From 32f319183c439b239294cb2d70ada3564c4c7c39 Mon Sep 17 00:00:00 2001 From: Steve French Date: Tue, 12 Jul 2022 00:11:42 -0500 Subject: smb3: workaround negprot bug in some Samba servers Mount can now fail to older Samba servers due to a server bug handling padding at the end of the last negotiate context (negotiate contexts typically are rounded up to 8 bytes by adding padding if needed). This server bug can be avoided by switching the order of negotiate contexts, placing a negotiate context at the end that does not require padding (prior to the recent netname context fix this was the case on the client). Fixes: 73130a7b1ac9 ("smb3: fix empty netname context on secondary channels") Reported-by: Julian Sikorski Tested-by: Julian Sikorski Reviewed-by: Shyam Prasad N Signed-off-by: Steve French --- fs/cifs/smb2pdu.c | 13 +++++++------ 1 file changed, 7 insertions(+), 6 deletions(-) (limited to 'fs/cifs') diff --git a/fs/cifs/smb2pdu.c b/fs/cifs/smb2pdu.c index 12b4dddaedb0..c705de32e225 100644 --- a/fs/cifs/smb2pdu.c +++ b/fs/cifs/smb2pdu.c @@ -571,10 +571,6 @@ assemble_neg_contexts(struct smb2_negotiate_req *req, *total_len += ctxt_len; pneg_ctxt += ctxt_len; - build_posix_ctxt((struct smb2_posix_neg_context *)pneg_ctxt); - *total_len += sizeof(struct smb2_posix_neg_context); - pneg_ctxt += sizeof(struct smb2_posix_neg_context); - /* * secondary channels don't have the hostname field populated * use the hostname field in the primary channel instead @@ -586,9 +582,14 @@ assemble_neg_contexts(struct smb2_negotiate_req *req, hostname); *total_len += ctxt_len; pneg_ctxt += ctxt_len; - neg_context_count = 4; - } else /* second channels do not have a hostname */ neg_context_count = 3; + } else + neg_context_count = 2; + + build_posix_ctxt((struct smb2_posix_neg_context *)pneg_ctxt); + *total_len += sizeof(struct smb2_posix_neg_context); + pneg_ctxt += sizeof(struct smb2_posix_neg_context); + neg_context_count++; if (server->compress_algorithm) { build_compression_ctxt((struct smb2_compression_capabilities_context *) -- cgit v1.2.3