Merge tag 'for-netdev' of https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf

Daniel Borkmann says:

====================
bpf 2023-01-27

We've added 10 non-merge commits during the last 9 day(s) which contain
a total of 10 files changed, 170 insertions(+), 59 deletions(-).

The main changes are:

1) Fix preservation of register's parent/live fields when copying
   range-info, from Eduard Zingerman.

2) Fix an off-by-one bug in bpf_mem_cache_idx() to select the right
   cache, from Hou Tao.

3) Fix stack overflow from infinite recursion in sock_map_close(),
   from Jakub Sitnicki.

4) Fix missing btf_put() in register_btf_id_dtor_kfuncs()'s error path,
   from Jiri Olsa.

5) Fix a splat from bpf_setsockopt() via lsm_cgroup/socket_sock_rcv_skb,
   from Kui-Feng Lee.

6) Fix bpf_send_signal[_thread]() helpers to hold a reference on the task,
   from Yonghong Song.

* tag 'for-netdev' of https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf:
  bpf: Fix the kernel crash caused by bpf_setsockopt().
  selftests/bpf: Cover listener cloning with progs attached to sockmap
  selftests/bpf: Pass BPF skeleton to sockmap_listen ops tests
  bpf, sockmap: Check for any of tcp_bpf_prots when cloning a listener
  bpf, sockmap: Don't let sock_map_{close,destroy,unhash} call itself
  bpf: Add missing btf_put to register_btf_id_dtor_kfuncs
  selftests/bpf: Verify copy_register_state() preserves parent/live fields
  bpf: Fix to preserve reg parent/live fields when copying range info
  bpf: Fix a possible task gone issue with bpf_send_signal[_thread]() helpers
  bpf: Fix off-by-one error in bpf_mem_cache_idx()
====================

Link: https://lore.kernel.org/r/20230127215820.4993-1-daniel@iogearbox.net
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

4 files changed, 21 insertions, 11 deletions

diff --git a/kernel/bpf/bpf_lsm.c b/kernel/bpf/bpf_lsm.c
index a4a41ee3e80b..e14c822f8911 100644
--- a/kernel/bpf/bpf_lsm.c
+++ b/kernel/bpf/bpf_lsm.c
@@ -51,7 +51,6 @@ BTF_SET_END(bpf_lsm_current_hooks)
  */
 BTF_SET_START(bpf_lsm_locked_sockopt_hooks)
 #ifdef CONFIG_SECURITY_NETWORK
-BTF_ID(func, bpf_lsm_socket_sock_rcv_skb)
 BTF_ID(func, bpf_lsm_sock_graft)
 BTF_ID(func, bpf_lsm_inet_csk_clone)
 BTF_ID(func, bpf_lsm_inet_conn_established)
diff --git a/kernel/bpf/btf.c b/kernel/bpf/btf.c
index f7dd8af06413..b7017cae6fd1 100644
--- a/kernel/bpf/btf.c
+++ b/kernel/bpf/btf.c
@@ -7782,9 +7782,9 @@ int register_btf_id_dtor_kfuncs(const struct btf_id_dtor_kfunc *dtors, u32 add_c
 
 	sort(tab->dtors, tab->cnt, sizeof(tab->dtors[0]), btf_id_cmp_func, NULL);
 
-	return 0;
 end:
-	btf_free_dtor_kfunc_tab(btf);
+	if (ret)
+		btf_free_dtor_kfunc_tab(btf);
 	btf_put(btf);
 	return ret;
 }
diff --git a/kernel/bpf/memalloc.c b/kernel/bpf/memalloc.c
index ebcc3dd0fa19..1db156405b68 100644
--- a/kernel/bpf/memalloc.c
+++ b/kernel/bpf/memalloc.c
@@ -71,7 +71,7 @@ static int bpf_mem_cache_idx(size_t size)
 	if (size <= 192)
 		return size_index[(size - 1) / 8] - 1;
 
