[PATCH] r/o bind mounts: elevate write count for xattr_permission() callers
This basically audits the callers of xattr_permission(), which calls
permission() and can perform writes to the filesystem.
[AV: add missing parts - removexattr() and nfsd posix acls, plug for a leak
spotted by Miklos]
Acked-by: Al Viro <viro@ZenIV.linux.org.uk>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Dave Hansen <haveblue@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
diff --git a/fs/nfsd/nfs4proc.c b/fs/nfsd/nfs4proc.c
index c593db0..c309c88 100644
--- a/fs/nfsd/nfs4proc.c
+++ b/fs/nfsd/nfs4proc.c
@@ -658,14 +658,19 @@
return status;
}
}
+ status = mnt_want_write(cstate->current_fh.fh_export->ex_path.mnt);
+ if (status)
+ return status;
status = nfs_ok;
if (setattr->sa_acl != NULL)
status = nfsd4_set_nfs4_acl(rqstp, &cstate->current_fh,
setattr->sa_acl);
if (status)
- return status;
+ goto out;
status = nfsd_setattr(rqstp, &cstate->current_fh, &setattr->sa_iattr,
0, (time_t)0);
+out:
+ mnt_drop_write(cstate->current_fh.fh_export->ex_path.mnt);
return status;
}