[PATCH] fsverity: use register_sysctl_init() to avoid kmemleak warning

[Eric Biggers <ebiggers@kernel.org>]

From: Eric Biggers <ebiggers@google.com>

Since the fsverity sysctl registration runs as a builtin initcall, there
is no corresponding sysctl deregistration and the resulting struct
ctl_table_header is not used.  This can cause a kmemleak warning just
after the system boots up.  (A pointer to the ctl_table_header is stored
in the fsverity_sysctl_header static variable, which kmemleak should
detect; however, the compiler can optimize out that variable.)  Avoid
the kmemleak warning by using register_sysctl_init() which is intended
for use by builtin initcalls and uses kmemleak_not_leak().

Reported-by: Yi Zhang <yi.zhang@redhat.com>
Closes: https://lore.kernel.org/r/CAHj4cs8DTSvR698UE040rs_pX1k-WVe7aR6N2OoXXuhXJPDC-w@mail.gmail.com
Cc: stable@vger.kernel.org
Signed-off-by: Eric Biggers <ebiggers@google.com>
---
 fs/verity/init.c | 7 +------
 1 file changed, 1 insertion(+), 6 deletions(-)

diff --git a/fs/verity/init.c b/fs/verity/init.c
index cb2c9aac61ed..f440f0e61e3e 100644
--- a/fs/verity/init.c
+++ b/fs/verity/init.c
@@ -8,12 +8,10 @@
 #include "fsverity_private.h"
 
 #include <linux/ratelimit.h>
 
 #ifdef CONFIG_SYSCTL
-static struct ctl_table_header *fsverity_sysctl_header;
-
 static struct ctl_table fsverity_sysctl_table[] = {
 #ifdef CONFIG_FS_VERITY_BUILTIN_SIGNATURES
 	{
 		.procname       = "require_signatures",
 		.data           = &fsverity_require_signatures,
@@ -26,14 +24,11 @@ static struct ctl_table fsverity_sysctl_table[] = {
 #endif
 };
 
 static void __init fsverity_init_sysctl(void)
 {
-	fsverity_sysctl_header = register_sysctl("fs/verity",
-						 fsverity_sysctl_table);
-	if (!fsverity_sysctl_header)
-		panic("fsverity sysctl registration failed");
+	register_sysctl_init("fs/verity", fsverity_sysctl_table);
 }
 #else /* CONFIG_SYSCTL */
 static inline void fsverity_init_sysctl(void)
 {
 }

base-commit: 18daea77cca626f590fb140fc11e3a43c5d41354
-- 
2.45.0