Messages in this thread Patch in this message | | | Date | Fri, 26 Oct 2018 10:19:51 +0300 | From | Dan Carpenter <> | Subject | [PATCH] uio: Fix an Oops on load |
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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.Thore@infinera.com> Signed-off-by: Dan Carpenter <dan.carpenter@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
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