Commit eb6c9927 authored by Ihor Solodrai's avatar Ihor Solodrai Committed by Andrii Nakryiko
Browse files

selftests/bpf: Add cmp_map_pointer_with_const test 



Add a test for CONST_PTR_TO_MAP comparison with a non-0 constant. A
BPF program with this code must not pass verification in unpriv.

Signed-off-by: default avatarIhor Solodrai <isolodrai@meta.com>
Signed-off-by: default avatarAndrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20250609183024.359974-3-isolodrai@meta.com
parent 5534e58f

tools/testing/selftests/bpf/progs/verifier_unpriv.c

+16 −1
Original line number Diff line number Diff line
@@ -624,7 +624,6 @@ __retval(0) 
__naked void cmp_map_pointer_with_zero(void)

{

	asm volatile ("					\

	r1 = 0;						\

	r1 = %[map_hash_8b] ll;				\

	if r1 == 0 goto l0_%=;				\

l0_%=:	r0 = 0;						\
@@ -634,6 +633,22 @@ l0_%=: r0 = 0; \ 
	: __clobber_all);

}



SEC("socket")

__description("unpriv: cmp map pointer with const")

__success __failure_unpriv __msg_unpriv("R1 pointer comparison prohibited")

__retval(0)

__naked void cmp_map_pointer_with_const(void)

{

	asm volatile ("					\

	r1 = %[map_hash_8b] ll;				\

	if r1 == 0x0000beef goto l0_%=;			\

l0_%=:	r0 = 0;						\

	exit;						\

"	:

	: __imm_addr(map_hash_8b)

	: __clobber_all);

}



SEC("socket")

__description("unpriv: write into frame pointer")

__failure __msg("frame pointer is read only")