Merge tag 'mm-hotfixes-stable-2023-02-17-15-16-2' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

Pull misc fixes from Andrew Morton:
 "Six hotfixes. Five are cc:stable: four for MM, one for nilfs2.

  Also a MAINTAINERS update"

* tag 'mm-hotfixes-stable-2023-02-17-15-16-2' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm:
  nilfs2: fix underflow in second superblock position calculations
  hugetlb: check for undefined shift on 32 bit architectures
  mm/migrate: fix wrongly apply write bit after mkdirty on sparc64
  MAINTAINERS: update FPU EMULATOR web page
  mm/MADV_COLLAPSE: set EAGAIN on unexpected page refcount
  mm/filemap: fix page end in filemap_get_read_batch

3 files changed, 23 insertions, 1 deletions

diff --git a/fs/nilfs2/ioctl.c b/fs/nilfs2/ioctl.c
index 87e1004b606d..b4041d0566a9 100644
--- a/fs/nilfs2/ioctl.c
+++ b/fs/nilfs2/ioctl.c
@@ -1114,7 +1114,14 @@ static int nilfs_ioctl_set_alloc_range(struct inode *inode, void __user *argp)
 
 	minseg = range[0] + segbytes - 1;
 	do_div(minseg, segbytes);
+
+	if (range[1] < 4096)
+		goto out;
+
 	maxseg = NILFS_SB2_OFFSET_BYTES(range[1]);
+	if (maxseg < segbytes)
+		goto out;
+
 	do_div(maxseg, segbytes);
 	maxseg--;
 
diff --git a/fs/nilfs2/super.c b/fs/nilfs2/super.c
index 6edb6e0dd61f..1422b8ba24ed 100644
--- a/fs/nilfs2/super.c
+++ b/fs/nilfs2/super.c
@@ -409,6 +409,15 @@ int nilfs_resize_fs(struct super_block *sb, __u64 newsize)
 		goto out;
 
 	/*
+	 * Prevent underflow in second superblock position calculation.
+	 * The exact minimum size check is done in nilfs_sufile_resize().
+	 */
+	if (newsize < 4096) {
+		ret = -ENOSPC;
+		goto out;
+	}
+
+	/*
 	 * Write lock is required to protect some functions depending
 	 * on the number of segments, the number of reserved segments,
 	 * and so forth.
diff --git a/fs/nilfs2/the_nilfs.c b/fs/nilfs2/the_nilfs.c
index 2064e6473d30..3a4c9c150cbf 100644
--- a/fs/nilfs2/the_nilfs.c
+++ b/fs/nilfs2/the_nilfs.c
@@ -544,9 +544,15 @@ static int nilfs_load_super_block(struct the_nilfs *nilfs,
 {
 	struct nilfs_super_block **sbp = nilfs->ns_sbp;
 	struct buffer_head **sbh = nilfs->ns_sbh;
-	u64 sb2off = NILFS_SB2_OFFSET_BYTES(bdev_nr_bytes(nilfs->ns_bdev));
+	u64 sb2off, devsize = bdev_nr_bytes(nilfs->ns_bdev);
 	int valid[2], swp = 0;
 
+	if (devsize < NILFS_SEG_MIN_BLOCKS * NILFS_MIN_BLOCK_SIZE + 4096) {
+		nilfs_err(sb, "device size too small");
+		return -EINVAL;
+	}
+	sb2off = NILFS_SB2_OFFSET_BYTES(devsize);
+
 	sbp[0] = nilfs_read_super_block(sb, NILFS_SB_OFFSET_BYTES, blocksize,
 					&sbh[0]);
 	sbp[1] = nilfs_read_super_block(sb, sb2off, blocksize, &sbh[1]);