kernel/git/stable/linux-stable.git/drivers/virtio, branch linux-6.12.y

virtio_pci: fix wrong queue index for admin vq in intx path

2026-09-14T11:32:52+00:00

[ Upstream commit dc3f1eef9ab678c396baf5df12aba61db061aa8c ] In vp_find_vqs_intx(), the admin vq was set up using the local queue_idx counter instead of avq->vq_index (the actual queue index obtained from the device). This differs from vp_find_vqs_msix() which correctly uses avq->vq_index. Using the wrong index causes the admin virtqueue to be mapped to an incorrect hardware queue. Fix it by using avq->vq_index consistent with the msix path. Fixes: af22bbe1f4a5 ("virtio: create admin queues alongside other virtqueues") Signed-off-by: Li RongQing Message-ID: <20260629033538.2476-1-lirongqing@baidu.com> Signed-off-by: Michael S. Tsirkin Signed-off-by: Sasha Levin

virtio_balloon: disable indirect descriptors

2026-09-14T11:32:52+00:00

[ Upstream commit 281eb4732aae5473141b84e106fe906c69b2ff3d ] The page reporting callback submits an sg list to the reporting virtqueue. With VIRTIO_RING_F_INDIRECT_DESC negotiated and total_sg > 1 (which it typically is), virtqueue_add reports it to the host by allocating an indirect descriptor via kmalloc(GFP_KERNEL). This is not pretty: the reporting worker isolates potentially hundreds of MB of free pages from the buddy allocator (reported pages are at least pageblock_order, and the sg can contain up to PAGE_REPORTING_CAPACITY entries of varying orders). As the result, very theoretically, the kmalloc might trigger OOM when we have in fact a ton of free memory. Clear VIRTIO_RING_F_INDIRECT_DESC, to avoid using indirect descriptors. Fixes: b0c504f15471 ("virtio-balloon: add support for providing free page reports to host") Assisted-by: Claude:claude-opus-4-6 Acked-by: David Hildenbrand (Arm) Signed-off-by: Michael S. Tsirkin Message-ID: <73fac8a629fd9aca7bb3265ac243a769c28af25d.1783232420.git.mst@redhat.com> Signed-off-by: Sasha Levin

virtio-mmio: fix device release warning on module unload

2026-07-18T14:52:00+00:00

commit c687bc35694698ec4c7f92bf929c3d659f0cecb8 upstream. Driver core expects devices to be allocated dynamically and complains loudly when a device that lacks a release function is freed. Use __root_device_register() to allocate and register the root device instead of open coding using a static device. Note that root_device_register(), which also creates a link to the module, cannot be used as the device is registered when parsing the module parameters which happens before the module kobject has been set up. Fixes: 81a054ce0b46 ("virtio-mmio: Devices parameter parsing") Cc: stable@vger.kernel.org # 3.5 Cc: Pawel Moll Signed-off-by: Johan Hovold Signed-off-by: Michael S. Tsirkin Message-ID: <20260427143710.14702-1-johan@kernel.org> Signed-off-by: Greg Kroah-Hartman

virtio_pci: fix vq info pointer lookup via wrong index

2026-07-18T14:52:00+00:00

commit f7d380fb525c13bdd114369a1979c80c346e6abc upstream. Unbinding a virtio balloon device: echo virtio0 > /sys/bus/virtio/drivers/virtio_balloon/unbind triggers a NULL pointer dereference. The dmesg says: BUG: kernel NULL pointer dereference, address: 0000000000000008 [...] RIP: 0010:__list_del_entry_valid_or_report+0x5/0xf0 Call Trace: vp_del_vqs+0x121/0x230 remove_common+0x135/0x150 virtballoon_remove+0xee/0x100 virtio_dev_remove+0x3b/0x80 device_release_driver_internal+0x187/0x2c0 unbind_store+0xb9/0xe0 kernfs_fop_write_iter.llvm.11660790530567441834+0xf6/0x180 vfs_write+0x2a9/0x3b0 ksys_write+0x5c/0xd0 do_syscall_64+0x54/0x230 entry_SYSCALL_64_after_hwframe+0x29/0x31 [...] The virtio_balloon device registers 5 queues (inflate, deflate, stats, free_page, reporting) but only the first two are unconditional. The stats, free_page and reporting queues are each conditional on their respective feature bits. When any of these features are absent, the corresponding vqs_info entry has name == NULL, creating holes in the array. The root cause is an indexing mismatch introduced when vq info storage was changed to be passed as an argument. vp_find_vqs_msix() and vp_find_vqs_intx() store the info pointer at vp_dev->vqs[i], where 'i' is the caller's sparse array index. However, the virtqueue itself gets vq->index assigned from queue_idx, a dense index that skips NULL entries. When holes exist, 'i' and queue_idx diverge. Later, vp_del_vqs() looks up info via vp_dev->vqs[vq->index] using the dense index into the sparsely-populated array, and hits NULL. Fix this by storing info at vp_dev->vqs[queue_idx] instead of vp_dev->vqs[i], so the store index matches the lookup index (vq->index). Apply the fix to both the MSIX and INTX paths. Cc: Yichun Zhang Cc: Jiri Pirko Cc: stable@vger.kernel.org # v6.11+ Tested-by: Yuka Fixes: 89a1c435aec2 ("virtio_pci: pass vq info as an argument to vp_setup_vq()") Signed-off-by: Ammar Faizi Message-Id: <20260315141808.547081-1-ammarfaizi2@openresty.com> Signed-off-by: Michael S. Tsirkin Signed-off-by: Greg Kroah-Hartman

