+ nilfs2-fix-data-corruption-in-dsync-block-recovery-for-small-block-sizes.patch added to mm-hotfixes-unstable branch

[Andrew Morton <akpm@linux-foundation.org>]

The patch titled
     Subject: nilfs2: fix data corruption in dsync block recovery for small block sizes
has been added to the -mm mm-hotfixes-unstable branch.  Its filename is
     nilfs2-fix-data-corruption-in-dsync-block-recovery-for-small-block-sizes.patch

This patch will shortly appear at
     https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/nilfs2-fix-data-corruption-in-dsync-block-recovery-for-small-block-sizes.patch

This patch will later appear in the mm-hotfixes-unstable branch at
    git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

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------------------------------------------------------
From: Ryusuke Konishi <konishi.ryusuke@gmail.com>
Subject: nilfs2: fix data corruption in dsync block recovery for small block sizes
Date: Wed, 24 Jan 2024 21:19:36 +0900

The helper function nilfs_recovery_copy_block() of
nilfs_recovery_dsync_blocks(), which recovers data from logs created by
data sync writes during a mount after an unclean shutdown, incorrectly
calculates the on-page offset when copying repair data to the file's page
cache.  In environments where the block size is smaller than the page
size, this flaw can cause data corruption and leak uninitialized memory
bytes during the recovery process.

Fix these issues by correcting this byte offset calculation on the page.

Link: https://lkml.kernel.org/r/20240124121936.10575-1-konishi.ryusuke@gmail.com
Signed-off-by: Ryusuke Konishi <konishi.ryusuke@gmail.com>
Tested-by: Ryusuke Konishi <konishi.ryusuke@gmail.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

 fs/nilfs2/recovery.c |    7 ++++---
 1 file changed, 4 insertions(+), 3 deletions(-)

--- a/fs/nilfs2/recovery.c~nilfs2-fix-data-corruption-in-dsync-block-recovery-for-small-block-sizes
+++ a/fs/nilfs2/recovery.c
@@ -472,9 +472,10 @@ static int nilfs_prepare_segment_for_rec
 
 static int nilfs_recovery_copy_block(struct the_nilfs *nilfs,
 				     struct nilfs_recovery_block *rb,
-				     struct page *page)
+				     loff_t pos, struct page *page)
 {
 	struct buffer_head *bh_org;
+	size_t from = pos & ~PAGE_MASK;
 	void *kaddr;
 
 	bh_org = __bread(nilfs->ns_bdev, rb->blocknr, nilfs->ns_blocksize);
@@ -482,7 +483,7 @@ static int nilfs_recovery_copy_block(str
 		return -EIO;
 
 	kaddr = kmap_atomic(page);
-	memcpy(kaddr + bh_offset(bh_org), bh_org->b_data, bh_org->b_size);
+	memcpy(kaddr + from, bh_org->b_data, bh_org->b_size);
 	kunmap_atomic(kaddr);
 	brelse(bh_org);
 	return 0;
@@ -521,7 +522,7 @@ static int nilfs_recover_dsync_blocks(st
 			goto failed_inode;
 		}
 
-		err = nilfs_recovery_copy_block(nilfs, rb, page);
+		err = nilfs_recovery_copy_block(nilfs, rb, pos, page);
 		if (unlikely(err))
 			goto failed_page;
 
_

Patches currently in -mm which might be from konishi.ryusuke@gmail.com are

nilfs2-fix-data-corruption-in-dsync-block-recovery-for-small-block-sizes.patch
nilfs2-convert-recovery-logic-to-use-kmap_local.patch
nilfs2-convert-segment-buffer-to-use-kmap_local.patch
nilfs2-convert-nilfs_copy_buffer-to-use-kmap_local.patch
nilfs2-convert-metadata-file-common-code-to-use-kmap_local.patch
nilfs2-convert-sufile-to-use-kmap_local.patch
nilfs2-convert-persistent-object-allocator-to-use-kmap_local.patch
nilfs2-convert-dat-to-use-kmap_local.patch
nilfs2-move-nilfs_bmap_write-call-out-of-nilfs_write_inode_common.patch
nilfs2-do-not-acquire-rwsem-in-nilfs_bmap_write.patch
nilfs2-convert-ifile-to-use-kmap_local.patch
nilfs2-localize-highmem-mapping-for-checkpoint-creation-within-cpfile.patch
nilfs2-localize-highmem-mapping-for-checkpoint-finalization-within-cpfile.patch
nilfs2-localize-highmem-mapping-for-checkpoint-reading-within-cpfile.patch
nilfs2-remove-nilfs_cpfile_getput_checkpoint.patch
nilfs2-convert-cpfile-to-use-kmap_local.patch