454 lines
13 KiB
C
454 lines
13 KiB
C
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// SPDX-License-Identifier: GPL-2.0
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/* Converted from tools/testing/selftests/bpf/verifier/spill_fill.c */
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#include <linux/bpf.h>
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#include <bpf/bpf_helpers.h>
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#include "bpf_misc.h"
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struct {
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__uint(type, BPF_MAP_TYPE_RINGBUF);
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__uint(max_entries, 4096);
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} map_ringbuf SEC(".maps");
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SEC("socket")
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__description("check valid spill/fill")
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__success __failure_unpriv __msg_unpriv("R0 leaks addr")
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__retval(POINTER_VALUE)
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__naked void check_valid_spill_fill(void)
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{
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asm volatile (" \
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/* spill R1(ctx) into stack */ \
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*(u64*)(r10 - 8) = r1; \
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/* fill it back into R2 */ \
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r2 = *(u64*)(r10 - 8); \
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/* should be able to access R0 = *(R2 + 8) */ \
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/* BPF_LDX_MEM(BPF_DW, BPF_REG_0, BPF_REG_2, 8), */\
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r0 = r2; \
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exit; \
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" ::: __clobber_all);
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}
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SEC("socket")
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__description("check valid spill/fill, skb mark")
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__success __success_unpriv __retval(0)
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__naked void valid_spill_fill_skb_mark(void)
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{
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asm volatile (" \
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r6 = r1; \
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*(u64*)(r10 - 8) = r6; \
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r0 = *(u64*)(r10 - 8); \
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r0 = *(u32*)(r0 + %[__sk_buff_mark]); \
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exit; \
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" :
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: __imm_const(__sk_buff_mark, offsetof(struct __sk_buff, mark))
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: __clobber_all);
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}
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SEC("socket")
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__description("check valid spill/fill, ptr to mem")
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__success __success_unpriv __retval(0)
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__naked void spill_fill_ptr_to_mem(void)
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{
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asm volatile (" \
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/* reserve 8 byte ringbuf memory */ \
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r1 = 0; \
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*(u64*)(r10 - 8) = r1; \
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r1 = %[map_ringbuf] ll; \
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r2 = 8; \
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r3 = 0; \
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call %[bpf_ringbuf_reserve]; \
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/* store a pointer to the reserved memory in R6 */\
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r6 = r0; \
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/* check whether the reservation was successful */\
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if r0 == 0 goto l0_%=; \
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/* spill R6(mem) into the stack */ \
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*(u64*)(r10 - 8) = r6; \
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/* fill it back in R7 */ \
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r7 = *(u64*)(r10 - 8); \
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/* should be able to access *(R7) = 0 */ \
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r1 = 0; \
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*(u64*)(r7 + 0) = r1; \
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/* submit the reserved ringbuf memory */ \
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r1 = r7; \
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r2 = 0; \
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call %[bpf_ringbuf_submit]; \
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l0_%=: r0 = 0; \
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exit; \
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" :
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: __imm(bpf_ringbuf_reserve),
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__imm(bpf_ringbuf_submit),
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__imm_addr(map_ringbuf)
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: __clobber_all);
