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[PATCH OLK-6.6] iommu: disable SVA when CONFIG_X86 is set
by Zhang Yuwei 07 Mar '26

07 Mar '26

From: Lu Baolu <baolu.lu(a)linux.intel.com> mainline inclusion from mainline-v6.19-rc1 commit 72f98ef9a4be30d2a60136dd6faee376f780d06c category: bugfix bugzilla: https://atomgit.com/src-openeuler/kernel/issues/13400 CVE: CVE-2025-71089 Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?… -------------------------------- Patch series "Fix stale IOTLB entries for kernel address space", v7. This proposes a fix for a security vulnerability related to IOMMU Shared Virtual Addressing (SVA). In an SVA context, an IOMMU can cache kernel page table entries. When a kernel page table page is freed and reallocated for another purpose, the IOMMU might still hold stale, incorrect entries. This can be exploited to cause a use-after-free or write-after-free condition, potentially leading to privilege escalation or data corruption. This solution introduces a deferred freeing mechanism for kernel page table pages, which provides a safe window to notify the IOMMU to invalidate its caches before the page is reused. This patch (of 8): In the IOMMU Shared Virtual Addressing (SVA) context, the IOMMU hardware shares and walks the CPU's page tables. The x86 architecture maps the kernel's virtual address space into the upper portion of every process's page table. Consequently, in an SVA context, the IOMMU hardware can walk and cache kernel page table entries. The Linux kernel currently lacks a notification mechanism for kernel page table changes, specifically when page table pages are freed and reused. The IOMMU driver is only notified of changes to user virtual address mappings. This can cause the IOMMU's internal caches to retain stale entries for kernel VA. Use-After-Free (UAF) and Write-After-Free (WAF) conditions arise when kernel page table pages are freed and later reallocated. The IOMMU could misinterpret the new data as valid page table entries. The IOMMU might then walk into attacker-controlled memory, leading to arbitrary physical memory DMA access or privilege escalation. This is also a Write-After-Free issue, as the IOMMU will potentially continue to write Accessed and Dirty bits to the freed memory while attempting to walk the stale page tables. Currently, SVA contexts are unprivileged and cannot access kernel mappings. However, the IOMMU will still walk kernel-only page tables all the way down to the leaf entries, where it realizes the mapping is for the kernel and errors out. This means the IOMMU still caches these intermediate page table entries, making the described vulnerability a real concern. Disable SVA on x86 architecture until the IOMMU can receive notification to flush the paging cache before freeing the CPU kernel page table pages. Link: https://lkml.kernel.org/r/20251022082635.2462433-1-baolu.lu@linux.intel.com Link: https://lkml.kernel.org/r/20251022082635.2462433-2-baolu.lu@linux.intel.com Fixes: 26b25a2b98e4 ("iommu: Bind process address spaces to devices") Signed-off-by: Lu Baolu <baolu.lu(a)linux.intel.com> Suggested-by: Jason Gunthorpe <jgg(a)nvidia.com> Reviewed-by: Jason Gunthorpe <jgg(a)nvidia.com> Cc: Alistair Popple <apopple(a)nvidia.com> Cc: Andy Lutomirski <luto(a)kernel.org> Cc: Borislav Betkov <bp(a)alien8.de> Cc: Dave Hansen <dave.hansen(a)intel.com> Cc: David Hildenbrand <david(a)redhat.com> Cc: Ingo Molnar <mingo(a)redhat.com> Cc: Jann Horn <jannh(a)google.com> Cc: Jean-Philippe Brucker <jean-philippe(a)linaro.org> Cc: Joerg Roedel <joro(a)8bytes.org> Cc: Kevin Tian <kevin.tian(a)intel.com> Cc: Liam Howlett <liam.howlett(a)oracle.com> Cc: Lorenzo Stoakes <lorenzo.stoakes(a)oracle.com> Cc: Matthew Wilcox (Oracle) <willy(a)infradead.org> Cc: Michal Hocko <mhocko(a)kernel.org> Cc: Mike Rapoport <rppt(a)kernel.org> Cc: Peter Zijlstra <peterz(a)infradead.org> Cc: Robin Murohy <robin.murphy(a)arm.com> Cc: Thomas Gleinxer <tglx(a)linutronix.de> Cc: "Uladzislau Rezki (Sony)" <urezki(a)gmail.com> Cc: Vasant Hegde <vasant.hegde(a)amd.com> Cc: Vinicius Costa Gomes <vinicius.gomes(a)intel.com> Cc: Vlastimil Babka <vbabka(a)suse.cz> Cc: Will Deacon <will(a)kernel.org> Cc: Yi Lai <yi1.lai(a)intel.com> Cc: <stable(a)vger.kernel.org> Signed-off-by: Andrew Morton <akpm(a)linux-foundation.org> Signed-off-by: Zhang Yuwei <zhangyuwei20(a)huawei.com> --- drivers/iommu/iommu-sva.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/drivers/iommu/iommu-sva.c b/drivers/iommu/iommu-sva.c index 96c77d43928a..b65177bbd75f 100644 --- a/drivers/iommu/iommu-sva.c +++ b/drivers/iommu/iommu-sva.c @@ -81,6 +81,9 @@ struct iommu_sva *iommu_sva_bind_device(struct device *dev, struct mm_struct *mm if (!group) return ERR_PTR(-ENODEV); + if (IS_ENABLED(CONFIG_X86)) + return ERR_PTR(-EOPNOTSUPP); + mutex_lock(&iommu_sva_lock); /* Allocate mm->pasid if necessary. */ -- 2.22.0

