On 2/27/18 9:56 AM, Steve French wrote: > This shouldn't be too hard to figure out if willing to backport a > slightly larger set of fixes to the older stable, but I don't have a > system running 4.9 stable. > If you have the proposed patches that apply on 4.9, I'd be happy to try them out! [ I would have offered to backport the patches myself, but actually I already tried doing that with a larger set of patches from mainline (picking those commits between the regression and the fix that seemed relevant), but I felt quite out-of-depth trying to adapt them to 4.9 and 4.4, as I'm not that familiar with the internals of SMB/CIFS. ] > Is this the correct stable tree branch? > https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux-stable.git/log/?h=linux-4.9.y > Yep! Regards, Srivatsa > On Tue, Feb 27, 2018 at 11:45 AM, Srivatsa S. Bhat > <srivatsa@xxxxxxxxxxxxx> wrote: >> On 2/27/18 4:40 AM, Greg Kroah-Hartman wrote: >>> On Tue, Feb 27, 2018 at 01:22:31AM -0800, Srivatsa S. Bhat wrote: >>>> On 2/27/18 12:54 AM, Greg Kroah-Hartman wrote: >>>>> On Mon, Feb 26, 2018 at 07:44:28PM -0800, Srivatsa S. Bhat wrote: >>>>>> On 1/3/18 6:15 PM, Srivatsa S. Bhat wrote: >>>>>>> On 11/1/17 8:18 AM, Greg Kroah-Hartman wrote: >>>>>>>> On Tue, Oct 31, 2017 at 03:02:11PM +0200, Thomas Backlund wrote: >>>>>>>>> Den 31.10.2017 kl. 11:55, skrev Greg Kroah-Hartman: >>>>>>>>>> 4.13-stable review patch. If anyone has any objections, please let me know. >>>>>>>>>> >>>>>>>>>> ------------------ >>>>>>>>>> >>>>>>>>>> From: Steve French <smfrench@xxxxxxxxx> >>>>>>>>>> >>>>>>>>>> commit 4587eee04e2ac7ac3ac9fa2bc164fb6e548f99cd upstream. >>>>>>>>>> >>>>>>>>>> According to MS-SMB2 3.2.55 validate_negotiate request must >>>>>>>>>> always be signed. Some Windows can fail the request if you send it unsigned >>>>>>>>>> >>>>>>>>>> See kernel bugzilla bug 197311 >>>>>>>>>> >>>>>>>>>> Acked-by: Ronnie Sahlberg <lsahlber.redhat.com> >>>>>>>>>> Signed-off-by: Steve French <smfrench@xxxxxxxxx> >>>>>>>>>> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> >>>>>>>>>> >>>>>>>>>> --- >>>>>>>>>> fs/cifs/smb2pdu.c | 3 +++ >>>>>>>>>> 1 file changed, 3 insertions(+) >>>>>>>>>> >>>>>>>>>> --- a/fs/cifs/smb2pdu.c >>>>>>>>>> +++ b/fs/cifs/smb2pdu.c >>>>>>>>>> @@ -1963,6 +1963,9 @@ SMB2_ioctl(const unsigned int xid, struc >>>>>>>>>> } else >>>>>>>>>> iov[0].iov_len = get_rfc1002_length(req) + 4; >>>>>>>>>> + /* validate negotiate request must be signed - see MS-SMB2 3.2.5.5 */ >>>>>>>>>> + if (opcode == FSCTL_VALIDATE_NEGOTIATE_INFO) >>>>>>>>>> + req->hdr.sync_hdr.Flags |= SMB2_FLAGS_SIGNED; >>>>>>>>>> rc = SendReceive2(xid, ses, iov, n_iov, &resp_buftype, flags, &rsp_iov); >>>>>>>>>> cifs_small_buf_release(req); >>>>>>>>>> >>>>>>>>>> >>>>>>>>>> >>>>>>>>> >>>>>>>>> This one needs to be backported to all stable kernels as the commit that >>>>>>>>> introduced the regression: >>>>>>>>> ' >>>>>>>>> 0603c96f3af50e2f9299fa410c224ab1d465e0f9 >>>>>>>>> SMB: Validate negotiate (to protect against downgrade) even if signing off >>>>>>>>> >>>>>>>>> is backported in stable trees as of: 4.9.53, 4.4.90, 3.18.73 >>>>>>>> >>>>>>>> Oh wait, it breaks the builds on older kernels, that's why I didn't >>>>>>>> apply it :) >>>>>>>> >>>>>>>> Can you provide me with a working backport? >>>>>>>> >>>>>>> >>>>>>> Hi Steve, >>>>>>> >>>>>>> Is there a version of