Commit 6c2128505f61 for kernel

commit 6c2128505f61b504c79a20b89596feba61388112
Author: Ihor Solodrai <ihor.solodrai@linux.dev>
Date:   Thu Mar 19 17:08:08 2026 -0700

    bpf: Fix exception exit lock checking for subprogs

    process_bpf_exit_full() passes check_lock = !curframe to
    check_resource_leak(), which is false in cases when bpf_throw() is
    called from a static subprog. This makes check_resource_leak() to skip
    validation of active_rcu_locks, active_preempt_locks, and
    active_irq_id on exception exits from subprogs.

    At runtime bpf_throw() unwinds the stack via ORC without releasing any
    user-acquired locks, which may cause various issues as the result.

    Fix by setting check_lock = true for exception exits regardless of
    curframe, since exceptions bypass all intermediate frame
    cleanup. Update the error message prefix to "bpf_throw" for exception
    exits to distinguish them from normal BPF_EXIT.

    Fix reject_subprog_with_rcu_read_lock test which was previously
    passing for the wrong reason. Test program returned directly from the
    subprog call without closing the RCU section, so the error was
    triggered by the unclosed RCU lock on normal exit, not by
    bpf_throw. Update __msg annotations for affected tests to match the
    new "bpf_throw" error prefix.

    The spin_lock case is not affected because they are already checked [1]
    at the call site in do_check_insn() before bpf_throw can run.

    [1] https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/kernel/bpf/verifier.c?h=v7.0-rc4#n21098

    Assisted-by: Claude:claude-opus-4-6
    Fixes: f18b03fabaa9 ("bpf: Implement BPF exceptions")
    Signed-off-by: Ihor Solodrai <ihor.solodrai@linux.dev>
    Acked-by: Yonghong Song <yonghong.song@linux.dev>
    Acked-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
    Link: https://lore.kernel.org/r/20260320000809.643798-1-ihor.solodrai@linux.dev
    Signed-off-by: Alexei Starovoitov <ast@kernel.org>

diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c
index df22bfc572e2..5c0e6809024f 100644
--- a/kernel/bpf/verifier.c
+++ b/kernel/bpf/verifier.c
@@ -20911,7 +20911,8 @@ static int process_bpf_exit_full(struct bpf_verifier_env *env,
 	 * state when it exits.
 	 */
 	int err = check_resource_leak(env, exception_exit,
-				      !env->cur_state->curframe,
+				      exception_exit || !env->cur_state->curframe,
+				      exception_exit ? "bpf_throw" :
 				      "BPF_EXIT instruction in main prog");
 	if (err)
 		return err;
diff --git a/tools/testing/selftests/bpf/progs/exceptions_fail.c b/tools/testing/selftests/bpf/progs/exceptions_fail.c
index 8a0fdff89927..d7f1c492e3dd 100644
--- a/tools/testing/selftests/bpf/progs/exceptions_fail.c
+++ b/tools/testing/selftests/bpf/progs/exceptions_fail.c
@@ -8,6 +8,7 @@
 #include "bpf_experimental.h"

 extern void bpf_rcu_read_lock(void) __ksym;
+extern void bpf_rcu_read_unlock(void) __ksym;

 #define private(name) SEC(".bss." #name) __hidden __attribute__((aligned(8)))

@@ -131,7 +132,7 @@ int reject_subprog_with_lock(void *ctx)
 }

 SEC("?tc")
-__failure __msg("BPF_EXIT instruction in main prog cannot be used inside bpf_rcu_read_lock-ed region")
+__failure __msg("bpf_throw cannot be used inside bpf_rcu_read_lock-ed region")
 int reject_with_rcu_read_lock(void *ctx)
 {
 	bpf_rcu_read_lock();
@@ -147,11 +148,13 @@ __noinline static int throwing_subprog(struct __sk_buff *ctx)
 }

 SEC("?tc")
-__failure __msg("BPF_EXIT instruction in main prog cannot be used inside bpf_rcu_read_lock-ed region")
+__failure __msg("bpf_throw cannot be used inside bpf_rcu_read_lock-ed region")
 int reject_subprog_with_rcu_read_lock(void *ctx)
 {
 	bpf_rcu_read_lock();
-	return throwing_subprog(ctx);
+	throwing_subprog(ctx);
+	bpf_rcu_read_unlock();
+	return 0;
 }

 static bool rbless(struct bpf_rb_node *n1, const struct bpf_rb_node *n2)