perf hisi-ptt: Strengthen auxtrace event handling and packet type detection

Fix pre-existing robustness issues in the hisi-ptt auxtrace decoder
reported by Sashiko:

1. Endianness in hisi_ptt_check_packet_type(): The first 32-bit word was
read with a host-endian memory cast (*(uint32_t *)buf). On big-endian
hosts analyzing a little-endian trace, the bit[31:11] 8DW magic check
fails and every 8DW packet is misclassified as 4DW. Read the header
with get_unaligned_le32().

2. Heap out-of-bounds read: hisi_ptt_dump() called
hisi_ptt_check_packet_type() which dereferenced 4 bytes of the buffer
without any size check. A malformed or truncated event with
auxtrace.size in {0,1,2,3} may cause a heap OOB read. Pass the buffer
length to hisi_ptt_check_packet_type() and return (defaulting to
4DW) when the buffer is shorter than HISI_PTT_FIELD_LENTH.

3. Integer truncation: event->auxtrace.size is __u64 but was stored in
an int. Traces larger than 2GB became negative (malloc failure), and
huge sizes wrapping to a small positive caused a short readn() that
left unread payload in the pipe and permanently desynchronized the
stream. Use u64 for the size, reject anything larger than SSIZE_MAX
before malloc (same bound used by auxtrace_copy_data()), and compare
readn()'s return value against (ssize_t)size to detect truncation.

Signed-off-by: Sizhe Liu <liusizhe5@huawei.com>
Signed-off-by: Namhyung Kim <namhyung@kernel.org>

0 files changed, 0 insertions, 0 deletions