diff --git a/drivers/md/dm-clone-metadata.c b/drivers/md/dm-clone-metadata.c
index c43d55672bce035b50549f070eb2a5535b4447d4..47c1fa7aad8b5b993af919b9ae98cdaa0f3f0559 100644
--- a/drivers/md/dm-clone-metadata.c
+++ b/drivers/md/dm-clone-metadata.c
@@ -465,11 +465,6 @@ static void __destroy_persistent_data_structures(struct dm_clone_metadata *cmd)
 
 /*---------------------------------------------------------------------------*/
 
-static size_t bitmap_size(unsigned long nr_bits)
-{
-	return BITS_TO_LONGS(nr_bits) * sizeof(long);
-}
-
 static int __dirty_map_init(struct dirty_map *dmap, unsigned long nr_words,
 			    unsigned long nr_regions)
 {
diff --git a/drivers/s390/cio/idset.c b/drivers/s390/cio/idset.c
index 45f9c0736be4fd3fc58e0ae58e28ec7fadd24e5d..e5f28370a9039d71e9b353908632aba61c9fa307 100644
--- a/drivers/s390/cio/idset.c
+++ b/drivers/s390/cio/idset.c
@@ -16,20 +16,21 @@ struct idset {
 	unsigned long bitmap[];
 };
 
-static inline unsigned long bitmap_size(int num_ssid, int num_id)
+static inline unsigned long idset_bitmap_size(int num_ssid, int num_id)
 {
-	return BITS_TO_LONGS(num_ssid * num_id) * sizeof(unsigned long);
+	return bitmap_size(size_mul(num_ssid, num_id));
 }
 
 static struct idset *idset_new(int num_ssid, int num_id)
 {
 	struct idset *set;
 
-	set = vmalloc(sizeof(struct idset) + bitmap_size(num_ssid, num_id));
+	set = vmalloc(sizeof(struct idset) +
+		      idset_bitmap_size(num_ssid, num_id));
 	if (set) {
 		set->num_ssid = num_ssid;
 		set->num_id = num_id;
-		memset(set->bitmap, 0, bitmap_size(num_ssid, num_id));
+		memset(set->bitmap, 0, idset_bitmap_size(num_ssid, num_id));
 	}
 	return set;
 }
@@ -41,7 +42,8 @@ void idset_free(struct idset *set)
 
 void idset_fill(struct idset *set)
 {
-	memset(set->bitmap, 0xff, bitmap_size(set->num_ssid, set->num_id));
+	memset(set->bitmap, 0xff,
+	       idset_bitmap_size(set->num_ssid, set->num_id));
 }
 
 static inline void idset_add(struct idset *set, int ssid, int id)
diff --git a/fs/file.c b/fs/file.c
index b74dc85d56d0659dd189840ee5e4ad6617aead7d..a9569adf42d953eadc09cca9ac15564826d73ad9 100644
--- a/fs/file.c
+++ b/fs/file.c
@@ -47,27 +47,23 @@ static void free_fdtable_rcu(struct rcu_head *rcu)
 #define BITBIT_NR(nr)	BITS_TO_LONGS(BITS_TO_LONGS(nr))
 #define BITBIT_SIZE(nr)	(BITBIT_NR(nr) * sizeof(long))
 
