From: 胡玮文 <huweiwen.hww@alibaba-inc.com>
Date: Mon, 28 Jul 2025 06:32:13 +0000 (+0800)
Subject: libblkid: (ext) reduce false positive
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=0c5d55e52d27be933e9e61b82bd386943bd9e05c;p=thirdparty%2Futil-linux.git

libblkid: (ext) reduce false positive

Signed-off-by: 胡玮文 <huweiwen.hww@alibaba-inc.com>
---

diff --git a/libblkid/src/superblocks/ext.c b/libblkid/src/superblocks/ext.c
index c0779c233..ab4d7a827 100644
--- a/libblkid/src/superblocks/ext.c
+++ b/libblkid/src/superblocks/ext.c
@@ -180,6 +180,15 @@ static struct ext2_super_block *ext_get_super(
 			return NULL;
 #endif
 		}
+	} else {
+		/*
+		 * For legacy fs without checksum, additionally verify the
+		 * block size to reduce false positive. Currently max allowed
+		 * block size is 64KiB (s_log_block_size <= 6), check for 256
+		 * to be more future proof.
+		 */
+		if (le32_to_cpu(es->s_log_block_size) >= 256)
+			return NULL;
 	}
 	if (fc)
 		*fc = le32_to_cpu(es->s_feature_compat);