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[PATCH OLK-5.10 0/2] CVE-2024-57979
by Wang Hai 07 Mar '26

07 Mar '26

Calvin Owens (1): pps: Fix a use-after-free Wang Hai (1): pps: Fix kabi in pps_device drivers/pps/clients/pps-gpio.c | 4 +- drivers/pps/clients/pps-ktimer.c | 4 +- drivers/pps/clients/pps-ldisc.c | 2 +- drivers/pps/kapi.c | 2 +- drivers/pps/pps.c | 84 +++++++++++++++++--------------- 5 files changed, 51 insertions(+), 45 deletions(-) -- 2.17.1

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[PATCH OLK-5.10] ALSA: aloop: Fix racy access at PCM trigger
by Lin Ruifeng 07 Mar '26

07 Mar '26

From: Takashi Iwai <tiwai(a)suse.de> stable inclusion from stable-v6.12.70 commit bad15420050db1803767e58756114800cce91ea4 category: bugfix bugzilla: https://atomgit.com/src-openeuler/kernel/issues/13748 CVE: CVE-2026-23191 Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id… -------------------------------- commit 826af7fa62e347464b1b4e0ba2fe19a92438084f upstream. The PCM trigger callback of aloop driver tries to check the PCM state and stop the stream of the tied substream in the corresponding cable. Since both check and stop operations are performed outside the cable lock, this may result in UAF when a program attempts to trigger frequently while opening/closing the tied stream, as spotted by fuzzers. For addressing the UAF, this patch changes two things: - It covers the most of code in loopback_check_format() with cable->lock spinlock, and add the proper NULL checks. This avoids already some racy accesses. - In addition, now we try to check the state of the capture PCM stream that may be stopped in this function, which was the major pain point leading to UAF. Reported-by: syzbot+5f8f3acdee1ec7a7ef7b(a)syzkaller.appspotmail.com Closes: https://lore.kernel.org/69783ba1.050a0220.c9109.0011.GAE@google.com Cc: <stable(a)vger.kernel.org> Link: https://patch.msgid.link/20260203141003.116584-1-tiwai@suse.de Signed-off-by: Takashi Iwai <tiwai(a)suse.de> Signed-off-by: Greg Kroah-Hartman <gregkh(a)linuxfoundation.org> Conflicts: sound/drivers/aloop.c [Context Conflicts] Signed-off-by: Lin Ruifeng <linruifeng4(a)huawei.com> --- sound/drivers/aloop.c | 89 +++++++++++++++++++++++++++---------------- 1 file changed, 56 insertions(+), 33 deletions(-) diff --git a/sound/drivers/aloop.c b/sound/drivers/aloop.c index fb45a32d99cd..b8ea26719bbc 100644 --- a/sound/drivers/aloop.c +++ b/sound/drivers/aloop.c @@ -320,51 +320,74 @@ static int loopback_snd_timer_close_cable(struct loopback_pcm *dpcm) static int loopback_check_format(struct loopback_cable *cable, int stream) { + struct loopback_pcm *dpcm_play, *dpcm_capt; struct snd_pcm_runtime *runtime, *cruntime; struct loopback_setup *setup; struct snd_card *card; + bool stop_capture = false; int check; + unsigned long flags; + + spin_lock_irqsave(&cable->lock, flags); + + dpcm_play = cable->streams[SNDRV_PCM_STREAM_PLAYBACK]; + dpcm_capt = cable->streams[SNDRV_PCM_STREAM_CAPTURE]; if (cable->valid != CABLE_VALID_BOTH) { - if (stream == SNDRV_PCM_STREAM_PLAYBACK) - goto __notify; - return 0; - } - runtime = cable->streams[SNDRV_PCM_STREAM_PLAYBACK]-> - substream->runtime; - cruntime = cable->streams[SNDRV_PCM_STREAM_CAPTURE]-> - substream->runtime; - check = runtime->format != cruntime->format || + if (stream == SNDRV_PCM_STREAM_CAPTURE || !dpcm_play) { + spin_unlock_irqrestore(&cable->lock, flags); + return 0; + } + } else { + if (!dpcm_play || !dpcm_capt) { + spin_unlock_irqrestore(&cable->lock, flags); + return -EIO; + } + runtime = dpcm_play->substream->runtime; + cruntime = dpcm_capt->substream->runtime; + if (!runtime || !cruntime) { + spin_unlock_irqrestore(&cable->lock, flags); + return -EIO; + } + check = runtime->format != cruntime->format || runtime->rate != cruntime->rate || runtime->channels != cruntime->channels; - if (!check) - return 0; - if (stream == SNDRV_PCM_STREAM_CAPTURE) { - return -EIO; - } else { - snd_pcm_stop(cable->streams[SNDRV_PCM_STREAM_CAPTURE]-> - substream, SNDRV_PCM_STATE_DRAINING); - __notify: - runtime = cable->streams[SNDRV_PCM_STREAM_PLAYBACK]-> - substream->runtime; - setup = get_setup(cable->streams[SNDRV_PCM_STREAM_PLAYBACK]); - card = cable->streams[SNDRV_PCM_STREAM_PLAYBACK]->loopback->card; - if (setup->format != runtime->format) { - snd_ctl_notify(card, SNDRV_CTL_EVENT_MASK_VALUE, - &setup->format_id); - setup->format = runtime->format; + if (!check) { + spin_unlock_irqrestore(&cable->lock, flags); + return 0; } - if (setup->rate != runtime->rate) { - snd_ctl_notify(card, SNDRV_CTL_EVENT_MASK_VALUE, - &setup->rate_id); - setup->rate = runtime->rate; + if (stream == SNDRV_PCM_STREAM_CAPTURE) { + spin_unlock_irqrestore(&cable->lock, flags); + return -EIO; } - if (setup->channels != runtime->channels) { - snd_ctl_notify(card, SNDRV_CTL_EVENT_MASK_VALUE, - &setup->channels_id); - setup->channels = runtime->channels; + else if (cruntime->status->state == SNDRV_PCM_STATE_RUNNING) { + stop_capture = true; } } + + setup = get_setup(dpcm_play); + card = dpcm_play->loopback->card; + runtime = dpcm_play->substream->runtime; + if (setup->format != runtime->format) { + snd_ctl_notify(card, SNDRV_CTL_EVENT_MASK_VALUE, + &setup->format_id); + setup->format = runtime->format; + } + if (setup->rate != runtime->rate) { + snd_ctl_notify(card, SNDRV_CTL_EVENT_MASK_VALUE, + &setup->rate_id); + setup->rate = runtime->rate; + } + if (setup->channels != runtime->channels) { + snd_ctl_notify(card, SNDRV_CTL_EVENT_MASK_VALUE, + &setup->channels_id); + setup->channels = runtime->channels; + } + spin_unlock_irqrestore(&cable->lock, flags); + + if (stop_capture) + snd_pcm_stop(dpcm_capt->substream, SNDRV_PCM_STATE_DRAINING); + return 0; } -- 2.43.0

