diff options
author | Jakub Kicinski <kuba@kernel.org> | 2021-12-16 13:06:49 -0800 |
---|---|---|
committer | Jakub Kicinski <kuba@kernel.org> | 2021-12-16 13:06:49 -0800 |
commit | 0c3e2474605581375d808bb3b9ce0927ed3eef70 (patch) | |
tree | 176e03e13d7d977f2874b24a5d1ebfb8443a34de | |
parent | e28587cc491ef0f3c51258fdc87fbc386b1d4c59 (diff) | |
parent | c2fcbf81c332b42382a0c439bfe2414a241e4f5b (diff) | |
download | linux-0c3e2474605581375d808bb3b9ce0927ed3eef70.tar.bz2 |
Merge https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf
Daniel Borkmann says:
====================
pull-request: bpf 2021-12-16
We've added 15 non-merge commits during the last 7 day(s) which contain
a total of 12 files changed, 434 insertions(+), 30 deletions(-).
The main changes are:
1) Fix incorrect verifier state pruning behavior for <8B register spill/fill,
from Paul Chaignon.
2) Fix x86-64 JIT's extable handling for fentry/fexit when return pointer
is an ERR_PTR(), from Alexei Starovoitov.
3) Fix 3 different possibilities that BPF verifier missed where unprivileged
could leak kernel addresses, from Daniel Borkmann.
4) Fix xsk's poll behavior under need_wakeup flag, from Magnus Karlsson.
5) Fix an oob-write in test_verifier due to a missed MAX_NR_MAPS bump,
from Kumar Kartikeya Dwivedi.
6) Fix a race in test_btf_skc_cls_ingress selftest, from Martin KaFai Lau.
* https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf:
bpf, selftests: Fix racing issue in btf_skc_cls_ingress test
selftest/bpf: Add a test that reads various addresses.
bpf: Fix extable address check.
bpf: Fix extable fixup offset.
bpf, selftests: Add test case trying to taint map value pointer
bpf: Make 32->64 bounds propagation slightly more robust
bpf: Fix signed bounds propagation after mov32
bpf, selftests: Update test case for atomic cmpxchg on r0 with pointer
bpf: Fix kernel address leakage in atomic cmpxchg's r0 aux reg
bpf, selftests: Add test case for atomic fetch on spilled pointer
bpf: Fix kernel address leakage in atomic fetch
selftests/bpf: Fix OOB write in test_verifier
xsk: Do not sleep in poll() when need_wakeup set
selftests/bpf: Tests for state pruning with u32 spill/fill
bpf: Fix incorrect state pruning for <8B spill/fill
====================
Link: https://lore.kernel.org/r/20211216210005.13815-1-daniel@iogearbox.net
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
-rw-r--r-- | arch/x86/net/bpf_jit_comp.c | 51 | ||||
-rw-r--r-- | kernel/bpf/verifier.c | 53 | ||||
-rw-r--r-- | net/xdp/xsk.c | 4 | ||||
-rw-r--r-- | tools/testing/selftests/bpf/bpf_testmod/bpf_testmod.c | 20 | ||||
-rw-r--r-- | tools/testing/selftests/bpf/prog_tests/btf_skc_cls_ingress.c | 16 | ||||
-rw-r--r-- | tools/testing/selftests/bpf/progs/test_module_attach.c | 12 | ||||
-rw-r--r-- | tools/testing/selftests/bpf/test_verifier.c | 2 | ||||
-rw-r--r-- | tools/testing/selftests/bpf/verifier/atomic_cmpxchg.c | 86 | ||||
-rw-r--r-- | tools/testing/selftests/bpf/verifier/atomic_fetch.c | 94 | ||||
-rw-r--r-- | tools/testing/selftests/bpf/verifier/search_pruning.c | 71 | ||||
-rw-r--r-- | tools/testing/selftests/bpf/verifier/spill_fill.c | 32 | ||||
-rw-r--r-- | tools/testing/selftests/bpf/verifier/value_ptr_arith.c | 23 |
12 files changed, 434 insertions, 30 deletions
