public-mirrors/linux
1
0
Fork 0
mirror of git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git synced 2025-08-05 16:54:27 +00:00
Code Issues Projects Releases Packages Wiki Activity Actions
linux/tools/testing/selftests/bpf/progs/verifier_unpriv.c
Luis Gerhorst 92974cef83 selftests/bpf: Add Spectre v4 tests 
Add the following tests:

1. A test with an (unimportant) ldimm64 (16 byte insn) and a
   Spectre-v4--induced nospec that clarifies and serves as a basic
   Spectre v4 test.

2. Make sure a Spectre v4 nospec_result does not prevent a Spectre v1
   nospec from being added before the dangerous instruction (tests that
   [1] is fixed).

3. Combine the two, which is the combination that triggers the warning
   in [2]. This is because the unanalyzed stack write has nospec_result
   set, but the ldimm64 (which was just analyzed) had incremented
   insn_idx by 2. That violates the assertion that nospec_result is only
   used after insns that increment insn_idx by 1 (i.e., stack writes).

[1] https://lore.kernel.org/bpf/4266fd5de04092aa4971cbef14f1b4b96961f432.camel@gmail.com/
[2] https://lore.kernel.org/bpf/685b3c1b.050a0220.2303ee.0010.GAE@google.com/

Signed-off-by: Luis Gerhorst <luis.gerhorst@fau.de>
Link: https://lore.kernel.org/r/20250705190908.1756862-3-luis.gerhorst@fau.de
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2025-07-07 08:32:34 -07:00

953 lines
23 KiB
C
Raw Permalink Blame History

// SPDX-License-Identifier: GPL-2.0
/* Converted from tools/testing/selftests/bpf/verifier/unpriv.c */
#include <linux/bpf.h>
#include <bpf/bpf_helpers.h>
#include "../../../include/linux/filter.h"
#include "bpf_misc.h"
#define BPF_SK_LOOKUP(func) \
/* struct bpf_sock_tuple tuple = {} */ \
"r2 = 0;" \
"*(u32*)(r10 - 8) = r2;" \
"*(u64*)(r10 - 16) = r2;" \
"*(u64*)(r10 - 24) = r2;" \
"*(u64*)(r10 - 32) = r2;" \
"*(u64*)(r10 - 40) = r2;" \
"*(u64*)(r10 - 48) = r2;" \
/* sk = func(ctx, &tuple, sizeof tuple, 0, 0) */ \
"r2 = r10;" \
"r2 += -48;" \
"r3 = %[sizeof_bpf_sock_tuple];"\
"r4 = 0;" \
"r5 = 0;" \
"call %[" #func "];"
struct {
__uint(type, BPF_MAP_TYPE_HASH);
__uint(max_entries, 1);
__type(key, long long);
__type(value, long long);
} map_hash_8b SEC(".maps");
void dummy_prog_42_socket(void);
void dummy_prog_24_socket(void);
void dummy_prog_loop1_socket(void);
struct {
__uint(type, BPF_MAP_TYPE_PROG_ARRAY);
__uint(max_entries, 4);
__uint(key_size, sizeof(int));
__array(values, void (void));
} map_prog1_socket SEC(".maps") = {
.values = {
[0] = (void *)&dummy_prog_42_socket,
[1] = (void *)&dummy_prog_loop1_socket,
[2] = (void *)&dummy_prog_24_socket,
},
};
SEC("socket")
__auxiliary __auxiliary_unpriv
__naked void dummy_prog_42_socket(void)
{
asm volatile ("r0 = 42; exit;");
}
SEC("socket")
__auxiliary __auxiliary_unpriv
__naked void dummy_prog_24_socket(void)
{
asm volatile ("r0 = 24; exit;");
}
SEC("socket")
__auxiliary __auxiliary_unpriv
__naked void dummy_prog_loop1_socket(void)
{
asm volatile (" \
r3 = 1; \
r2 = %[map_prog1_socket] ll; \
