FAILED: patch "[PATCH] udf: Make sure there's enough space for LVID implementation use field" failed to apply to 5.15-stable tree

[Sasha Levin <sashal@kernel.org>]

The patch below does not apply to the 5.15-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 <stable@vger.kernel.org>.

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-5.15.y
git checkout FETCH_HEAD
git cherry-pick -x a61fb39759d719a4f4966742b4d28387e33d81c4
# <resolve conflicts, build, test, etc.>
git commit -s
git send-email --to '<stable@vger.kernel.org>' --in-reply-to '20261107055724-failed-5.15-a61fb39759d7@kernel.org' --subject-prefix 'PATCH 5.15.y' 'HEAD^..'

Thanks,
Sasha

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

From a61fb39759d719a4f4966742b4d28387e33d81c4 Mon Sep 17 00:00:00 2001
From: Jan Kara <jack@suse.cz>
Date: Mon, 31 Aug 2026 11:17:14 +0200
Subject: [PATCH] udf: Make sure there's enough space for LVID implementation
 use field

udf_lvid_valid() verifies that the LVID has enough space for all the
tables and the reported length of ImplementationUse field. However it
doesn't make sure the reported length is large enough to contain
logicalVolIntegrityDescImpUse structure which OSTA specification
requires. This can thus lead to accesses beyond the end of LVID buffer
for suitably corrupted UDF filesystem. Add the length check.

Reported-by: Yunpeng Tian <shionthanatos@gmail.com>
Reported-by: Gongming Wang <gmwgg05@gmail.com>
Reported-by: Mingda Zhang <npczmd@qq.com>
Reported-by: Qinrun Dai <jupmouse@gmail.com>
Cc: stable@vger.kernel.org
Fixes: 781d2a9a2fc7 ("udf: Check LVID earlier")
Signed-off-by: Jan Kara <jack@suse.cz>
---
 fs/udf/super.c | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/fs/udf/super.c b/fs/udf/super.c
index 2ba5973ef4dd4..5351755aca3ec 100644
--- a/fs/udf/super.c
+++ b/fs/udf/super.c
@@ -1617,7 +1617,10 @@ static bool udf_lvid_valid(struct super_block *sb,
 
 	parts = le32_to_cpu(lvid->numOfPartitions);
 	impuselen = le32_to_cpu(lvid->lengthOfImpUse);
-	if (parts >= sb->s_blocksize || impuselen >= sb->s_blocksize ||
+	if (sizeof(struct logicalVolIntegrityDescImpUse) > impuselen ||
+	    impuselen >= sb->s_blocksize)
+		return false;
+	if (parts >= sb->s_blocksize ||
 	    sizeof(struct logicalVolIntegrityDesc) + impuselen +
 	    2 * parts * sizeof(u32) > sb->s_blocksize)
 		return false;
-- 
2.53.0