-	return fls(size - 1) - 1;
+	return fls(size - 1) - 2;
 }
 
 #define NUM_CACHES 11
diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c
index dbef0b0967ae..7ee218827259 100644
--- a/kernel/bpf/verifier.c
+++ b/kernel/bpf/verifier.c
@@ -3243,13 +3243,24 @@ static bool __is_pointer_value(bool allow_ptr_leaks,
 	return reg->type != SCALAR_VALUE;
 }
 
+/* Copy src state preserving dst->parent and dst->live fields */
+static void copy_register_state(struct bpf_reg_state *dst, const struct bpf_reg_state *src)
+{
+	struct bpf_reg_state *parent = dst->parent;
+	enum bpf_reg_liveness live = dst->live;
+
+	*dst = *src;
+	dst->parent = parent;
+	dst->live = live;
+}
+
 static void save_register_state(struct bpf_func_state *state,
 				int spi, struct bpf_reg_state *reg,
 				int size)
 {
 	int i;
 
-	state->stack[spi].spilled_ptr = *reg;
+	copy_register_state(&state->stack[spi].spilled_ptr, reg);
 	if (size == BPF_REG_SIZE)
 		state->stack[spi].spilled_ptr.live |= REG_LIVE_WRITTEN;
 
@@ -3577,7 +3588,7 @@ static int check_stack_read_fixed_off(struct bpf_verifier_env *env,
 				 */
 				s32 subreg_def = state->regs[dst_regno].subreg_def;
 
-				state->regs[dst_regno] = *reg;
+				copy_register_state(&state->regs[dst_regno], reg);
 				state->regs[dst_regno].subreg_def = subreg_def;
 			} else {
 				for (i = 0; i < size; i++) {
@@ -3598,7 +3609,7 @@ static int check_stack_read_fixed_off(struct bpf_verifier_env *env,
 
 		if (dst_regno >= 0) {
 			/* restore register state from stack */
-			state->regs[dst_regno] = *reg;
+			copy_register_state(&state->regs[dst_regno], reg);
 			/* mark reg as written since spilled pointer state likely
 			 * has its liveness marks cleared by is_state_visited()
 			 * which resets stack/reg liveness for state transitions
@@ -9592,7 +9603,7 @@ do_sim:
 	 */
 	if (!ptr_is_dst_reg) {
 		tmp = *dst_reg;
-		*dst_reg = *ptr_reg;
+		copy_register_state(dst_reg, ptr_reg);
 	}
 	ret = sanitize_speculative_path(env, NULL, env->insn_idx + 1,
 					env->insn_idx);
@@ -10845,7 +10856,7 @@ static int check_alu_op(struct bpf_verifier_env *env, struct bpf_insn *insn)
 					 * to propagate min/max range.
 					 */
 					src_reg->id = ++env->id_gen;
-				*dst_reg = *src_reg;
+				copy_register_state(dst_reg, src_reg);
 				dst_reg->live |= REG_LIVE_WRITTEN;
 				dst_reg->subreg_def = DEF_NOT_SUBREG;
 			} else {
@@ -10856,7 +10867,7 @@ static int check_alu_op(struct bpf_verifier_env *env, struct bpf_insn *insn)
 						insn->src_reg);
 					return -EACCES;
 				} else if (src_reg->type == SCALAR_VALUE) {
-					*dst_reg = *src_reg;
+					copy_register_state(dst_reg, src_reg);
 					/* Make sure ID is cleared otherwise
 					 * dst_reg min/max could be incorrectly
 					 * propagated into src_reg by find_equal_scalars()
@@ -11655,7 +11666,7 @@ static void find_equal_scalars(struct bpf_verifier_state *vstate,
 
 	bpf_for_each_reg_in_vstate(vstate, state, reg, ({
 		if (reg->type == SCALAR_VALUE && reg->id == known_reg->id)
-			*reg = *known_reg;
+			copy_register_state(reg, known_reg);
 	}));
 }