Re: [PULL 0/6] virtiofs queue

[Dr. David Alan Gilbert]

Dear Stable,
  From this series, the fixes:

       virtiofsd: add --rlimit-nofile=NUM option
       virtiofsd: stay below fs.file-max sysctl value (CVE-2020-10717)

and
       virtiofsd: Show submounts

should probably be backported.

Dave

* Dr. David Alan Gilbert (git) (address@hidden) wrote:
> From: "Dr. David Alan Gilbert" <address@hidden>
> 
> The following changes since commit 1c47613588ccff44422d4bdeea0dc36a0a308ec7:
> 
>   Merge remote-tracking branch 'remotes/kevin/tags/for-upstream' into staging 
> (2020-04-30 19:25:41 +0100)
> 
> are available in the Git repository at:
> 
>   https://gitlab.com/dagrh/qemu.git tags/pull-virtiofs-20200501
> 
> for you to fetch changes up to 66502bbca37ca7a3bfa57e82cfc03b89a7a11eae:
> 
>   virtiofsd: drop all capabilities in the wait parent process (2020-05-01 
> 20:05:37 +0100)
> 
> ----------------------------------------------------------------
> virtiofsd: Pull 2020-05-01 (includes CVE fix)
> 
> This set includes a security fix, other fixes and improvements.
> 
> Security fix:
> The security fix is for CVE-2020-10717 where, on low RAM hosts,
> the guest can potentially exceed the maximum fd limit.
> This fix adds some more configuration so that the user
> can explicitly set the limit.
> Thank you to Yuval Avrahami for reporting this.
> 
> Fixes:
> 
> Recursive mounting of the exported directory is now used in
> the sandbox, such that if there was a mount underneath present at
> the time the virtiofsd was started, that mount is also
> visible to the guest; in the existing code, only mounts that
> happened after startup were visible.
> 
> Security improvements:
> 
> The jailing for /proc/self/fd is improved - but it's something
> that shouldn't be accessible anyway.
> 
> Most capabilities are now dropped at startup; again this shouldn't
> change any behaviour but is extra protection.
> 
> ----------------------------------------------------------------
> Max Reitz (1):
>       virtiofsd: Show submounts
> 
> Miklos Szeredi (1):
>       virtiofsd: jail lo->proc_self_fd
> 
> Stefan Hajnoczi (4):
>       virtiofsd: add --rlimit-nofile=NUM option
>       virtiofsd: stay below fs.file-max sysctl value (CVE-2020-10717)
>       virtiofsd: only retain file system capabilities
>       virtiofsd: drop all capabilities in the wait parent process
> 
>  tools/virtiofsd/fuse_lowlevel.h  |   1 +
>  tools/virtiofsd/helper.c         |  47 ++++++++++++++++++
>  tools/virtiofsd/passthrough_ll.c | 102 
> ++++++++++++++++++++++++++++++++-------
>  3 files changed, 133 insertions(+), 17 deletions(-)
> 
> 
--
Dr. David Alan Gilbert / address@hidden / Manchester, UK