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}
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SEC("socket")
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__description("check with invalid reg offset 0")
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__failure __msg("R0 pointer arithmetic on ringbuf_mem_or_null prohibited")
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__failure_unpriv
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__naked void with_invalid_reg_offset_0(void)
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{
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asm volatile (" \
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/* reserve 8 byte ringbuf memory */ \
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r1 = 0; \
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*(u64*)(r10 - 8) = r1; \
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r1 = %[map_ringbuf] ll; \
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r2 = 8; \
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r3 = 0; \
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call %[bpf_ringbuf_reserve]; \
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/* store a pointer to the reserved memory in R6 */\
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r6 = r0; \
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/* add invalid offset to memory or NULL */ \
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r0 += 1; \
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/* check whether the reservation was successful */\
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if r0 == 0 goto l0_%=; \
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/* should not be able to access *(R7) = 0 */ \
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r1 = 0; \
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*(u32*)(r6 + 0) = r1; \
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/* submit the reserved ringbuf memory */ \
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r1 = r6; \
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r2 = 0; \
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call %[bpf_ringbuf_submit]; \
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l0_%=: r0 = 0; \
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exit; \
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" :
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: __imm(bpf_ringbuf_reserve),
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__imm(bpf_ringbuf_submit),
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__imm_addr(map_ringbuf)
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: __clobber_all);
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}
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SEC("socket")
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__description("check corrupted spill/fill")
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__failure __msg("R0 invalid mem access 'scalar'")
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__msg_unpriv("attempt to corrupt spilled")
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__flag(BPF_F_ANY_ALIGNMENT)
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__naked void check_corrupted_spill_fill(void)
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{
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asm volatile (" \
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/* spill R1(ctx) into stack */ \
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*(u64*)(r10 - 8) = r1; \
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/* mess up with R1 pointer on stack */ \
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r0 = 0x23; \
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*(u8*)(r10 - 7) = r0; \
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/* fill back into R0 is fine for priv. \
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* R0 now becomes SCALAR_VALUE. \
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*/ \
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r0 = *(u64*)(r10 - 8); \
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/* Load from R0 should fail. */ \
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r0 = *(u64*)(r0 + 8); \
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exit; \
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" ::: __clobber_all);
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}
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SEC("socket")
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__description("check corrupted spill/fill, LSB")
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__success __failure_unpriv __msg_unpriv("attempt to corrupt spilled")
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__retval(POINTER_VALUE)
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__naked void check_corrupted_spill_fill_lsb(void)
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{
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asm volatile (" \
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*(u64*)(r10 - 8) = r1; \
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r0 = 0xcafe; \
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*(u16*)(r10 - 8) = r0; \
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r0 = *(u64*)(r10 - 8); \
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exit; \
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" ::: __clobber_all);
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}
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SEC("socket")
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__description("check corrupted spill/fill, MSB")
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__success __failure_unpriv __msg_unpriv("attempt to corrupt spilled")
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__retval(POINTER_VALUE)