this fix available for stable kernels? >>>>>>> >>>>>> >>>>>> Hi Greg, >>>>>> >>>>>> Mounting SMB3 shares continues to fail for me on 4.4.118 and 4.9.84 >>>>>> due to the issues that I have described in detail on this mail thread. >>>>>> >>>>>> Since there is no apparent fix for this bug on stable kernels, could >>>>>> you please consider reverting the original commit that caused this >>>>>> regression? >>>>>> >>>>>> That commit was intended to enhance security, which is probably why it >>>>>> was backported to stable kernels in the first place; but instead it >>>>>> ends up breaking basic functionality itself (mounting). So in the >>>>>> absence of a proper fix, I don't see much of an option but to revert >>>>>> that commit. >>>>>> >>>>>> So, please consider reverting the following: >>>>>> >>>>>> commit 02ef29f9cbb616bf419 "SMB: Validate negotiate (to protect >>>>>> against downgrade) even if signing off" on 4.4.118 >>>>>> >>>>>> commit 0e1b85a41a25ac888fb "SMB: Validate negotiate (to protect >>>>>> against downgrade) even if signing off" on 4.9.84 >>>>>> >>>>>> They correspond to commit 0603c96f3af50e2f9299fa410c224ab1d465e0f9 >>>>>> upstream. Both these patches should revert cleanly. >>>>> >>>>> Do you still have this same problem on 4.14 and 4.15? If so, the issue >>>>> needs to get fixed there, not papered-over by reverting these old >>>>> changes, as you will hit the issue again in the future when you update >>>>> to a newer kernel version. >>>>> >>>> >>>> 4.14 and 4.15 work great! (I had mentioned this is in my original bug >>>> report but forgot to summarize it here, sorry). >>> >>> >>> Then what is the bugfix that should be applied here in order to keep >>> things working with these patches applied? >>> >> >> That would be the one mentioned in the subject line of this thread :) >> However, a working backport of that fix is not available for 4.4 and >> 4.9, hence the trouble. >> >> It looks like we are reconstructing elements of this email thread all >> over again, so let me quickly summarize the status so far: >> >> In 4.14/4.15/mainline, >> - commit 0603c96f3af50e2f9 (SMB: Validate negotiate (to protect against >> downgrade) even if signing off) caused mount regression with SMB v3. >> >> - commit 4587eee04e2ac7ac3 (SMB3: Validate negotiate request must >> always be signed) fixed the issue. >> >> - [ There was a lot of code churn in the CIFS/SMB codebase between >> these two commits in mainline. ] >> >> In this email thread, you backported the fix to stable 4.13. Thomas >> noticed that the problematic commit had also made it to stable series >> such as 4.4 and 4.9, and requested a backport of the fix to those >> trees as well. However, a straight-forward backport of the fix to 4.4 >> and 4.9 breaks the build, so no fix was available for those kernels. >> >> I investigated this and tried to produce a working backport of the fix >> to 4.4 and 4.9, but didn't succeed, despite trying several variations >> as well as suggestions from Aurelien [1][2]. So, given that there is >> still no known fix for the mount regression on 4.4 and 4.9 stable >> series at this point, I decided to request a revert of the problematic >> commit that caused the regression in those kernels. >> >> [1]. https://lkml.org/lkml/2018/1/3/892 >> [2]. https://lkml.org/lkml/2018/1/29/1009 >> >> Regards, >> Srivatsa > > >