stable inclusion from stable-v5.10.261 commit 0ad2d09a8d66fa8dc6f9b70d660b5fb4478ea934 category: bugfix bugzilla: https://atomgit.com/src-openeuler/kernel/issues/16619 Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=... -------------------------------- udf_load_vat() takes the virtual partition's start offset straight from the on-disk VAT 2.0 header without checking it against the VAT inode size: map->s_type_specific.s_virtual.s_start_offset = le16_to_cpu(vat20->lengthHeader); map->s_type_specific.s_virtual.s_num_entries = (sbi->s_vat_inode->i_size - map->s_type_specific.s_virtual.s_start_offset) >> 2; lengthHeader is a fully attacker-controlled 16-bit value. If it exceeds the VAT inode size, the s_num_entries subtraction underflows to a huge count, which defeats the "block > s_num_entries" bound in udf_get_pblock_virt15(); and on the ICB-inline path that function reads ((__le32 *)(iinfo->i_data + s_start_offset))[block] so a large s_start_offset indexes past the inode's in-ICB data. Mounting a crafted UDF image with a virtual (VAT) partition then triggers an out-of-bounds read. Reject a VAT whose header length does not leave room for at least one entry within the VAT inode. Fixes: fa5e08156335 ("udf: Handle VAT packed inside inode properly") Cc: stable@vger.kernel.org Signed-off-by: Bryam Vargas <hexlabsecurity@proton.me> Link: https://patch.msgid.link/20260612-b4-disp-9a2317ee-v1-1-fefef5736154@proton.... Signed-off-by: Jan Kara <jack@suse.cz> Signed-off-by: Lai Zewei <laizewei3@huawei.com> --- fs/udf/super.c | 8 ++++++++ 1 file changed, 8 insertions(+) diff --git a/fs/udf/super.c b/fs/udf/super.c index df74f685b2e1..aa50c6d0e1df 100644 --- a/fs/udf/super.c +++ b/fs/udf/super.c @@ -1226,6 +1226,14 @@ 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) { + 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); + brelse(bh); + return -EFSCORRUPTED; + } map->s_type_specific.s_virtual.s_num_entries = (sbi->s_vat_inode->i_size - map->s_type_specific.s_virtual. -- 2.52.0