CVE-2021-47528

In the Linux kernel, the following vulnerability has been resolved:<br /> <br /> usb: cdnsp: Fix a NULL pointer dereference in cdnsp_endpoint_init()<br /> <br /> In cdnsp_endpoint_init(), cdnsp_ring_alloc() is assigned to pep-&gt;ring<br /> and there is a dereference of it in cdnsp_endpoint_init(), which could<br /> lead to a NULL pointer dereference on failure of cdnsp_ring_alloc().<br /> <br /> Fix this bug by adding a check of pep-&gt;ring.<br /> <br /> This bug was found by a static analyzer. The analysis employs<br /> differential checking to identify inconsistent security operations<br /> (e.g., checks or kfrees) between two code paths and confirms that the<br /> inconsistent operations are not recovered in the current function or<br /> the callers, so they constitute bugs.<br /> <br /> Note that, as a bug found by static analysis, it can be a false<br /> positive or hard to trigger. Multiple researchers have cross-reviewed<br /> the bug.<br /> <br /> Builds with CONFIG_USB_CDNSP_GADGET=y show no new warnings,<br /> and our static analyzer no longer warns about this code.