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__naked void check_corrupted_spill_fill_msb(void)
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{
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asm volatile (" \
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*(u64*)(r10 - 8) = r1; \
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r0 = 0x12345678; \
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*(u32*)(r10 - 4) = r0; \
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r0 = *(u64*)(r10 - 8); \
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exit; \
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" ::: __clobber_all);
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}
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SEC("tc")
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__description("Spill and refill a u32 const scalar. Offset to skb->data")
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__success __retval(0)
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__naked void scalar_offset_to_skb_data_1(void)
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{
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asm volatile (" \
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r2 = *(u32*)(r1 + %[__sk_buff_data]); \
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r3 = *(u32*)(r1 + %[__sk_buff_data_end]); \
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w4 = 20; \
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*(u32*)(r10 - 8) = r4; \
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r4 = *(u32*)(r10 - 8); \
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r0 = r2; \
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/* r0 += r4 R0=pkt R2=pkt R3=pkt_end R4=20 */ \
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r0 += r4; \
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/* if (r0 > r3) R0=pkt,off=20 R2=pkt R3=pkt_end R4=20 */\
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if r0 > r3 goto l0_%=; \
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/* r0 = *(u32 *)r2 R0=pkt,off=20,r=20 R2=pkt,r=20 R3=pkt_end R4=20 */\
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r0 = *(u32*)(r2 + 0); \
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l0_%=: r0 = 0; \
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exit; \
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" :
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: __imm_const(__sk_buff_data, offsetof(struct __sk_buff, data)),
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__imm_const(__sk_buff_data_end, offsetof(struct __sk_buff, data_end))
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: __clobber_all);
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}
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SEC("socket")
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__description("Spill a u32 const, refill from another half of the uninit u32 from the stack")
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/* in privileged mode reads from uninitialized stack locations are permitted */
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__success __failure_unpriv
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__msg_unpriv("invalid read from stack off -4+0 size 4")
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__retval(0)
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__naked void uninit_u32_from_the_stack(void)
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{
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asm volatile (" \
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w4 = 20; \
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*(u32*)(r10 - 8) = r4; \
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/* r4 = *(u32 *)(r10 -4) fp-8=????rrrr*/ \
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r4 = *(u32*)(r10 - 4); \
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r0 = 0; \
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exit; \
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" ::: __clobber_all);
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}
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SEC("tc")
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__description("Spill a u32 const scalar. Refill as u16. Offset to skb->data")
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__failure __msg("invalid access to packet")
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__naked void u16_offset_to_skb_data(void)
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{
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asm volatile (" \
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r2 = *(u32*)(r1 + %[__sk_buff_data]); \
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r3 = *(u32*)(r1 + %[__sk_buff_data_end]); \
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w4 = 20; \
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*(u32*)(r10 - 8) = r4; \
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r4 = *(u16*)(r10 - 8); \
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r0 = r2; \
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/* r0 += r4 R0=pkt R2=pkt R3=pkt_end R4=umax=65535 */\
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r0 += r4; \
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/* if (r0 > r3) R0=pkt,umax=65535 R2=pkt R3=pkt_end R4=umax=65535 */\
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if r0 > r3 goto l0_%=; \
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/* r0 = *(u32 *)r2 R0=pkt,umax=65535 R2=pkt R3=pkt_end R4=20 */\
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r0 = *(u32*)(r2 + 0); \
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l0_%=: r0 = 0; \
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exit; \
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" :
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: __imm_const(__sk_buff_data, offsetof(struct __sk_buff, data)),
