Merge git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf

Daniel Borkmann says:

====================
pull-request: bpf 2019-08-24

The following pull-request contains BPF updates for your *net* tree.

The main changes are:

1) Fix verifier precision tracking with BPF-to-BPF calls, from Alexei.

2) Fix a use-after-free in prog symbol exposure, from Daniel.

3) Several s390x JIT fixes plus BE related fixes in BPF kselftests, from Ilya.

4) Fix memory leak by unpinning XDP umem pages in error path, from Ivan.

5) Fix a potential use-after-free on flow dissector detach, from Jakub.

6) Fix bpftool to close prog fd after showing metadata, from Quentin.

7) BPF kselftest config and TEST_PROGS_EXTENDED fixes, from Anders.
====================

Signed-off-by: David S. Miller <davem@davemloft.net>

12 files changed, 62 insertions, 34 deletions

diff --git a/arch/s390/net/bpf_jit_comp.c b/arch/s390/net/bpf_jit_comp.c
index e636728ab452e1..955eb355c2fdea 100644
--- a/arch/s390/net/bpf_jit_comp.c
+++ b/arch/s390/net/bpf_jit_comp.c
@@ -863,7 +863,7 @@ static noinline int bpf_jit_insn(struct bpf_jit *jit, struct bpf_prog *fp, int i
 		break;
 	case BPF_ALU64 | BPF_NEG: /* dst = -dst */
 		/* lcgr %dst,%dst */
-		EMIT4(0xb9130000, dst_reg, dst_reg);
+		EMIT4(0xb9030000, dst_reg, dst_reg);
 		break;
 	/*
 	 * BPF_FROM_BE/LE
@@ -1049,8 +1049,8 @@ static noinline int bpf_jit_insn(struct bpf_jit *jit, struct bpf_prog *fp, int i
 		/* llgf %w1,map.max_entries(%b2) */
 		EMIT6_DISP_LH(0xe3000000, 0x0016, REG_W1, REG_0, BPF_REG_2,
 			      offsetof(struct bpf_array, map.max_entries));
-		/* clgrj %b3,%w1,0xa,label0: if %b3 >= %w1 goto out */
-		EMIT6_PCREL_LABEL(0xec000000, 0x0065, BPF_REG_3,
+		/* clrj %b3,%w1,0xa,label0: if (u32)%b3 >= (u32)%w1 goto out */
+		EMIT6_PCREL_LABEL(0xec000000, 0x0077, BPF_REG_3,
 				  REG_W1, 0, 0xa);
 
 		/*
@@ -1076,8 +1076,10 @@ static noinline int bpf_jit_insn(struct bpf_jit *jit, struct bpf_prog *fp, int i
 		 *         goto out;
 		 */
 
-		/* sllg %r1,%b3,3: %r1 = index * 8 */
-		EMIT6_DISP_LH(0xeb000000, 0x000d, REG_1, BPF_REG_3, REG_0, 3);
+		/* llgfr %r1,%b3: %r1 = (u32) index */
+		EMIT4(0xb9160000, REG_1, BPF_REG_3);
+		/* sllg %r1,%r1,3: %r1 *= 8 */
+		EMIT6_DISP_LH(0xeb000000, 0x000d, REG_1, REG_1, REG_0, 3);
 		/* lg %r1,prog(%b2,%r1) */
 		EMIT6_DISP_LH(0xe3000000, 0x0004, REG_1, BPF_REG_2,
 			      REG_1, offsetof(struct bpf_array, ptrs));
diff --git a/kernel/bpf/syscall.c b/kernel/bpf/syscall.c
index 5d141f16f6fa95..272071e9112f3b 100644
--- a/kernel/bpf/syscall.c
+++ b/kernel/bpf/syscall.c
@@ -1707,20 +1707,26 @@ static int bpf_prog_load(union bpf_attr *attr, union bpf_attr __user *uattr)
 	if (err)
 		goto free_used_maps;
 
