CVE-2026-98248arm64: percpu: Fix LSE operations on {8,16}-bit types

Official description

In the Linux kernel, the following vulnerability has been resolved: arm64: percpu: Fix LSE operations on {8,16}-bit types The assembly for __percpu_##name##_case_##sz() and __percpu_##name##_return_case_##sz() doesn't use the 'sfx' macro argument to form the LSE instruction. Without 'sfx', a W register argument will imply a 32-bit memory location, and consequently {8,16}-bit ops will erroneously read and write 32 bits of memory when the LSE instruction is used. Fix this by appending 'sfx' to 'op_lse' to LSE instruction. It is not necessary (and not valid) to append 'sfx' to 'op_llsc', as 'op_llsc' is a register-register operation which does not access memory (and does not take a size suffix).

Affected packages & fixed versions

Affected products (as reported)

References

• https://git.kernel.org/stable/c/d69ab4480e49bf925f4781afcc9f284affcb96b6
• https://git.kernel.org/stable/c/390742871a723b52de9b92a94c0d1c85a2531e3e
• https://git.kernel.org/stable/c/843ace1d0a39e9b1cfcbfb3856a7b0fbdd9cd003
• https://git.kernel.org/stable/c/8cf2093f5372952a9ebc805c418d45df7112cd14