call %[bpf_tail_call]; \
r0 = 41; \
exit; \
" :
: __imm(bpf_tail_call),
__imm_addr(map_prog1_socket)
: __clobber_all);
}
SEC("socket")
__description("unpriv: return pointer")
__success __failure_unpriv __msg_unpriv("R0 leaks addr")
__retval(POINTER_VALUE)
__naked void unpriv_return_pointer(void)
{
asm volatile (" \
r0 = r10; \
exit; \
" ::: __clobber_all);
}
SEC("socket")
__description("unpriv: add const to pointer")
__success __success_unpriv __retval(0)
__naked void unpriv_add_const_to_pointer(void)
{
asm volatile (" \
r1 += 8; \
r0 = 0; \
exit; \
" ::: __clobber_all);
}
SEC("socket")
__description("unpriv: add pointer to pointer")
__failure __msg("R1 pointer += pointer")
__failure_unpriv
__naked void unpriv_add_pointer_to_pointer(void)
{
asm volatile (" \
r1 += r10; \
r0 = 0; \
exit; \
" ::: __clobber_all);
}
SEC("socket")
__description("unpriv: neg pointer")
__success __failure_unpriv __msg_unpriv("R1 pointer arithmetic")
__retval(0)
__naked void unpriv_neg_pointer(void)
{
asm volatile (" \
r1 = -r1; \
r0 = 0; \
exit; \
" ::: __clobber_all);
}
SEC("socket")
__description("unpriv: cmp pointer with const")
__success __failure_unpriv __msg_unpriv("R1 pointer comparison")
__retval(0)
__naked void unpriv_cmp_pointer_with_const(void)
{
asm volatile (" \
if r1 == 0 goto l0_%=; \
l0_%=: r0 = 0; \
exit; \
" ::: __clobber_all);
}
SEC("socket")
__description("unpriv: cmp pointer with pointer")
__success __failure_unpriv __msg_unpriv("R10 pointer comparison")
__retval(0)
__naked void unpriv_cmp_pointer_with_pointer(void)
{
asm volatile (" \
if r1 == r10 goto l0_%=; \
l0_%=: r0 = 0; \
exit; \
" ::: __clobber_all);
}
SEC("tracepoint")
__description("unpriv: check that printk is disallowed")
__success
__naked void check_that_printk_is_disallowed(void)
{
asm volatile (" \
r1 = 0; \
*(u64*)(r10 - 8) = r1; \
r1 = r10; \
r1 += -8; \
r2 = 8; \
r3 = r1; \
call %[bpf_trace_printk]; \
r0 = 0; \
exit; \
" :
: __imm(bpf_trace_printk)
: __clobber_all);
}
SEC("socket")
__description("unpriv: pass pointer to helper function")
__success __failure_unpriv __msg_unpriv("R4 leaks addr")
__retval(0)
__naked void pass_pointer_to_helper_function(void)
{
asm volatile (" \
r1 = 0; \
*(u64*)(r10 - 8) = r1; \
r2 = r10; \
r2 += -8; \
r1 = %[map_hash_8b] ll; \
r3 = r2; \
r4 = r2; \
call %[bpf_map_update_elem]; \
r0 = 0; \
exit; \
" :
: __imm(bpf_map_update_elem),
__imm_addr(map_hash_8b)
: __clobber_all);
}
SEC("socket")
__description("unpriv: indirectly pass pointer on stack to helper function")
__success __failure_unpriv
__msg_unpriv("invalid read from stack R2 off -8+0 size 8")
__retval(0)
__naked void on_stack_to_helper_function(void)
{
asm volatile (" \
*(u64*)(r10 - 8) = r10; \
r2 = r10; \
r2 += -8; \
r1 = %[map_hash_8b] ll; \
call %[bpf_map_lookup_elem]; \
r0 = 0; \
exit; \
" :
: __imm(bpf_map_lookup_elem),
__imm_addr(map_hash_8b)
: __clobber_all);
}
SEC("socket")
__description("unpriv: mangle pointer on stack 1")
__success __failure_unpriv __msg_unpriv("attempt to corrupt spilled")
__retval(0)
__naked void mangle_pointer_on_stack_1(void)
{
