From: Yongpeng Yang <yangyongpeng@xiaomi.com>
Date: Tue, 4 Nov 2025 12:50:07 +0000 (+0800)
Subject: exfat: check return value of sb_min_blocksize in exfat_read_boot_sector
X-Git-Tag: v6.12.60~100
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=93c8a03a107fa1814f730a51b3614e38af964c2c;p=thirdparty%2Fkernel%2Fstable.git

exfat: check return value of sb_min_blocksize in exfat_read_boot_sector

commit f2c1f631630e01821fe4c3fdf6077bc7a8284f82 upstream.

sb_min_blocksize() may return 0. Check its return value to avoid
accessing the filesystem super block when sb->s_blocksize is 0.

Cc: stable@vger.kernel.org # v6.15
Fixes: 719c1e1829166d ("exfat: add super block operations")
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Yongpeng Yang <yangyongpeng@xiaomi.com>
Link: https://patch.msgid.link/20251104125009.2111925-3-yangyongpeng.storage@gmail.com
Signed-off-by: Christian Brauner <brauner@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---

diff --git a/fs/exfat/super.c b/fs/exfat/super.c
index 7aaf1ed6aee91..82acff400f4cd 100644
--- a/fs/exfat/super.c
+++ b/fs/exfat/super.c
@@ -452,7 +452,10 @@ static int exfat_read_boot_sector(struct super_block *sb)
 	struct exfat_sb_info *sbi = EXFAT_SB(sb);
 
 	/* set block size to read super block */
-	sb_min_blocksize(sb, 512);
+	if (!sb_min_blocksize(sb, 512)) {
+		exfat_err(sb, "unable to set blocksize");
+		return -EINVAL;
+	}
 
 	/* read boot sector */
 	sbi->boot_bh = sb_bread(sb, 0);