From: Ronnie Sahlberg <lsahlber@redhat.com>
To: linux-cifs <linux-cifs@vger.kernel.org>
Cc: Steve French <smfrench@gmail.com>, Ronnie Sahlberg <lsahlber@redhat.com>
Subject: [PATCH] cifs: fix parsing of symbolic link error response
Date: Tue, 9 Jul 2019 18:41:11 +1000 [thread overview]
Message-ID: <20190709084111.10788-1-lsahlber@redhat.com> (raw)
RHBZ: 1672539
In smb2_query_symlink(), if we are parsing the error buffer but it is not something
we recognize as a symlink we should return -EINVAL and not -ENOENT.
I.e. the entry does exist, it is just not something we recognize.
Additionally, add check to verify that that the errortag and the reparsetag all make sense.
Signed-off-by: Ronnie Sahlberg <lsahlber@redhat.com>
---
fs/cifs/smb2ops.c | 14 ++++++++++----
fs/cifs/smb2pdu.h | 2 ++
2 files changed, 12 insertions(+), 4 deletions(-)
diff --git a/fs/cifs/smb2ops.c b/fs/cifs/smb2ops.c
index 4b0b14946343..e704e04891fb 100644
--- a/fs/cifs/smb2ops.c
+++ b/fs/cifs/smb2ops.c
@@ -2605,26 +2605,32 @@ smb2_query_symlink(const unsigned int xid, struct cifs_tcon *tcon,
err_buf = err_iov.iov_base;
if (le32_to_cpu(err_buf->ByteCount) < sizeof(struct smb2_symlink_err_rsp) ||
err_iov.iov_len < SMB2_SYMLINK_STRUCT_SIZE) {
- rc = -ENOENT;
+ rc = -EINVAL;
+ goto querty_exit;
+ }
+
+ symlink = (struct smb2_symlink_err_rsp *)err_buf->ErrorData;
+ if (le32_to_cpu(symlink->SymLinkErrorTag) != SYMLINK_ERROR_TAG ||
+ le32_to_cpu(symlink->ReparseTag) != IO_REPARSE_TAG_SYMLINK) {
+ rc = -EINVAL;
goto querty_exit;
}
/* open must fail on symlink - reset rc */
rc = 0;
- symlink = (struct smb2_symlink_err_rsp *)err_buf->ErrorData;
sub_len = le16_to_cpu(symlink->SubstituteNameLength);
sub_offset = le16_to_cpu(symlink->SubstituteNameOffset);
print_len = le16_to_cpu(symlink->PrintNameLength);
print_offset = le16_to_cpu(symlink->PrintNameOffset);
if (err_iov.iov_len < SMB2_SYMLINK_STRUCT_SIZE + sub_offset + sub_len) {
- rc = -ENOENT;
+ rc = -EINVAL;
goto querty_exit;
}
if (err_iov.iov_len <
SMB2_SYMLINK_STRUCT_SIZE + print_offset + print_len) {
- rc = -ENOENT;
+ rc = -EINVAL;
goto querty_exit;
}
diff --git a/fs/cifs/smb2pdu.h b/fs/cifs/smb2pdu.h
index 458bad01ca74..7e2e782f8edd 100644
--- a/fs/cifs/smb2pdu.h
+++ b/fs/cifs/smb2pdu.h
@@ -166,6 +166,8 @@ struct smb2_err_rsp {
__u8 ErrorData[1]; /* variable length */
} __packed;
+#define SYMLINK_ERROR_TAG 0x4c4d5953
+
struct smb2_symlink_err_rsp {
__le32 SymLinkLength;
__le32 SymLinkErrorTag;
--
2.13.6
reply other threads:[~2019-07-09 8:41 UTC|newest]
Thread overview: [no followups] expand[flat|nested] mbox.gz Atom feed
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20190709084111.10788-1-lsahlber@redhat.com \
--to=lsahlber@redhat.com \
--cc=linux-cifs@vger.kernel.org \
--cc=smfrench@gmail.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).