-	err = bpf_prog_new_fd(prog);
-	if (err < 0) {
-		/* failed to allocate fd.
-		 * bpf_prog_put() is needed because the above
-		 * bpf_prog_alloc_id() has published the prog
-		 * to the userspace and the userspace may
-		 * have refcnt-ed it through BPF_PROG_GET_FD_BY_ID.
-		 */
-		bpf_prog_put(prog);
-		return err;
-	}
-
+	/* Upon success of bpf_prog_alloc_id(), the BPF prog is
+	 * effectively publicly exposed. However, retrieving via
+	 * bpf_prog_get_fd_by_id() will take another reference,
+	 * therefore it cannot be gone underneath us.
+	 *
+	 * Only for the time /after/ successful bpf_prog_new_fd()
+	 * and before returning to userspace, we might just hold
+	 * one reference and any parallel close on that fd could
+	 * rip everything out. Hence, below notifications must
+	 * happen before bpf_prog_new_fd().
+	 *
+	 * Also, any failure handling from this point onwards must
+	 * be using bpf_prog_put() given the program is exposed.
+	 */
 	bpf_prog_kallsyms_add(prog);
 	perf_event_bpf_event(prog, PERF_BPF_EVENT_PROG_LOAD, 0);
+
+	err = bpf_prog_new_fd(prog);
+	if (err < 0)
+		bpf_prog_put(prog);
 	return err;
 
 free_used_maps:
diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c
index c84d83f86141f8..b5c14c9d7b9870 100644
--- a/kernel/bpf/verifier.c
+++ b/kernel/bpf/verifier.c
@@ -985,9 +985,6 @@ static void __mark_reg_unbounded(struct bpf_reg_state *reg)
 	reg->smax_value = S64_MAX;
 	reg->umin_value = 0;
 	reg->umax_value = U64_MAX;
-
-	/* constant backtracking is enabled for root only for now */
-	reg->precise = capable(CAP_SYS_ADMIN) ? false : true;
 }
 
 /* Mark a register as having a completely unknown (scalar) value. */
@@ -1014,7 +1011,11 @@ static void mark_reg_unknown(struct bpf_verifier_env *env,
 			__mark_reg_not_init(regs + regno);
 		return;
 	}
-	__mark_reg_unknown(regs + regno);
+	regs += regno;
+	__mark_reg_unknown(regs);
+	/* constant backtracking is enabled for root without bpf2bpf calls */
+	regs->precise = env->subprog_cnt > 1 || !env->allow_ptr_leaks ?
+			true : false;
 }
 
 static void __mark_reg_not_init(struct bpf_reg_state *reg)
diff --git a/net/core/filter.c b/net/core/filter.c
index 7878f918b8c057..4c6a252d42122d 100644
--- a/net/core/filter.c
+++ b/net/core/filter.c
@@ -8757,13 +8757,13 @@ sk_reuseport_is_valid_access(int off, int size,
 		return size == size_default;
 
 	/* Fields that allow narrowing */
-	case offsetof(struct sk_reuseport_md, eth_protocol):
+	case bpf_ctx_range(struct sk_reuseport_md, eth_protocol):
 		if (size < FIELD_SIZEOF(struct sk_buff, protocol))
 			return false;
 		/* fall through */
-	case offsetof(struct sk_reuseport_md, ip_protocol):
-	case offsetof(struct sk_reuseport_md, bind_inany):
-	case offsetof(struct sk_reuseport_md, len):
+	case bpf_ctx_range(struct sk_reuseport_md, ip_protocol):
+	case bpf_ctx_range(struct sk_reuseport_md, bind_inany):
+	case bpf_ctx_range(struct sk_reuseport_md, len):
 		bpf_ctx_record_field_size(info, size_default);
 		return bpf_ctx_narrow_access_ok(off, size, size_default);
 
diff --git a/net/core/flow_dissector.c b/net/core/flow_dissector.c
index 3e6fedb57bc100..2470b4b404e62e 100644
--- a/net/core/flow_dissector.c
+++ b/net/core/flow_dissector.c
@@ -142,8 +142,8 @@ int skb_flow_dissector_bpf_prog_detach(const union bpf_attr *attr)
 		mutex_unlock(&flow_dissector_mutex);
 		return -ENOENT;
 	}
-	bpf_prog_put(attached);
 	RCU_INIT_POINTER(net->flow_dissector_prog, NULL);
+	bpf_prog_put(attached);
 	mutex_unlock(&flow_dissector_mutex);
 	return 0;
 }
diff --git a/net/xdp/xdp_umem.c b/net/xdp/xdp_umem.c
index 83de74ca729a39..688aac7a6943a9 100644
--- a/net/xdp/xdp_umem.c
+++ b/net/xdp/xdp_umem.c
@@ -365,7 +365,7 @@ static int xdp_umem_reg(struct xdp_umem *umem, struct xdp_umem_reg *mr)
 	umem->pages = kcalloc(umem->npgs, sizeof(*umem->pages), GFP_KERNEL);
 	if (!umem->pages) {
 		err = -ENOMEM;
-		goto out_account;
+		goto out_pin;
 	}
 
 	for (i = 0; i < umem->npgs; i++)
@@ -373,6 +373,8 @@ static int xdp_umem_reg(struct xdp_umem *umem, struct xdp_umem_reg *mr)
 
 	return 0;
 
