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authorRyusuke Konishi <konishi.ryusuke@gmail.com>2024-01-24 15:19:36 +0300
committerAndrew Morton <akpm@linux-foundation.org>2024-02-08 08:20:34 +0300
commit67b8bcbaed4777871bb0dcc888fb02a614a98ab1 (patch)
treed2298ec0d377f20a6813f0864fd25a08db784da3 /fs/nilfs2
parent56ae10cf628b02279980d17439c6241a643959c2 (diff)
downloadlinux-67b8bcbaed4777871bb0dcc888fb02a614a98ab1.tar.xz
nilfs2: fix data corruption in dsync block recovery for small block sizes
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>
Diffstat (limited to 'fs/nilfs2')
-rw-r--r--fs/nilfs2/recovery.c7
1 files changed, 4 insertions, 3 deletions
diff --git a/fs/nilfs2/recovery.c b/fs/nilfs2/recovery.c
index 0955b657938f..a9b8d77c8c1d 100644
--- a/fs/nilfs2/recovery.c
+++ b/fs/nilfs2/recovery.c
@@ -472,9 +472,10 @@ static int nilfs_prepare_segment_for_recovery(struct the_nilfs *nilfs,
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(struct the_nilfs *nilfs,
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(struct the_nilfs *nilfs,
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;