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__imm_const(__sk_buff_data_end, offsetof(struct __sk_buff, data_end))
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: __clobber_all);
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}
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SEC("tc")
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__description("Spill u32 const scalars. Refill as u64. Offset to skb->data")
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__failure __msg("invalid access to packet")
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__naked void u64_offset_to_skb_data(void)
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{
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asm volatile (" \
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r2 = *(u32*)(r1 + %[__sk_buff_data]); \
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r3 = *(u32*)(r1 + %[__sk_buff_data_end]); \
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w6 = 0; \
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w7 = 20; \
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*(u32*)(r10 - 4) = r6; \
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*(u32*)(r10 - 8) = r7; \
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r4 = *(u16*)(r10 - 8); \
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r0 = r2; \
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/* r0 += r4 R0=pkt R2=pkt R3=pkt_end R4=umax=65535 */\
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r0 += r4; \
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/* if (r0 > r3) R0=pkt,umax=65535 R2=pkt R3=pkt_end R4=umax=65535 */\
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if r0 > r3 goto l0_%=; \
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/* r0 = *(u32 *)r2 R0=pkt,umax=65535 R2=pkt R3=pkt_end R4=20 */\
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r0 = *(u32*)(r2 + 0); \
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l0_%=: r0 = 0; \
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exit; \
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" :
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: __imm_const(__sk_buff_data, offsetof(struct __sk_buff, data)),
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__imm_const(__sk_buff_data_end, offsetof(struct __sk_buff, data_end))
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: __clobber_all);
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}
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SEC("tc")
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__description("Spill a u32 const scalar. Refill as u16 from fp-6. Offset to skb->data")
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__failure __msg("invalid access to packet")
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__naked void _6_offset_to_skb_data(void)
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{
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asm volatile (" \
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r2 = *(u32*)(r1 + %[__sk_buff_data]); \
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r3 = *(u32*)(r1 + %[__sk_buff_data_end]); \
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w4 = 20; \
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*(u32*)(r10 - 8) = r4; \
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r4 = *(u16*)(r10 - 6); \
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r0 = r2; \
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/* r0 += r4 R0=pkt R2=pkt R3=pkt_end R4=umax=65535 */\
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r0 += r4; \
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/* if (r0 > r3) R0=pkt,umax=65535 R2=pkt R3=pkt_end R4=umax=65535 */\
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if r0 > r3 goto l0_%=; \
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/* r0 = *(u32 *)r2 R0=pkt,umax=65535 R2=pkt R3=pkt_end R4=20 */\
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r0 = *(u32*)(r2 + 0); \
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l0_%=: r0 = 0; \
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exit; \
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" :
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: __imm_const(__sk_buff_data, offsetof(struct __sk_buff, data)),
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__imm_const(__sk_buff_data_end, offsetof(struct __sk_buff, data_end))
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: __clobber_all);
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}
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SEC("tc")
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__description("Spill and refill a u32 const scalar at non 8byte aligned stack addr. Offset to skb->data")
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__failure __msg("invalid access to packet")
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__naked void addr_offset_to_skb_data(void)
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{
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asm volatile (" \
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r2 = *(u32*)(r1 + %[__sk_buff_data]); \
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r3 = *(u32*)(r1 + %[__sk_buff_data_end]); \
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w4 = 20; \
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*(u32*)(r10 - 8) = r4; \
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*(u32*)(r10 - 4) = r4; \
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r4 = *(u32*)(r10 - 4); \
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r0 = r2; \
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/* r0 += r4 R0=pkt R2=pkt R3=pkt_end R4=umax=U32_MAX */\
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r0 += r4; \
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/* if (r0 > r3) R0=pkt,umax=U32_MAX R2=pkt R3=pkt_end R4= */\