diff --git a/arch/x86/net/bpf_jit_comp.c b/arch/x86/net/bpf_jit_comp.c index 726700fabca6..bafe36e69227 100644 --- a/arch/x86/net/bpf_jit_comp.c +++ b/arch/x86/net/bpf_jit_comp.c @@ -1252,19 +1252,54 @@ st: if (is_imm8(insn->off)) case BPF_LDX | BPF_MEM | BPF_DW: case BPF_LDX | BPF_PROBE_MEM | BPF_DW: if (BPF_MODE(insn->code) == BPF_PROBE_MEM) { - /* test src_reg, src_reg */ - maybe_emit_mod(&prog, src_reg, src_reg, true); /* always 1 byte */ - EMIT2(0x85, add_2reg(0xC0, src_reg, src_reg)); - /* jne start_of_ldx */ - EMIT2(X86_JNE, 0); + /* Though the verifier prevents negative insn->off in BPF_PROBE_MEM + * add abs(insn->off) to the limit to make sure that negative + * offset won't be an issue. + * insn->off is s16, so it won't affect valid pointers. + */ + u64 limit = TASK_SIZE_MAX + PAGE_SIZE + abs(insn->off); + u8 *end_of_jmp1, *end_of_jmp2; + + /* Conservatively check that src_reg + insn->off is a kernel address: + * 1. src_reg + insn->off >= limit + * 2. src_reg + insn->off doesn't become small positive. + * Cannot do src_reg + insn->off >= limit in one branch, + * since it needs two spare registers, but JIT has only one. + */ + + /* movabsq r11, limit */ + EMIT2(add_1mod(0x48, AUX_REG), add_1reg(0xB8, AUX_REG)); + EMIT((u32)limit, 4); + EMIT(limit >> 32, 4); + /* cmp src_reg, r11 */ + maybe_emit_mod(&prog, src_reg, AUX_REG, true); + EMIT2(0x39, add_2reg(0xC0, src_reg, AUX_REG)); + /* if unsigned '<' goto end_of_jmp2 */ + EMIT2(X86_JB, 0); + end_of_jmp1 = prog; + + /* mov r11, src_reg */ + emit_mov_reg(&prog, true, AUX_REG, src_reg); + /* add r11, insn->off */ + maybe_emit_1mod(&prog, AUX_REG, true); + EMIT2_off32(0x81, add_1reg(0xC0, AUX_REG), insn->off); + /* jmp if not carry to start_of_ldx + * Otherwise ERR_PTR(-EINVAL) + 128 will be the user addr + * that has to be rejected. + */ + EMIT2(0x73 /* JNC */, 0); + end_of_jmp2 = prog; + /* xor dst_reg, dst_reg */ emit_mov_imm32(&prog, false, dst_reg, 0); /* jmp byte_after_ldx */ EMIT2(0xEB, 0); - /* populate jmp_offset for JNE above */ - temp[4] = prog - temp - 5 /* sizeof(test + jne) */; + /* populate jmp_offset for JB above to jump to xor dst_reg */ + end_of_jmp1[-1] = end_of_jmp2 - end_of_jmp1; + /* populate jmp_offset for JNC above to jump to start_of_ldx */ start_of_ldx = prog; + end_of_jmp2[-1] = start_of_ldx - end_of_jmp2; } emit_ldx(&prog, BPF_SIZE(insn->code), dst_reg, src_reg, insn->off); if (BPF_MODE(insn->code) == BPF_PROBE_MEM) { @@ -1305,7 +1340,7 @@ st: if (is_imm8(insn->off)) * End result: x86 insn "mov rbx, qword ptr [rax+0x14]" * of 4 bytes will be ignored and rbx will be zero inited. */ - ex->fixup = (prog - temp) | (reg2pt_regs[dst_reg] << 8); + ex->fixup = (prog - start_of_ldx) | (reg2pt_regs[dst_reg] << 8); } break; diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c index f3001937bbb9..b532f1058d35 100644 --- a/kernel/bpf/verifier.c +++ b/kernel/bpf/verifier.c @@ -1366,22 +1366,28 @@ static void __reg_bound_offset(struct bpf_reg_state *reg) reg->var_off = tnum_or(tnum_clear_subreg(var64_off), var32_off); } +static bool __reg32_bound_s64(s32 a) +{ + return a >= 0 && a <= S32_MAX; +} + static void __reg_assign_32_into_64(struct bpf_reg_state *reg) { reg->umin_value = reg->u32_min_value; reg->umax_value = reg->u32_max_value; - /* Attempt to pull 32-bit signed bounds into 64-bit bounds - * but must be positive otherwise set to worse