Re: [syzbot] [integrity?] [lsm?] KMSAN: uninit-value in ima_add_template_entry (2)

[Yuezhang.Mo@xxxxxxxx]

#syz testFrom 51b0e3cfc5c0c4ac0000ff97d236d2434618f7fc Mon Sep 17 00:00:00 2001
From: Yuezhang Mo <Yuezhang.Mo@xxxxxxxx>
Date: Thu, 12 Dec 2024 16:29:23 +0800
Subject: [PATCH v1] exfat: zero new buffer

Signed-off-by: Yuezhang Mo <Yuezhang.Mo@xxxxxxxx>
---
 fs/exfat/file.c | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/fs/exfat/file.c b/fs/exfat/file.c
index a25d7eb789f4..d91437831835 100644
--- a/fs/exfat/file.c
+++ b/fs/exfat/file.c
@@ -545,6 +545,7 @@ static int exfat_extend_valid_size(struct file *file, loff_t new_valid_size)
 	while (pos < new_valid_size) {
 		u32 len;
 		struct folio *folio;
+		unsigned long off;
 
 		len = PAGE_SIZE - (pos & (PAGE_SIZE - 1));
 		if (pos + len > new_valid_size)
@@ -554,6 +555,9 @@ static int exfat_extend_valid_size(struct file *file, loff_t new_valid_size)
 		if (err)
 			goto out;
 
+		off = offset_in_folio(folio, pos);
+		folio_zero_new_buffers(folio, off, off + len);
+
 		err = ops->write_end(file, mapping, pos, len, len, folio, NULL);
 		if (err < 0)
 			goto out;
@@ -563,6 +567,8 @@ static int exfat_extend_valid_size(struct file *file, loff_t new_valid_size)
 		cond_resched();
 	}
 
+	return 0;
+
 out:
 	return err;
 }
-- 
2.43.0