Patch "KEYS: trusted: Remove redundant static calls usage" has been added to the 5.15-stable tree

[Sasha Levin <sashal@xxxxxxxxxx>]

This is a note to let you know that I've just added the patch titled

    KEYS: trusted: Remove redundant static calls usage

to the 5.15-stable tree which can be found at:
    http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
     keys-trusted-remove-redundant-static-calls-usage.patch
and it can be found in the queue-5.15 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.



commit f43ea73a001e725413df02b2414170748291a03b
Author: Sumit Garg <sumit.garg@xxxxxxxxxx>
Date:   Fri Oct 6 10:48:01 2023 +0530

    KEYS: trusted: Remove redundant static calls usage
    
    [ Upstream commit 01bbafc63b65689cb179ca537971286bc27f3b74 ]
    
    Static calls invocations aren't well supported from module __init and
    __exit functions. Especially the static call from cleanup_trusted() led
    to a crash on x86 kernel with CONFIG_DEBUG_VIRTUAL=y.
    
    However, the usage of static call invocations for trusted_key_init()
    and trusted_key_exit() don't add any value from either a performance or
    security perspective. Hence switch to use indirect function calls instead.
    
    Note here that although it will fix the current crash report, ultimately
    the static call infrastructure should be fixed to either support its
    future usage from module __init and __exit functions or not.
    
    Reported-and-tested-by: Hyeonggon Yoo <42.hyeyoo@xxxxxxxxx>
    Link: https://lore.kernel.org/lkml/ZRhKq6e5nF%2F4ZIV1@fedora/#t
    Fixes: 5d0682be3189 ("KEYS: trusted: Add generic trusted keys framework")
    Signed-off-by: Sumit Garg <sumit.garg@xxxxxxxxxx>
    Signed-off-by: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx>
    Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>

diff --git a/security/keys/trusted-keys/trusted_core.c b/security/keys/trusted-keys/trusted_core.c
index 79806594384e3..386e5f6e368ab 100644
--- a/security/keys/trusted-keys/trusted_core.c
+++ b/security/keys/trusted-keys/trusted_core.c
@@ -40,13 +40,12 @@ static const struct trusted_key_source trusted_key_sources[] = {
 #endif
 };
 
-DEFINE_STATIC_CALL_NULL(trusted_key_init, *trusted_key_sources[0].ops->init);
 DEFINE_STATIC_CALL_NULL(trusted_key_seal, *trusted_key_sources[0].ops->seal);
 DEFINE_STATIC_CALL_NULL(trusted_key_unseal,
 			*trusted_key_sources[0].ops->unseal);
 DEFINE_STATIC_CALL_NULL(trusted_key_get_random,
 			*trusted_key_sources[0].ops->get_random);
-DEFINE_STATIC_CALL_NULL(trusted_key_exit, *trusted_key_sources[0].ops->exit);
+static void (*trusted_key_exit)(void);
 static unsigned char migratable;
 
 enum {
@@ -355,19 +354,16 @@ static int __init init_trusted(void)
 		if (!get_random)
 			get_random = kernel_get_random;
 
-		static_call_update(trusted_key_init,
-				   trusted_key_sources[i].ops->init);
 		static_call_update(trusted_key_seal,
 				   trusted_key_sources[i].ops->seal);
 		static_call_update(trusted_key_unseal,
 				   trusted_key_sources[i].ops->unseal);
 		static_call_update(trusted_key_get_random,
 				   get_random);
-		static_call_update(trusted_key_exit,
-				   trusted_key_sources[i].ops->exit);
+		trusted_key_exit = trusted_key_sources[i].ops->exit;
 		migratable = trusted_key_sources[i].ops->migratable;
 
-		ret = static_call(trusted_key_init)();
+		ret = trusted_key_sources[i].ops->init();
 		if (!ret)
 			break;
 	}
@@ -384,7 +380,8 @@ static int __init init_trusted(void)
 
 static void __exit cleanup_trusted(void)
 {
-	static_call_cond(trusted_key_exit)();
+	if (trusted_key_exit)
+		(*trusted_key_exit)();
 }
 
 late_initcall(init_trusted);