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author | Vivek Goyal <vgoyal@redhat.com> | 2022-07-29 09:17:06 -0400 |
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committer | Dr. David Alan Gilbert <dgilbert@redhat.com> | 2022-08-02 16:46:52 +0100 |
commit | a21ba54dd5ca38cd05da9035fc65374d7af54f13 (patch) | |
tree | 46fb2b1949255b48cb481a580b9c8f62cb857e37 | |
parent | 4bcb7de072fd8ab9de40b24aac00c7b6659f7f7d (diff) | |
download | qemu-a21ba54dd5ca38cd05da9035fc65374d7af54f13.zip qemu-a21ba54dd5ca38cd05da9035fc65374d7af54f13.tar.gz qemu-a21ba54dd5ca38cd05da9035fc65374d7af54f13.tar.bz2 |
virtiofsd: Disable killpriv_v2 by default
We are having bunch of issues with killpriv_v2 enabled by default. First
of all it relies on clearing suid/sgid bits as needed by dropping
capability CAP_FSETID. This does not work for remote filesystems like
NFS (and possibly others).
Secondly, we are noticing other issues related to clearing of SGID
which leads to failures for xfstests generic/355 and generic/193.
Thirdly, there are other issues w.r.t caching of metadata (suid/sgid)
bits in fuse client with killpriv_v2 enabled. Guest can cache that
data for sometime even if cleared on server.
Second and Third issue are fixable. Just that it might take a little
while to get it fixed in kernel. First one will probably not see
any movement for a long time.
Given these issues, killpriv_v2 does not seem to be a good candidate
for enabling by default. We have already disabled it by default in
rust version of virtiofsd.
Hence this patch disabled killpriv_v2 by default. User can choose to
enable it by passing option "-o killpriv_v2".
Signed-off-by: Vivek Goyal <vgoyal@redhat.com>
Message-Id: <YuPd0itNIAz4tQRt@redhat.com>
Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
-rw-r--r-- | tools/virtiofsd/passthrough_ll.c | 13 |
1 files changed, 2 insertions, 11 deletions
diff --git a/tools/virtiofsd/passthrough_ll.c b/tools/virtiofsd/passthrough_ll.c index 7a73dfc..371a7be 100644 --- a/tools/virtiofsd/passthrough_ll.c +++ b/tools/virtiofsd/passthrough_ll.c @@ -767,19 +767,10 @@ static void lo_init(void *userdata, struct fuse_conn_info *conn) fuse_log(FUSE_LOG_DEBUG, "lo_init: enabling killpriv_v2\n"); conn->want |= FUSE_CAP_HANDLE_KILLPRIV_V2; lo->killpriv_v2 = 1; - } else if (lo->user_killpriv_v2 == -1 && - conn->capable & FUSE_CAP_HANDLE_KILLPRIV_V2) { - /* - * User did not specify a value for killpriv_v2. By default enable it - * if connection offers this capability - */ - fuse_log(FUSE_LOG_DEBUG, "lo_init: enabling killpriv_v2\n"); - conn->want |= FUSE_CAP_HANDLE_KILLPRIV_V2; - lo->killpriv_v2 = 1; } else { /* - * Either user specified to disable killpriv_v2, or connection does - * not offer this capability. Disable killpriv_v2 in both the cases + * Either user specified to disable killpriv_v2, or did not + * specify anything. Disable killpriv_v2 in both the cases. */ fuse_log(FUSE_LOG_DEBUG, "lo_init: disabling killpriv_v2\n"); conn->want &= ~FUSE_CAP_HANDLE_KILLPRIV_V2; |