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[PATCH OLK-6.6 0/3] *** fix CVE-2026-23207 ***
by Lin Ruifeng 07 Mar '26

07 Mar '26

*** fix CVE-2026-23207 *** Breno Leitao (2): spi: tegra210-quad: Move curr_xfer read inside spinlock spi: tegra210-quad: Protect curr_xfer check in IRQ handler Vishwaroop A (1): spi: tegra210-quad: Fix timeout handling drivers/spi/spi-tegra210-quad.c | 49 ++++++++++++++++++++++++++++++--- 1 file changed, 45 insertions(+), 4 deletions(-) -- 2.43.0

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[PATCH OLK-5.10 0/2] CVE-2024-57979
by Wang Hai 07 Mar '26

07 Mar '26

Calvin Owens (1): pps: Fix a use-after-free Wang Hai (1): pps: Fix kabi in pps_device drivers/pps/clients/pps-gpio.c | 4 +- drivers/pps/clients/pps-ktimer.c | 4 +- drivers/pps/clients/pps-ldisc.c | 2 +- drivers/pps/kapi.c | 2 +- drivers/pps/pps.c | 84 +++++++++++++++++--------------- 5 files changed, 51 insertions(+), 45 deletions(-) -- 2.17.1

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[PATCH OLK-6.6 0/2] CVE-2024-57979
by Wang Hai 07 Mar '26

07 Mar '26

Calvin Owens (1): [Backport] pps: Fix a use-after-free Wang Hai (1): pps: Fix a use-after-free - fix kabi drivers/pps/clients/pps-gpio.c | 4 +- drivers/pps/clients/pps-ktimer.c | 4 +- drivers/pps/clients/pps-ldisc.c | 2 +- drivers/pps/kapi.c | 2 +- drivers/pps/pps.c | 84 +++++++++++++++++--------------- 5 files changed, 51 insertions(+), 45 deletions(-) -- 2.17.1

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[PATCH OLK-6.6] platform/x86: classmate-laptop: Add missing NULL pointer checks
by Zeng Heng 07 Mar '26

