| Message ID | 20180504142526.9504-1-palcantara@suse.de (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
The bug can be triggered by listing the xattr with getfattr on a samba
smb2 mount point:
$ echo foo > foo.txt ; getfattr foo.txt ; echo $?
getfattr: foo.txt: No such attribute
1
vs on an xfs mount point and on a patched kernel:
$ echo foo > foo.txt ; getfattr foo.txt ; echo $?
0
Reviewed-by: Aurelien Aptel <aaptel@suse.com>
On Fri, 04 May 2018 16:35:27 +0200, Aurélien Aptel wrote: > The bug can be triggered by listing the xattr with getfattr on a samba > smb2 mount point: > > $ echo foo > foo.txt ; getfattr foo.txt ; echo $? > getfattr: foo.txt: No such attribute > 1 > > vs on an xfs mount point and on a patched kernel: > > $ echo foo > foo.txt ; getfattr foo.txt ; echo $? > 0 Is there already coverage of this in xfstests? If not, please make sure it gets submitted. Cheers, David -- To unsubscribe from this list: send the line "unsubscribe linux-cifs" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
Looks good.
Reviewed-by: David Disseldorp <ddiss@suse.de>
Cheers, David
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On Fri, May 4, 2018 at 9:38 AM, David Disseldorp <ddiss@suse.de> wrote: > On Fri, 04 May 2018 16:35:27 +0200, Aurélien Aptel wrote: > >> The bug can be triggered by listing the xattr with getfattr on a samba >> smb2 mount point: >> >> $ echo foo > foo.txt ; getfattr foo.txt ; echo $? >> getfattr: foo.txt: No such attribute >> 1 >> >> vs on an xfs mount point and on a patched kernel: >> >> $ echo foo > foo.txt ; getfattr foo.txt ; echo $? >> 0 > > Is there already coverage of this in xfstests? If not, please make sure > it gets submitted. That is a good point. The new xfstest could be mount with nouser_xattr and see what happens (as we see with tests which append other mount options like nodiratime etc.) user_xattr Enables Extended User Attributes. Additionally, you need to have extended attribute support enabled in the kernel configuration (CONFIG_EXT4_FS_XATTR). See the attr(5) manual page and http://acl.bestbits.at/ to learn more about extended attributes. nouser_xattr Disables Extended User Attributes.
merged into cifs-2.6.git for-next thx On Fri, May 4, 2018 at 9:25 AM, Paulo Alcantara <palcantara@suse.de> wrote: > As per listxattr(2): > > On success, a nonnegative number is returned indicating the size > of the extended attribute name list. On failure, -1 is returned > and errno is set appropriately. > > In SMB1, when the server returns an empty EA list through a listxattr(), > it will correctly return 0 as there are no EAs for the given file. > > However, in SMB2+, it returns -ENODATA in listxattr() which is wrong since > the request and response were sent successfully, although there's no actual > EA for the given file. > > This patch fixes listxattr() for SMB2+ by returning 0 in cifs_listxattr() > when the server returns an empty list of EAs. > > Signed-off-by: Paulo Alcantara <palcantara@suse.de> > --- > fs/cifs/smb2ops.c | 6 ++++++ > 1 file changed, 6 insertions(+) > > diff --git a/fs/cifs/smb2ops.c b/fs/cifs/smb2ops.c > index 117603b83b6c..12875d55c5a9 100644 > --- a/fs/cifs/smb2ops.c > +++ b/fs/cifs/smb2ops.c > @@ -632,9 +632,15 @@ smb2_query_eas(const unsigned int xid, struct cifs_tcon *tcon, > > SMB2_close(xid, tcon, fid.persistent_fid, fid.volatile_fid); > > + /* > + * If ea_name is NULL (listxattr) and there are no EAs, return 0 as it's > + * not an error. Otherwise, the specified ea_name was not found. > + */ > if (!rc) > rc = move_smb2_ea_to_cifs(ea_data, buf_size, smb2_data, > SMB2_MAX_EA_BUF, ea_name); > + else if (!ea_name && rc == -ENODATA) > + rc = 0; > > kfree(smb2_data); > return rc; > -- > 2.13.6 >
diff --git a/fs/cifs/smb2ops.c b/fs/cifs/smb2ops.c index 117603b83b6c..12875d55c5a9 100644 --- a/fs/cifs/smb2ops.c +++ b/fs/cifs/smb2ops.c @@ -632,9 +632,15 @@ smb2_query_eas(const unsigned int xid, struct cifs_tcon *tcon, SMB2_close(xid, tcon, fid.persistent_fid, fid.volatile_fid); + /* + * If ea_name is NULL (listxattr) and there are no EAs, return 0 as it's + * not an error. Otherwise, the specified ea_name was not found. + */ if (!rc) rc = move_smb2_ea_to_cifs(ea_data, buf_size, smb2_data, SMB2_MAX_EA_BUF, ea_name); + else if (!ea_name && rc == -ENODATA) + rc = 0; kfree(smb2_data); return rc;
As per listxattr(2): On success, a nonnegative number is returned indicating the size of the extended attribute name list. On failure, -1 is returned and errno is set appropriately. In SMB1, when the server returns an empty EA list through a listxattr(), it will correctly return 0 as there are no EAs for the given file. However, in SMB2+, it returns -ENODATA in listxattr() which is wrong since the request and response were sent successfully, although there's no actual EA for the given file. This patch fixes listxattr() for SMB2+ by returning 0 in cifs_listxattr() when the server returns an empty list of EAs. Signed-off-by: Paulo Alcantara <palcantara@suse.de> --- fs/cifs/smb2ops.c | 6 ++++++ 1 file changed, 6 insertions(+)