Merge branch 'misc-bug-fixes-part-1'

Kumar Kartikeya Dwivedi says:

====================
Misc bug fixes - part 1

A set of miscellaneous fixes for bugs reported by Nicholas. These are
easy ones and should not require any major discussion, hence batched
together. See commit logs and selftests for details.
====================

Link: https://patch.msgid.link/20260903144433.1716731-1-memxor@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>

3 files changed, 25 insertions, 0 deletions

diff --git a/kernel/bpf/btf.c b/kernel/bpf/btf.c
index 85ae92c920e4..5d93fd82e764 100644
--- a/kernel/bpf/btf.c
+++ b/kernel/bpf/btf.c
@@ -6672,6 +6672,10 @@ struct bpf_raw_tp_null_args {
 static const struct bpf_raw_tp_null_args raw_tp_null_args[] = {
 	/* sched */
 	{ "sched_pi_setprio", 0x10 },
+	/*
+	 * do_wait() passes NULL for wait4(-1) and waitid(P_ALL).
+	 */
+	{ "sched_process_wait", 0x1 },
 	/* ... from sched_numa_pair_template event class */
 	{ "sched_stick_numa", 0x100 },
 	{ "sched_swap_numa", 0x100 },
@@ -6732,6 +6736,9 @@ static const struct bpf_raw_tp_null_args raw_tp_null_args[] = {
 	{ "rxrpc_resend", 0x10 },
 	{ "rxrpc_tq", 0x10 },
 	{ "rxrpc_client", 0x1 },
+	/* signal */
+	{ "signal_generate", 0x20 },
+	{ "signal_deliver", 0x20 },
 	/* skb */
 	{"kfree_skb", 0x1000},
 	/* sunrpc */
diff --git a/kernel/bpf/syscall.c b/kernel/bpf/syscall.c
index 6874ba1424af..c7bc9ba9b331 100644
--- a/kernel/bpf/syscall.c
+++ b/kernel/bpf/syscall.c
@@ -6568,6 +6568,7 @@ EXPORT_SYMBOL_NS(kern_sys_bpf, "BPF_INTERNAL");
 static const struct bpf_func_proto bpf_sys_bpf_proto = {
 	.func		= bpf_sys_bpf,
 	.gpl_only	= false,
+	.might_sleep	= true,
 	.ret_type	= RET_INTEGER,
 	.arg1_type	= ARG_ANYTHING,
 	.arg2_type	= ARG_PTR_TO_MEM | MEM_RDONLY,
@@ -6593,6 +6594,7 @@ BPF_CALL_1(bpf_sys_close, u32, fd)
 static const struct bpf_func_proto bpf_sys_close_proto = {
 	.func		= bpf_sys_close,
 	.gpl_only	= false,
+	.might_sleep	= true,
 	.ret_type	= RET_INTEGER,
 	.arg1_type	= ARG_ANYTHING,
 };
diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c
index 7d8ddb1bee00..32d31fa67036 100644
--- a/kernel/bpf/verifier.c
+++ b/kernel/bpf/verifier.c
@@ -11228,6 +11228,17 @@ static int check_helper_call(struct bpf_verifier_env *env, struct bpf_insn *insn
 		if (env->cur_state->curframe) {
 			struct bpf_verifier_state *branch;
 
+			/*
+			 * A taken tail call is modeled as a return from the current
+			 * frame. A callback frame cannot be left that way because
+			 * prepare_func_exit() would apply its return contract to the
+			 * unknown R0 synthesized below. Stack-depth validation rejects
+			 * this construct anyway.
+			 */
+			if (cur_func(env)->in_callback_fn) {
+				verbose(env, "cannot tail call within callback\n");
+				return -EINVAL;
+			}
 			mark_reg_scratched(env, BPF_REG_0);
 			branch = push_stack(env, env->insn_idx + 1, env->insn_idx, false);
 			if (IS_ERR(branch))
@@ -13230,6 +13241,11 @@ check_ok:
 		{
 			int flags = PROCESS_RES_LOCK;
 
+			if (in_rbtree_lock_required_cb(env)) {
+				verbose(env, "can't res_spin_{lock,unlock} in rbtree cb\n");
+				return -EACCES;
+			}
+
 			if (reg->type != PTR_TO_MAP_VALUE && reg->type != (PTR_TO_BTF_ID | MEM_ALLOC)) {
 				verbose(env, "%s doesn't point to map value or allocated object\n",
 					reg_arg_name(env, argno));