binfmt_elf_fdpic: fix AUXV size calculation for ELF_HWCAP3 and ELF_HWCAP4

binfmt_elf_fdpic: fix AUXV size calculation for ELF_HWCAP3 and ELF_HWCAP4

[ Upstream commit 4ced4cf5c9d172d91f181df3accdf949d3761aab ]

Commit 4e6e8c2b757f ("binfmt_elf: Wire up AT_HWCAP3 at AT_HWCAP4") added
support for AT_HWCAP3 and AT_HWCAP4, but it missed updating the AUX
vector size calculation in create_elf_fdpic_tables() and
AT_VECTOR_SIZE_BASE in include/linux/auxvec.h.

Similar to the fix for AT_HWCAP2 in commit c6a09e342f8e ("binfmt_elf_fdpic:
fix AUXV size calculation when ELF_HWCAP2 is defined"), this omission
leads to a mismatch between the reserved space and the actual number of
AUX entries, eventually triggering a kernel BUG_ON(csp != sp).

Fix this by incrementing nitems when ELF_HWCAP3 or ELF_HWCAP4 are
defined and updating AT_VECTOR_SIZE_BASE.

Cc: Mark Brown <broonie@kernel.org>
Cc: Max Filippov <jcmvbkbc@gmail.com>
Reviewed-by: Michal Koutný <mkoutny@suse.com>
Reviewed-by: Mark Brown <broonie@kernel.org>
Reviewed-by: Cyrill Gorcunov <gorcunov@gmail.com>
Reviewed-by: Alexander Mikhalitsyn <aleksandr.mikhalitsyn@futurfusion.io>
Fixes: 4e6e8c2b757f ("binfmt_elf: Wire up AT_HWCAP3 at AT_HWCAP4")
Signed-off-by: Andrei Vagin <avagin@google.com>
Link: https://patch.msgid.link/20260217180108.1420024-2-avagin@google.com
Signed-off-by: Kees Cook <kees@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>