case bounds - * and refine later from tnum. + + /* Attempt to pull 32-bit signed bounds into 64-bit bounds but must + * be positive otherwise set to worse case bounds and refine later + * from tnum. */ - if (reg->s32_min_value >= 0 && reg->s32_max_value >= 0) - reg->smax_value = reg->s32_max_value; - else - reg->smax_value = U32_MAX; - if (reg->s32_min_value >= 0) + if (__reg32_bound_s64(reg->s32_min_value) && + __reg32_bound_s64(reg->s32_max_value)) { reg->smin_value = reg->s32_min_value; - else + reg->smax_value = reg->s32_max_value; + } else { reg->smin_value = 0; + reg->smax_value = U32_MAX; + } } static void __reg_combine_32_into_64(struct bpf_reg_state *reg) @@ -2379,8 +2385,6 @@ static int backtrack_insn(struct bpf_verifier_env *env, int idx, */ if (insn->src_reg != BPF_REG_FP) return 0; - if (BPF_SIZE(insn->code) != BPF_DW) - return 0; /* dreg = *(u64 *)[fp - off] was a fill from the stack. * that [fp - off] slot contains scalar that needs to be @@ -2403,8 +2407,6 @@ static int backtrack_insn(struct bpf_verifier_env *env, int idx, /* scalars can only be spilled into stack */ if (insn->dst_reg != BPF_REG_FP) return 0; - if (BPF_SIZE(insn->code) != BPF_DW) - return 0; spi = (-insn->off - 1) / BPF_REG_SIZE; if (spi >= 64) { verbose(env, "BUG spi %d\n", spi); @@ -4551,9 +4553,16 @@ static int check_atomic(struct bpf_verifier_env *env, int insn_idx, struct bpf_i if (insn->imm == BPF_CMPXCHG) { /* Check comparison of R0 with memory location */ - err = check_reg_arg(env, BPF_REG_0, SRC_OP); + const u32 aux_reg = BPF_REG_0; + + err = check_reg_arg(env, aux_reg, SRC_OP); if (err) return err; + + if (is_pointer_value(env, aux_reg)) { + verbose(env, "R%d leaks addr into mem\n", aux_reg); + return -EACCES; + } } if (is_pointer_value(env, insn->src_reg)) { @@ -4588,13 +4597,19 @@ static int check_atomic(struct bpf_verifier_env *env, int insn_idx, struct bpf_i load_reg = -1; } - /* check whether we can read the memory */ + /* Check whether we can read the memory, with second call for fetch + * case to simulate the register fill. + */ err = check_mem_access(env, insn_idx, insn->dst_reg, insn->off, - BPF_SIZE(insn->code), BPF_READ, load_reg, true); + BPF_SIZE(insn->code), BPF_READ, -1, true); + if (!err && load_reg >= 0) + err = check_mem_access(env, insn_idx, insn->dst_reg, insn->off, + BPF_SIZE(insn->code), BPF_READ, load_reg, + true); if (err) return err; - /* check whether we can write into the same memory */ + /* Check whether we can write into the same memory. */ err = check_mem_access(env, insn_idx, insn->dst_reg, insn->off, BPF_SIZE(insn->code), BPF_WRITE, -1, true); if (err) @@ -8308,6 +8323,10 @@ static int check_alu_op(struct bpf_verifier_env *env, struct bpf_insn *insn) insn->dst_reg); } zext_32_to_64(dst_reg); + + __update_reg_bounds(dst_reg); + __reg_deduce_bounds(dst_reg); + __reg_bound_offset(dst_reg); } } else { /* case: R = imm diff --git a/net/xdp/xsk.c b/net/xdp/xsk.c index f16074eb53c7..7a466ea962c5 100644 --- a/net/xdp/xsk.c +++ b/net/xdp/xsk.c @@ -677,8 +677,6 @@ static __poll_t xsk_poll(struct file *file, struct socket *sock, struct xdp_sock *xs = xdp_sk(sk); struct xsk_buff_pool *pool; - sock_poll_wait(file, sock, wait); - if (unlikely(!xsk_is_bound(xs))) return mask; @@ -690,6 +688,8 @@ static __poll_t xsk_poll(struct file *file, struct socket *sock, else /* Poll needs to drive Tx also in copy mode */ __xsk_sendmsg(sk); + } else { + sock_poll_wait(file, sock, wait); } if (xs->rx && !xskq_prod_is_empty(xs->rx)) diff --git a/tools/testing/selftests/bpf/bpf_testmod/bpf_testmod.c b/tools/testing/selftests/bpf/bpf_testmod/bpf_testmod.c index 5d52ea2768df..df3b292a8ffe 100644 --- a/tools/testing/selftests/bpf/bpf_testmod/bpf_testmod.c +++ b/tools/testing/selftests/bpf/bpf_testmod/bpf_testmod.c @@ -33,6 +33,22 @@ noinline int bpf_testmod_loop_test(int n) return sum; } +__weak noinline struct file *bpf_testmod_return_ptr(int arg) +{ + static struct file f = {}; + + switch (arg) { + case 1: return (void *)EINVAL; /* user addr */ + case 2: return (void *)0xcafe4a11; /* user addr */ + case 3: return (void *)-EINVAL; /* canonical, but invalid */ + case 4: return (void *)(1ull << 60); /* non-canonical and invalid */ + case 5: return (void *)~(1ull << 30); /* trigger extable */ + case 6: return &f; /* valid addr */ + case 7: return (void *)((long)&f | 1); /* kernel tricks */ + default: return NULL; + } +} + noinline ssize_t bpf_testmod_test_read(struct file *file, struct kobject *kobj, struct bin_attribute *bin_attr, @@ -43,6 +59,10 @@ bpf_testmod_test_read(struct file *file, struct kobject *kobj, .off = off, .len = len, }; + int i = 1; + + while (bpf_testmod_return_ptr(i)) + i++; /* This is always true. Use the check to make sure the compiler * doesn't remove bpf_testmod_loop_test. diff --git a/tools/testing/selftests/bpf/prog_tests/btf_skc_cls_ingress.c b/tools/testing/selftests/bpf/prog_tests/btf_skc_cls_ingress.c index 762f6a9da8b5..664ffc0364f4 100644 --- a/tools/testing/selftests/bpf/prog_tests/btf_skc_cls_ingress.c +++ b/tools/testing/selftests/bpf/prog_tests/btf_skc_cls_ingress.c @@ -90,7 +90,7 @@ static void print_err_line(void) static void test_conn(void) { - int listen_fd = -1, cli_fd = -1, err; + int listen_fd = -1, cli_fd = -1, srv_fd = -1, err; socklen_t addrlen = sizeof(srv_sa6); int srv_port; @@ -112,6 +112,10 @@ static void test_conn(void) if (CHECK_FAIL(cli_fd == -1)) goto done; + srv_fd = accept(listen_fd, NULL, NULL); + if (CHECK_FAIL(srv_fd == -1)) + goto done; + if (CHECK(skel->bss->listen_tp_sport != srv_port || skel->bss->req_sk_sport != srv_port, "Unexpected sk src port", @@ -134,11 +138,13 @@ done: close(listen_fd); if (cli_fd != -1) close(cli_fd); + if (srv_fd != -1) + close(srv_fd); } static void test_syncookie(void) { - int listen_fd = -1, cli_fd = -1, err; + int listen_fd = -1, cli_fd = -1, srv_fd = -1, err; socklen_t addrlen = sizeof(srv_sa6); int srv_port; @@ -161,6 +167,10 @@ static void test_syncookie(void) if (CHECK_FAIL(cli_fd == -1)) goto done; + srv_fd = accept(listen_fd, NULL, NULL); + if (CHECK_FAIL(srv_fd == -1)) + goto done; + if (CHECK(skel->bss->listen_tp_sport != srv_port, "Unexpected tp src port", "listen_tp_sport:%u expected:%u\n", @@ -188,6 +198,8 @@ done: close(listen_fd); if (cli_fd != -1) close(cli_fd); + if (srv_fd != -1) + close(srv_fd); } struct test { diff --git a/tools/testing/selftests/bpf/progs/test_module_attach.c b/tools/testing/selftests/bpf/progs/test_module_attach.c index b36857093f71..50ce16d02da7 100644 --- a/tools/testing/selftests/bpf/progs/test_module_attach.c +++ b/tools/testing/selftests/bpf/progs/test_module_attach.c @@ -87,6 +87,18 @@ int