *tcon, struct smb_rqst *rqst) } /* SMB headers in a compound are 8 byte aligned. */ - if (!IS_ALIGNED(len, 8)) { - num_padding = 8 - (len & 7); + if (IS_ALIGNED(len, 8)) + goto out; + + num_padding = 8 - (len & 7); + if (smb3_encryption_required(tcon)) { + int i; + + /* + * Flatten request into a single buffer with required padding as + * the encryption layer can't handle the padding iovs. + */ + for (i = 1; i < rqst->rq_nvec; i++) { + memcpy(rqst->rq_iov[0].iov_base + + rqst->rq_iov[0].iov_len, + rqst->rq_iov[i].iov_base, + rqst->rq_iov[i].iov_len); + rqst->rq_iov[0].iov_len += rqst->rq_iov[i].iov_len; + } + memset(rqst->rq_iov[0].iov_base + rqst->rq_iov[0].iov_len, + 0, num_padding); + rqst->rq_iov[0].iov_len += num_padding; + rqst->rq_nvec = 1; + } else { rqst->rq_iov[rqst->rq_nvec].iov_base = smb2_padding; rqst->rq_iov[rqst->rq_nvec].iov_len = num_padding; rqst->rq_nvec++; - len += num_padding; } + len += num_padding; +out: shdr->NextCommand = cpu_to_le32(len); } -- 2.39.5