+out_pin:
+	xdp_umem_unpin_pages(umem);
 out_account:
 	xdp_umem_unaccount_pages(umem);
 	return err;
diff --git a/tools/bpf/bpftool/prog.c b/tools/bpf/bpftool/prog.c
index 66f04a4846a587..43fdbbfe41bb24 100644
--- a/tools/bpf/bpftool/prog.c
+++ b/tools/bpf/bpftool/prog.c
@@ -363,7 +363,9 @@ static int do_show(int argc, char **argv)
 		if (fd < 0)
 			return -1;
 
-		return show_prog(fd);
+		err = show_prog(fd);
+		close(fd);
+		return err;
 	}
 
 	if (argc)
diff --git a/tools/testing/selftests/bpf/Makefile b/tools/testing/selftests/bpf/Makefile
index c085964e1d05a2..96752ebd938fa7 100644
--- a/tools/testing/selftests/bpf/Makefile
+++ b/tools/testing/selftests/bpf/Makefile
@@ -34,6 +34,9 @@ TEST_GEN_PROGS = test_verifier test_tag test_maps test_lru_map test_lpm_map test
 BPF_OBJ_FILES = $(patsubst %.c,%.o, $(notdir $(wildcard progs/*.c)))
 TEST_GEN_FILES = $(BPF_OBJ_FILES)
 
+BTF_C_FILES = $(wildcard progs/btf_dump_test_case_*.c)
+TEST_FILES = $(BTF_C_FILES)
+
 # Also test sub-register code-gen if LLVM has eBPF v3 processor support which
 # contains both ALU32 and JMP32 instructions.
 SUBREG_CODEGEN := $(shell echo "int cal(int a) { return a > 0; }" | \
@@ -68,7 +71,8 @@ TEST_PROGS := test_kmod.sh \
 TEST_PROGS_EXTENDED := with_addr.sh \
 	with_tunnels.sh \
 	tcp_client.py \
-	tcp_server.py
+	tcp_server.py \
+	test_xdp_vlan.sh
 
 # Compile but not part of 'make run_tests'
 TEST_GEN_PROGS_EXTENDED = test_libbpf_open test_sock_addr test_skb_cgroup_id_user \
diff --git a/tools/testing/selftests/bpf/config b/tools/testing/selftests/bpf/config
index f7a0744db31e1b..5dc109f4c0970f 100644
--- a/tools/testing/selftests/bpf/config
+++ b/tools/testing/selftests/bpf/config
@@ -34,3 +34,4 @@ CONFIG_NET_MPLS_GSO=m
 CONFIG_MPLS_ROUTING=m
 CONFIG_MPLS_IPTUNNEL=m
 CONFIG_IPV6_SIT=m
+CONFIG_BPF_JIT=y
diff --git a/tools/testing/selftests/bpf/test_btf_dump.c b/tools/testing/selftests/bpf/test_btf_dump.c
index 8f850823d35f83..6e75dd3cb14f97 100644
--- a/tools/testing/selftests/bpf/test_btf_dump.c
+++ b/tools/testing/selftests/bpf/test_btf_dump.c
@@ -97,6 +97,13 @@ int test_btf_dump_case(int n, struct btf_dump_test_case *test_case)
 	}
 
