fuse: avoid out-of-scope stack access
The all pointers within fuse_req must point to valid memory once
fuse_force_forget() returns.
This bug appeared in "fuse: implement NFS-like readdirplus support"
and was never in any official Linux release.
I tested the fuse_force_forget() code path by injecting to fake -ENOMEM and
verified the FORGET operation was called properly in userspace.
Signed-off-by: Eric Wong <normalperson@yhbt.net>
Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
diff --git a/fs/fuse/dev.c b/fs/fuse/dev.c
index cbae09e..e9bdec0 100644
--- a/fs/fuse/dev.c
+++ b/fs/fuse/dev.c
@@ -440,9 +440,8 @@
}
}
-void fuse_request_send(struct fuse_conn *fc, struct fuse_req *req)
+static void __fuse_request_send(struct fuse_conn *fc, struct fuse_req *req)
{
- req->isreply = 1;
spin_lock(&fc->lock);
if (!fc->connected)
req->out.h.error = -ENOTCONN;
@@ -459,6 +458,12 @@
}
spin_unlock(&fc->lock);
}
+
+void fuse_request_send(struct fuse_conn *fc, struct fuse_req *req)
+{
+ req->isreply = 1;
+ __fuse_request_send(fc, req);
+}
EXPORT_SYMBOL_GPL(fuse_request_send);
static void fuse_request_send_nowait_locked(struct fuse_conn *fc,
@@ -541,7 +546,9 @@
req->in.args[0].size = sizeof(inarg);
req->in.args[0].value = &inarg;
req->isreply = 0;
- fuse_request_send_nowait(fc, req);
+ __fuse_request_send(fc, req);
+ /* ignore errors */
+ fuse_put_request(fc, req);
}
/*