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authorDan Carpenter <dan.carpenter@oracle.com>2018-10-26 10:19:51 +0300
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2018-11-11 09:21:46 -0800
commit432798195bbce1f8cd33d1c0284d0538835e25fb (patch)
treebb33155c3b0cb77622e2352520ccd95b9a377e62
parent8bb0a88600f0267cfcc245d34f8c4abe8c282713 (diff)
downloadblackbird-op-linux-432798195bbce1f8cd33d1c0284d0538835e25fb.tar.gz
blackbird-op-linux-432798195bbce1f8cd33d1c0284d0538835e25fb.zip
uio: Fix an Oops on load
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> Cc: stable <stable@vger.kernel.org> Tested-by: Mathias Thore <Mathias.Thore@infinera.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
-rw-r--r--drivers/uio/uio.c7
1 files 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:
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