CVE-2026-97930ALSA: usbusx2y: fix in04_last array size mismatch with in04_buf

Official description

In the Linux kernel, the following vulnerability has been resolved: ALSA: usbusx2y: fix in04_last array size mismatch with in04_buf The in04_last array in struct usx2ydev is declared as char[24], but in04_buf is allocated as sizeof(struct us428_ctls) which is 21 bytes. In i_usx2y_in04_int(), when ctl_snapshot_last == -2 (initialization path): memcpy(usx2y->in04_last, usx2y->in04_buf, sizeof(usx2y->in04_last)); This copies 24 bytes from a 21-byte slab allocation, reading 3 bytes past the end of the source object. Introduce a USX2Y_IN04_SIZE constant defined as sizeof(struct us428_ctls) and use it consistently for the in04_last array, the in04_buf allocation, the URB transfer length, and the comparison loop, replacing the bare 24 and 21 literals throughout.

Affected packages & fixed versions

Affected products (as reported)

References

• https://git.kernel.org/stable/c/e75e4b0e647137f4c9f6dee4a7ef5b7b09e16f57
• https://git.kernel.org/stable/c/869fb83c072e884b80d93eab498e6040ffb010ba
• https://git.kernel.org/stable/c/d170cfbe38c8817ac787f605655546a6d343017d
• https://git.kernel.org/stable/c/229cab526580f82839ae8e4e379753c8cf16952e
• https://git.kernel.org/stable/c/381495b5b3da12d714e53d9d12d955b13fe26eac
• https://git.kernel.org/stable/c/b5753bdfd909f7f095fb464d67802b5e52cbadbf
• https://git.kernel.org/stable/c/861111a14740e12c36d363e9830f8daa734279c9