kernel.git/drivers/s390, branch linux-6.1.y

s390/cio: Fix device lifecycle handling in css_alloc_subchannel()

2026-03-04T12:19:26Z

[ Upstream commit f65c75b0b9b5a390bc3beadcde0a6fbc3ad118f7 ] `css_alloc_subchannel()` calls `device_initialize()` before setting up the DMA masks. If `dma_set_coherent_mask()` or `dma_set_mask()` fails, the error path frees the subchannel structure directly, bypassing the device model reference counting. Once `device_initialize()` has been called, the embedded struct device must be released via `put_device()`, allowing the release callback to free the container structure. Fix the error path by dropping the initial device reference with `put_device()` instead of calling `kfree()` directly. This ensures correct device lifetime handling and avoids potential use-after-free or double-free issues. Fixes: e5dcf0025d7af ("s390/css: move subchannel lock allocation") Signed-off-by: Salah Triki Reviewed-by: Vineeth Vijayan Signed-off-by: Heiko Carstens Signed-off-by: Sasha Levin

s390/dasd: Fix gendisk parent after copy pair swap

2026-01-11T14:18:50Z

commit c943bfc6afb8d0e781b9b7406f36caa8bbf95cb9 upstream. After a copy pair swap the block device's "device" symlink points to the secondary CCW device, but the gendisk's parent remained the primary, leaving /sys/block/ under the wrong parent. Move the gendisk to the secondary's device with device_move(), keeping the sysfs topology consistent after the swap. Fixes: 413862caad6f ("s390/dasd: add copy pair swap capability") Cc: stable@vger.kernel.org #6.1 Reviewed-by: Jan Hoeppner Signed-off-by: Stefan Haberland Signed-off-by: Jens Axboe Signed-off-by: Greg Kroah-Hartman

s390/ap: Don't leak debug feature files if AP instructions are not available

2026-01-11T14:18:19Z

[ Upstream commit 020d5dc57874e58d3ebae398f3fe258f029e3d06 ] If no AP instructions are available the AP bus module leaks registered debug feature files. Change function call order to fix this. Fixes: cccd85bfb7bf ("s390/zcrypt: Rework debug feature invocations.") Reviewed-by: Harald Freudenberger Signed-off-by: Heiko Carstens Signed-off-by: Sasha Levin

s390/ctcm: Fix double-kfree

2025-12-06T21:12:39Z

[ Upstream commit da02a1824884d6c84c5e5b5ac373b0c9e3288ec2 ] The function 'mpc_rcvd_sweep_req(mpcginfo)' is called conditionally from function 'ctcmpc_unpack_skb'. It frees passed mpcginfo. After that a call to function 'kfree' in function 'ctcmpc_unpack_skb' frees it again. Remove 'kfree' call in function 'mpc_rcvd_sweep_req(mpcginfo)'. Bug detected by the clang static analyzer. Fixes: 0c0b20587b9f25a2 ("s390/ctcm: fix potential memory leak") Reviewed-by: Aswin Karuvally Signed-off-by: Aleksei Nikiforov Signed-off-by: Aswin Karuvally Reviewed-by: Simon Horman Link: https://patch.msgid.link/20251112182724.1109474-1-aswin@linux.ibm.com Signed-off-by: Jakub Kicinski Signed-off-by: Sasha Levin

s390/cio: Update purge function to unregister the unused subchannels

2025-10-29T13:04:42Z

commit 9daa5a8795865f9a3c93d8d1066785b07ded6073 upstream. Starting with 'commit 2297791c92d0 ("s390/cio: dont unregister subchannel from child-drivers")', cio no longer unregisters subchannels when the attached device is invalid or unavailable. As an unintended side-effect, the cio_ignore purge function no longer removes subchannels for devices on the cio_ignore list if no CCW device is attached. This situation occurs when a CCW device is non-operational or unavailable To ensure the same outcome of the purge function as when the current cio_ignore list had been active during boot, update the purge function to remove I/O subchannels without working CCW devices if the associated device number is found on the cio_ignore list. Fixes: 2297791c92d0 ("s390/cio: dont unregister subchannel from child-drivers") Suggested-by: Peter Oberparleiter Reviewed-by: Peter Oberparleiter Signed-off-by: Vineeth Vijayan Signed-off-by: Heiko Carstens Signed-off-by: Greg Kroah-Hartman

s390/sclp: Fix SCCB present check

2025-08-28T14:26:13Z

commit 430fa71027b6ac9bb0ce5532b8d0676777d4219a upstream. Tracing code called by the SCLP interrupt handler contains early exits if the SCCB address associated with an interrupt is NULL. This check is performed after physical to virtual address translation. If the kernel identity mapping does not start at address zero, the resulting virtual address is never zero, so that the NULL checks won't work. Subsequently this may result in incorrect accesses to the first page of the identity mapping. Fix this by introducing a function that handles the NULL case before address translation. Fixes: ada1da31ce34 ("s390/sclp: sort out physical vs virtual pointers usage") Cc: stable@vger.kernel.org Reviewed-by: Alexander Gordeev Signed-off-by: Peter Oberparleiter Signed-off-by: Alexander Gordeev Signed-off-by: Greg Kroah-Hartman

s390/pkey: Prevent overflow in size calculation for memdup_user()

