From: Ritesh Harjani (IBM) Date: Thu, 29 Feb 2024 06:10:13 +0000 (+0530) Subject: ext4: Fixes len calculation in mpage_journal_page_buffers X-Git-Tag: v6.10-rc1~107^2~39 X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=c2a09f3d782de952f09a3962d03b939e7fa7ffa4;p=thirdparty%2Flinux.git ext4: Fixes len calculation in mpage_journal_page_buffers 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@kernel.org # v6.5 Fixes: 80be8c5cc925 ("Fixes: ext4: Make mpage_journal_page_buffers use folio") Signed-off-by: Ritesh Harjani (IBM) Reviewed-by: Jan Kara Link: https://lore.kernel.org/r/cff4953b5c9306aba71e944ab176a5d396b9a1b7.1709182250.git.ritesh.list@gmail.com Signed-off-by: Theodore Ts'o --- diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c index 537803250ca9a..bab9223d94ac4 100644 --- a/fs/ext4/inode.c +++ b/fs/ext4/inode.c @@ -2334,7 +2334,7 @@ static int mpage_journal_page_buffers(handle_t *handle, 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); }