This is a note to let you know that I've just added the patch titled
gadgetfs: use-after-free in ->aio_read()
to the 3.19-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
gadgetfs-use-after-free-in-aio_read.patch
and it can be found in the queue-3.19 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From f01d35a15fa04162a58b95970fc01fa70ec9dacd Mon Sep 17 00:00:00 2001
From: Al Viro <viro@xxxxxxxxxxxxxxxxxx>
Date: Fri, 6 Feb 2015 02:07:45 -0500
Subject: gadgetfs: use-after-free in ->aio_read()
From: Al Viro <viro@xxxxxxxxxxxxxxxxxx>
commit f01d35a15fa04162a58b95970fc01fa70ec9dacd upstream.
AIO_PREAD requests call ->aio_read() with iovec on caller's stack, so if
we are going to access it asynchronously, we'd better get ourselves
a copy - the one on kernel stack of aio_run_iocb() won't be there
anymore. function/f_fs.c take care of doing that, legacy/inode.c
doesn't...
Signed-off-by: Al Viro <viro@xxxxxxxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/usb/gadget/legacy/inode.c | 15 ++++++++++++---
1 file changed, 12 insertions(+), 3 deletions(-)
--- a/drivers/usb/gadget/legacy/inode.c
+++ b/drivers/usb/gadget/legacy/inode.c
@@ -566,7 +566,6 @@ static ssize_t ep_copy_to_user(struct ki
if (total == 0)
break;
}
-
return len;
}
@@ -585,6 +584,7 @@ static void ep_user_copy_worker(struct w
aio_complete(iocb, ret, ret);
kfree(priv->buf);
+ kfree(priv->iv);
kfree(priv);
}
@@ -605,6 +605,7 @@ static void ep_aio_complete(struct usb_e
*/
if (priv->iv == NULL || unlikely(req->actual == 0)) {
kfree(req->buf);
+ kfree(priv->iv);
kfree(priv);
iocb->private = NULL;
/* aio_complete() reports bytes-transferred _and_ faults */
@@ -640,7 +641,7 @@ ep_aio_rwtail(
struct usb_request *req;
ssize_t value;
- priv = kmalloc(sizeof *priv, GFP_KERNEL);
+ priv = kzalloc(sizeof *priv, GFP_KERNEL);
if (!priv) {
value = -ENOMEM;
fail:
@@ -649,7 +650,14 @@ fail:
}
iocb->private = priv;
priv->iocb = iocb;
- priv->iv = iv;
+ if (iv) {
+ priv->iv = kmemdup(iv, nr_segs * sizeof(struct iovec),
+ GFP_KERNEL);
+ if (!priv->iv) {
+ kfree(priv);
+ goto fail;
+ }
+ }
priv->nr_segs = nr_segs;
INIT_WORK(&priv->work, ep_user_copy_worker);
@@ -689,6 +697,7 @@ fail:
mutex_unlock(&epdata->lock);
if (unlikely(value)) {
+ kfree(priv->iv);
kfree(priv);
put_ep(epdata);
} else
Patches currently in stable-queue which might be from viro@xxxxxxxxxxxxxxxxxx are
queue-3.19/net-validate-the-range-we-feed-to-iov_iter_init-in-sys_sendto-sys_recvfrom.patch
queue-3.19/caif-fix-msg_oob-test-in-caif_seqpkt_recvmsg.patch
queue-3.19/fuse-notify-don-t-move-pages.patch
queue-3.19/nilfs2-fix-deadlock-of-segment-constructor-during-recovery.patch
queue-3.19/rxrpc-bogus-msg_peek-test-in-rxrpc_recvmsg.patch
queue-3.19/gadgetfs-use-after-free-in-aio_read.patch
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