2025-07-06T08:57:59Z

commit 7360ee47599af91a1d5f4e74d635d9408a54e489 upstream. Number of apqn target list entries contained in 'nr_apqns' variable is determined by userspace via an ioctl call so the result of the product in calculation of size passed to memdup_user() may overflow. In this case the actual size of the allocated area and the value describing it won't be in sync leading to various types of unpredictable behaviour later. Use a proper memdup_array_user() helper which returns an error if an overflow is detected. Note that it is different from when nr_apqns is initially zero - that case is considered valid and should be handled in subsequent pkey_handler implementations. Found by Linux Verification Center (linuxtesting.org). Fixes: f2bbc96e7cfa ("s390/pkey: add CCA AES cipher key support") Cc: stable@vger.kernel.org Signed-off-by: Fedor Pchelkin Reviewed-by: Holger Dengler Reviewed-by: Heiko Carstens Link: https://lore.kernel.org/r/20250611192011.206057-1-pchelkin@ispras.ru Signed-off-by: Alexander Gordeev Signed-off-by: Greg Kroah-Hartman

scsi: s390: zfcp: Ensure synchronous unit_add

2025-06-27T10:07:37Z

commit 9697ca0d53e3db357be26d2414276143c4a2cd49 upstream. Improve the usability of the unit_add sysfs attribute by ensuring that the associated FCP LUN scan processing is completed synchronously. This enables configuration tooling to consistently determine the end of the scan process to allow for serialization of follow-on actions. While the scan process associated with unit_add typically completes synchronously, it is deferred to an asynchronous background process if unit_add is used before initial remote port scanning has completed. This occurs when unit_add is used immediately after setting the associated FCP device online. To ensure synchronous unit_add processing, wait for remote port scanning to complete before initiating the FCP LUN scan. Cc: stable@vger.kernel.org Reviewed-by: M Nikhil Reviewed-by: Nihar Panda Signed-off-by: Peter Oberparleiter Signed-off-by: Nihar Panda Link: https://lore.kernel.org/r/20250603182252.2287285-2-niharp@linux.ibm.com Signed-off-by: Martin K. Petersen Signed-off-by: Greg Kroah-Hartman

s390/vfio-ap: Fix no AP queue sharing allowed message written to kernel log

2025-06-04T12:40:02Z

[ Upstream commit d33d729afcc8ad2148d99f9bc499b33fd0c0d73b ] An erroneous message is written to the kernel log when either of the following actions are taken by a user: 1. Assign an adapter or domain to a vfio_ap mediated device via its sysfs assign_adapter or assign_domain attributes that would result in one or more AP queues being assigned that are already assigned to a different mediated device. Sharing of queues between mdevs is not allowed. 2. Reserve an adapter or domain for the host device driver via the AP bus driver's sysfs apmask or aqmask attribute that would result in providing host access to an AP queue that is in use by a vfio_ap mediated device. Reserving a queue for a host driver that is in use by an mdev is not allowed. In both cases, the assignment will return an error; however, a message like the following is written to the kernel log: vfio_ap_mdev e1839397-51a0-4e3c-91e0-c3b9c3d3047d: Userspace may not re-assign queue 00.0028 already assigned to \ e1839397-51a0-4e3c-91e0-c3b9c3d3047d Notice the mdev reporting the error is the same as the mdev identified in the message as the one to which the queue is being assigned. It is perfectly okay to assign a queue to an mdev to which it is already assigned; the assignment is simply ignored by the vfio_ap device driver. This patch logs more descriptive and accurate messages for both 1 and 2 above to the kernel log: Example for 1: vfio_ap_mdev 0fe903a0-a323-44db-9daf-134c68627d61: Userspace may not assign queue 00.0033 to mdev: already assigned to \ 62177883-f1bb-47f0-914d-32a22e3a8804 Example for 2: vfio_ap_mdev 62177883-f1bb-47f0-914d-32a22e3a8804: Can not reserve queue 00.0033 for host driver: in use by mdev Signed-off-by: Anthony Krowiak Link: https://lore.kernel.org/r/20250311103304.1539188-1-akrowiak@linux.ibm.com Signed-off-by: Heiko Carstens Signed-off-by: Vasily Gorbik Signed-off-by: Sasha Levin

s390/tty: Fix a potential memory leak bug

2025-05-02T05:47:02Z

[ Upstream commit ad9bb8f049717d64c5e62b2a44954be9f681c65b ] The check for get_zeroed_page() leads to a direct return and overlooked the memory leak caused by loop allocation. Add a free helper to free spaces allocated by get_zeroed_page(). Signed-off-by: Haoxiang Li Acked-by: Heiko Carstens Link: https://lore.kernel.org/r/20250218034104.2436469-1-haoxiang_li2024@163.com Signed-off-by: Vasily Gorbik Signed-off-by: Sasha Levin