Merge tag 'sysctl-6.11-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/sysctl/sysctl

Pull sysctl updates from Joel Granados:

 - Remove "->procname == NULL" check when iterating through sysctl table
   arrays

   Removing sentinels in ctl_table arrays reduces the build time size
   and runtime memory consumed by ~64 bytes per array. With all
   ctl_table sentinels gone, the additional check for ->procname == NULL
   that worked in tandem with the ARRAY_SIZE to calculate the size of
   the ctl_table arrays is no longer needed and has been removed. The
   sysctl register functions now returns an error if a sentinel is used.

 - Preparation patches for sysctl constification

   Constifying ctl_table structs prevents the modification of
   proc_handler function pointers as they would reside in .rodata. The
   ctl_table arguments in sysctl utility functions are const qualified
   in preparation for a future treewide proc_handler argument
   constification commit.

 - Misc fixes

   Increase robustness of set_ownership by providing sane default
   ownership values in case the callee doesn't set them. Bound check
   proc_dou8vec_minmax to avoid loading buggy modules and give sysctl
   testing module a name to avoid compiler complaints.

* tag 'sysctl-6.11-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/sysctl/sysctl:
  sysctl: Warn on an empty procname element
  sysctl: Remove ctl_table sentinel code comments
  sysctl: Remove "child" sysctl code comments
  sysctl: Remove superfluous empty allocations from sysctl internals
  sysctl: Replace nr_entries with ctl_table_size in new_links
  sysctl: Remove check for sentinel element in ctl_table arrays
  mm profiling: Remove superfluous sentinel element from ctl_table
  locking: Remove superfluous sentinel element from kern_lockdep_table
  sysctl: Add module description to sysctl-testing
  sysctl: constify ctl_table arguments of utility function
  utsname: constify ctl_table arguments of utility function
  sysctl: move the extra1/2 boundary check of u8 to sysctl_check_table_array
  sysctl: always initialize i_uid/i_gid

4 files changed, 64 insertions, 20 deletions

diff --git a/kernel/locking/lockdep.c b/kernel/locking/lockdep.c
index 151bd3de5936..726b22ce7d0b 100644
--- a/kernel/locking/lockdep.c
+++ b/kernel/locking/lockdep.c
@@ -97,7 +97,6 @@ static struct ctl_table kern_lockdep_table[] = {
 		.proc_handler   = proc_dointvec,
 	},
 #endif /* CONFIG_LOCK_STAT */
-	{ }
 };
 
 static __init int kernel_lockdep_sysctls_init(void)
diff --git a/kernel/sysctl-test.c b/kernel/sysctl-test.c
index 6ef887c19c48..3ac98bb7fb82 100644
--- a/kernel/sysctl-test.c
+++ b/kernel/sysctl-test.c
@@ -367,6 +367,54 @@ static void sysctl_test_api_dointvec_write_single_greater_int_max(
 	KUNIT_EXPECT_EQ(test, 0, *((int *)table.data));
 }
 
+/*
+ * Test that registering an invalid extra value is not allowed.
+ */
+static void sysctl_test_register_sysctl_sz_invalid_extra_value(
+		struct kunit *test)
+{
+	unsigned char data = 0;
+	struct ctl_table table_foo[] = {
+		{
+			.procname	= "foo",
+			.data		= &data,
+			.maxlen		= sizeof(u8),
+			.mode		= 0644,
+			.proc_handler	= proc_dou8vec_minmax,
+			.extra1		= SYSCTL_FOUR,
+			.extra2		= SYSCTL_ONE_THOUSAND,
+		},
+	};
+
+	struct ctl_table table_bar[] = {
+		{
+			.procname	= "bar",
+			.data		= &data,
+			.maxlen		= sizeof(u8),
+			.mode		= 0644,
+			.proc_handler	= proc_dou8vec_minmax,
+			.extra1		= SYSCTL_NEG_ONE,
+			.extra2		= SYSCTL_ONE_HUNDRED,
+		},
+	};
+
+	struct ctl_table table_qux[] = {
+		{
+			.procname	= "qux",
+			.data		= &data,
+			.maxlen		= sizeof(u8),
+			.mode		= 0644,
+			.proc_handler	= proc_dou8vec_minmax,
+			.extra1		= SYSCTL_ZERO,
+			.extra2		= SYSCTL_TWO_HUNDRED,
+		},
+	};
+
+	KUNIT_EXPECT_NULL(test, register_sysctl("foo", table_foo));
+	KUNIT_EXPECT_NULL(test, register_sysctl("foo", table_bar));
+	KUNIT_EXPECT_NOT_NULL(test, register_sysctl("foo", table_qux));
+}
+
 static struct kunit_case sysctl_test_cases[] = {
 	KUNIT_CASE(sysctl_test_api_dointvec_null_tbl_data),
 	KUNIT_CASE(sysctl_test_api_dointvec_table_maxlen_unset),
@@ -378,6 +426,7 @@ static struct kunit_case sysctl_test_cases[] = {
 	KUNIT_CASE(sysctl_test_dointvec_write_happy_single_negative),
 	KUNIT_CASE(sysctl_test_api_dointvec_write_single_less_int_min),
 	KUNIT_CASE(sysctl_test_api_dointvec_write_single_greater_int_max),
+	KUNIT_CASE(sysctl_test_register_sysctl_sz_invalid_extra_value),
 	{}
 };
 
