CVE-2026-81014platform/x86: hp-bioscfg: fix heap OOB read in sk_store() and kek_store()

Official description

In the Linux kernel, the following vulnerability has been resolved: platform/x86: hp-bioscfg: fix heap OOB read in sk_store() and kek_store() sk_store() and kek_store() strip a trailing newline from the sysfs write before allocating the key buffer: length = count; if (buf[length - 1] == '\n') length--; bioscfg_drv.spm_data.signing_key = kmemdup(buf, length, GFP_KERNEL); but then pass the original "count" (not "length") as the copy size to hp_wmi_perform_query(), which memcpy()s that many bytes out of the "length"-sized allocation, reading one byte past it whenever the write ends in a newline, the normal case for a shell "echo" into sysfs. KASAN confirms this directly: BUG: KASAN: slab-out-of-bounds in hp_wmi_perform_query+0x1e9/0x460 [hp_bioscfg] Read of size 28 at addr ffff88813c8e2b80 by task python3/16022 ... sk_store+0xa7/0x240 [hp_bioscfg] kernfs_fop_write_iter+0x3e1/0x5d0 ... The buggy address is located 0 bytes inside of allocated 27-byte region [ffff88813c8e2b80, ffff88813c8e2b9b) Reproduced identically for kek_store, and at multiple write sizes (28, 57, 201 bytes), each time reading exactly one byte past a kmemdup() allocation one byte smaller than the write. Fix by passing "length" instead of "count" to hp_wmi_perform_query() in both functions.

Affected packages & fixed versions

Affected products (as reported)

References

• https://git.kernel.org/stable/c/81db79fed115640736188e56595b1e9aec317d5b
• https://git.kernel.org/stable/c/4c6374dcb270d12907b880cf82a5a5ef21785fc3
• https://git.kernel.org/stable/c/7cd8fe01aba303a2382db0966eb6c8ab41d5f3c2
• https://git.kernel.org/stable/c/67b60703d7d8af1ca0e49f72e1bdb1ccecd41b5b
• https://git.kernel.org/stable/c/a7508c7959ff8d037327d377ed21a9c0eabe4674