mm/balloon_compaction: convert balloon_page_delete() to balloon_page_finalize()

2026-01-08T09:15:05+00:00

[ Upstream commit 15504b1163007bbfbd9a63460d5c14737c16e96d ] Let's move the removal of the page from the balloon list into the single caller, to remove the dependency on the PG_isolated flag and clarify locking requirements. Note that for now, balloon_page_delete() was used on two paths: (1) Removing a page from the balloon for deflation through balloon_page_list_dequeue() (2) Removing an isolated page from the balloon for migration in the per-driver migration handlers. Isolated pages were already removed from the balloon list during isolation. So instead of relying on the flag, we can just distinguish both cases directly and handle it accordingly in the caller. We'll shuffle the operations a bit such that they logically make more sense (e.g., remove from the list before clearing flags). In balloon migration functions we can now move the balloon_page_finalize() out of the balloon lock and perform the finalization just before dropping the balloon reference. Document that the page lock is currently required when modifying the movability aspects of a page; hopefully we can soon decouple this from the page lock. Link: https://lkml.kernel.org/r/20250704102524.326966-3-david@redhat.com Signed-off-by: David Hildenbrand Reviewed-by: Lorenzo Stoakes Cc: Alistair Popple Cc: Al Viro Cc: Arnd Bergmann Cc: Brendan Jackman Cc: Byungchul Park Cc: Chengming Zhou Cc: Christian Brauner Cc: Christophe Leroy Cc: Eugenio Pé rez Cc: Greg Kroah-Hartman Cc: Gregory Price Cc: Harry Yoo Cc: "Huang, Ying" Cc: Jan Kara Cc: Jason Gunthorpe Cc: Jason Wang Cc: Jerrin Shaji George Cc: Johannes Weiner Cc: John Hubbard Cc: Jonathan Corbet Cc: Joshua Hahn Cc: Liam Howlett Cc: Madhavan Srinivasan Cc: Mathew Brost Cc: Matthew Wilcox (Oracle) Cc: Miaohe Lin Cc: Michael Ellerman Cc: "Michael S. Tsirkin" Cc: Michal Hocko Cc: Mike Rapoport Cc: Minchan Kim Cc: Naoya Horiguchi Cc: Nicholas Piggin Cc: Oscar Salvador Cc: Peter Xu Cc: Qi Zheng Cc: Rakie Kim Cc: Rik van Riel Cc: Sergey Senozhatsky Cc: Shakeel Butt Cc: Suren Baghdasaryan Cc: Vlastimil Babka Cc: Xuan Zhuo Cc: xu xin Cc: Zi Yan Signed-off-by: Andrew Morton Stable-dep-of: 0da2ba35c0d5 ("powerpc/pseries/cmm: adjust BALLOON_MIGRATE when migrating pages") Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman

virtio_vdpa: fix misleading return in void function

2025-12-18T12:55:09+00:00

[ Upstream commit e40b6abe0b1247d43bc61942aa7534fca7209e44 ] virtio_vdpa_set_status() is declared as returning void, but it used "return vdpa_set_status()" Since vdpa_set_status() also returns void, the return statement is unnecessary and misleading. Remove it. Fixes: c043b4a8cf3b ("virtio: introduce a vDPA based transport") Signed-off-by: Alok Tiwari Message-Id: <20251001191653.1713923-1-alok.a.tiwari@oracle.com> Signed-off-by: Michael S. Tsirkin Acked-by: Jason Wang Signed-off-by: Sasha Levin