BPF_PROG(handle_fexit, return 0; } +SEC("fexit/bpf_testmod_return_ptr") +int BPF_PROG(handle_fexit_ret, int arg, struct file *ret) +{ + long buf = 0; + + bpf_probe_read_kernel(&buf, 8, ret); + bpf_probe_read_kernel(&buf, 8, (char *)ret + 256); + *(volatile long long *)ret; + *(volatile int *)&ret->f_mode; + return 0; +} + __u32 fmod_ret_read_sz = 0; SEC("fmod_ret/bpf_testmod_test_read") diff --git a/tools/testing/selftests/bpf/test_verifier.c b/tools/testing/selftests/bpf/test_verifier.c index 465ef3f112c0..d3bf83d5c6cf 100644 --- a/tools/testing/selftests/bpf/test_verifier.c +++ b/tools/testing/selftests/bpf/test_verifier.c @@ -54,7 +54,7 @@ #define MAX_INSNS BPF_MAXINSNS #define MAX_TEST_INSNS 1000000 #define MAX_FIXUPS 8 -#define MAX_NR_MAPS 21 +#define MAX_NR_MAPS 22 #define MAX_TEST_RUNS 8 #define POINTER_VALUE 0xcafe4all #define TEST_DATA_LEN 64 diff --git a/tools/testing/selftests/bpf/verifier/atomic_cmpxchg.c b/tools/testing/selftests/bpf/verifier/atomic_cmpxchg.c index c22dc83a41fd..b39665f33524 100644 --- a/tools/testing/selftests/bpf/verifier/atomic_cmpxchg.c +++ b/tools/testing/selftests/bpf/verifier/atomic_cmpxchg.c @@ -138,6 +138,8 @@ BPF_EXIT_INSN(), }, .result = ACCEPT, + .result_unpriv = REJECT, + .errstr_unpriv = "R0 leaks addr into mem", }, { "Dest pointer in r0 - succeed", @@ -156,4 +158,88 @@ BPF_EXIT_INSN(), }, .result = ACCEPT, + .result_unpriv = REJECT, + .errstr_unpriv = "R0 leaks addr into mem", +}, +{ + "Dest pointer in r0 - succeed, check 2", + .insns = { + /* r0 = &val */ + BPF_MOV64_REG(BPF_REG_0, BPF_REG_10), + /* val = r0; */ + BPF_STX_MEM(BPF_DW, BPF_REG_10, BPF_REG_0, -8), + /* r5 = &val */ + BPF_MOV64_REG(BPF_REG_5, BPF_REG_10), + /* r0 = atomic_cmpxchg(&val, r0, r5); */ + BPF_ATOMIC_OP(BPF_DW, BPF_CMPXCHG, BPF_REG_10, BPF_REG_5, -8), + /* r1 = *r0 */ + BPF_LDX_MEM(BPF_DW, BPF_REG_1, BPF_REG_0, -8), + /* exit(0); */ + BPF_MOV64_IMM(BPF_REG_0, 0), + BPF_EXIT_INSN(), + }, + .result = ACCEPT, + .result_unpriv = REJECT, + .errstr_unpriv = "R0 leaks addr into mem", +}, +{ + "Dest pointer in r0 - succeed, check 3", + .insns = { + /* r0 = &val */ + BPF_MOV64_REG(BPF_REG_0, BPF_REG_10), + /* val = r0; */ + BPF_STX_MEM(BPF_DW, BPF_REG_10, BPF_REG_0, -8), + /* r5 = &val */ + BPF_MOV64_REG(BPF_REG_5, BPF_REG_10), + /* r0 = atomic_cmpxchg(&val, r0, r5); */ + BPF_ATOMIC_OP(BPF_W, BPF_CMPXCHG, BPF_REG_10, BPF_REG_5, -8), + /* exit(0); */ + BPF_MOV64_IMM(BPF_REG_0, 0), + BPF_EXIT_INSN(), + }, + .result = REJECT, + .errstr = "invalid size of register fill", + .errstr_unpriv = "R0 leaks addr into mem", +}, +{ + "Dest pointer in r0 - succeed, check 4", + .insns = { + /* r0 = &val */ + BPF_MOV32_REG(BPF_REG_0, BPF_REG_10), + /* val = r0; */ + BPF_STX_MEM(BPF_W, BPF_REG_10, BPF_REG_0, -8), + /* r5 = &val */ + BPF_MOV32_REG(BPF_REG_5, BPF_REG_10), + /* r0 = atomic_cmpxchg(&val, r0, r5); */ + BPF_ATOMIC_OP(BPF_W, BPF_CMPXCHG, BPF_REG_10, BPF_REG_5, -8), + /* r1 = *r10 */ + BPF_LDX_MEM(BPF_W, BPF_REG_1, BPF_REG_10, -8), + /* exit(0); */ + BPF_MOV64_IMM(BPF_REG_0, 0), + BPF_EXIT_INSN(), + }, + .result = ACCEPT, + .result_unpriv = REJECT, + .errstr_unpriv = "R10 partial copy of pointer", +}, +{ + "Dest pointer in r0 - succeed, check 5", + .insns = { + /* r0 = &val */ + BPF_MOV32_REG(BPF_REG_0, BPF_REG_10), + /* val = r0; */ + BPF_STX_MEM(BPF_W, BPF_REG_10, BPF_REG_0, -8), + /* r5 = &val */ + BPF_MOV32_REG(BPF_REG_5, BPF_REG_10), + /* r0 = atomic_cmpxchg(&val, r0, r5); */ + BPF_ATOMIC_OP(BPF_W, BPF_CMPXCHG, BPF_REG_10, BPF_REG_5, -8), + /* r1 = *r0 */ + BPF_LDX_MEM(BPF_W, BPF_REG_1, BPF_REG_0, -8), + /* exit(0); */ + BPF_MOV64_IMM(BPF_REG_0, 0), + BPF_EXIT_INSN(), + }, + .result = REJECT, + .errstr = "R0 invalid mem access", + .errstr_unpriv = "R10 partial copy of pointer", }, diff --git a/tools/testing/selftests/bpf/verifier/atomic_fetch.c b/tools/testing/selftests/bpf/verifier/atomic_fetch.c index 3bc9ff7a860b..5bf03fb4fa2b 100644 --- a/tools/testing/selftests/bpf/verifier/atomic_fetch.c +++ b/tools/testing/selftests/bpf/verifier/atomic_fetch.c @@ -1,3 +1,97 @@ +{ + "atomic dw/fetch and address leakage of (map ptr & -1) via stack slot", + .insns = { + BPF_LD_IMM64(BPF_REG_1, -1), + BPF_LD_MAP_FD(BPF_REG_8, 0), + BPF_LD_MAP_FD(BPF_REG_9, 0), + BPF_MOV64_REG(BPF_REG_2, BPF_REG_10), + BPF_ALU64_IMM(BPF_ADD, BPF_REG_2, -8), + BPF_STX_MEM(BPF_DW, BPF_REG_2, BPF_REG_9, 0), + BPF_ATOMIC_OP(BPF_DW, BPF_AND | BPF_FETCH, BPF_REG_2, BPF_REG_1, 0), + BPF_LDX_MEM(BPF_DW, BPF_REG_9, BPF_REG_2, 0), + BPF_ST_MEM(BPF_DW, BPF_REG_2, 0, 0), + BPF_MOV64_REG(BPF_REG_1, BPF_REG_8), + BPF_EMIT_CALL(BPF_FUNC_map_lookup_elem), + BPF_JMP_IMM(BPF_JEQ, BPF_REG_0, 0, 1), + BPF_STX_MEM(BPF_DW, BPF_REG_0, BPF_REG_9, 0), + BPF_MOV64_IMM(BPF_REG_0, 0), + BPF_EXIT_INSN(), + }, + .fixup_map_array_48b = { 2, 4 }, + .result = ACCEPT, + .result_unpriv = REJECT, + .errstr_unpriv = "leaking pointer from stack off -8", +}, +{ + "atomic dw/fetch and address leakage of (map ptr & -1) via returned value", + .insns = { + BPF_LD_IMM64(BPF_REG_1, -1), + BPF_LD_MAP_FD(BPF_REG_8, 0), + BPF_LD_MAP_FD(BPF_REG_9, 0), + BPF_MOV64_REG(BPF_REG_2, BPF_REG_10), + BPF_ALU64_IMM(BPF_ADD, BPF_REG_2, -8), + BPF_STX_MEM(BPF_DW, BPF_REG_2, BPF_REG_9, 0), + BPF_ATOMIC_OP(BPF_DW, BPF_AND | BPF_FETCH, BPF_REG_2, BPF_REG_1, 0), + BPF_MOV64_REG(BPF_REG_9, BPF_REG_1), + BPF_ST_MEM(BPF_DW, BPF_REG_2, 0, 0), + BPF_MOV64_REG(BPF_REG_1, BPF_REG_8), + BPF_EMIT_CALL(BPF_FUNC_map_lookup_elem), + BPF_JMP_IMM(BPF_JEQ, BPF_REG_0, 0, 1), + BPF_STX_MEM(BPF_DW, BPF_REG_0, BPF_REG_9, 0), + BPF_MOV64_IMM(BPF_REG_0, 0), + BPF_EXIT_INSN(), + }, + .fixup_map_array_48b = { 2, 4 }, + .result = ACCEPT, + .result_unpriv = REJECT, + .errstr_unpriv = "leaking pointer from stack off -8", +}, +{ + "atomic w/fetch and address leakage of (map ptr & -1) via stack slot", + .insns = { + BPF_LD_IMM64(BPF_REG_1, -1), + BPF_LD_MAP_FD(BPF_REG_8, 0), + BPF_LD_MAP_FD(BPF_REG_9, 0), + BPF_MOV64_REG(BPF_REG_2, BPF_REG_10), + BPF_ALU64_IMM(BPF_ADD, BPF_REG_2, -8), + BPF_STX_MEM(BPF_DW, BPF_REG_2, BPF_REG_9, 0), + BPF_ATOMIC_OP(BPF_W, BPF_AND | BPF_FETCH, BPF_REG_2, BPF_REG_1, 0), + BPF_LDX_MEM(BPF_DW, BPF_REG_9, BPF_REG_2, 0), + BPF_ST_MEM(BPF_DW, BPF_REG_2, 0, 0), + BPF_MOV64_REG(BPF_REG_1, BPF_REG_8), + BPF_EMIT_CALL(BPF_FUNC_map_lookup_elem), + BPF_JMP_IMM(BPF_JEQ, BPF_REG_0, 0, 1), + BPF_STX_MEM(BPF_DW, BPF_REG_0, BPF_REG_9, 0), + BPF_MOV64_IMM(BPF_REG_0, 0), + BPF_EXIT_INSN(), + }, + .fixup_map_array_48b = { 2, 4 }, + .result = REJECT, + .errstr = "invalid size of register fill", +}, +{ + "atomic w/fetch and address leakage of (map ptr & -1) via returned value", + .insns = { + BPF_LD_IMM64(BPF_REG_1, -1), + BPF_LD_MAP_FD(BPF_REG_8, 0), + BPF_LD_MAP_FD(BPF_REG_9, 0), + BPF_MOV64_REG(BPF_REG_2, BPF_REG_10), + BPF_ALU64_IMM(BPF_ADD, BPF_REG_2, -8), + BPF_STX_MEM(BPF_DW, BPF_REG_2, BPF_REG_9, 0), + BPF_ATOMIC_OP(BPF_W, BPF_AND | BPF_FETCH, BPF_REG_2, BPF_REG_1, 0), + BPF_MOV64_REG(BPF_REG_9, BPF_REG_1), + BPF_ST_MEM(BPF_DW, BPF_REG_2, 0, 0), + BPF_MOV64_REG(BPF_REG_1, BPF_REG_8), + BPF_EMIT_CALL(BPF_FUNC_map_lookup_elem), + BPF_JMP_IMM(BPF_JEQ, BPF_REG_0, 0, 1), + BPF_STX_MEM(BPF_DW, BPF_REG_0, BPF_REG_9, 0), + BPF_MOV64_IMM(BPF_REG_0, 0), + BPF_EXIT_INSN(), + }, + .fixup_map_array_48b = { 2, 4 }, + .result = REJECT, + .errstr = "invalid size of register fill", +}, #define __ATOMIC_FETCH_OP_TEST(src_reg, dst_reg, operand1, op, operand2, expect) \ { \ "atomic fetch " #op ", src=" #dst_reg " dst=" #dst_reg, \ diff --git a/tools/testing/selftests/bpf/verifier/search_pruning.c b/tools/testing/selftests/bpf/verifier/search_pruning.c index 7e50cb80873a..682519769fe3 100644 --- a/tools/testing/selftests/bpf/verifier/search_pruning.c +++ b/tools/testing/selftests/bpf/verifier/search_pruning.c @@ -133,6 +133,77 @@ .prog_type = BPF_PROG_TYPE_TRACEPOINT, }, { + "precision tracking for u32 spill/fill", + .insns = { + BPF_MOV64_REG(BPF_REG_7, BPF_REG_1), + BPF_EMIT_CALL(BPF_FUNC_get_prandom_u32), + BPF_MOV32_IMM(BPF_REG_6, 32), + BPF_JMP_IMM(BPF_JEQ, BPF_REG_0, 0, 1), + BPF_MOV32_IMM(BPF_REG_6, 4), + /* Additional insns to introduce a pruning point. */ + BPF_EMIT_CALL(BPF_FUNC_get_prandom_u32), + BPF_MOV64_IMM(BPF_REG_3, 0), + BPF_MOV64_IMM(BPF_REG_3, 0), + BPF_JMP_IMM(BPF_JEQ, BPF_REG_0, 0, 1), + BPF_MOV64_IMM(BPF_REG_3, 0), + /* u32 spill/fill */ + BPF_STX_MEM(BPF_W, BPF_REG_10, BPF_REG_6, -8), + BPF_LDX_MEM(BPF_W, BPF_REG_8, BPF_REG_10, -8), + /* out-of-bound map value access for r6=32 */ + BPF_ST_MEM(BPF_DW, BPF_REG_10, -16, 0), + BPF_MOV64_REG(BPF_REG_2, BPF_REG_10), + BPF_ALU64_IMM(BPF_ADD, BPF_REG_2, -16), + BPF_LD_MAP_FD(BPF_REG_1, 0), + BPF_RAW_INSN(BPF_JMP | BPF_CALL, 0, 0, 0, BPF_FUNC_map_lookup_elem), + BPF_JMP_IMM(BPF_JEQ, BPF_REG_0, 0, 2), + BPF_ALU64_REG(BPF_ADD, BPF_REG_0, BPF_REG_8), + BPF_LDX_MEM(BPF_W, BPF_REG_1, BPF_REG_0, 0), + BPF_MOV64_IMM(BPF_REG_0, 0), + BPF_EXIT_INSN(), + }, + .fixup_map_hash_8b = { 15 }, + .result = REJECT, + .errstr = "R0 min value is outside of the allowed memory range", + .prog_type = BPF_PROG_TYPE_TRACEPOINT, +}, +{ + "precision tracking for u32 spills, u64 fill", + .insns = { + BPF_EMIT_CALL(BPF_FUNC_get_prandom_u32), + BPF_MOV64_REG(BPF_REG_6, BPF_REG_0), + BPF_MOV32_IMM(BPF_REG_7, 0xffffffff), + /* Additional insns to introduce a pruning point. */ + BPF_MOV64_IMM(BPF_REG_3, 1), + BPF_MOV64_IMM(BPF_REG_3, 1), + BPF_MOV64_IMM(BPF_REG_3, 1), + BPF_MOV64_IMM(BPF_REG_3, 1), + BPF_EMIT_CALL(BPF_FUNC_get_prandom_u32), + BPF_JMP_IMM(BPF_JEQ, BPF_REG_0, 0, 1), + BPF_MOV64_IMM(BPF_REG_3, 1), + BPF_ALU32_IMM(BPF_DIV, BPF_REG_3, 0), + /* u32 spills, u64 fill */ + BPF_STX_MEM(BPF_W, BPF_REG_10, BPF_REG_6, -4), + BPF_STX_MEM(BPF_W, BPF_REG_10, BPF_REG_7, -8), + BPF_LDX_MEM(BPF_DW, BPF_REG_8, BPF_REG_10, -8), + /* if r8 != X goto pc+1 r8 known in fallthrough branch */ + BPF_JMP_IMM(BPF_JNE, BPF_REG_8, 0xffffffff, 1), + BPF_MOV64_IMM(BPF_REG_3, 1), + /* if r8 == X goto pc+1 condition always true on first + * traversal, so starts backtracking