From 8d1bca328b7c17af33bcf966d799c556ecbf370f Mon Sep 17 00:00:00 2001 From: Jeff Layton Date: Sat, 11 Jun 2011 21:17:10 -0400 Subject: [PATCH] cifs: correctly handle NULL tcon pointer in CIFSTCon Long ago (in commit 00e485b0), I added some code to handle share-level passwords in CIFSTCon. That code ignored the fact that it's legit to pass in a NULL tcon pointer when connecting to the IPC$ share on the server. This wasn't really a problem until recently as we only called CIFSTCon this way when the server returned -EREMOTE. With the introduction of commit c1508ca2 however, it gets called this way on every mount, causing an oops when share-level security is in effect. Fix this by simply treating a NULL tcon pointer as if user-level security were in effect. I'm not aware of any servers that protect the IPC$ share with a specific password anyway. Also, add a comment to the top of CIFSTCon to ensure that we don't make the same mistake again. Cc: Reported-by: Martijn Uffing Signed-off-by: Jeff Layton Signed-off-by: Steve French --- fs/cifs/connect.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) diff --git a/fs/cifs/connect.c b/fs/cifs/connect.c index fa73e2a51cf2..12cf72dd0c42 100644 --- a/fs/cifs/connect.c +++ b/fs/cifs/connect.c @@ -3174,6 +3174,10 @@ out: return rc; } +/* + * Issue a TREE_CONNECT request. Note that for IPC$ shares, that the tcon + * pointer may be NULL. + */ int CIFSTCon(unsigned int xid, struct cifs_ses *ses, const char *tree, struct cifs_tcon *tcon, @@ -3208,7 +3212,7 @@ CIFSTCon(unsigned int xid, struct cifs_ses *ses, pSMB->AndXCommand = 0xFF; pSMB->Flags = cpu_to_le16(TCON_EXTENDED_SECINFO); bcc_ptr = &pSMB->Password[0]; - if ((ses->server->sec_mode) & SECMODE_USER) { + if (!tcon || (ses->server->sec_mode & SECMODE_USER)) { pSMB->PasswordLength = cpu_to_le16(1); /* minimum */ *bcc_ptr = 0; /* password is null byte */ bcc_ptr++; /* skip password */ -- 2.20.1