CVE-2026-64402

Summary

In the Linux kernel, the following vulnerability has been resolved:

coresight: ultrasoc-smb: Fix OOB write in smb_sync_perf_buffer()

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.

Normalize head modulo the AUX buffer size before deriving the page index and offset, mirroring tmc_etr_sync_perf_buffer().

Affected Software

VendorProductVersion RangeStatus
LinuxLinux06f5c2926aaa0fba7f99678da6ef77cbbbda1441 < 38dbc8db8341ccdf8e1e1a067453d33ad751864baffected
LinuxLinux06f5c2926aaa0fba7f99678da6ef77cbbbda1441 < 4c5a0a946373da99a80398289b28845b5ae40cd1affected
LinuxLinux06f5c2926aaa0fba7f99678da6ef77cbbbda1441 < 661a019ac0413ecec9e5d1dfcc12fbca8e78d5fbaffected
LinuxLinux06f5c2926aaa0fba7f99678da6ef77cbbbda1441 < daf6246ab988fc8bdc82ad7c8d0b1c182d11b15faffected
LinuxLinux06f5c2926aaa0fba7f99678da6ef77cbbbda1441 < 98495b5a4d77dd22e106f462b76e1093a55b29a7affected
LinuxLinux6.3affected
LinuxLinux0 < 6.3unaffected
LinuxLinux6.6.145 <= 6.6.*unaffected
LinuxLinux6.12.96 <= 6.12.*unaffected
LinuxLinux6.18.39 <= 6.18.*unaffected
LinuxLinux7.1.4 <= 7.1.*unaffected
LinuxLinux7.2-rc1 <= *unaffected

Weaknesses

References