+#define fdt_words(fdt) ((fdt)->max_fds / BITS_PER_LONG) // words in ->open_fds
 /*
  * Copy 'count' fd bits from the old table to the new table and clear the extra
  * space if any.  This does not copy the file pointers.  Called with the files
  * spinlock held for write.
  */
-static void copy_fd_bitmaps(struct fdtable *nfdt, struct fdtable *ofdt,
-			    unsigned int count)
+static inline void copy_fd_bitmaps(struct fdtable *nfdt, struct fdtable *ofdt,
+			    unsigned int copy_words)
 {
-	unsigned int cpy, set;
-
-	cpy = count / BITS_PER_BYTE;
-	set = (nfdt->max_fds - count) / BITS_PER_BYTE;
-	memcpy(nfdt->open_fds, ofdt->open_fds, cpy);
-	memset((char *)nfdt->open_fds + cpy, 0, set);
-	memcpy(nfdt->close_on_exec, ofdt->close_on_exec, cpy);
-	memset((char *)nfdt->close_on_exec + cpy, 0, set);
-
-	cpy = BITBIT_SIZE(count);
-	set = BITBIT_SIZE(nfdt->max_fds) - cpy;
-	memcpy(nfdt->full_fds_bits, ofdt->full_fds_bits, cpy);
-	memset((char *)nfdt->full_fds_bits + cpy, 0, set);
+	unsigned int nwords = fdt_words(nfdt);
+
+	bitmap_copy_and_extend(nfdt->open_fds, ofdt->open_fds,
+			copy_words * BITS_PER_LONG, nwords * BITS_PER_LONG);
+	bitmap_copy_and_extend(nfdt->close_on_exec, ofdt->close_on_exec,
+			copy_words * BITS_PER_LONG, nwords * BITS_PER_LONG);
+	bitmap_copy_and_extend(nfdt->full_fds_bits, ofdt->full_fds_bits,
+			copy_words, nwords);
 }
 
 /*
@@ -85,7 +81,7 @@ static void copy_fdtable(struct fdtable *nfdt, struct fdtable *ofdt)
 	memcpy(nfdt->fd, ofdt->fd, cpy);
 	memset((char *)nfdt->fd + cpy, 0, set);
 
-	copy_fd_bitmaps(nfdt, ofdt, ofdt->max_fds);
+	copy_fd_bitmaps(nfdt, ofdt, fdt_words(ofdt));
 }
 
 /*
@@ -376,7 +372,7 @@ struct files_struct *dup_fd(struct files_struct *oldf, unsigned int max_fds, int
 		open_files = sane_fdtable_size(old_fdt, max_fds);
 	}
 
-	copy_fd_bitmaps(new_fdt, old_fdt, open_files);
+	copy_fd_bitmaps(new_fdt, old_fdt, open_files / BITS_PER_LONG);
 
 	old_fds = old_fdt->fd;
 	new_fds = new_fdt->fd;
diff --git a/fs/ntfs3/bitmap.c b/fs/ntfs3/bitmap.c
index 931a7744d1865497770323851e7358d433928b88..cf4fe21a50399b0baec20ca2682eca12a2c950e2 100644
--- a/fs/ntfs3/bitmap.c
+++ b/fs/ntfs3/bitmap.c
@@ -654,7 +654,7 @@ int wnd_init(struct wnd_bitmap *wnd, struct super_block *sb, size_t nbits)
 	wnd->total_zeroes = nbits;
 	wnd->extent_max = MINUS_ONE_T;
 	wnd->zone_bit = wnd->zone_end = 0;
-	wnd->nwnd = bytes_to_block(sb, bitmap_size(nbits));
+	wnd->nwnd = bytes_to_block(sb, ntfs3_bitmap_size(nbits));
 	wnd->bits_last = nbits & (wbits - 1);
 	if (!wnd->bits_last)
 		wnd->bits_last = wbits;
@@ -1347,7 +1347,7 @@ int wnd_extend(struct wnd_bitmap *wnd, size_t new_bits)
 		return -EINVAL;
 
 	/* Align to 8 byte boundary. */
-	new_wnd = bytes_to_block(sb, bitmap_size(new_bits));
+	new_wnd = bytes_to_block(sb, ntfs3_bitmap_size(new_bits));
 	new_last = new_bits & (wbits - 1);
 	if (!new_last)
 		new_last = wbits;
diff --git a/fs/ntfs3/fsntfs.c b/fs/ntfs3/fsntfs.c
index c66b0eab6a1606a36583bfa8ff8684cceb999bd5..e19b13db4f91eef238e7e0baa69eb833ef619e8d 100644
--- a/fs/ntfs3/fsntfs.c
+++ b/fs/ntfs3/fsntfs.c
@@ -522,7 +522,7 @@ static int ntfs_extend_mft(struct ntfs_sb_info *sbi)
 	ni->mi.dirty = true;
 
