Thanks for the quick fix. I've tested it and it seems OK. Tested-by: Mathias Thore <mathias.th...@infinera.com>
-----Original Message----- From: Dan Carpenter [mailto:dan.carpen...@oracle.com] Sent: Friday, 26 October 2018 09:20 To: Greg Kroah-Hartman <gre...@linuxfoundation.org>; Mathias Thore <mathias.th...@infinera.com> Cc: linux-kernel@vger.kernel.org Subject: [PATCH] uio: Fix an Oops on load CAUTION: This email originated from outside of the organization. Do not click links or open attachments unless you recognize the sender and know the content is safe. I was trying to solve a double free but I introduced a more serious NULL dereference bug. The problem is that if there is an IRQ which triggers immediately, then we need "info->uio_dev" but it's not set yet. This patch puts the original initialization back to how it was and just sets info->uio_dev to NULL on the error path so it should solve both the Oops and the double free. Fixes: f019f07ecf6a ("uio: potential double frees if __uio_register_device() fails") Reported-by: Mathias Thore <mathias.th...@infinera.com> Signed-off-by: Dan Carpenter <dan.carpen...@oracle.com> --- drivers/uio/uio.c | 7 +++++-- 1 file changed, 5 insertions(+), 2 deletions(-) diff --git a/drivers/uio/uio.c b/drivers/uio/uio.c index 85644669fbe7..0a357db4b31b 100644 --- a/drivers/uio/uio.c +++ b/drivers/uio/uio.c @@ -961,6 +961,8 @@ int __uio_register_device(struct module *owner, if (ret) goto err_uio_dev_add_attributes; + info->uio_dev = idev; + if (info->irq && (info->irq != UIO_IRQ_CUSTOM)) { /* * Note that we deliberately don't use devm_request_irq @@ -972,11 +974,12 @@ int __uio_register_device(struct module *owner, */ ret = request_irq(info->irq, uio_interrupt, info->irq_flags, info->name, idev); - if (ret) + if (ret) { + info->uio_dev = NULL; goto err_request_irq; + } } - info->uio_dev = idev; return 0; err_request_irq: -- 2.11.0