asm volatile (" \
*(u64*)(r10 - 8) = r10; \
r0 = 0; \
*(u32*)(r10 - 8) = r0; \
r0 = 0; \
exit; \
" ::: __clobber_all);
}
SEC("socket")
__description("unpriv: mangle pointer on stack 2")
__success __failure_unpriv __msg_unpriv("attempt to corrupt spilled")
__retval(0)
__naked void mangle_pointer_on_stack_2(void)
{
asm volatile (" \
*(u64*)(r10 - 8) = r10; \
r0 = 0; \
*(u8*)(r10 - 1) = r0; \
r0 = 0; \
exit; \
" ::: __clobber_all);
}
SEC("socket")
__description("unpriv: read pointer from stack in small chunks")
__failure __msg("invalid size")
__failure_unpriv
__naked void from_stack_in_small_chunks(void)
{
asm volatile (" \
*(u64*)(r10 - 8) = r10; \
r0 = *(u32*)(r10 - 8); \
r0 = 0; \
exit; \
" ::: __clobber_all);
}
SEC("socket")
__description("unpriv: write pointer into ctx")
__failure __msg("invalid bpf_context access")
__failure_unpriv __msg_unpriv("R1 leaks addr")
__naked void unpriv_write_pointer_into_ctx(void)
{
asm volatile (" \
*(u64*)(r1 + 0) = r1; \
r0 = 0; \
exit; \
" ::: __clobber_all);
}
SEC("socket")
__description("unpriv: spill/fill of ctx")
__success __success_unpriv __retval(0)
__naked void unpriv_spill_fill_of_ctx(void)
{
asm volatile (" \
r6 = r10; \
r6 += -8; \
*(u64*)(r6 + 0) = r1; \
r1 = *(u64*)(r6 + 0); \
r0 = 0; \
exit; \
" ::: __clobber_all);
}
SEC("tc")
__description("unpriv: spill/fill of ctx 2")
__success __retval(0)
__naked void spill_fill_of_ctx_2(void)
{
asm volatile (" \
r6 = r10; \
r6 += -8; \
*(u64*)(r6 + 0) = r1; \
r1 = *(u64*)(r6 + 0); \
call %[bpf_get_hash_recalc]; \
r0 = 0; \
exit; \
" :
: __imm(bpf_get_hash_recalc)
: __clobber_all);
}
SEC("tc")
__description("unpriv: spill/fill of ctx 3")
__failure __msg("R1 type=fp expected=ctx")
__naked void spill_fill_of_ctx_3(void)
{
asm volatile (" \
r6 = r10; \
r6 += -8; \
*(u64*)(r6 + 0) = r1; \
*(u64*)(r6 + 0) = r10; \
r1 = *(u64*)(r6 + 0); \
call %[bpf_get_hash_recalc]; \
exit; \
" :
: __imm(bpf_get_hash_recalc)
: __clobber_all);
}
SEC("tc")
__description("unpriv: spill/fill of ctx 4")
__failure __msg("R1 type=scalar expected=ctx")
__naked void spill_fill_of_ctx_4(void)
{
asm volatile (" \
r6 = r10; \
r6 += -8; \
*(u64*)(r6 + 0) = r1; \
r0 = 1; \
lock *(u64 *)(r10 - 8) += r0; \
r1 = *(u64*)(r6 + 0); \
call %[bpf_get_hash_recalc]; \
exit; \
" :
: __imm(bpf_get_hash_recalc)
: __clobber_all);
}
SEC("tc")
__description("unpriv: spill/fill of different pointers stx")
__failure __msg("same insn cannot be used with different pointers")
__naked void fill_of_different_pointers_stx(void)
{
asm volatile (" \
r3 = 42; \
r6 = r10; \
r6 += -8; \
if r1 == 0 goto l0_%=; \
r2 = r10; \
r2 += -16; \
*(u64*)(r6 + 0) = r2; \
l0_%=: if r1 != 0 goto l1_%=; \
*(u64*)(r6 + 0) = r1; \
l1_%=: r1 = *(u64*)(r6 + 0); \
*(u32*)(r1 + %[__sk_buff_mark]) = r3; \
r0 = 0; \
exit; \
" :
: __imm_const(__sk_buff_mark, offsetof(struct __sk_buff, mark))
: __clobber_all);
}
/* Same as above, but use BPF_ST_MEM to save 42
* instead of BPF_STX_MEM.
