CVE-2026-90024
UnknownSummary
A null-pointer dereference vulnerability exists in the Linux kernel's USB gadget MIDI 2.0 function, specifically in f_midi2_free_ep_reqs(). When configuring a MIDI 2.0 gadget via configfs with block direction set to SNDRV_UMP_DIR_INPUT, the midi1_ep_out endpoint is not initialized, leaving usb_ep->card as NULL. When the host later sets the alternate setting, f_midi2_free_ep_reqs() is called for the uninitialized endpoint, causing a kernel crash.
Risk Assessment
The vulnerability can cause a kernel oops and denial of service (DoS) on systems using the USB MIDI 2.0 gadget. Exploitation requires local gadget configuration via configfs and USB host interaction, which limits the attack surface.
Recommendation
Update the Linux kernel to a version containing the fix that replaces usb_ep->card->info.num_reqs with usb_ep->num_reqs in f_midi2_free_ep_reqs() and f_midi2_alloc_ep_reqs(). Until patched, avoid configuring the MIDI 2.0 gadget with SNDRV_UMP_DIR_INPUT direction.
Other vulnerabilities in Linux kernel
See all- CVE-2026-90046High
In the Linux kernel, free_pages_nolock() uses spin_trylock() in NMI context on uniprocessor (UP) systems, which is unsafe. The bug affects the page freeing path and can crash the kernel. It is likely exploitable by local attackers for privilege escalation.
- CVE-2026-90045High
In the Linux kernel USB gadget ffs driver, the io_data structure stores a pointer to the submitting task's mm_struct but does not hold a reference while async requests are pending. This can cause a use-after-free if the task exits before completion handling finishes. The fix takes a reference with mmgrab() when queuing and releases it with mmdrop() on completion.
- CVE-2026-90044High
In the Linux kernel USB gadget f_fs driver, a use-after-free exists in the AIO error path. When ffs_epfile_io() fails with an error other than -EIOCBQUEUED, the io_data structure is freed, but the kiocb cancel function remains armed and points to the freed pointer. A concurrent cancel (e.g., sys_io_cancel()) can cause a use-after-free. The fix safely disarms the cancellation via kiocb->ki_complete() and returns -EIOCBQUEUED.
- CVE-2026-90043High
In the Linux kernel zram module, the slot lock bit is set in the wrong position on 64-bit big-endian systems. Instead of landing in the flags field, it lands in ac_time, so with ZRAM_TRACK_ENTRY_ACTIME enabled, storing the access time wipes out the held lock bit and lets another CPU take the same slot lock. An access time value with that bit set can make the slot appear locked forever. The fix shifts the lock bit into the flags half on big-endian 64-bit.
- CVE-2026-90041High
In the Linux kernel, the HID sony driver fails to remove a controller from the device list when HID core input device registration fails. The devres-managed sony_sc is freed while its list node remains linked, leading to use-after-free when the next matching controller is handled.
- CVE-2026-90039Unknown
In the Linux kernel, NFSD admin state-revocation handlers (unlock_filesystem, NFSD_CMD_UNLOCK_FILESYSTEM, NFSD_CMD_UNLOCK_EXPORT) only check nn->nfsd_serv, which is set before nn->conf_id_hashtbl is allocated. This leads to a NULL dereference when the server has not yet started.
- CVE-2026-90035Unknown
In the Linux kernel, get_estimated_bw() in the drm/amd/display driver divides by bw_granularity, which is zeroed and only populated after DP_TUNNELING_BW_ALLOC_CAP_CHANGED is handled. If a USB4/DPIA device reports an estimated-bandwidth change before a capability change, the DPCD interrupt handler triggers a division by zero.
- CVE-2026-90034Unknown
In the Linux kernel, the usb image mdc800 driver uses kmalloc() for irq_urb_buffer and download_urb_buffer in usb_mdc800_init(). If a shorter message is received in mdc800_usb_irq() or mdc800_usb_download_notify(), stack data may leak.
- CVE-2026-90033Unknown
In the Linux kernel, snd_usbmidi_us122l_output() in ALSA usb-audio picks a count of 2 for anything slower than high speed without relating it to ep->max_transfer. With a device declaring a one-byte bulk endpoint, the memset computes 1 - 2 in int and wraps to SIZE_MAX, causing an out-of-bounds write.
- CVE-2026-90022High
In the Linux kernel, f_midi2_opts_str_show() in the USB gadget driver has a use-after-free. Callers dereference the opts->info.<field> pointer before taking the lock, racing with f_midi2_opts_str_store(), which frees the old string under the lock. A concurrent attribute write can cause a read of a freed pointer.
Original NVD description (English source)
In the Linux kernel, the following vulnerability has been resolved: usb: gadget: midi2: Fix null-pointer dereference in f_midi2_free_ep_reqs A null-pointer dereference occurs in f_midi2_free_ep_reqs() when attempting to clean up an endpoint that was never initialized. When configuring the MIDI 2.0 gadget via configfs and setting the block direction to SNDRV_UMP_DIR_INPUT, the initialization of the midi1_ep_out endpoint is explicitly skipped during the gadget bind phase (f_midi2_bind()). As a result, the usb_ep->card field remains NULL. Later, when the host sets the alternate setting, f_midi2_set_alt() unconditionally stops both the IN and OUT endpoints by calling f_midi2_stop_eps(), which in turn calls f_midi2_free_ep_reqs() for both endpoints. When f_midi2_free_ep_reqs() is called for the uninitialized midi1_ep_out, it attempts to dereference usb_ep->card to determine the number of requests to free, leading to a crash. Fix this by using usb_ep->num_reqs instead of usb_ep->card->info.num_reqs in f_midi2_free_ep_reqs(). usb_ep->num_reqs is correctly set during f_midi2_init_ep() and remains 0 if the endpoint was never initialized, safely avoiding the loop. For consistency, apply the same change to f_midi2_alloc_ep_reqs(). Oops: general protection fault, probably for non-canonical address 0xdffffc00000000ee: 0000 [#1] SMP KASAN NOPTI KASAN: null-ptr-deref in range [0x0000000000000770-0x0000000000000777] ... RIP: 0010:f_midi2_free_ep_reqs drivers/usb/gadget/function/f_midi2.c:1166 [inline] RIP: 0010:f_midi2_stop_eps+0x28e/0x4d0 drivers/usb/gadget/function/f_midi2.c:1246 ... Call Trace: <TASK> f_midi2_set_alt+0x11c/0xf00 drivers/usb/gadget/function/f_midi2.c:1296 composite_setup+0x1ffd/0x3480 drivers/usb/gadget/composite.c:1933 configfs_composite_setup+0xbd/0x100 drivers/usb/gadget/configfs.c:1877