 	snprintf(test_file, sizeof(test_file), "progs/%s.c", test_case->name);
+	if (access(test_file, R_OK) == -1)
+		/*
+		 * When the test is run with O=, kselftest copies TEST_FILES
+		 * without preserving the directory structure.
+		 */
+		snprintf(test_file, sizeof(test_file), "%s.c",
+			test_case->name);
 	/*
 	 * Diff test output and expected test output, contained between
 	 * START-EXPECTED-OUTPUT and END-EXPECTED-OUTPUT lines in test case.
diff --git a/tools/testing/selftests/bpf/test_cgroup_storage.c b/tools/testing/selftests/bpf/test_cgroup_storage.c
index 2fc4625c1a1502..65572900439118 100644
--- a/tools/testing/selftests/bpf/test_cgroup_storage.c
+++ b/tools/testing/selftests/bpf/test_cgroup_storage.c
@@ -20,9 +20,9 @@ int main(int argc, char **argv)
 		BPF_MOV64_IMM(BPF_REG_2, 0), /* flags, not used */
 		BPF_RAW_INSN(BPF_JMP | BPF_CALL, 0, 0, 0,
 			     BPF_FUNC_get_local_storage),
-		BPF_LDX_MEM(BPF_W, BPF_REG_3, BPF_REG_0, 0),
+		BPF_LDX_MEM(BPF_DW, BPF_REG_3, BPF_REG_0, 0),
 		BPF_ALU64_IMM(BPF_ADD, BPF_REG_3, 0x1),
-		BPF_STX_MEM(BPF_W, BPF_REG_0, BPF_REG_3, 0),
+		BPF_STX_MEM(BPF_DW, BPF_REG_0, BPF_REG_3, 0),
 
 		BPF_LD_MAP_FD(BPF_REG_1, 0), /* map fd */
 		BPF_MOV64_IMM(BPF_REG_2, 0), /* flags, not used */
@@ -30,7 +30,7 @@ int main(int argc, char **argv)
 			     BPF_FUNC_get_local_storage),
 		BPF_MOV64_IMM(BPF_REG_1, 1),
 		BPF_STX_XADD(BPF_DW, BPF_REG_0, BPF_REG_1, 0),
-		BPF_LDX_MEM(BPF_W, BPF_REG_1, BPF_REG_0, 0),
+		BPF_LDX_MEM(BPF_DW, BPF_REG_1, BPF_REG_0, 0),
 		BPF_ALU64_IMM(BPF_AND, BPF_REG_1, 0x1),
 		BPF_MOV64_REG(BPF_REG_0, BPF_REG_1),
 		BPF_EXIT_INSN(),
diff --git a/tools/testing/selftests/bpf/test_sock.c b/tools/testing/selftests/bpf/test_sock.c
index fb679ac3d4b07a..0e665273346237 100644
--- a/tools/testing/selftests/bpf/test_sock.c
+++ b/tools/testing/selftests/bpf/test_sock.c
@@ -13,6 +13,7 @@
 #include <bpf/bpf.h>
 
 #include "cgroup_helpers.h"
+#include "bpf_endian.h"
 #include "bpf_rlimit.h"
 #include "bpf_util.h"
 
@@ -232,7 +233,8 @@ static struct sock_test tests[] = {
 			/* if (ip == expected && port == expected) */
 			BPF_LDX_MEM(BPF_W, BPF_REG_7, BPF_REG_6,
 				    offsetof(struct bpf_sock, src_ip6[3])),
-			BPF_JMP_IMM(BPF_JNE, BPF_REG_7, 0x01000000, 4),
+			BPF_JMP_IMM(BPF_JNE, BPF_REG_7,
+				    __bpf_constant_ntohl(0x00000001), 4),
 			BPF_LDX_MEM(BPF_W, BPF_REG_7, BPF_REG_6,
 				    offsetof(struct bpf_sock, src_port)),
 			BPF_JMP_IMM(BPF_JNE, BPF_REG_7, 0x2001, 2),
@@ -261,7 +263,8 @@ static struct sock_test tests[] = {
 			/* if (ip == expected && port == expected) */
 			BPF_LDX_MEM(BPF_W, BPF_REG_7, BPF_REG_6,
 				    offsetof(struct bpf_sock, src_ip4)),
-			BPF_JMP_IMM(BPF_JNE, BPF_REG_7, 0x0100007F, 4),
+			BPF_JMP_IMM(BPF_JNE, BPF_REG_7,
+				    __bpf_constant_ntohl(0x7F000001), 4),
 			BPF_LDX_MEM(BPF_W, BPF_REG_7, BPF_REG_6,
 				    offsetof(struct bpf_sock, src_port)),
 			BPF_JMP_IMM(BPF_JNE, BPF_REG_7, 0x1002, 2),