6.9-stable review patch. If anyone has any objections, please let me know.
------------------
From: Ritesh Harjani (IBM) <ritesh.list@xxxxxxxxx>
commit c2a09f3d782de952f09a3962d03b939e7fa7ffa4 upstream.
Truncate operation can race with writeback, in which inode->i_size can get
truncated and therefore size - folio_pos() can be negative. This fixes the
len calculation. However this path doesn't get easily triggered even
with data journaling.
Cc: stable@xxxxxxxxxx # v6.5
Fixes: 80be8c5cc925 ("Fixes: ext4: Make mpage_journal_page_buffers use folio")
Signed-off-by: Ritesh Harjani (IBM) <ritesh.list@xxxxxxxxx>
Reviewed-by: Jan Kara <jack@xxxxxxx>
Link: https://lore.kernel.org/r/cff4953b5c9306aba71e944ab176a5d396b9a1b7.1709182250.git.ritesh.list@xxxxxxxxx
Signed-off-by: Theodore Ts'o <tytso@xxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
fs/ext4/inode.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
--- a/fs/ext4/inode.c
+++ b/fs/ext4/inode.c
@@ -2334,7 +2334,7 @@ static int mpage_journal_page_buffers(ha
if (folio_pos(folio) + len > size &&
!ext4_verity_in_progress(inode))
- len = size - folio_pos(folio);
+ len = size & (len - 1);
return ext4_journal_folio_buffers(handle, folio, len);
}
