On Thu, 04 Jun 2026 15:34:25 +0800, Junrui Luo wrote:

When the SMB sink is used as a perf AUX sink, smb_update_buffer() calls smb_sync_perf_buffer() to copy hardware trace data into the perf AUX ring buffer pages. It derives pg_idx = head >> PAGE_SHIFT from @head, which is handle->head, and indexes dst_pages[pg_idx]. The pg_idx %= nr_pages normalization is only applied after the first loop iteration.

This leaves the initial page index underived from the buffer size, which can result in an out-of-bounds write past dst_pages[] when head exceeds the AUX buffer size.

[...]

Applied, thanks!

[1/1] coresight: ultrasoc-smb: Fix OOB write in smb_sync_perf_buffer() https://git.kernel.org/coresight/c/98495b5a4d77

Best regards,