// SPDX-License-Identifier: GPL-2.0 /* Converted from tools/testing/selftests/bpf/verifier/spill_fill.c */ #include #include #include "bpf_misc.h" struct { __uint(type, BPF_MAP_TYPE_RINGBUF); __uint(max_entries, 4096); } map_ringbuf SEC(".maps"); SEC("socket") __description("check valid spill/fill") __success __failure_unpriv __msg_unpriv("R0 leaks addr") __retval(POINTER_VALUE) __naked void check_valid_spill_fill(void) { asm volatile (" \ /* spill R1(ctx) into stack */ \ *(u64*)(r10 - 8) = r1; \ /* fill it back into R2 */ \ r2 = *(u64*)(r10 - 8); \ /* should be able to access R0 = *(R2 + 8) */ \ /* BPF_LDX_MEM(BPF_DW, BPF_REG_0, BPF_REG_2, 8), */\ r0 = r2; \ exit; \ " ::: __clobber_all); } SEC("socket") __description("check valid spill/fill, skb mark") __success __success_unpriv __retval(0) __naked void valid_spill_fill_skb_mark(void) { asm volatile (" \ r6 = r1; \ *(u64*)(r10 - 8) = r6; \ r0 = *(u64*)(r10 - 8); \ r0 = *(u32*)(r0 + %[__sk_buff_mark]); \ exit; \ " : : __imm_const(__sk_buff_mark, offsetof(struct __sk_buff, mark)) : __clobber_all); } SEC("socket") __description("check valid spill/fill, ptr to mem") __success __success_unpriv __retval(0) __naked void spill_fill_ptr_to_mem(void) { asm volatile (" \ /* reserve 8 byte ringbuf memory */ \ r1 = 0; \ *(u64*)(r10 - 8) = r1; \ r1 = %[map_ringbuf] ll; \ r2 = 8; \ r3 = 0; \ call %[bpf_ringbuf_reserve]; \ /* store a pointer to the reserved memory in R6 */\ r6 = r0; \ /* check whether the reservation was successful */\ if r0 == 0 goto l0_%=; \ /* spill R6(mem) into the stack */ \ *(u64*)(r10 - 8) = r6; \ /* fill it back in R7 */ \ r7 = *(u64*)(r10 - 8); \ /* should be able to access *(R7) = 0 */ \ r1 = 0; \ *(u64*)(r7 + 0) = r1; \ /* submit the reserved ringbuf memory */ \ r1 = r7; \ r2 = 0; \ call %[bpf_ringbuf_submit]; \ l0_%=: r0 = 0; \ exit; \ " : : __imm(bpf_ringbuf_reserve), __imm(bpf_ringbuf_submit), __imm_addr(map_ringbuf) : __clobber_all); } SEC("socket") __description("check with invalid reg offset 0") __failure __msg("R0 pointer arithmetic on ringbuf_mem_or_null prohibited") __failure_unpriv __naked void with_invalid_reg_offset_0(void) { asm volatile (" \ /* reserve 8 byte ringbuf memory */ \ r1 = 0; \ *(u64*)(r10 - 8) = r1; \ r1 = %[map_ringbuf] ll; \ r2 = 8; \ r3 = 0; \ call %[bpf_ringbuf_reserve]; \ /* store a pointer to the reserved memory in R6 */\ r6 = r0; \ /* add invalid offset to memory or NULL */ \ r0 += 1; \ /* check whether the reservation was successful */\ if r0 == 0 goto l0_%=; \ /* should not be able to access *(R7) = 0 */ \ r1 = 0; \ *(u32*)(r6 + 0) = r1; \ /* submit the reserved ringbuf memory */ \ r1 = r6; \ r2 = 0; \ call %[bpf_ringbuf_submit]; \ l0_%=: r0 = 0; \ exit; \ " : : __imm(bpf_ringbuf_reserve), __imm(bpf_ringbuf_submit), __imm_addr(map_ringbuf) : __clobber_all); } SEC("socket") __description("check corrupted spill/fill") __failure __msg("R0 invalid mem access 'scalar'") __msg_unpriv("attempt to corrupt spilled") __flag(BPF_F_ANY_ALIGNMENT) __naked void check_corrupted_spill_fill(void) { asm volatile (" \ /* spill R1(ctx) into stack */ \ *(u64*)(r10 - 8) = r1; \ /* mess up with R1 pointer on stack */ \ r0 = 0x23; \ *(u8*)(r10 - 7) = r0; \ /* fill back into R0 is fine for priv. \ * R0 now becomes SCALAR_VALUE. \ */ \ r0 = *(u64*)(r10 - 8); \ /* Load from R0 should fail. */ \ r0 = *(u64*)(r0 + 8); \ exit; \ " ::: __clobber_all); } SEC("socket") __description("check corrupted spill/fill, LSB") __success __failure_unpriv __msg_unpriv("attempt to corrupt spilled") __retval(POINTER_VALUE) __naked void check_corrupted_spill_fill_lsb(void) { asm volatile (" \ *(u64*)(r10 - 8) = r1; \ r0 = 0xcafe; \ *(u16*)(r10 - 8) = r0; \ r0 = *(u64*)(r10 - 8); \ exit; \ " ::: __clobber_all); } SEC("socket") __description("check corrupted spill/fill, MSB") __success __failure_unpriv __msg_unpriv("attempt to corrupt spilled") __retval(POINTER_VALUE) __naked void check_corrupted_spill_fill_msb(void) { asm volatile (" \ *(u64*)(r10 - 8) = r1; \ r0 = 0x12345678; \ *(u32*)(r10 - 4) = r0; \ r0 = *(u64*)(r10 - 8); \ exit; \ " ::: __clobber_all); } SEC("tc") __description("Spill and refill a u32 const scalar. Offset to skb->data") __success __retval(0) __naked void scalar_offset_to_skb_data_1(void) { asm volatile (" \ r2 = *(u32*)(r1 + %[__sk_buff_data]); \ r3 = *(u32*)(r1 + %[__sk_buff_data_end]); \ w4 = 20; \ *(u32*)(r10 - 8) = r4; \ r4 = *(u32*)(r10 - 8); \ r0 = r2; \ /* r0 += r4 R0=pkt R2=pkt R3=pkt_end R4=20 */ \ r0 += r4; \ /* if (r0 > r3) R0=pkt,off=20 R2=pkt R3=pkt_end R4=20 */\ if r0 > r3 goto l0_%=; \ /* r0 = *(u32 *)r2 R0=pkt,off=20,r=20 R2=pkt,r=20 R3=pkt_end R4=20 */\ r0 = *(u32*)(r2 + 0); \ l0_%=: 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)) : __clobber_all); } SEC("socket") __description("Spill a u32 const, refill from another half of the uninit u32 from the stack") /* in privileged mode reads from uninitialized stack locations are permitted */ __success __failure_unpriv __msg_unpriv("invalid read from stack off -4+0 size 4") __retval(0) __naked void uninit_u32_from_the_stack(void) { asm volatile (" \ w4 = 20; \ *(u32*)(r10 - 8) = r4; \ /* r4 = *(u32 *)(r10 -4) fp-8=????rrrr*/ \ r4 = *(u32*)(r10 - 4); \ r0 = 0; \ exit; \ " ::: __clobber_all); } SEC("tc") __description("Spill a u32 const scalar. Refill as u16. Offset to skb->data") __failure __msg("invalid access to packet") __naked void u16_offset_to_skb_data(void) { asm volatile (" \ r2 = *(u32*)(r1 + %[__sk_buff_data]); \ r3 = *(u32*)(r1 + %[__sk_buff_data_end]); \ w4 = 20; \ *(u32*)(r10 - 8) = r4; \ r4 = *(u16*)(r10 - 8); \ r0 = r2; \ /* r0 += r4 R0=pkt R2=pkt R3=pkt_end R4=umax=65535 */\ r0 += r4; \ /* if (r0 > r3) R0=pkt,umax=65535 R2=pkt R3=pkt_end R4=umax=65535 */\ if r0 > r3 goto l0_%=; \ /* r0 = *(u32 *)r2 R0=pkt,umax=65535 R2=pkt R3=pkt_end R4=20 */\ r0 = *(u32*)(r2 + 0); \ l0_%=: 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)) : __clobber_all); } SEC("tc") __description("Spill u32 const scalars. Refill as u64. Offset to skb->data") __failure __msg("invalid access to packet") __naked void u64_offset_to_skb_data(void) { asm volatile (" \ r2 = *(u32*)(r1 + %[__sk_buff_data]); \ r3 = *(u32*)(r1 + %[__sk_buff_data_end]); \ w6 = 0; \ w7 = 20; \ *(u32*)(r10 - 4) = r6; \ *(u32*)(r10 - 8) = r7; \ r4 = *(u16*)(r10 - 8); \ r0 = r2; \ /* r0 += r4 R0=pkt R2=pkt R3=pkt_end R4=umax=65535 */\ r0 += r4; \ /* if (r0 > r3) R0=pkt,umax=65535 R2=pkt R3=pkt_end R4=umax=65535 */\ if r0 > r3 goto l0_%=; \ /* r0 = *(u32 *)r2 R0=pkt,umax=65535 R2=pkt R3=pkt_end R4=20 */\ r0 = *(u32*)(r2 + 0); \ l0_%=: 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)) : __clobber_all); } SEC("tc") __description("Spill a u32 const scalar. Refill as u16 from fp-6. Offset to skb->data") __failure __msg("invalid access to packet") __naked void _6_offset_to_skb_data(void) { asm volatile (" \ r2 = *(u32*)(r1 + %[__sk_buff_data]); \ r3 = *(u32*)(r1 + %[__sk_buff_data_end]); \ w4 = 20; \ *(u32*)(r10 - 8) = r4; \ r4 = *(u16*)(r10 - 6); \ r0 = r2; \ /* r0 += r4 R0=pkt R2=pkt R3=pkt_end R4=umax=65535 */\ r0 += r4; \ /* if (r0 > r3) R0=pkt,umax=65535 R2=pkt R3=pkt_end R4=umax=65535 */\ if r0 > r3 goto l0_%=; \ /* r0 = *(u32 *)r2 R0=pkt,umax=65535 R2=pkt R3=pkt_end R4=20 */\ r0 = *(u32*)(r2 + 0); \ l0_%=: 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)) : __clobber_all); } SEC("tc") __description("Spill and refill a u32 const scalar at non 8byte aligned stack addr. Offset to skb->data") __failure __msg("invalid access to packet") __naked void addr_offset_to_skb_data(void) { asm volatile (" \ r2 = *(u32*)(r1 + %[__sk_buff_data]); \ r3 = *(u32*)(r1 + %[__sk_buff_data_end]); \ w4 = 20; \ *(u32*)(r10 - 8) = r4; \ *(u32*)(r10 - 4) = r4; \ r4 = *(u32*)(r10 - 4); \ r0 = r2; \ /* r0 += r4 R0=pkt R2=pkt R3=pkt_end R4=umax=U32_MAX */\ r0 += r4; \ /* if (r0 > r3) R0=pkt,umax=U32_MAX R2=pkt R3=pkt_end R4= */\ if r0 > r3 goto l0_%=; \ /* r0 = *(u32 *)r2 R0=pkt,umax=U32_MAX R2=pkt R3=pkt_end R4= */\ r0 = *(u32*)(r2 + 0); \ l0_%=: 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)) : __clobber_all); } SEC("tc") __description("Spill and refill a umax=40 bounded scalar. Offset to skb->data") __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); } char _license[] SEC("license") = "GPL";