*/
SEC("tc")
__description("unpriv: spill/fill of different pointers st")
__failure __msg("same insn cannot be used with different pointers")
__naked void fill_of_different_pointers_st(void)
{
asm volatile (" \
r6 = r10; \
r6 += -8; \
if r1 == 0 goto l0_%=; \
r2 = r10; \
r2 += -16; \
*(u64*)(r6 + 0) = r2; \
l0_%=: if r1 != 0 goto l1_%=; \
*(u64*)(r6 + 0) = r1; \
l1_%=: r1 = *(u64*)(r6 + 0); \
.8byte %[st_mem]; \
r0 = 0; \
exit; \
" :
: __imm_const(__sk_buff_mark, offsetof(struct __sk_buff, mark)),
__imm_insn(st_mem,
BPF_ST_MEM(BPF_W, BPF_REG_1, offsetof(struct __sk_buff, mark), 42))
: __clobber_all);
}
SEC("tc")
__description("unpriv: spill/fill of different pointers stx - ctx and sock")
__failure __msg("type=ctx expected=sock")
__naked void pointers_stx_ctx_and_sock(void)
{
asm volatile (" \
r8 = r1; \
/* struct bpf_sock *sock = bpf_sock_lookup(...); */\
" BPF_SK_LOOKUP(bpf_sk_lookup_tcp)
" r2 = r0; \
/* u64 foo; */ \
/* void *target = &foo; */ \
r6 = r10; \
r6 += -8; \
r1 = r8; \
/* if (skb == NULL) *target = sock; */ \
if r1 == 0 goto l0_%=; \
*(u64*)(r6 + 0) = r2; \
l0_%=: /* else *target = skb; */ \
if r1 != 0 goto l1_%=; \
*(u64*)(r6 + 0) = r1; \
l1_%=: /* struct __sk_buff *skb = *target; */ \
r1 = *(u64*)(r6 + 0); \
/* skb->mark = 42; */ \
r3 = 42; \
*(u32*)(r1 + %[__sk_buff_mark]) = r3; \
/* if (sk) bpf_sk_release(sk) */ \
if r1 == 0 goto l2_%=; \
call %[bpf_sk_release]; \
l2_%=: r0 = 0; \
exit; \
" :
: __imm(bpf_sk_lookup_tcp),
__imm(bpf_sk_release),
__imm_const(__sk_buff_mark, offsetof(struct __sk_buff, mark)),
__imm_const(sizeof_bpf_sock_tuple, sizeof(struct bpf_sock_tuple))
: __clobber_all);
}
SEC("tc")
__description("unpriv: spill/fill of different pointers stx - leak sock")
__failure
//.errstr = "same insn cannot be used with different pointers",
__msg("Unreleased reference")
__naked void different_pointers_stx_leak_sock(void)
{
asm volatile (" \
r8 = r1; \
/* struct bpf_sock *sock = bpf_sock_lookup(...); */\
" BPF_SK_LOOKUP(bpf_sk_lookup_tcp)
" r2 = r0; \
/* u64 foo; */ \
/* void *target = &foo; */ \
r6 = r10; \
r6 += -8; \
r1 = r8; \
/* if (skb == NULL) *target = sock; */ \
if r1 == 0 goto l0_%=; \
*(u64*)(r6 + 0) = r2; \
l0_%=: /* else *target = skb; */ \
if r1 != 0 goto l1_%=; \
*(u64*)(r6 + 0) = r1; \
l1_%=: /* struct __sk_buff *skb = *target; */ \
r1 = *(u64*)(r6 + 0); \
/* skb->mark = 42; */ \
r3 = 42; \
*(u32*)(r1 + %[__sk_buff_mark]) = r3; \
exit; \
" :
: __imm(bpf_sk_lookup_tcp),
__imm_const(__sk_buff_mark, offsetof(struct __sk_buff, mark)),
__imm_const(sizeof_bpf_sock_tuple, sizeof(struct bpf_sock_tuple))
: __clobber_all);
}
SEC("tc")
__description("unpriv: spill/fill of different pointers stx - sock and ctx (read)")
__failure __msg("same insn cannot be used with different pointers")
__naked void stx_sock_and_ctx_read(void)
{
asm volatile (" \
r8 = r1; \
/* struct bpf_sock *sock = bpf_sock_lookup(...); */\
