Hi Max,

On 26/8/24 13:27, Max Filippov wrote:

create_elf_fdpic_tables() does not correctly account the space for the AUX vector when an architecture has ELF_HWCAP2 defined. Prior to the commit 10e29251be0e ("binfmt_elf_fdpic: fix /proc/<pid>/auxv") it resulted in the last entry of the AUX vector being set to zero, but with that change it results in a kernel BUG.

Fix that by adding one to the number of AUXV entries (nitems) when ELF_HWCAP2 is defined.

Fixes: 10e29251be0e ("binfmt_elf_fdpic: fix /proc/<pid>/auxv") Cc: stable@vger.kernel.org Reported-by: Greg Ungerer gregungerer@westnet.com.au

Feel free to use my gerg@kernel.org email for this.

Closes: https://lore.kernel.org/lkml/5b51975f-6d0b-413c-8b38-39a6a45e8821@westnet.co... Signed-off-by: Max Filippov jcmvbkbc@gmail.com

Certainly fixes it for all my failing test cases, so:

Tested-by: Greg Ungerer gerg@kernel.org

Thanks for looking into it and the fix.

Regards Greg

---

fs/binfmt_elf_fdpic.c | 3 +++ 1 file changed, 3 insertions(+)

diff --git a/fs/binfmt_elf_fdpic.c b/fs/binfmt_elf_fdpic.c index c11289e1301b..a5cb45cb30c8 100644 --- a/fs/binfmt_elf_fdpic.c +++ b/fs/binfmt_elf_fdpic.c @@ -594,6 +594,9 @@ static int create_elf_fdpic_tables(struct linux_binprm *bprm, if (bprm->have_execfd) nitems++; +#ifdef ELF_HWCAP2

• nitems++;

+#endif csp = sp; sp -= nitems * 2 * sizeof(unsigned long);