From: ronnie sahlberg <ronniesahlberg@gmail.com>
To: Murphy Zhou <jencce.kernel@gmail.com>
Cc: linux-cifs <linux-cifs@vger.kernel.org>,
Steve French <sfrench@samba.org>, Long Li <longli@microsoft.com>
Subject: Re: [PATCH] fs/cifs/smb2pdu.c: fix buffer free in SMB2_ioctl_free
Date: Fri, 24 May 2019 10:44:17 +1000 [thread overview]
Message-ID: <CAN05THTBYkDOdqLaS8Pt6n3xs-v9GSXsrzFbnj+NOUGb=RwyCA@mail.gmail.com> (raw)
In-Reply-To: <20190523041243.12340-1-jencce.kernel@gmail.com>
On Thu, May 23, 2019 at 2:14 PM Murphy Zhou <jencce.kernel@gmail.com> wrote:
>
> The 2nd buffer could be NULL even if iov_len is not zero. This can
> trigger a panic when handling symlinks. It's easy to reproduce with
> LTP fs_racer scripts[1] which are randomly craete/delete/link files
> and dirs. Fix this panic by checking if the 2nd buffer is padding
> before kfree, like what we do in SMB2_open_free.
Looks good.
Reviewed-by: Ronnie Sahlberg <lsahlber@redhat.com>
>
> [1] https://github.com/linux-test-project/ltp/tree/master/testcases/kernel/fs/racer
>
> Fixes: 2c87d6a ("cifs: Allocate memory for all iovs in smb2_ioctl")
> Signed-off-by: Murphy Zhou <jencce.kernel@gmail.com>
> ---
> fs/cifs/smb2pdu.c | 6 ++++--
> 1 file changed, 4 insertions(+), 2 deletions(-)
>
> diff --git a/fs/cifs/smb2pdu.c b/fs/cifs/smb2pdu.c
> index 710ceb8..c36f940 100644
> --- a/fs/cifs/smb2pdu.c
> +++ b/fs/cifs/smb2pdu.c
> @@ -2619,10 +2619,12 @@ int smb311_posix_mkdir(const unsigned int xid, struct inode *inode,
> void
> SMB2_ioctl_free(struct smb_rqst *rqst)
> {
> + int i;
> if (rqst && rqst->rq_iov) {
> cifs_small_buf_release(rqst->rq_iov[0].iov_base); /* request */
> - if (rqst->rq_iov[1].iov_len)
> - kfree(rqst->rq_iov[1].iov_base);
> + for (i = 1; i < rqst->rq_nvec; i++)
> + if (rqst->rq_iov[i].iov_base != smb2_padding)
> + kfree(rqst->rq_iov[i].iov_base);
> }
> }
>
> --
> 1.8.3.1
>
prev parent reply other threads:[~2019-05-24 0:44 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-05-23 4:12 [PATCH] fs/cifs/smb2pdu.c: fix buffer free in SMB2_ioctl_free Murphy Zhou
2019-05-24 0:44 ` ronnie sahlberg [this message]
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='CAN05THTBYkDOdqLaS8Pt6n3xs-v9GSXsrzFbnj+NOUGb=RwyCA@mail.gmail.com' \
--to=ronniesahlberg@gmail.com \
--cc=jencce.kernel@gmail.com \
--cc=linux-cifs@vger.kernel.org \
--cc=longli@microsoft.com \
--cc=sfrench@samba.org \
/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).