 	/* Step 2: Resize $MFT::BITMAP. */
-	new_bitmap_bytes = bitmap_size(new_mft_total);
+	new_bitmap_bytes = ntfs3_bitmap_size(new_mft_total);
 
 	err = attr_set_size(ni, ATTR_BITMAP, NULL, 0, &sbi->mft.bitmap.run,
 			    new_bitmap_bytes, &new_bitmap_bytes, true, NULL);
diff --git a/fs/ntfs3/index.c b/fs/ntfs3/index.c
index 0d8a96136b084095f47b966fa48dfaf1ce98cd0d..9089c58a005ce1b51d0ec291f1dbc6f4b4b0d153 100644
--- a/fs/ntfs3/index.c
+++ b/fs/ntfs3/index.c
@@ -1456,8 +1456,8 @@ static int indx_create_allocate(struct ntfs_index *indx, struct ntfs_inode *ni,
 
 	alloc->nres.valid_size = alloc->nres.data_size = cpu_to_le64(data_size);
 
-	err = ni_insert_resident(ni, bitmap_size(1), ATTR_BITMAP, in->name,
-				 in->name_len, &bitmap, NULL, NULL);
+	err = ni_insert_resident(ni, ntfs3_bitmap_size(1), ATTR_BITMAP,
+				 in->name, in->name_len, &bitmap, NULL, NULL);
 	if (err)
 		goto out2;
 
@@ -1518,8 +1518,9 @@ static int indx_add_allocate(struct ntfs_index *indx, struct ntfs_inode *ni,
 	if (bmp) {
 		/* Increase bitmap. */
 		err = attr_set_size(ni, ATTR_BITMAP, in->name, in->name_len,
-				    &indx->bitmap_run, bitmap_size(bit + 1),
-				    NULL, true, NULL);
+				    &indx->bitmap_run,
+				    ntfs3_bitmap_size(bit + 1), NULL, true,
+				    NULL);
 		if (err)
 			goto out1;
 	}
@@ -2098,7 +2099,7 @@ static int indx_shrink(struct ntfs_index *indx, struct ntfs_inode *ni,
 	if (in->name == I30_NAME)
 		i_size_write(&ni->vfs_inode, new_data);
 
-	bpb = bitmap_size(bit);
+	bpb = ntfs3_bitmap_size(bit);
 	if (bpb * 8 == nbits)
 		return 0;
 
diff --git a/fs/ntfs3/ntfs_fs.h b/fs/ntfs3/ntfs_fs.h
index 1ca40c1d966b8e336289f64d6fc8077d6975658b..28788cf6ba4074988004149694bd6aeffb207cb1 100644
--- a/fs/ntfs3/ntfs_fs.h
+++ b/fs/ntfs3/ntfs_fs.h
@@ -964,9 +964,9 @@ static inline bool run_is_empty(struct runs_tree *run)
 }
 
 /* NTFS uses quad aligned bitmaps. */
-static inline size_t bitmap_size(size_t bits)
+static inline size_t ntfs3_bitmap_size(size_t bits)
 {
-	return ALIGN((bits + 7) >> 3, 8);
+	return BITS_TO_U64(bits) * sizeof(u64);
 }
 
 #define _100ns2seconds 10000000
diff --git a/fs/ntfs3/super.c b/fs/ntfs3/super.c
index d47cfa215a367975af4d3a97e6f2c0fe3225b1e9..c14b55cdea85c25b8d452773caf7cbfb3d75faad 100644
--- a/fs/ntfs3/super.c
+++ b/fs/ntfs3/super.c
@@ -1341,7 +1341,7 @@ static int ntfs_fill_super(struct super_block *sb, struct fs_context *fc)
 
