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| author | Jeff Layton <jlayton@redhat.com> | 2011-06-11 21:17:10 -0400 |
|---|---|---|
| committer | Steve French <sfrench@us.ibm.com> | 2011-06-13 20:34:34 +0000 |
| commit | 8d1bca328b7c17af33bcf966d799c556ecbf370f (patch) | |
| tree | 734c3909bd750f8de39d04ee656eae6d31d2e24a /fs/cifs/connect.c | |
| parent | 3e715513643f0207c8f3c22010b54954cd697474 (diff) | |
| download | lwn-8d1bca328b7c17af33bcf966d799c556ecbf370f.tar.gz lwn-8d1bca328b7c17af33bcf966d799c556ecbf370f.zip | |
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: <stable@kernel.org>
Reported-by: Martijn Uffing <mp3project@sarijopen.student.utwente.nl>
Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Steve French <sfrench@us.ibm.com>
Diffstat (limited to 'fs/cifs/connect.c')
| -rw-r--r-- | fs/cifs/connect.c | 6 |
1 files changed, 5 insertions, 1 deletions
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 */ |