------- Comment From a...@de.ibm.com 2019-05-21 08:32 EDT------- fix works as expected
verified on bionic with kernel: # apt show linux-image-4.15.0-51-generic Package: linux-image-4.15.0-51-generic Version: 4.15.0-51.55 Priority: optional Section: kernel Source: linux Origin: Ubuntu ... # apt changelog linux-image-4.15.0-51-generic linux (4.15.0-51.55) bionic; urgency=medium * linux: 4.15.0-51.55 -proposed tracker (LP: #1829219) * disable a.out support (LP: #1818552) - [Config] Disable a.out support * [UBUNTU] qdio: clear intparm during shutdown (LP: #1828394) - s390/qdio: clear intparm during shutdown ... -- You received this bug notification because you are a member of Kernel Packages, which is subscribed to linux in Ubuntu. https://bugs.launchpad.net/bugs/1828394 Title: [UBUNTU] qdio: clear intparm during shutdown Status in Ubuntu on IBM z Systems: Fix Committed Status in linux package in Ubuntu: Fix Released Status in linux source package in Bionic: Fix Committed Bug description: SRU Justification: [Impact] * Crash in qeth_irq() with "Unable to handle kernel pointer dereference in virtual kernel address space" [Fix] * 89286320a236d245834075fa13adb0bdd827ecaa 8928632 "s390/qdio: clear intparm during shutdown" [Test Case] * Offline an OSA CHPID with multiple active qeth interfaces. [Regression Potential] * The regression potential can be considered as very low since it only affects the s390x platform * and there it only affects the (ccW) qeth (OSA) network devices * and again this happens if the CHPID is offlined, which usually doesn't happen during regular operation. [Other Info] * The patch was upstream accepted with kernel 4.17, hence it's already part of cosmic, disco and eoan and proven there to work. * It needs to be applied to kernel 4.15 to land in 18.04 GA and 16.04.5 HWE. _________________________ Description: qdio: clear intparm during shutdown Symptom: Crash in qeth_irq() with "Unable to handle kernel pointer dereference in virtual kernel address space". Problem: During shutdown, qdio returns its ccw device back to control by qeth - but doesn't reset the interrupt parameter on the device. If qdio_shutdown() failed to terminate its long-running IO on the ccw_device, qeth will subsequently do so. In this case the IRQ for the IO completion is presented to qeth_irq() with the _old_ interrupt parameter, which gets mis-interpreted as a valid qeth_cmd_buffer pointer. Dereferencing this bogus pointer in qeth_release_buffer() triggers the crash. Solution: When returning the ccw device in qdio_shutdown(), also reset its interrupt parameter. Reproduction: Offline an OSA CHPID with multiple active qeth interfaces. Component: Kernel Upstream-ID: 89286320a236d245834075fa13adb0bdd827ecaa Reported: Ubuntu 18.04 To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu-z-systems/+bug/1828394/+subscriptions -- Mailing list: https://launchpad.net/~kernel-packages Post to : kernel-packages@lists.launchpad.net Unsubscribe : https://launchpad.net/~kernel-packages More help : https://help.launchpad.net/ListHelp
