Re: [PATCH 0/2] smb: client: fix "df: Resource temporarily unavailable" on 5.10 stable kernel

[Steve French]

On Sat, Jan 27, 2024 at 12:43 AM Harshit Mogalapalli
<harshit.m.mogalapalli@xxxxxxxxxx> wrote:
>
> Hi,
>
> Adding more people to CC.(who have looked at this issue)
>
> On 27/01/24 6:19 am, Greg KH wrote:
> > On Fri, Jan 26, 2024 at 10:31:41PM +0300, kovalev@xxxxxxxxxxxx wrote:
> >> After mounting a remote cifs resource, it becomes unavailable:
> >> df: /mnt/sambashare: Resource temporarily unavailable
> >>
> >> It was tested on the following Linux kernels:
> >> Linux altlinux 5.10.208-std-def-alt1
> >> Linux fedora 5.10.208-200.el8.x86_64
> >>
> >> The error appeared starting from kernel 5.10.206 after adding
> >> the commit [1] "smb: client: fix OOB in SMB2_query_info_init()",
> >> in which the buffer length increases by 1 as a result of changes:
> >> ...
> >> -      iov[0].iov_len = total_len - 1 + input_len;
> >> +      iov[0].iov_len = len;
> >> ...
> >>
>
> We can reproduce this on 5.15.148(latest 5.15.y) and Mohamed reported
> this on 6.1.y, so we need backports there as well.
>
> https://lore.kernel.org/all/09738f0f-53a2-43f1-a09d-a2bef48e1344@xxxxxxxxxx/
>
>
> [root@vm1 xfstests-dev]# ./check -g quick -s smb3
> TEST_DEV=//<SERVER_IP>/TEST is mounted but not a type cifs filesystem
> [root@vm1 xfstests-dev]# df
> df: /mnt/test: Resource temporarily unavailable
>
>
> This two patch series doesn't cleanly apply to 5.15.y.
>
> Also I am unsure, which is the better approach to go with
>
> Approach 1 - suggested by Paulo:
> https://lore.kernel.org/all/446860c571d0699ed664175262a9e84b@xxxxxxxxxxxxx/
>
> Approach 2 - this series
> Pulling in [PATCH 2/2] smb3: Replace smb2pdu 1-element arrays with
> flex-arrays like this series did.
>
> I think approach 1 is better as the changes are minimal, but please
> correct me if that seems wrong.

Yes - Paulo's fix looks simple


-- 
Thanks,

Steve