 	/* Check bitmap boundary. */
 	tt = sbi->used.bitmap.nbits;
-	if (inode->i_size < bitmap_size(tt)) {
+	if (inode->i_size < ntfs3_bitmap_size(tt)) {
 		ntfs_err(sb, "$Bitmap is corrupted.");
 		err = -EINVAL;
 		goto put_inode_out;
diff --git a/include/linux/bitmap.h b/include/linux/bitmap.h
index 03644237e1efb5316b62e9831515d12b9f9f28b6..3c8d2b87a9edcede372d569ac71074709959f0cc 100644
--- a/include/linux/bitmap.h
+++ b/include/linux/bitmap.h
@@ -237,9 +237,11 @@ extern int bitmap_print_list_to_buf(char *buf, const unsigned long *maskp,
 #define BITMAP_FIRST_WORD_MASK(start) (~0UL << ((start) & (BITS_PER_LONG - 1)))
 #define BITMAP_LAST_WORD_MASK(nbits) (~0UL >> (-(nbits) & (BITS_PER_LONG - 1)))
 
+#define bitmap_size(nbits)	(ALIGN(nbits, BITS_PER_LONG) / BITS_PER_BYTE)
+
 static inline void bitmap_zero(unsigned long *dst, unsigned int nbits)
 {
-	unsigned int len = BITS_TO_LONGS(nbits) * sizeof(unsigned long);
+	unsigned int len = bitmap_size(nbits);
 
 	if (small_const_nbits(nbits))
 		*dst = 0;
@@ -249,7 +251,7 @@ static inline void bitmap_zero(unsigned long *dst, unsigned int nbits)
 
 static inline void bitmap_fill(unsigned long *dst, unsigned int nbits)
 {
-	unsigned int len = BITS_TO_LONGS(nbits) * sizeof(unsigned long);
+	unsigned int len = bitmap_size(nbits);
 
 	if (small_const_nbits(nbits))
 		*dst = ~0UL;
@@ -260,7 +262,7 @@ static inline void bitmap_fill(unsigned long *dst, unsigned int nbits)
 static inline void bitmap_copy(unsigned long *dst, const unsigned long *src,
 			unsigned int nbits)
 {
-	unsigned int len = BITS_TO_LONGS(nbits) * sizeof(unsigned long);
+	unsigned int len = bitmap_size(nbits);
 
 	if (small_const_nbits(nbits))
 		*dst = *src;
@@ -279,6 +281,18 @@ static inline void bitmap_copy_clear_tail(unsigned long *dst,
 		dst[nbits / BITS_PER_LONG] &= BITMAP_LAST_WORD_MASK(nbits);
 }
 
+static inline void bitmap_copy_and_extend(unsigned long *to,
+					  const unsigned long *from,
+					  unsigned int count, unsigned int size)
+{
+	unsigned int copy = BITS_TO_LONGS(count);
+
+	memcpy(to, from, copy * sizeof(long));
+	if (count % BITS_PER_LONG)
+		to[copy - 1] &= BITMAP_LAST_WORD_MASK(count);
+	memset(to + copy, 0, bitmap_size(size) - copy * sizeof(long));
+}
+
 /*
  * On 32-bit systems bitmaps are represented as u32 arrays internally. On LE64
  * machines the order of hi and lo parts of numbers match the bitmap structure.
diff --git a/include/linux/cpumask.h b/include/linux/cpumask.h
index a29ee03f13ffb34dc5b7c98ef3a4976abf9dcfc8..4c26ede3b87d311283306c014b072c1ac233affa 100644
--- a/include/linux/cpumask.h
+++ b/include/linux/cpumask.h
@@ -824,7 +824,7 @@ static inline int cpulist_parse(const char *buf, struct cpumask *dstp)
  */
 static inline unsigned int cpumask_size(void)
 {
-	return BITS_TO_LONGS(large_cpumask_bits) * sizeof(long);
+	return bitmap_size(large_cpumask_bits);
 }
 
