security: revalidate rw permissions for sys_splice and sys_vmsplice
Revalidate read/write permissions for splice(2) and vmslice(2), in case
security policy has changed since the files were opened.
Acked-by: Stephen Smalley <sds@tycho.nsa.gov>
Signed-off-by: James Morris <jmorris@namei.org>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
diff --git a/fs/splice.c b/fs/splice.c
index ed2ce99..ef80822 100644
--- a/fs/splice.c
+++ b/fs/splice.c
@@ -28,6 +28,7 @@
#include <linux/module.h>
#include <linux/syscalls.h>
#include <linux/uio.h>
+#include <linux/security.h>
/*
* Attempt to steal a page from a pipe buffer. This should perhaps go into
@@ -961,6 +962,10 @@
if (unlikely(ret < 0))
return ret;
+ ret = security_file_permission(out, MAY_WRITE);
+ if (unlikely(ret < 0))
+ return ret;
+
return out->f_op->splice_write(pipe, out, ppos, len, flags);
}
@@ -983,6 +988,10 @@
if (unlikely(ret < 0))
return ret;
+ ret = security_file_permission(in, MAY_READ);
+ if (unlikely(ret < 0))
+ return ret;
+
return in->f_op->splice_read(in, ppos, pipe, len, flags);
}