FAILED: patch "[PATCH] nilfs2: fix kernel bug due to missing clearing of checked" failed to apply to 6.6-stable tree

The patch below does not apply to the 6.6-stable tree.
If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <[email protected]>.

To reproduce the conflict and resubmit, you may use the following commands:

git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-6.6.y
git checkout FETCH_HEAD
git cherry-pick -x 41e192ad2779cae0102879612dfe46726e4396aa
# <resolve conflicts, build, test, etc.>
git commit -s
git send-email --to '<[email protected]>' --in-reply-to '2024110529-clapper-deferred-1146@gregkh' --subject-prefix 'PATCH 6.6.y' HEAD^..

Possible dependencies:

thanks,

greg k-h

------------------ original commit in Linus's tree ------------------

From 41e192ad2779cae0102879612dfe46726e4396aa Mon Sep 17 00:00:00 2001
From: Ryusuke Konishi <[email protected]>
Date: Fri, 18 Oct 2024 04:33:10 +0900
Subject: [PATCH] nilfs2: fix kernel bug due to missing clearing of checked
flag

Syzbot reported that in directory operations after nilfs2 detects filesystem corruption and degrades to read-only, __block_write_begin_int(), which is called to prepare block writes, may fail the BUG_ON check for accesses exceeding the folio/page size, triggering a kernel bug.

This was found to be because the "checked" flag of a page/folio was not cleared when it was discarded by nilfs2's own routine, which causes the sanity check of directory entries to be skipped when the directory page/folio is reloaded. So, fix that.

This was necessary when the use of nilfs2's own page discard routine was applied to more than just metadata files.

index 5436eb0424bd..10def4b55995 100644
@@ -401,6 +401,7 @@ void nilfs_clear_folio_dirty(struct folio *folio)
 
 	folio_clear_uptodate(folio);
 	folio_clear_mappedtodisk(folio);
+	folio_clear_checked(folio);
 
 	head = folio_buffers(folio);
 	if (head) {

commit 41e192ad2779cae0102879612dfe46726e4396aa upstream.

Syzbot reported that in directory operations after nilfs2 detects filesystem corruption and degrades to read-only, __block_write_begin_int(), which is called to prepare block writes, may fail the BUG_ON check for accesses exceeding the folio/page size, triggering a kernel bug.

This was found to be because the "checked" flag of a page/folio was not cleared when it was discarded by nilfs2's own routine, which causes the sanity check of directory entries to be skipped when the directory page/folio is reloaded. So, fix that.

This was necessary when the use of nilfs2's own page discard routine was applied to more than just metadata files.

---
Please apply this patch to the stable trees indicated by the subject prefix instead of the failed patches.

This patch is tailored to take page/folio conversion into account. Compiled and tested successfully.

Thanks,
Ryusuke Konishi

 fs/nilfs2/page.c | 1 +
 1 file changed, 1 insertion(+)

index 36d29c183bb7..956c90700e15 100644
@@ -405,6 +405,7 @@ void nilfs_clear_dirty_page(struct page *page, bool silent)
 
 	ClearPageUptodate(page);
 	ClearPageMappedToDisk(page);
+	ClearPageChecked(page);
 
 	if (page_has_buffers(page)) {
 		struct buffer_head *bh, *head;

2.43.5