virtio_ring: Fix error reporting in virtqueue_resize

2025-08-01T08:48:39+00:00

[ Upstream commit 45ebc7e6c125ce93d2ddf82cd5bea20121bb0258 ] The virtqueue_resize() function was not correctly propagating error codes from its internal resize helper functions, specifically virtqueue_resize_packet() and virtqueue_resize_split(). If these helpers returned an error, but the subsequent call to virtqueue_enable_after_reset() succeeded, the original error from the resize operation would be masked. Consequently, virtqueue_resize() could incorrectly report success to its caller despite an underlying resize failure. This change restores the original code behavior: if (vdev->config->enable_vq_after_reset(_vq)) return -EBUSY; return err; Fix: commit ad48d53b5b3f ("virtio_ring: separate the logic of reset/enable from virtqueue_resize") Cc: xuanzhuo@linux.alibaba.com Signed-off-by: Laurent Vivier Acked-by: Jason Wang Link: https://patch.msgid.link/20250521092236.661410-2-lvivier@redhat.com Tested-by: Lei Yang Acked-by: Michael S. Tsirkin Signed-off-by: Paolo Abeni Signed-off-by: Sasha Levin

virtio_ring: Fix data race by tagging event_triggered as racy for KCSAN

2025-05-29T09:01:58+00:00

[ Upstream commit 2e2f925fe737576df2373931c95e1a2b66efdfef ] syzbot reports a data-race when accessing the event_triggered, here is the simplified stack when the issue occurred: ================================================================== BUG: KCSAN: data-race in virtqueue_disable_cb / virtqueue_enable_cb_delayed write to 0xffff8881025bc452 of 1 bytes by task 3288 on cpu 0: virtqueue_enable_cb_delayed+0x42/0x3c0 drivers/virtio/virtio_ring.c:2653 start_xmit+0x230/0x1310 drivers/net/virtio_net.c:3264 __netdev_start_xmit include/linux/netdevice.h:5151 [inline] netdev_start_xmit include/linux/netdevice.h:5160 [inline] xmit_one net/core/dev.c:3800 [inline] read to 0xffff8881025bc452 of 1 bytes by interrupt on cpu 1: virtqueue_disable_cb_split drivers/virtio/virtio_ring.c:880 [inline] virtqueue_disable_cb+0x92/0x180 drivers/virtio/virtio_ring.c:2566 skb_xmit_done+0x5f/0x140 drivers/net/virtio_net.c:777 vring_interrupt+0x161/0x190 drivers/virtio/virtio_ring.c:2715 __handle_irq_event_percpu+0x95/0x490 kernel/irq/handle.c:158 handle_irq_event_percpu kernel/irq/handle.c:193 [inline] value changed: 0x01 -> 0x00 ================================================================== When the data race occurs, the function virtqueue_enable_cb_delayed() sets event_triggered to false, and virtqueue_disable_cb_split/packed() reads it as false due to the race condition. Since event_triggered is an unreliable hint used for optimization, this should only cause the driver temporarily suggest that the device not send an interrupt notification when the event index is used. Fix this KCSAN reported data-race issue by explicitly tagging the access as data_racy. Reported-by: syzbot+efe683d57990864b8c8e@syzkaller.appspotmail.com Closes: https://lore.kernel.org/all/67c7761a.050a0220.15b4b9.0018.GAE@google.com/ Signed-off-by: Zhongqiu Han Message-Id: <20250312130412.3516307-1-quic_zhonhan@quicinc.com> Signed-off-by: Michael S. Tsirkin Acked-by: Jason Wang Signed-off-by: Sasha Levin

virtio_ring: add a func argument 'recycle_done' to virtqueue_reset()

2025-05-22T12:29:38+00:00

[ Upstream commit 8d2da07c813ad333c20eb803e15f8c4541f25350 ] When virtqueue_reset() has actually recycled all unused buffers, additional work may be required in some cases. Relying solely on its return status is fragile, so introduce a new function argument 'recycle_done', which is invoked when it really occurs. Signed-off-by: Koichiro Den Acked-by: Jason Wang Reviewed-by: Xuan Zhuo Signed-off-by: Paolo Abeni Stable-dep-of: 76a771ec4c9a ("virtio_net: ensure netdev_tx_reset_queue is called on bind xsk for tx") Signed-off-by: Sasha Levin

virtio_ring: add a func argument 'recycle_done' to virtqueue_resize()

2024-12-19T17:12:59+00:00

commit 8d6712c892019b9b9dc5c7039edd3c9d770b510b upstream. When virtqueue_resize() has actually recycled all unused buffers, additional work may be required in some cases. Relying solely on its return status is fragile, so introduce a new function argument 'recycle_done', which is invoked when the recycle really occurs. Cc: # v6.11+ Signed-off-by: Koichiro Den Acked-by: Jason Wang Reviewed-by: Xuan Zhuo Signed-off-by: Paolo Abeni Signed-off-by: Greg Kroah-Hartman