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envelope-from=mjrosato@linux.ibm.com; helo=mx0b-001b2d01.pphosted.com X-Spam_score_int: -26 X-Spam_score: -2.7 X-Spam_bar: -- X-Spam_report: (-2.7 / 5.0 requ) BAYES_00=-1.9, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_EF=-0.1, RCVD_IN_DNSWL_LOW=-0.7, RCVD_IN_MSPIKE_H3=0.001, RCVD_IN_MSPIKE_WL=0.001, SPF_HELO_NONE=0.001, SPF_PASS=-0.001 autolearn=ham autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: qemu development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org On 8/14/26 8:58 AM, Christian Borntraeger wrote: > From: Christian Borntraeger > > With variable length and EXTENDED_LENGTH_SCCB, some callbacks might > change the length field. For example read SCP info might write a new > length into the SCCB header. We must not use that new length for the > buffer copy, since the buffer was allocated with the original length. > Only the length field in the work SCCB is changed, to indicate the > "necessary" size. Using the new length reads past the allocation, so > tools like ASAN might detect a buffer overrun. > > Secure guests do not have EXTENDED_LENGTH_SCCB, and the ultravisor checks > and sanitizes the length field, so no qemu heap contents are exposed to > the guest and the non pv-path already has the same header.length. > > Fixes: 0f73c5b30b8b ("s390x: protvirt: SCLP interpretation") > Signed-off-by: Christian Borntraeger Reviewed-by: Matthew Rosato