From: Hui Peng <benquike@gmail.com>
To: jack@suse.com, brauner@kernel.org
Cc: linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: [PATCH] udf: validate vat20->lengthHeader and VAT inode size in udf_load_vat()
Date: Sat, 19 Sep 2026 22:26:00 +0000 [thread overview]
Message-ID: <20260919222600.3793513-1-benquike@gmail.com> (raw)
In udf_load_vat() (fs/udf/super.c), validate that vat20->lengthHeader is
at least sizeof(struct virtualAllocationTable20) and does not exceed the
mapped buffer or VAT inode size so computing the VAT table pointer and
entry count cannot underflow or read out of bounds.
Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")
Assisted-by: LLM
Signed-off-by: Hui Peng <benquike@gmail.com>
---
diff --git a/fs/udf/super.c b/fs/udf/super.c
index 2ba5973ef4dd..2f0f087bcced 100644
--- a/fs/udf/super.c
+++ b/fs/udf/super.c
@@ -1252,6 +1252,15 @@ static int udf_load_vat(struct super_block *sb, int p_index, int type1_index)
(sbi->s_vat_inode->i_size - 36) >> 2;
} else if (map->s_partition_type == UDF_VIRTUAL_MAP20) {
vati = UDF_I(sbi->s_vat_inode);
+ if (sbi->s_vat_inode->i_size <
+ sizeof(struct virtualAllocationTable20) ||
+ (vati->i_alloc_type == ICBTAG_FLAG_AD_IN_ICB &&
+ vati->i_lenAlloc <
+ sizeof(struct virtualAllocationTable20))) {
+ udf_err(sb, "Too short VAT inode size %lld\n",
+ sbi->s_vat_inode->i_size);
+ return -EFSCORRUPTED;
+ }
if (vati->i_alloc_type != ICBTAG_FLAG_AD_IN_ICB) {
int err = 0;
@@ -1269,8 +1278,15 @@ static int udf_load_vat(struct super_block *sb, int p_index, int type1_index)
map->s_type_specific.s_virtual.s_start_offset =
le16_to_cpu(vat20->lengthHeader);
- if (map->s_type_specific.s_virtual.s_start_offset
- > sbi->s_vat_inode->i_size) {
+ if (map->s_type_specific.s_virtual.s_start_offset <
+ sizeof(struct virtualAllocationTable20) ||
+ map->s_type_specific.s_virtual.s_start_offset >
+ sb->s_blocksize ||
+ map->s_type_specific.s_virtual.s_start_offset >
+ sbi->s_vat_inode->i_size ||
+ (vati->i_alloc_type == ICBTAG_FLAG_AD_IN_ICB &&
+ map->s_type_specific.s_virtual.s_start_offset >
+ vati->i_lenAlloc)) {
udf_err(sb, "Corrupted VAT header length %u (VAT inode size %lld)\n",
map->s_type_specific.s_virtual.s_start_offset,
sbi->s_vat_inode->i_size);
next reply other threads:[~2026-09-19 22:26 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-09-19 22:26 Hui Peng [this message]
2026-10-21 11:53 ` Jan Kara
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20260919222600.3793513-1-benquike@gmail.com \
--to=benquike@gmail.com \
--cc=brauner@kernel.org \
--cc=jack@suse.com \
--cc=linux-fsdevel@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox
all inboxes | Powered by JetHome®