linux-kernel - [PATCH] f2fs: add sanity check on ei.len in __update_extent_tree

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Message-ID: <20250916085243.4165099-1-chao@kernel.org>
Date: Tue, 16 Sep 2025 16:52:43 +0800
From: Chao Yu <chao@...nel.org>
To: jaegeuk@...nel.org
Cc: linux-f2fs-devel@...ts.sourceforge.net,
	linux-kernel@...r.kernel.org,
	Chao Yu <chao@...nel.org>,
	wangzijie <wangzijie1@...or.com>
Subject: [PATCH] f2fs: add sanity check on ei.len in __update_extent_tree_range()

Add a sanity check in __update_extent_tree_range() to detect any
zero-sized extent update.

Signed-off-by: wangzijie <wangzijie1@...or.com>
Signed-off-by: Chao Yu <chao@...nel.org>
---
 fs/f2fs/extent_cache.c | 9 +++++++++
 1 file changed, 9 insertions(+)

diff --git a/fs/f2fs/extent_cache.c b/fs/f2fs/extent_cache.c
index 199c1e7a83ef..3070d1cb0676 100644
--- a/fs/f2fs/extent_cache.c
+++ b/fs/f2fs/extent_cache.c
@@ -664,6 +664,15 @@ static void __update_extent_tree_range(struct inode *inode,
 	if (!et)
 		return;
 
+	if (unlikely(len == 0)) {
+		f2fs_err_ratelimited(sbi, "%s: extent len is zero, type: %d, "
+			"extent [%u, %u, %u], age [%llu, %llu]",
+			__func__, type, tei->fofs, tei->blk, tei->len,
+			tei->age, tei->last_blocks);
+		f2fs_bug_on(sbi, 1);
+		return;
+	}
+
 	if (type == EX_READ)
 		trace_f2fs_update_read_extent_tree_range(inode, fofs, len,
 						tei->blk, 0);
-- 
2.49.0