diff --git a/fs/binfmt_misc.c b/fs/binfmt_misc.c
index 70a18623a22b..d568cd5cc928 100644
--- a/fs/binfmt_misc.c
+++ b/fs/binfmt_misc.c
@@ -10,6 +10,7 @@
 
 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
 
+#include <linux/array_size.h>
 #include <linux/binfmt_misc.h>
 #include <linux/binfmts.h>
 #include <linux/bitops.h>
@@ -51,6 +52,36 @@ enum binfmt_misc_entry_flags {
 	MISC_FMT_OPEN_FILE	= (1U << 28),
 };
 
+/**
+ * struct binfmt_misc_flag - a flag character of the register string
+ * @c: the character userspace writes and reads back
+ * @flag: the entry flag it sets
+ * @implies: entry flags it turns on in addition
+ * @desc: what it does, for the registration debug output
+ */
+struct binfmt_misc_flag {
+	char		c;
+	unsigned long	flag;
+	unsigned long	implies;
+	const char	*desc;
+};
+
+static const struct binfmt_misc_flag misc_flags[] = {
+	{ 'P', MISC_FMT_PRESERVE_ARGV0,	0,			"preserve argv0"		},
+	{ 'O', MISC_FMT_OPEN_BINARY,	0,			"open binary"			},
+	{ 'C', MISC_FMT_CREDENTIALS,	MISC_FMT_OPEN_BINARY,	"credentials from the binary"	},
+	{ 'F', MISC_FMT_OPEN_FILE,	0,			"open interpreter file now"	},
+};
+
+/* Look up a flag character, NULL if @c is not one. */
+static const struct binfmt_misc_flag *misc_flag_by_char(const char c)
+{
+	for (int i = 0; i < ARRAY_SIZE(misc_flags); i++)
+		if (misc_flags[i].c == c)
+			return &misc_flags[i];
+	return NULL;
+}
+
 struct binfmt_misc_entry {
 	struct hlist_node node;
 	unsigned long flags;		/* type, status, etc. */
@@ -424,30 +455,16 @@ static char *scanarg(char *s, char del)
 	return s;
 }
 
+/* Parse the 'flags' field, stopping at the first character that is not one. */
 static char *check_special_flags(char *p, struct binfmt_misc_entry *e)
 {
 	for (;; p++) {
-		switch (*p) {
-		case 'P':
-			pr_debug("register: flag: P (preserve argv0)\n");
-			e->flags |= MISC_FMT_PRESERVE_ARGV0;
-			break;
-		case 'O':
-			pr_debug("register: flag: O (open binary)\n");
-			e->flags |= MISC_FMT_OPEN_BINARY;
-			break;
-		case 'C':
-			pr_debug("register: flag: C (preserve creds)\n");
-			/* C implies O */
-			e->flags |= MISC_FMT_CREDENTIALS | MISC_FMT_OPEN_BINARY;
-			break;
-		case 'F':
-			pr_debug("register: flag: F: open interpreter file now\n");
-			e->flags |= MISC_FMT_OPEN_FILE;
-			break;
-		default:
+		const struct binfmt_misc_flag *f = misc_flag_by_char(*p);
+
+		if (!f)
 			return p;
-		}
+		pr_debug("register: flag: %c (%s)\n", f->c, f->desc);
+		e->flags |= f->flag | f->implies;
 	}
 }
 
@@ -570,7 +587,7 @@ static struct binfmt_misc_entry *create_entry(const char __user *buffer,
 					      size_t count)
 {
 	struct binfmt_misc_entry *e __free(kfree) = NULL;
-	char *buf, *p;
+	char *buf, *p, *flags;
 	char del;
 
 	pr_debug("register: received %zu bytes\n", count);
@@ -595,7 +612,7 @@ static struct binfmt_misc_entry *create_entry(const char __user *buffer,
 	pr_debug("register: delim: %#x {%c}\n", del, del);
 
 	/* A flag-char delimiter runs the flag scan off the buffer. */
-	if (del == 'P' || del == 'O' || del == 'C' || del == 'F')
+	if (misc_flag_by_char(del))
 		return ERR_PTR(-EINVAL);
 
 	/* Pad the buffer with the delim to simplify parsing below. */
@@ -666,21 +683,21 @@ static struct binfmt_misc_entry *create_entry(const char __user *buffer,
 	}
 
 	/* Parse the 'flags' field. */
+	flags = p;
 	p = check_special_flags(p, e);
-	if (*p == '\n')
-		p++;
-	if (p != buf + count)
-		return ERR_PTR(-EINVAL);
 
 	/*
 	 * A bpf handler decides the invocation flags per exec with
-	 * bpf_binprm_set_flags() rather than fixing them at registration, so a
-	 * 'B' entry carries no flags: 'P', 'C' and 'O' become per-exec choices
-	 * and 'F' (pre-open a fixed interpreter) is meaningless for it.
+	 * bpf_binprm_set_flags() rather than fixing them at registration, and
+	 * 'F' (pre-open a fixed interpreter) is meaningless for it, so a 'B'
+	 * entry's flags field has to be empty.
 	 */
-	if (test_bit(MISC_FMT_BPF_BIT, &e->flags) &&
-	    (e->flags & (MISC_FMT_PRESERVE_ARGV0 | MISC_FMT_OPEN_BINARY |
-			 MISC_FMT_CREDENTIALS | MISC_FMT_OPEN_FILE)))
+	if (test_bit(MISC_FMT_BPF_BIT, &e->flags) && p != flags)
+		return ERR_PTR(-EINVAL);
+
+	if (*p == '\n')
+		p++;
+	if (p != buf + count)
 		return ERR_PTR(-EINVAL);
 
 	/* Non-F opens the interp at exec against the caller's cwd; require absolute. */
@@ -749,14 +766,9 @@ static int bm_entry_show(struct seq_file *m, void *unused)
 
 	/* print the special flags */
 	seq_puts(m, "flags: ");
-	if (e->flags & MISC_FMT_PRESERVE_ARGV0)
-		seq_putc(m, 'P');
-	if (e->flags & MISC_FMT_OPEN_BINARY)
-		seq_putc(m, 'O');
-	if (e->flags & MISC_FMT_CREDENTIALS)
-		seq_putc(m, 'C');
-	if (e->flags & MISC_FMT_OPEN_FILE)
-		seq_putc(m, 'F');
+	for (int i = 0; i < ARRAY_SIZE(misc_flags); i++)
+		if (e->flags & misc_flags[i].flag)
+			seq_putc(m, misc_flags[i].c);
 	seq_putc(m, '\n');
 
 	if (test_bit(MISC_FMT_BPF_BIT, &e->flags)) {