| Message ID | 20220331215910.884374-1-jakobkoschel@gmail.com |
|---|---|
| State | Accepted |
| Commit | 7b2206d8809259b0dd297f0ccf017bf2dea98a02 |
| Headers | show |
| Series | crypto: cavium/nitrox - remove check of list iterator against head past the loop body | expand |
On Thu, Mar 31, 2022 at 11:59:10PM +0200, Jakob Koschel wrote: > When list_for_each_entry() completes the iteration over the whole list > without breaking the loop, the iterator value will be a bogus pointer > computed based on the head element. > > While it is safe to use the pointer to determine if it was computed > based on the head element, either with list_entry_is_head() or > &pos->member == head, using the iterator variable after the loop should > be avoided. > > In preparation to limit the scope of a list iterator to the list > traversal loop, use a dedicated pointer to point to the found element [1]. > > Link: https://lore.kernel.org/all/CAHk-=wgRr_D8CB-D9Kg-c=EHreAsk5SqXPwr9Y7k9sA6cWXJ6w@mail.gmail.com/ [1] > Signed-off-by: Jakob Koschel <jakobkoschel@gmail.com> > --- > drivers/crypto/cavium/nitrox/nitrox_main.c | 10 ++++++---- > 1 file changed, 6 insertions(+), 4 deletions(-) Patch applied. Thanks.
diff --git a/drivers/crypto/cavium/nitrox/nitrox_main.c b/drivers/crypto/cavium/nitrox/nitrox_main.c index 6c61817996a3..432a61aca0c5 100644 --- a/drivers/crypto/cavium/nitrox/nitrox_main.c +++ b/drivers/crypto/cavium/nitrox/nitrox_main.c @@ -269,15 +269,17 @@ static void nitrox_remove_from_devlist(struct nitrox_device *ndev) struct nitrox_device *nitrox_get_first_device(void) { - struct nitrox_device *ndev; + struct nitrox_device *ndev = NULL, *iter; mutex_lock(&devlist_lock); - list_for_each_entry(ndev, &ndevlist, list) { - if (nitrox_ready(ndev)) + list_for_each_entry(iter, &ndevlist, list) { + if (nitrox_ready(iter)) { + ndev = iter; break; + } } mutex_unlock(&devlist_lock); - if (&ndev->list == &ndevlist) + if (!ndev) return NULL; refcount_inc(&ndev->refcnt);
When list_for_each_entry() completes the iteration over the whole list without breaking the loop, the iterator value will be a bogus pointer computed based on the head element. While it is safe to use the pointer to determine if it was computed based on the head element, either with list_entry_is_head() or &pos->member == head, using the iterator variable after the loop should be avoided. In preparation to limit the scope of a list iterator to the list traversal loop, use a dedicated pointer to point to the found element [1]. Link: https://lore.kernel.org/all/CAHk-=wgRr_D8CB-D9Kg-c=EHreAsk5SqXPwr9Y7k9sA6cWXJ6w@mail.gmail.com/ [1] Signed-off-by: Jakob Koschel <jakobkoschel@gmail.com> --- drivers/crypto/cavium/nitrox/nitrox_main.c | 10 ++++++---- 1 file changed, 6 insertions(+), 4 deletions(-) base-commit: f82da161ea75dc4db21b2499e4b1facd36dab275