Messages in this thread Patch in this message | | | Date | Mon, 12 May 2008 15:38:26 +0200 (CEST) | From | Julia Lawall <> | Subject | [PATCH 4/6] drivers/net/fs_enet: remove null pointer dereference |
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From: Julia Lawall <julia@diku.dk>
The following code appears in the function fs_init_instance in the file drivers/net/fs_enet/fs_enet-main.c.
if (fep->ops == NULL) { printk(KERN_ERR DRV_MODULE_NAME ": %s No matching ops found (%d).\n", ndev->name, fpi->fs_no); err = -EINVAL; goto err; }
This code implies that at the point of err, fep->ops can be NULL, so an extra test is needed before dereferencing this value.
This problem was found using the following semantic match (http://www.emn.fr/x-info/coccinelle/)
// <smpl> @@ expression E, E1; identifier f; statement S1,S2,S3; @@
* if (E == NULL) { ... when != if (E == NULL) S1 else S2 when != E = E1 * E->f ... when any return ...; } else S3 // </smpl>
Signed-off-by: Julia Lawall <julia@diku.dk>
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diff -u -p a/drivers/net/fs_enet/fs_enet-main.c b/drivers/net/fs_enet/fs_enet-main.c --- a/drivers/net/fs_enet/fs_enet-main.c 2008-04-27 11:41:11.000000000 +0200 +++ b/drivers/net/fs_enet/fs_enet-main.c 2008-05-12 09:41:52.000000000 +0200 @@ -1093,7 +1093,7 @@ err: if (registered) unregister_netdev(ndev); - if (fep != NULL) { + if (fep && fep->ops) { (*fep->ops->free_bd)(ndev); (*fep->ops->cleanup_data)(ndev); }
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