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if r0 > r3 goto l0_%=; \
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/* r0 = *(u32 *)r2 R0=pkt,umax=U32_MAX R2=pkt R3=pkt_end R4= */\
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r0 = *(u32*)(r2 + 0); \
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l0_%=: r0 = 0; \
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exit; \
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" :
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: __imm_const(__sk_buff_data, offsetof(struct __sk_buff, data)),
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__imm_const(__sk_buff_data_end, offsetof(struct __sk_buff, data_end))
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: __clobber_all);
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}
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SEC("tc")
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__description("Spill and refill a umax=40 bounded scalar. Offset to skb->data")
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__success __retval(0)
|
||
|
|
__naked void scalar_offset_to_skb_data_2(void)
|
||
|
|
{
|
||
|
|
asm volatile (" \
|
||
|
|
r2 = *(u32*)(r1 + %[__sk_buff_data]); \
|
||
|
|
r3 = *(u32*)(r1 + %[__sk_buff_data_end]); \
|
||
|
|
r4 = *(u64*)(r1 + %[__sk_buff_tstamp]); \
|
||
|
|
if r4 <= 40 goto l0_%=; \
|
||
|
|
r0 = 0; \
|
||
|
|
exit; \
|
||
|
|
l0_%=: /* *(u32 *)(r10 -8) = r4 R4=umax=40 */ \
|
||
|
|
*(u32*)(r10 - 8) = r4; \
|
||
|
|
/* r4 = (*u32 *)(r10 - 8) */ \
|
||
|
|
r4 = *(u32*)(r10 - 8); \
|
||
|
|
/* r2 += r4 R2=pkt R4=umax=40 */ \
|
||
|
|
r2 += r4; \
|
||
|
|
/* r0 = r2 R2=pkt,umax=40 R4=umax=40 */ \
|
||
|
|
r0 = r2; \
|
||
|
|
/* r2 += 20 R0=pkt,umax=40 R2=pkt,umax=40 */ \
|
||
|
|
r2 += 20; \
|
||
|
|
/* if (r2 > r3) R0=pkt,umax=40 R2=pkt,off=20,umax=40 */\
|
||
|
|
if r2 > r3 goto l1_%=; \
|
||
|
|
/* r0 = *(u32 *)r0 R0=pkt,r=20,umax=40 R2=pkt,off=20,r=20,umax=40 */\
|
||
|
|
r0 = *(u32*)(r0 + 0); \
|
||
|
|
l1_%=: r0 = 0; \
|
||
|
|
exit; \
|
||
|
|
" :
|
||
|
|
: __imm_const(__sk_buff_data, offsetof(struct __sk_buff, data)),
|
||
|
|
__imm_const(__sk_buff_data_end, offsetof(struct __sk_buff, data_end)),
|
||
|
|
__imm_const(__sk_buff_tstamp, offsetof(struct __sk_buff, tstamp))
|
||
|
|
: __clobber_all);
|
||
|
|
}
|
||
|
|
|
||
|
|
SEC("tc")
|
||
|
|
__description("Spill a u32 scalar at fp-4 and then at fp-8")
|
||
|
|
__success __retval(0)
|
||
|
|
__naked void and_then_at_fp_8(void)
|
||
|
|
{
|
||
|
|
asm volatile (" \
|
||
|
|
w4 = 4321; \
|
||
|
|
*(u32*)(r10 - 4) = r4; \
|
||
|
|
*(u32*)(r10 - 8) = r4; \
|
||
|
|
r4 = *(u64*)(r10 - 8); \
|
||
|
|
r0 = 0; \
|
||
|
|
exit; \
|
||
|
|
" ::: __clobber_all);
|
||
|
|
}
|
||
|
|
|
||
|
|
SEC("xdp")
|
||
|
|
__description("32-bit spill of 64-bit reg should clear ID")
|
||
|
|
__failure __msg("math between ctx pointer and 4294967295 is not allowed")
|
||
|
|
__naked void spill_32bit_of_64bit_fail(void)
|
||
|
|
{
|
||
|
|
asm volatile (" \
|
||
|
|
r6 = r1; \
|
||
|
|
/* Roll one bit to force the verifier to track both branches. */\
|
||
|
|
call %[bpf_get_prandom_u32]; \
|
||
|
|
r0 &= 0x8; \
|
||
|
|
/* Put a large number into r1. */ \
|
||
|
|
r1 = 0xffffffff; \
|
||
|
|
r1 <<= 32; \
|
||
|
|
r1 += r0; \
|
||
|
|
/* Assign an ID to r1. */ \
|
||
|
|
r2 = r1; \
|
||
|
|
/* 32-bit spill r1 to stack - should clear the ID! */\
|
||
|
|
*(u32*)(r10 - 8) = r1; \
|
||
|
|
/* 32-bit fill r2 from stack. */ \
|
||
|
|
r2 = *(u32*)(r10 - 8); \
|
||
|
|
/* Compare r2 with another register to trigger find_equal_scalars.\
|
||
|
|
* Having one random bit is important here, otherwise the verifier cuts\
|
||
|
|
* the corners. If the ID was mistakenly preserved on spill, this would\
|
||
|
|
* cause the verifier to think that r1 is also equal to zero in one of\
|
||
|
|
* the branches, and equal to eight on the other branch.\
|
||
|
|
*/ \
|
||
|
|
r3 = 0; \
|
||
|
|
if r2 != r3 goto l0_%=; \
|
||
|
|
l0_%=: r1 >>= 32; \
|
||
|
|
/* At this point, if the verifier thinks that r1 is 0, an out-of-bounds\
|
||
|
|
* read will happen, because it actually contains 0xffffffff.\
|
||
|
|
*/ \
|
||
|
|
r6 += r1; \
|
||
|
|
r0 = *(u32*)(r6 + 0); \
|
||
|
|
exit; \
|
||
|
|
" :
|
||
|
|
: __imm(bpf_get_prandom_u32)
|
||
|
|
: __clobber_all);
|
||
|
|
}
|
||
|
|
|
||
|
|
SEC("xdp")
|
||
|
|
__description("16-bit spill of 32-bit reg should clear ID")
|
||
|
|
__failure __msg("dereference of modified ctx ptr R6 off=65535 disallowed")
|
||
|
|
__naked void spill_16bit_of_32bit_fail(void)
|
||
|
|
{
|
||
|
|
asm volatile (" \
|
||
|
|
r6 = r1; \
|
||
|
|
/* Roll one bit to force the verifier to track both branches. */\
|
||
|
|
call %[bpf_get_prandom_u32]; \
|
||
|
|
r0 &= 0x8; \
|
||
|
|
/* Put a large number into r1. */ \
|
||
|
|
w1 = 0xffff0000; \
|
||
|
|
r1 += r0; \
|
||
|
|
/* Assign an ID to r1. */ \
|
||
|
|
r2 = r1; \
|
||
|
|
/* 16-bit spill r1 to stack - should clear the ID! */\
|
||
|
|
*(u16*)(r10 - 8) = r1; \
|
||
|
|
/* 16-bit fill r2 from stack. */ \
|
||
|
|
r2 = *(u16*)(r10 - 8); \
|
||
|
|
/* Compare r2 with another register to trigger find_equal_scalars.\
|
||
|
|
* Having one random bit is important here, otherwise the verifier cuts\
|
||
|
|
* the corners. If the ID was mistakenly preserved on spill, this would\
|
||
|
|
* cause the verifier to think that r1 is also equal to zero in one of\
|
||
|
|
* the branches, and equal to eight on the other branch.\
|
||
|
|
*/ \
|
||
|
|
r3 = 0; \
|
||
|
|
if r2 != r3 goto l0_%=; \
|
||
|
|
l0_%=: r1 >>= 16; \
|
||
|
|
/* At this point, if the verifier thinks that r1 is 0, an out-of-bounds\
|
||
|
|
* read will happen, because it actually contains 0xffff.\
|
||
|
|
*/ \
|
||
|
|
r6 += r1; \
|
||
|
|
r0 = *(u32*)(r6 + 0); \
|
||
|
|
exit; \
|
||
|
|
" :
|
||
|
|
: __imm(bpf_get_prandom_u32)
|
||
|
|
: __clobber_all);
|
||
|
|
}
|
||
|
|
|
||
|
|
char _license[] SEC("license") = "GPL";
|