CyberRota Analysis
AI-GeneratedThe vulnerability in the Linux kernel affects the ALSA usb-audio subsystem, specifically in the handling of stream disable requests when no active interface is present. This flaw can lead to memory corruption and potential kernel crashes due to unsafe dereferencing of pointers, allowing unprivileged local users to exploit the issue. Organizations using Linux systems with audio interfaces should prioritize patching this vulnerability to mitigate risks associated with local user exploitation.
Original NVD Description
In the Linux kernel, the following vulnerability has been resolved: ALSA: usb-audio: qcom: reject stream disable with no active interface handle_uaudio_stream_req() resolves an interface index with info_idx_from_ifnum(), which returns -EINVAL when no interface matches. The enable branch and the response: cleanup label both guard against a negative index, but the disable branch does not: it forms info = &uadev[pcm_card_num].info[info_idx] and dereferences it. uadev[].info is a pointer allocated only when a stream is first enabled, so a negative info_idx on the disable path is unsafe in two ways: - If the card was never enabled, .info is NULL and &info[-EINVAL] is a wild pointer; reading info->data_ep_pipe faults (kernel oops). - If the card was enabled at least once (.info allocated) and the disable names an interface that does not match, &info[-EINVAL] points before the allocation; info->data_ep_pipe / info->sync_ep_pipe are an out-of-bounds slab read and, when non-zero, an out-of-bounds 4-byte write (both pipe fields are cleared to 0). That is memory corruption, not just a NULL dereference. The request is reachable from unprivileged local userspace over AF_QIPCRTR. Reject a disable request with no resolved interface, matching the guard the enable path already has.