Re: [PATCH] fuse: Send FUSE_WRITE_KILL_SUIDGID for killpriv v1

From: Connor Kuehl
Date: Mon Jun 21 2021 - 09:54:40 EST


On 6/21/21 3:26 AM, Miklos Szeredi wrote:
> On Fri, 23 Apr 2021 at 17:19, Connor Kuehl <ckuehl@xxxxxxxxxx> wrote:
>>
>> FUSE doesn't seem to be adding the FUSE_WRITE_KILL_SUIDGID flag on write
>> requests for FUSE connections that support FUSE_HANDLE_KILLPRIV but not
>> FUSE_HANDLE_KILLPRIV_V2.
>>
>> However, the FUSE userspace header states:
>>
>> FUSE_HANDLE_KILLPRIV: fs handles killing suid/sgid/cap on
>> write/chown/trunc
>> ^^^^^
>>
>> To improve backwards compatibility with file servers that don't support
>> FUSE_HANDLE_KILLPRIV_V2, add the FUSE_WRITE_KILL_SUIDGID flag to write
>> requests if FUSE_HANDLE_KILLPRIV has been negotiated -OR- if the
>> conditions for FUSE_HANDLE_KILLPRIV_V2 support are met.
>
>
> If server does not support FUSE_HANDLE_KILLPRIV_V2, then it does not
> support FUSE_WRITE_KILL_SUIDGID either. The two were introduced
> together and the latter is only meaningful if the
> FUSE_HANDLE_KILLPRIV_V2 feature was negotiated.
>
> What am I missing?

You're not missing anything, this patch is wrong. Let's nack this.

Thanks!

Connor