 /*
diff --git a/lib/math/prime_numbers.c b/lib/math/prime_numbers.c
index d42cebf7407fc45cc698c406e2d38846b248ae12..d3b64b10da1c5e3459de5124cf699b57c026c232 100644
--- a/lib/math/prime_numbers.c
+++ b/lib/math/prime_numbers.c
@@ -6,8 +6,6 @@
 #include <linux/prime_numbers.h>
 #include <linux/slab.h>
 
-#define bitmap_size(nbits) (BITS_TO_LONGS(nbits) * sizeof(unsigned long))
-
 struct primes {
 	struct rcu_head rcu;
 	unsigned long last, sz;
diff --git a/tools/include/linux/bitmap.h b/tools/include/linux/bitmap.h
index f3566ea0f932ee85791e809521aa4ceac531b4f2..3fa30e8dd351ee591a7b6371d4e8f912d351ba59 100644
--- a/tools/include/linux/bitmap.h
+++ b/tools/include/linux/bitmap.h
@@ -25,13 +25,14 @@ bool __bitmap_intersects(const unsigned long *bitmap1,
 #define BITMAP_FIRST_WORD_MASK(start) (~0UL << ((start) & (BITS_PER_LONG - 1)))
 #define BITMAP_LAST_WORD_MASK(nbits) (~0UL >> (-(nbits) & (BITS_PER_LONG - 1)))
 
+#define bitmap_size(nbits)	(ALIGN(nbits, BITS_PER_LONG) / BITS_PER_BYTE)
+
 static inline void bitmap_zero(unsigned long *dst, unsigned int nbits)
 {
 	if (small_const_nbits(nbits))
 		*dst = 0UL;
 	else {
-		int len = BITS_TO_LONGS(nbits) * sizeof(unsigned long);
-		memset(dst, 0, len);
+		memset(dst, 0, bitmap_size(nbits));
 	}
 }
 
@@ -83,7 +84,7 @@ static inline void bitmap_or(unsigned long *dst, const unsigned long *src1,
  */
 static inline unsigned long *bitmap_zalloc(int nbits)
 {
-	return calloc(1, BITS_TO_LONGS(nbits) * sizeof(unsigned long));
+	return calloc(1, bitmap_size(nbits));
 }
 
 /*
diff --git a/tools/testing/selftests/core/close_range_test.c b/tools/testing/selftests/core/close_range_test.c
index 749239930ca83fc45c3424a7b4d36841b78d12c3..190c57b0efeba916efed62ba3aff05fc9fdf994f 100644
--- a/tools/testing/selftests/core/close_range_test.c
+++ b/tools/testing/selftests/core/close_range_test.c
@@ -563,4 +563,39 @@ TEST(close_range_cloexec_unshare_syzbot)
 	EXPECT_EQ(close(fd3), 0);
 }
 
+TEST(close_range_bitmap_corruption)
+{
+	pid_t pid;
+	int status;
+	struct __clone_args args = {
+		.flags = CLONE_FILES,
+		.exit_signal = SIGCHLD,
+	};
+
+	/* get the first 128 descriptors open */
+	for (int i = 2; i < 128; i++)
+		EXPECT_GE(dup2(0, i), 0);
+
+	/* get descriptor table shared */
+	pid = sys_clone3(&args, sizeof(args));
+	ASSERT_GE(pid, 0);
+
+	if (pid == 0) {
+		/* unshare and truncate descriptor table down to 64 */
+		if (sys_close_range(64, ~0U, CLOSE_RANGE_UNSHARE))
+			exit(EXIT_FAILURE);
+
+		ASSERT_EQ(fcntl(64, F_GETFD), -1);
+		/* ... and verify that the range 64..127 is not
+		   stuck "fully used" according to secondary bitmap */
+		EXPECT_EQ(dup(0), 64)
+			exit(EXIT_FAILURE);
+		exit(EXIT_SUCCESS);
+	}
+
+	EXPECT_EQ(waitpid(pid, &status, 0), pid);
+	EXPECT_EQ(true, WIFEXITED(status));
+	EXPECT_EQ(0, WEXITSTATUS(status));
+}
+
 TEST_HARNESS_MAIN