to mark r8 as requiring + * precision. r7 marked as needing precision. r6 not marked + * since it's not tracked. + */ + BPF_JMP_IMM(BPF_JEQ, BPF_REG_8, 0xffffffff, 1), + /* fails if r8 correctly marked unknown after fill. */ + BPF_ALU32_IMM(BPF_DIV, BPF_REG_3, 0), + BPF_MOV64_IMM(BPF_REG_0, 0), + BPF_EXIT_INSN(), + }, + .result = REJECT, + .errstr = "div by zero", + .prog_type = BPF_PROG_TYPE_TRACEPOINT, +}, +{ "allocated_stack", .insns = { BPF_ALU64_REG(BPF_MOV, BPF_REG_6, BPF_REG_1), diff --git a/tools/testing/selftests/bpf/verifier/spill_fill.c b/tools/testing/selftests/bpf/verifier/spill_fill.c index 7ab3de108761..6c907144311f 100644 --- a/tools/testing/selftests/bpf/verifier/spill_fill.c +++ b/tools/testing/selftests/bpf/verifier/spill_fill.c @@ -176,6 +176,38 @@ .prog_type = BPF_PROG_TYPE_SCHED_CLS, }, { + "Spill u32 const scalars. Refill as u64. Offset to skb->data", + .insns = { + BPF_LDX_MEM(BPF_W, BPF_REG_2, BPF_REG_1, + offsetof(struct __sk_buff, data)), + BPF_LDX_MEM(BPF_W, BPF_REG_3, BPF_REG_1, + offsetof(struct __sk_buff, data_end)), + /* r6 = 0 */ + BPF_MOV32_IMM(BPF_REG_6, 0), + /* r7 = 20 */ + BPF_MOV32_IMM(BPF_REG_7, 20), + /* *(u32 *)(r10 -4) = r6 */ + BPF_STX_MEM(BPF_W, BPF_REG_10, BPF_REG_6, -4), + /* *(u32 *)(r10 -8) = r7 */ + BPF_STX_MEM(BPF_W, BPF_REG_10, BPF_REG_7, -8), + /* r4 = *(u64 *)(r10 -8) */ + BPF_LDX_MEM(BPF_H, BPF_REG_4, BPF_REG_10, -8), + /* r0 = r2 */ + BPF_MOV64_REG(BPF_REG_0, BPF_REG_2), + /* r0 += r4 R0=pkt R2=pkt R3=pkt_end R4=inv,umax=65535 */ + BPF_ALU64_REG(BPF_ADD, BPF_REG_0, BPF_REG_4), + /* if (r0 > r3) R0=pkt,umax=65535 R2=pkt R3=pkt_end R4=inv,umax=65535 */ + BPF_JMP_REG(BPF_JGT, BPF_REG_0, BPF_REG_3, 1), + /* r0 = *(u32 *)r2 R0=pkt,umax=65535 R2=pkt R3=pkt_end R4=inv20 */ + BPF_LDX_MEM(BPF_W, BPF_REG_0, BPF_REG_2, 0), + BPF_MOV64_IMM(BPF_REG_0, 0), + BPF_EXIT_INSN(), + }, + .result = REJECT, + .errstr = "invalid access to packet", + .prog_type = BPF_PROG_TYPE_SCHED_CLS, +}, +{ "Spill a u32 const scalar. Refill as u16 from fp-6. Offset to skb->data", .insns = { BPF_LDX_MEM(BPF_W, BPF_REG_2, BPF_REG_1, diff --git a/tools/testing/selftests/bpf/verifier/value_ptr_arith.c b/tools/testing/selftests/bpf/verifier/value_ptr_arith.c index 2debba4e8a3a..4d347bc53aa2 100644 --- a/tools/testing/selftests/bpf/verifier/value_ptr_arith.c +++ b/tools/testing/selftests/bpf/verifier/value_ptr_arith.c @@ -1078,6 +1078,29 @@ .errstr_unpriv = "R0 pointer -= pointer prohibited", }, { + "map access: trying to leak tained dst reg", + .insns = { + BPF_MOV64_IMM(BPF_REG_0, 0), + BPF_ST_MEM(BPF_DW, BPF_REG_10, -8, 0), + BPF_MOV64_REG(BPF_REG_2, BPF_REG_10), + BPF_ALU64_IMM(BPF_ADD, BPF_REG_2, -8), + BPF_LD_MAP_FD(BPF_REG_1, 0), + BPF_RAW_INSN(BPF_JMP | BPF_CALL, 0, 0, 0, BPF_FUNC_map_lookup_elem), + BPF_JMP_IMM(BPF_JNE, BPF_REG_0, 0, 1), + BPF_EXIT_INSN(), + BPF_MOV64_REG(BPF_REG_2, BPF_REG_0), + BPF_MOV32_IMM(BPF_REG_1, 0xFFFFFFFF), + BPF_MOV32_REG(BPF_REG_1, BPF_REG_1), + BPF_ALU64_REG(BPF_SUB, BPF_REG_2, BPF_REG_1), + BPF_STX_MEM(BPF_DW, BPF_REG_0, BPF_REG_2, 0), + BPF_MOV64_IMM(BPF_REG_0, 0), + BPF_EXIT_INSN(), + }, + .fixup_map_array_48b = { 4 }, + .result = REJECT, + .errstr = "math between map_value pointer and 4294967295 is not allowed", +}, +{ "32bit pkt_ptr -= scalar", .insns = { BPF_LDX_MEM(BPF_W, BPF_REG_8, BPF_REG_1, |