In the Linux kernel, the following vulnerability has been resolved:<\/p>\n
usb: gadget: at91_udc: drain polled-VBUS timer\/work before udc is freed<\/p>\n
In polled-VBUS mode (board.vbus_pin && board.vbus_polled), probe arms a
\nself-restarting cycle: at91_vbus_timer() schedules vbus_timer_work, and
\nat91_vbus_timer_work() calls at91_vbus_update() and re-arms the timer via
\nmod_timer(). Both recover the same udc through container_of and dereference
\nit on every iteration.<\/p>\n
Neither teardown path cancels this cycle. udc is devm-allocated, so it is
\nfreed after at91udc_remove() returns, and is likewise freed when probe
\nfails and devres runs. A timer callback or work item that is pending or
\nrunning at either point dereferences the freed udc.<\/p>\n
Add at91_udc_shutdown_vbus_timer() and call it from at91udc_remove() and
\nfrom the usb_add_gadget_udc() failure path in probe; the remaining probe
\nerror paths fail before the timer is armed. timer_shutdown_sync() waits
\nfor a running callback and clears timer->function, which makes the work
\nhandler’s mod_timer() a permanent no-op; cancel_work_sync() then drains
\nany pending or running work whose re-arm attempt now does nothing. The
\ntimer must be shut down first, since cancelling the work alone would let
\nthe timer re-queue it. The guard mirrors probe: in IRQ mode the timer and
\nwork_struct are never initialized.<\/p>\n
This does not require a fault; a normal driver unbind can interleave with
\nan already queued work item.<\/p>\n
This issue was found by an in-house static analysis tool.<\/p>\n","protected":false},"excerpt":{"rendered":"
In the Linux kernel, the following vulnerability has been resolved:<\/p>\n
usb: gadget: at91_udc: drain polled-VBUS timer\/work before udc is freed<\/p>\n
In polled-VBUS mode (board.vbus_pin && board.vbus_polled),<\/p>\n","protected":false},"template":"","meta":[],"categories":[],"tags":[],"class_list":["post-21660","vuln","type-vuln","status-publish","hentry"],"_links":{"self":[{"href":"https:\/\/www.54iter.cn\/index.php?rest_route=\/wp\/v2\/vuln\/21660","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.54iter.cn\/index.php?rest_route=\/wp\/v2\/vuln"}],"about":[{"href":"https:\/\/www.54iter.cn\/index.php?rest_route=\/wp\/v2\/types\/vuln"}],"wp:attachment":[{"href":"https:\/\/www.54iter.cn\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=21660"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.54iter.cn\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=21660"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.54iter.cn\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=21660"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}