udf: validate extent partition references in udf_current_aext()

Long allocation descriptors carry an on-disk
extLocation.partitionReferenceNum. udf_current_aext() copies that value
into a kernel_lb_addr and returns it to several consumers.

If the partition reference is outside s_partitions, callers can later
index s_partmaps out of bounds. The truncate/free path can pass such an
extent to udf_free_blocks(), where the invalid partition reference
causes a slab out-of-bounds read.

Validate eloc->partitionReferenceNum in udf_current_aext() before
returning a decoded extent. This rejects invalid file extents and
indirect allocation descriptor extents in the common parser, so callers
do not need to duplicate the partition-map bounds check.

Assisted-by: Codex:gpt-5.5
Signed-off-by: Kyle Zeng <kylebot@openai.com>
Link: https://patch.msgid.link/20260612225846.97678-1-kylebot@openai.com
Signed-off-by: Jan Kara <jack@suse.cz>

0 files changed, 0 insertions, 0 deletions