@@ -388,4 +437,5 @@ static struct kunit_suite sysctl_test_suite = {
 
 kunit_test_suites(&sysctl_test_suite);
 
+MODULE_DESCRIPTION("KUnit test of proc sysctl");
 MODULE_LICENSE("GPL v2");
diff --git a/kernel/sysctl.c b/kernel/sysctl.c
index e0b917328cf9..e4421594fc25 100644
--- a/kernel/sysctl.c
+++ b/kernel/sysctl.c
@@ -205,7 +205,7 @@ static int _proc_do_string(char *data, int maxlen, int write,
 	return 0;
 }
 
-static void warn_sysctl_write(struct ctl_table *table)
+static void warn_sysctl_write(const struct ctl_table *table)
 {
 	pr_warn_once("%s wrote to %s when file position was not 0!\n"
 		"This will not be supported in the future. To silence this\n"
@@ -223,7 +223,7 @@ static void warn_sysctl_write(struct ctl_table *table)
  * handlers can ignore the return value.
  */
 static bool proc_first_pos_non_zero_ignore(loff_t *ppos,
-					   struct ctl_table *table)
+					   const struct ctl_table *table)
 {
 	if (!*ppos)
 		return false;
@@ -468,7 +468,7 @@ static int do_proc_douintvec_conv(unsigned long *lvalp,
 
 static const char proc_wspace_sep[] = { ' ', '\t', '\n' };
 
-static int __do_proc_dointvec(void *tbl_data, struct ctl_table *table,
+static int __do_proc_dointvec(void *tbl_data, const struct ctl_table *table,
 		  int write, void *buffer,
 		  size_t *lenp, loff_t *ppos,
 		  int (*conv)(bool *negp, unsigned long *lvalp, int *valp,
@@ -541,7 +541,7 @@ out:
 	return err;
 }
 
-static int do_proc_dointvec(struct ctl_table *table, int write,
+static int do_proc_dointvec(const struct ctl_table *table, int write,
 		  void *buffer, size_t *lenp, loff_t *ppos,
 		  int (*conv)(bool *negp, unsigned long *lvalp, int *valp,
 			      int write, void *data),
@@ -552,7 +552,7 @@ static int do_proc_dointvec(struct ctl_table *table, int write,
 }
 
 static int do_proc_douintvec_w(unsigned int *tbl_data,
-			       struct ctl_table *table,
+			       const struct ctl_table *table,
 			       void *buffer,
 			       size_t *lenp, loff_t *ppos,
 			       int (*conv)(unsigned long *lvalp,
@@ -639,7 +639,7 @@ out:
 	return err;
 }
 
-static int __do_proc_douintvec(void *tbl_data, struct ctl_table *table,
+static int __do_proc_douintvec(void *tbl_data, const struct ctl_table *table,
 			       int write, void *buffer,
 			       size_t *lenp, loff_t *ppos,
 			       int (*conv)(unsigned long *lvalp,
@@ -675,7 +675,7 @@ static int __do_proc_douintvec(void *tbl_data, struct ctl_table *table,
 	return do_proc_douintvec_r(i, buffer, lenp, ppos, conv, data);
 }
 
-int do_proc_douintvec(struct ctl_table *table, int write,
+int do_proc_douintvec(const struct ctl_table *table, int write,
 		      void *buffer, size_t *lenp, loff_t *ppos,
 		      int (*conv)(unsigned long *lvalp,
 				  unsigned int *valp,
@@ -977,16 +977,10 @@ int proc_dou8vec_minmax(struct ctl_table *table, int write,
 	if (table->maxlen != sizeof(u8))
 		return -EINVAL;
 
-	if (table->extra1) {
+	if (table->extra1)
 		min = *(unsigned int *) table->extra1;
-		if (min > 255U)
-			return -EINVAL;
-	}
-	if (table->extra2) {
+	if (table->extra2)
 		max = *(unsigned int *) table->extra2;
-		if (max > 255U)
-			return -EINVAL;
-	}
 
 	tmp = *table;
 
@@ -1023,8 +1017,9 @@ static int sysrq_sysctl_handler(struct ctl_table *table, int write,
 }
 #endif
 
-static int __do_proc_doulongvec_minmax(void *data, struct ctl_table *table,
-		int write, void *buffer, size_t *lenp, loff_t *ppos,
+static int __do_proc_doulongvec_minmax(void *data,
+		const struct ctl_table *table, int write,
+		void *buffer, size_t *lenp, loff_t *ppos,
 		unsigned long convmul, unsigned long convdiv)
 {
 	unsigned long *i, *min, *max;
@@ -1096,7 +1091,7 @@ out:
 	return err;
 }
 
-static int do_proc_doulongvec_minmax(struct ctl_table *table, int write,
+static int do_proc_doulongvec_minmax(const struct ctl_table *table, int write,
 		void *buffer, size_t *lenp, loff_t *ppos, unsigned long convmul,
 		unsigned long convdiv)
 {
diff --git a/kernel/utsname_sysctl.c b/kernel/utsname_sysctl.c
index 76a772072557..04e4513f2985 100644
--- a/kernel/utsname_sysctl.c
+++ b/kernel/utsname_sysctl.c
@@ -15,7 +15,7 @@
 
 #ifdef CONFIG_PROC_SYSCTL
 
-static void *get_uts(struct ctl_table *table)
+static void *get_uts(const struct ctl_table *table)
 {
 	char *which = table->data;
 	struct uts_namespace *uts_ns;