" BPF_SK_LOOKUP(bpf_sk_lookup_tcp)
" r2 = r0; \
/* u64 foo; */ \
/* void *target = &foo; */ \
r6 = r10; \
r6 += -8; \
r1 = r8; \
/* if (skb) *target = skb */ \
if r1 == 0 goto l0_%=; \
*(u64*)(r6 + 0) = r1; \
l0_%=: /* else *target = sock */ \
if r1 != 0 goto l1_%=; \
*(u64*)(r6 + 0) = r2; \
l1_%=: /* struct bpf_sock *sk = *target; */ \
r1 = *(u64*)(r6 + 0); \
/* if (sk) u32 foo = sk->mark; bpf_sk_release(sk); */\
if r1 == 0 goto l2_%=; \
r3 = *(u32*)(r1 + %[bpf_sock_mark]); \
call %[bpf_sk_release]; \
l2_%=: r0 = 0; \
exit; \
" :
: __imm(bpf_sk_lookup_tcp),
__imm(bpf_sk_release),
__imm_const(bpf_sock_mark, offsetof(struct bpf_sock, mark)),
__imm_const(sizeof_bpf_sock_tuple, sizeof(struct bpf_sock_tuple))
: __clobber_all);
}
SEC("tc")
__description("unpriv: spill/fill of different pointers stx - sock and ctx (write)")
__failure
//.errstr = "same insn cannot be used with different pointers",
__msg("cannot write into sock")
__naked void stx_sock_and_ctx_write(void)
{
asm volatile (" \
r8 = r1; \
/* struct bpf_sock *sock = bpf_sock_lookup(...); */\
" BPF_SK_LOOKUP(bpf_sk_lookup_tcp)
" r2 = r0; \
/* u64 foo; */ \
/* void *target = &foo; */ \
r6 = r10; \
r6 += -8; \
r1 = r8; \
/* if (skb) *target = skb */ \
if r1 == 0 goto l0_%=; \
*(u64*)(r6 + 0) = r1; \
l0_%=: /* else *target = sock */ \
if r1 != 0 goto l1_%=; \
*(u64*)(r6 + 0) = r2; \
l1_%=: /* struct bpf_sock *sk = *target; */ \
r1 = *(u64*)(r6 + 0); \
/* if (sk) sk->mark = 42; bpf_sk_release(sk); */\
if r1 == 0 goto l2_%=; \
r3 = 42; \
*(u32*)(r1 + %[bpf_sock_mark]) = r3; \
call %[bpf_sk_release]; \
l2_%=: r0 = 0; \
exit; \
" :
: __imm(bpf_sk_lookup_tcp),
__imm(bpf_sk_release),
__imm_const(bpf_sock_mark, offsetof(struct bpf_sock, mark)),
__imm_const(sizeof_bpf_sock_tuple, sizeof(struct bpf_sock_tuple))
: __clobber_all);
}
SEC("socket")
__description("unpriv: write pointer into map elem value")
__success __failure_unpriv __msg_unpriv("R0 leaks addr")
__retval(0)
__naked void pointer_into_map_elem_value(void)
{
asm volatile (" \
r1 = 0; \
*(u64*)(r10 - 8) = r1; \
r2 = r10; \
r2 += -8; \
r1 = %[map_hash_8b] ll; \
call %[bpf_map_lookup_elem]; \
if r0 == 0 goto l0_%=; \
*(u64*)(r0 + 0) = r0; \
l0_%=: exit; \
" :
: __imm(bpf_map_lookup_elem),
__imm_addr(map_hash_8b)
: __clobber_all);
}
SEC("socket")
__description("alu32: mov u32 const")
__success __success_unpriv
__retval(0)
#ifdef SPEC_V1
__xlated_unpriv("if r0 == 0x0 goto pc+2")
__xlated_unpriv("nospec") /* inserted to prevent `R7 invalid mem access 'scalar'` */
__xlated_unpriv("goto pc-1") /* sanitized dead code */
__xlated_unpriv("exit")
#endif
__naked void alu32_mov_u32_const(void)
{
asm volatile (" \
w7 = 0; \
w7 &= 1; \
w0 = w7; \
if r0 == 0 goto l0_%=; \
r0 = *(u64*)(r7 + 0); \
l0_%=: exit; \
" ::: __clobber_all);
}
SEC("socket")
