Add bugfix section about buffer sharing

Mention that arbitrary overlap is now supported, except whenever
MBEDTLS_PSA_ASSUME_EXCLUSIVE_BUFFERS is set.

Signed-off-by: David Horstmann <david.horstmann@arm.com>
diff --git a/ChangeLog.d/psa-shared-memory-protection.txt b/ChangeLog.d/psa-shared-memory-protection.txt
index 6322563..a158ae8 100644
--- a/ChangeLog.d/psa-shared-memory-protection.txt
+++ b/ChangeLog.d/psa-shared-memory-protection.txt
@@ -8,3 +8,7 @@
      PSA functions are owned exclusively by the PSA core for the duration of
      the function call, copying may be disabled by setting
      MBEDTLS_PSA_ASSUME_EXCLUSIVE_BUFFERS.
+Bugfix
+   * Fully support arbitrary overlap between inputs and outputs of PSA
+     functions. Note that overlap is only partial supported when
+     MBEDTLS_PSA_ASSUME_EXCLUSIVE_BUFFERS is set.