Merge tag 'bpf-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf

Pull bpf fixes from Alexei Starovoitov: - Fix incorrect usage of BPF_TRAMP_F_ORIG_STACK in riscv JIT (Menglong Dong) - Fix reference count leak in bpf_prog_test_run_xdp() (Tetsuo Handa) - Fix metadata size check in bpf_test_run() (Toke Høiland-Jørgensen) - Check that BPF insn array is not allowed as a map for const strings (Deepanshu Kartikey) * tag 'bpf-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf: bpf: Fix reference count leak in bpf_prog_test_run_xdp() bpf: Reject BPF_MAP_TYPE_INSN_ARRAY in check_reg_const_str() selftests/bpf: Update xdp_context_test_run test to check maximum metadata size bpf, test_run: Subtract size of xdp_frame from allowed metadata size riscv, bpf: Fix incorrect usage of BPF_TRAMP_F_ORIG_STACK

Linus Torvalds committed 10 months ago

Commit c537e122 parents b543459 ec69daa4 files · +35 −15Browse files

Unified · Split

4 files

arch/riscv/net/bpf_jit_comp64.c +2 −4
kernel/bpf/verifier.c +5 −0
net/bpf/test_run.c +17 −8
tools/testing/selftests/bpf/prog_tests/xdp_context_test_run.c +11 −3

arch/riscv/net/bpf_jit_comp64.c+2−4

 	store_args(nr_arg_slots, args_off, ctx);
-	/* skip to actual body of traced function */
-	if (flags & BPF_TRAMP_F_ORIG_STACK)
-		orig_call += RV_FENTRY_NINSNS * 4;
 	if (flags & BPF_TRAMP_F_CALL_ORIG) {
 		emit_imm(RV_REG_A0, ctx->insns ? (const s64)im : RV_MAX_COUNT_IMM, ctx);
 		ret = emit_call((const u64)__bpf_tramp_enter, true, ctx);
 	}
 	if (flags & BPF_TRAMP_F_CALL_ORIG) {
+		/* skip to actual body of traced function */
+		orig_call += RV_FENTRY_NINSNS * 4;
 		restore_args(min_t(int, nr_arg_slots, RV_MAX_REG_ARGS), args_off, ctx);
 		restore_stack_args(nr_arg_slots - RV_MAX_REG_ARGS, args_off, stk_arg_off, ctx);
 		ret = emit_call((const u64)orig_call, true, ctx);

kernel/bpf/verifier.c+5−0

 	if (reg->type != PTR_TO_MAP_VALUE)
 		return -EINVAL;
+	if (map->map_type == BPF_MAP_TYPE_INSN_ARRAY) {
+		verbose(env, "R%d points to insn_array map which cannot be used as const string\n", regno);
+		return -EACCES;
+	}
 	if (!bpf_map_is_rdonly(map)) {
 		verbose(env, "R%d does not point to a readonly map'\n", regno);
 		return -EACCES;

net/bpf/test_run.c+17−8

 			batch_size = NAPI_POLL_WEIGHT;
 		else if (batch_size > TEST_XDP_MAX_BATCH)
 			return -E2BIG;
-		headroom += sizeof(struct xdp_page_head);
 	} else if (batch_size) {
 		return -EINVAL;
 	}
 		/* There can't be user provided data before the meta data */
 		if (ctx->data_meta || ctx->data_end > kattr->test.data_size_in ||
 		    ctx->data > ctx->data_end ||
-		    unlikely(xdp_metalen_invalid(ctx->data)) ||
 		    (do_live && (kattr->test.data_out || kattr->test.ctx_out)))
 			goto free_ctx;
-		/* Meta data is allocated from the headroom */
-		headroom -= ctx->data;
 		meta_sz = ctx->data;
+		if (xdp_metalen_invalid(meta_sz) || meta_sz > headroom - sizeof(struct xdp_frame))
+			goto free_ctx;
+		/* Meta data is allocated from the headroom */
+		headroom -= meta_sz;
 		linear_sz = ctx->data_end;
 	}
+	/* The xdp_page_head structure takes up space in each page, limiting the
+         * size of the packet data; add the extra size to headroom here to make
+         * sure it's accounted in the length checks below, but not in the
+         * metadata size check above.
+         */
+        if (do_live)
+		headroom += sizeof(struct xdp_page_head);
 	max_linear_sz = PAGE_SIZE - headroom - tailroom;
 	linear_sz = min_t(u32, linear_sz, max_linear_sz);
 			if (sinfo->nr_frags == MAX_SKB_FRAGS) {
 				ret = -ENOMEM;
-				goto out;
+				goto out_put_dev;
 			}
 			page = alloc_page(GFP_KERNEL);
 			if (!page) {
 				ret = -ENOMEM;
-				goto out;
+				goto out_put_dev;
 			}
 			frag = &sinfo->frags[sinfo->nr_frags++];
 			if (copy_from_user(page_address(page), data_in + size,
 					   data_len)) {
 				ret = -EFAULT;
-				goto out;
+				goto out_put_dev;
 			}
 			sinfo->xdp_frags_size += data_len;
 			size += data_len;
 		ret = bpf_test_run_xdp_live(prog, &xdp, repeat, batch_size, &duration);
 	else
 		ret = bpf_test_run(prog, &xdp, repeat, &retval, &duration, true);
+out_put_dev:
 	/* We convert the xdp_buff back to an xdp_md before checking the return
 	 * code so the reference count of any held netdevice will be decremented
 	 * even if the test run failed.

tools/testing/selftests/bpf/prog_tests/xdp_context_test_run.c+11−3

 	struct test_xdp_context_test_run *skel = NULL;
 	char data[sizeof(pkt_v4) + sizeof(__u32)];
 	char bad_ctx[sizeof(struct xdp_md) + 1];
+	char large_data[256];
 	struct xdp_md ctx_in, ctx_out;
 	DECLARE_LIBBPF_OPTS(bpf_test_run_opts, opts,
 			    .data_in = &data,
 	test_xdp_context_error(prog_fd, opts, 4, sizeof(__u32), sizeof(data),
 			       0, 0, 0);
-	/* Meta data must be 255 bytes or smaller */
-	test_xdp_context_error(prog_fd, opts, 0, 256, sizeof(data), 0, 0, 0);
 	/* Total size of data must be data_end - data_meta or larger */
 	test_xdp_context_error(prog_fd, opts, 0, sizeof(__u32),
 			       sizeof(data) + 1, 0, 0, 0);
 	test_xdp_context_error(prog_fd, opts, 0, sizeof(__u32), sizeof(data),
 			       0, 0, 1);
+	/* Meta data must be 216 bytes or smaller (256 - sizeof(struct
+	 * xdp_frame)). Test both nearest invalid size and nearest invalid
+	 * 4-byte-aligned size, and make sure data_in is large enough that we
+	 * actually hit the check on metadata length
+	 */
+	opts.data_in = large_data;
+	opts.data_size_in = sizeof(large_data);
+	test_xdp_context_error(prog_fd, opts, 0, 217, sizeof(large_data), 0, 0, 0);
+	test_xdp_context_error(prog_fd, opts, 0, 220, sizeof(large_data), 0, 0, 0);
 	test_xdp_context_test_run__destroy(skel);
 }