__description("unpriv: partial copy of pointer")
__success __failure_unpriv __msg_unpriv("R10 partial copy")
__retval(0)
__naked void unpriv_partial_copy_of_pointer(void)
{
asm volatile (" \
w1 = w10; \
r0 = 0; \
exit; \
" ::: __clobber_all);
}
SEC("socket")
__description("unpriv: pass pointer to tail_call")
__success __failure_unpriv __msg_unpriv("R3 leaks addr into helper")
__retval(0)
__naked void pass_pointer_to_tail_call(void)
{
asm volatile (" \
r3 = r1; \
r2 = %[map_prog1_socket] ll; \
call %[bpf_tail_call]; \
r0 = 0; \
exit; \
" :
: __imm(bpf_tail_call),
__imm_addr(map_prog1_socket)
: __clobber_all);
}
SEC("socket")
__description("unpriv: cmp map pointer with zero")
__success __success_unpriv
__retval(0)
__naked void cmp_map_pointer_with_zero(void)
{
asm volatile (" \
r1 = %[map_hash_8b] ll; \
if r1 == 0 goto l0_%=; \
l0_%=: r0 = 0; \
exit; \
" :
: __imm_addr(map_hash_8b)
: __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")
__failure_unpriv
__naked void unpriv_write_into_frame_pointer(void)
{
asm volatile (" \
r10 = r1; \
r0 = 0; \
exit; \
" ::: __clobber_all);
}
SEC("socket")
__description("unpriv: spill/fill frame pointer")
__failure __msg("frame pointer is read only")
__failure_unpriv
__naked void unpriv_spill_fill_frame_pointer(void)
{
asm volatile (" \
r6 = r10; \
r6 += -8; \
*(u64*)(r6 + 0) = r10; \
r10 = *(u64*)(r6 + 0); \
r0 = 0; \
exit; \
" ::: __clobber_all);
}
SEC("socket")
__description("unpriv: cmp of frame pointer")
__success __failure_unpriv __msg_unpriv("R10 pointer comparison")
__retval(0)
__naked void unpriv_cmp_of_frame_pointer(void)
{
asm volatile (" \
if r10 == 0 goto l0_%=; \
l0_%=: r0 = 0; \
exit; \
" ::: __clobber_all);
}
SEC("socket")
__description("unpriv: adding of fp, reg")
__success __failure_unpriv
__msg_unpriv("R1 stack pointer arithmetic goes out of range")
__retval(0)
__naked void unpriv_adding_of_fp_reg(void)
{
asm volatile (" \
r0 = 0; \
r1 = 0; \
r1 += r10; \
*(u64*)(r1 - 8) = r0; \
exit; \
" ::: __clobber_all);
}
SEC("socket")
__description("unpriv: adding of fp, imm")
__success __failure_unpriv
__msg_unpriv("R1 stack pointer arithmetic goes out of range")
__retval(0)
__naked void unpriv_adding_of_fp_imm(void)
{
asm volatile (" \
r0 = 0; \
r1 = r10; \
r1 += 0; \
*(u64*)(r1 - 8) = r0; \
exit; \
" ::: __clobber_all);
}
SEC("socket")
__description("unpriv: cmp of stack pointer")
__success __failure_unpriv __msg_unpriv("R2 pointer comparison")
__retval(0)
__naked void unpriv_cmp_of_stack_pointer(void)
{
asm volatile (" \
r2 = r10; \
r2 += -8; \
if r2 == 0 goto l0_%=; \
l0_%=: r0 = 0; \
exit; \
" ::: __clobber_all);
}
SEC("socket")
__description("unpriv: Spectre v1 path-based type confusion of scalar as stack-ptr")
__success __success_unpriv __retval(0)
#ifdef SPEC_V1
__xlated_unpriv("if r0 != 0x1 goto pc+2")
/* This nospec prevents the exploit because it forces the mispredicted (not
* taken) `if r0 != 0x0 goto l0_%=` to resolve before using r6 as a pointer.
