In the Linux kernel, the following vulnerability has been resolved:

usb: gadget: u_serial: Add null pointer check in gserial_suspend

Consider a case where gserial_disconnect has already cleared
gser->ioport. And if gserial_suspend gets called afterwards,
it will lead to accessing of gser->ioport and thus causing
null pointer dereference.

Avoid this by adding a null pointer check. Added a static
spinlock to prevent gser->ioport from becoming null after
the newly added null pointer check.

References

• https://nvd.nist.gov/vuln/detail/CVE-2023-53356
• https://git.kernel.org/stable/c/2788a3553f7497075653210b42e2aeb6ba95e28e
• https://git.kernel.org/stable/c/2f6ecb89fe8feb2b60a53325b0eeb9866d88909a
• https://git.kernel.org/stable/c/374447e3367767156405bedd230c5d391f4b7962
• https://git.kernel.org/stable/c/a8ea7ed644cbf6314b5b0136b5398754b549fb8f
• https://git.kernel.org/stable/c/e60a827ac074ce6bd58305fe5a86afab5fce6a04