scsi: ufs: core: Validate string descriptors

The string descriptor length includes a two-byte header while the UTF-16
payload starts after it. utf16s_to_utf8s() expects a count of UTF-16 code
units, not bytes. Passing the payload byte count can make it read beyond
the descriptor buffer.

Validate that the payload has an even byte count, pass a code-unit count to
the converter, and allocate sufficient UTF-8 output space.

The raw string buffer starts after the descriptor header but its size is
bLength. Copying bLength bytes from that pointer can read beyond the
response buffer.

Allocate a zeroed bLength-sized buffer and copy only the UTF-16
payload. This preserves the raw buffer size consumed by the RPMB device-ID
ABI while avoiding the overread.

Fixes: 4b828fe156a6 ("scsi: ufs: revamp string descriptor reading")
Fixes: d794b499f948 ("scsi: ufs: core: fix incorrect buffer duplication in ufshcd_read_string_desc()")
Signed-off-by: Li Qiang <liqiang01@kylinos.cn>
Reviewed-by: Peter Wang <peter.wang@mediatek.com>
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Link: https://patch.msgid.link/20260717153914.26321-2-liqiang01@kylinos.cn
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

0 files changed, 0 insertions, 0 deletions