* This causes the CPU to realize that `r6 = r9` should have never executed. It
* ensures that r6 always contains a readable stack slot ptr when the insn after
* the nospec executes.
*/
__xlated_unpriv("nospec")
__xlated_unpriv("r9 = *(u8 *)(r6 +0)")
#endif
__naked void unpriv_spec_v1_type_confusion(void)
{
asm volatile (" \
r1 = 0; \
*(u64*)(r10 - 8) = r1; \
r2 = r10; \
r2 += -8; \
r1 = %[map_hash_8b] ll; \
call %[bpf_map_lookup_elem]; \
if r0 == 0 goto l2_%=; \
/* r0: pointer to a map array entry */ \
r2 = r10; \
r2 += -8; \
r1 = %[map_hash_8b] ll; \
/* r1, r2: prepared call args */ \
r6 = r10; \
r6 += -8; \
/* r6: pointer to readable stack slot */ \
r9 = 0xffffc900; \
r9 <<= 32; \
/* r9: scalar controlled by attacker */ \
r0 = *(u64 *)(r0 + 0); /* cache miss */ \
if r0 != 0x0 goto l0_%=; \
r6 = r9; \
l0_%=: if r0 != 0x1 goto l1_%=; \
r9 = *(u8 *)(r6 + 0); \
l1_%=: /* leak r9 */ \
r9 &= 1; \
r9 <<= 9; \
*(u64*)(r10 - 8) = r9; \
call %[bpf_map_lookup_elem]; \
if r0 == 0 goto l2_%=; \
/* leak secret into is_cached(map[0|512]): */ \
r0 = *(u64 *)(r0 + 0); \
l2_%=: \
r0 = 0; \
exit; \
" :
: __imm(bpf_map_lookup_elem),
__imm_addr(map_hash_8b)
: __clobber_all);
}
SEC("socket")
__description("unpriv: ldimm64 before Spectre v4 barrier")
__success __success_unpriv
__retval(0)
#ifdef SPEC_V4
__xlated_unpriv("r1 = 0x2020200005642020") /* should not matter */
__xlated_unpriv("*(u64 *)(r10 -8) = r1")
__xlated_unpriv("nospec")
#endif
__naked void unpriv_ldimm64_spectre_v4(void)
{
asm volatile (" \
r1 = 0x2020200005642020 ll; \
*(u64 *)(r10 -8) = r1; \
r0 = 0; \
exit; \
" ::: __clobber_all);
}
SEC("socket")
__description("unpriv: Spectre v1 and v4 barrier")
__success __success_unpriv
__retval(0)
#ifdef SPEC_V1
#ifdef SPEC_V4
/* starts with r0 == r8 == r9 == 0 */
__xlated_unpriv("if r8 != 0x0 goto pc+1")
__xlated_unpriv("goto pc+2")
__xlated_unpriv("if r9 == 0x0 goto pc+4")
__xlated_unpriv("r2 = r0")
/* Following nospec required to prevent following dangerous `*(u64 *)(NOT_FP -64)
* = r1` iff `if r9 == 0 goto pc+4` was mispredicted because of Spectre v1. The
* test therefore ensures the Spectre-v4--induced nospec does not prevent the
* Spectre-v1--induced speculative path from being fully analyzed.
