usb: idmouse: fix an uninit-value in idmouse_open
[ Upstream commit bce2b0539933e485d22d6f6f076c0fcd6f185c4c ] In idmouse_create_image, if any ftip_command fails, it will go to the reset label. However, this leads to the data in bulk_in_buffer[HEADER..IMGSIZE] uninitialized. And the check for valid image incurs an uninitialized dereference. Fix this by moving the check before reset label since this check only be valid if the data after bulk_in_buffer[HEADER] has concrete data. Note that this is found by KMSAN, so only kernel compilation is tested. Reported-by: syzbot+79832d33eb89fb3cd092@syzkaller.appspotmail.com Signed-off-by: Dongliang Mu <mudongliangabcd@gmail.com> Link: https://lore.kernel.org/r/20220922134847.1101921-1-dzm91@hust.edu.cn Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
This commit is contained in:

committed by
Greg Kroah-Hartman

parent
d5bb45f47b
commit
b8bbae3236
@@ -177,10 +177,6 @@ static int idmouse_create_image(struct usb_idmouse *dev)
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bytes_read += bulk_read;
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bytes_read += bulk_read;
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}
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}
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/* reset the device */
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reset:
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ftip_command(dev, FTIP_RELEASE, 0, 0);
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/* check for valid image */
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/* check for valid image */
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/* right border should be black (0x00) */
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/* right border should be black (0x00) */
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for (bytes_read = sizeof(HEADER)-1 + WIDTH-1; bytes_read < IMGSIZE; bytes_read += WIDTH)
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for (bytes_read = sizeof(HEADER)-1 + WIDTH-1; bytes_read < IMGSIZE; bytes_read += WIDTH)
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@@ -192,6 +188,10 @@ reset:
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if (dev->bulk_in_buffer[bytes_read] != 0xFF)
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if (dev->bulk_in_buffer[bytes_read] != 0xFF)
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return -EAGAIN;
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return -EAGAIN;
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/* reset the device */
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reset:
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ftip_command(dev, FTIP_RELEASE, 0, 0);
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/* should be IMGSIZE == 65040 */
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/* should be IMGSIZE == 65040 */
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dev_dbg(&dev->interface->dev, "read %d bytes fingerprint data\n",
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dev_dbg(&dev->interface->dev, "read %d bytes fingerprint data\n",
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bytes_read);
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bytes_read);
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