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https://github.com/Divested-Mobile/DivestOS-Build.git
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52 lines
1.9 KiB
Diff
52 lines
1.9 KiB
Diff
From 38740a5b87d53ceb89eb2c970150f6e94e00373a Mon Sep 17 00:00:00 2001
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From: Lars-Peter Clausen <lars@metafoo.de>
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Date: Thu, 14 Apr 2016 17:01:17 +0200
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Subject: usb: gadget: f_fs: Fix use-after-free
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When using asynchronous read or write operations on the USB endpoints the
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issuer of the IO request is notified by calling the ki_complete() callback
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of the submitted kiocb when the URB has been completed.
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Calling this ki_complete() callback will free kiocb. Make sure that the
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structure is no longer accessed beyond that point, otherwise undefined
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behaviour might occur.
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Fixes: 2e4c7553cd6f ("usb: gadget: f_fs: add aio support")
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Cc: <stable@vger.kernel.org> # v3.15+
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Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
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Signed-off-by: Felipe Balbi <felipe.balbi@linux.intel.com>
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---
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drivers/usb/gadget/function/f_fs.c | 5 ++---
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1 file changed, 2 insertions(+), 3 deletions(-)
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diff --git a/drivers/usb/gadget/function/f_fs.c b/drivers/usb/gadget/function/f_fs.c
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index e21ca2bd..15b648c 100644
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--- a/drivers/usb/gadget/function/f_fs.c
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+++ b/drivers/usb/gadget/function/f_fs.c
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@@ -646,6 +646,7 @@ static void ffs_user_copy_worker(struct work_struct *work)
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work);
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int ret = io_data->req->status ? io_data->req->status :
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io_data->req->actual;
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+ bool kiocb_has_eventfd = io_data->kiocb->ki_flags & IOCB_EVENTFD;
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if (io_data->read && ret > 0) {
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use_mm(io_data->mm);
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@@ -657,13 +658,11 @@ static void ffs_user_copy_worker(struct work_struct *work)
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io_data->kiocb->ki_complete(io_data->kiocb, ret, ret);
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- if (io_data->ffs->ffs_eventfd &&
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- !(io_data->kiocb->ki_flags & IOCB_EVENTFD))
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+ if (io_data->ffs->ffs_eventfd && !kiocb_has_eventfd)
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eventfd_signal(io_data->ffs->ffs_eventfd, 1);
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usb_ep_free_request(io_data->ep, io_data->req);
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- io_data->kiocb->private = NULL;
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if (io_data->read)
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kfree(io_data->to_free);
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kfree(io_data->buf);
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--
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cgit v1.1
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