*/
__xlated_unpriv("nospec") /* Spectre v1 */
__xlated_unpriv("*(u64 *)(r2 -64) = r1") /* could be used to leak r2 */
__xlated_unpriv("nospec") /* Spectre v4 */
#endif
#endif
__naked void unpriv_spectre_v1_and_v4(void)
{
asm volatile (" \
r1 = 0; \
*(u64*)(r10 - 8) = r1; \
r2 = r10; \
r2 += -8; \
r1 = %[map_hash_8b] ll; \
call %[bpf_map_lookup_elem]; \
r8 = r0; \
r2 = r10; \
r2 += -8; \
r1 = %[map_hash_8b] ll; \
call %[bpf_map_lookup_elem]; \
r9 = r0; \
r0 = r10; \
r1 = 0; \
r2 = r10; \
if r8 != 0 goto l0_%=; \
if r9 != 0 goto l0_%=; \
r0 = 0; \
l0_%=: if r8 != 0 goto l1_%=; \
goto l2_%=; \
l1_%=: if r9 == 0 goto l3_%=; \
r2 = r0; \
l2_%=: *(u64 *)(r2 -64) = r1; \
l3_%=: r0 = 0; \
exit; \
" :
: __imm(bpf_map_lookup_elem),
__imm_addr(map_hash_8b)
: __clobber_all);
}
SEC("socket")
__description("unpriv: Spectre v1 and v4 barrier (simple)")
__success __success_unpriv
__retval(0)
#ifdef SPEC_V1
#ifdef SPEC_V4
__xlated_unpriv("if r8 != 0x0 goto pc+1")
__xlated_unpriv("goto pc+2")
__xlated_unpriv("goto pc-1") /* if r9 == 0 goto l3_%= */
__xlated_unpriv("goto pc-1") /* r2 = r0 */
__xlated_unpriv("nospec")
__xlated_unpriv("*(u64 *)(r2 -64) = r1")
__xlated_unpriv("nospec")
#endif
#endif
__naked void unpriv_spectre_v1_and_v4_simple(void)
{
asm volatile (" \
r8 = 0; \
r9 = 0; \
r0 = r10; \
r1 = 0; \
r2 = r10; \
if r8 != 0 goto l0_%=; \
if r9 != 0 goto l0_%=; \
r0 = 0; \
l0_%=: if r8 != 0 goto l1_%=; \
goto l2_%=; \
l1_%=: if r9 == 0 goto l3_%=; \
r2 = r0; \
l2_%=: *(u64 *)(r2 -64) = r1; \
l3_%=: r0 = 0; \
exit; \
" ::: __clobber_all);
}
SEC("socket")
__description("unpriv: ldimm64 before Spectre v1 and v4 barrier (simple)")
__success __success_unpriv
__retval(0)
#ifdef SPEC_V1
#ifdef SPEC_V4
__xlated_unpriv("if r8 != 0x0 goto pc+1")
__xlated_unpriv("goto pc+4")
__xlated_unpriv("goto pc-1") /* if r9 == 0 goto l3_%= */
__xlated_unpriv("goto pc-1") /* r2 = r0 */
__xlated_unpriv("goto pc-1") /* r1 = 0x2020200005642020 ll */
__xlated_unpriv("goto pc-1") /* second part of ldimm64 */
__xlated_unpriv("nospec")
__xlated_unpriv("*(u64 *)(r2 -64) = r1")
__xlated_unpriv("nospec")
#endif
#endif
__naked void unpriv_ldimm64_spectre_v1_and_v4_simple(void)
{
asm volatile (" \
r8 = 0; \
r9 = 0; \
r0 = r10; \
r1 = 0; \
r2 = r10; \
if r8 != 0 goto l0_%=; \
if r9 != 0 goto l0_%=; \
r0 = 0; \
l0_%=: if r8 != 0 goto l1_%=; \
goto l2_%=; \
l1_%=: if r9 == 0 goto l3_%=; \
r2 = r0; \
r1 = 0x2020200005642020 ll; \
l2_%=: *(u64 *)(r2 -64) = r1; \
l3_%=: r0 = 0; \
exit; \
" ::: __clobber_all);
}
char _license[] SEC("license") = "GPL";
Reference in a new issue View git blame Copy permalink