07 Mar '26

From: "Rafael J. Wysocki" <rafael.j.wysocki(a)intel.com> mainline inclusion from mainline-v6.19 commit fe747d7112283f47169e9c16e751179a9b38611e category: bugfix bugzilla: https://atomgit.com/openeuler/kernel/issues/13842 CVE: CVE-2026-23237 Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id… -------------------------------- In a few places in the Classmate laptop driver, code using the accel object may run before that object's address is stored in the driver data of the input device using it. For example, cmpc_accel_sensitivity_store_v4() is the "show" method of cmpc_accel_sensitivity_attr_v4 which is added in cmpc_accel_add_v4(), before calling dev_set_drvdata() for inputdev->dev. If the sysfs attribute is accessed prematurely, the dev_get_drvdata(&inputdev->dev) call in in cmpc_accel_sensitivity_store_v4() returns NULL which leads to a NULL pointer dereference going forward. Moreover, sysfs attributes using the input device are added before initializing that device by cmpc_add_acpi_notify_device() and if one of them is accessed before running that function, a NULL pointer dereference will occur. For example, cmpc_accel_sensitivity_attr_v4 is added before calling cmpc_add_acpi_notify_device() and if it is read prematurely, the dev_get_drvdata(&acpi->dev) call in cmpc_accel_sensitivity_show_v4() returns NULL which leads to a NULL pointer dereference going forward. Fix this by adding NULL pointer checks in all of the relevant places. Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki(a)intel.com> Link: https://patch.msgid.link/12825381.O9o76ZdvQC@rafael.j.wysocki Reviewed-by: Ilpo Järvinen <ilpo.jarvinen(a)linux.intel.com> Signed-off-by: Ilpo Järvinen <ilpo.jarvinen(a)linux.intel.com> Conflicts: drivers/platform/x86/classmate-laptop.c [Context conflicts.] Signed-off-by: Zeng Heng <zengheng4(a)huawei.com> --- drivers/platform/x86/classmate-laptop.c | 32 +++++++++++++++++++++++++ 1 file changed, 32 insertions(+) diff --git a/drivers/platform/x86/classmate-laptop.c b/drivers/platform/x86/classmate-laptop.c index 2edaea2492df..053c8a86d5ec 100644 --- a/drivers/platform/x86/classmate-laptop.c +++ b/drivers/platform/x86/classmate-laptop.c @@ -208,7 +208,12 @@ static ssize_t cmpc_accel_sensitivity_show_v4(struct device *dev, acpi = to_acpi_device(dev); inputdev = dev_get_drvdata(&acpi->dev); + if (!inputdev) + return -ENXIO; + accel = dev_get_drvdata(&inputdev->dev); + if (!accel) + return -ENXIO; return sprintf(buf, "%d\n", accel->sensitivity); } @@ -225,7 +230,12 @@ static ssize_t cmpc_accel_sensitivity_store_v4(struct device *dev, acpi = to_acpi_device(dev); inputdev = dev_get_drvdata(&acpi->dev); + if (!inputdev) + return -ENXIO; + accel = dev_get_drvdata(&inputdev->dev); + if (!accel) + return -ENXIO; r = kstrtoul(buf, 0, &sensitivity); if (r) @@ -257,7 +267,12 @@ static ssize_t cmpc_accel_g_select_show_v4(struct device *dev, acpi = to_acpi_device(dev); inputdev = dev_get_drvdata(&acpi->dev); + if (!inputdev) + return -ENXIO; + accel = dev_get_drvdata(&inputdev->dev); + if (!accel) + return -ENXIO; return sprintf(buf, "%d\n", accel->g_select); } @@ -274,7 +289,12 @@ static ssize_t cmpc_accel_g_select_store_v4(struct device *dev, acpi = to_acpi_device(dev); inputdev = dev_get_drvdata(&acpi->dev); + if (!inputdev) + return -ENXIO; + accel = dev_get_drvdata(&inputdev->dev); + if (!accel) + return -ENXIO; r = kstrtoul(buf, 0, &g_select); if (r) @@ -303,6 +323,8 @@ static int cmpc_accel_open_v4(struct input_dev *input) acpi = to_acpi_device(input->dev.parent); accel = dev_get_drvdata(&input->dev); + if (!accel) + return -ENXIO; cmpc_accel_set_sensitivity_v4(acpi->handle, accel->sensitivity); cmpc_accel_set_g_select_v4(acpi->handle, accel->g_select); @@ -551,7 +573,12 @@ static ssize_t cmpc_accel_sensitivity_show(struct device *dev, acpi = to_acpi_device(dev); inputdev = dev_get_drvdata(&acpi->dev); + if (!inputdev) + return -ENXIO; + accel = dev_get_drvdata(&inputdev->dev); + if (!accel) + return -ENXIO; return sprintf(buf, "%d\n", accel->sensitivity); } @@ -568,7 +595,12 @@ static ssize_t cmpc_accel_sensitivity_store(struct device *dev, acpi = to_acpi_device(dev); inputdev = dev_get_drvdata(&acpi->dev); + if (!inputdev) + return -ENXIO; + accel = dev_get_drvdata(&inputdev->dev); + if (!accel) + return -ENXIO; r = kstrtoul(buf, 0, &sensitivity); if (r) -- 2.25.1

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[PATCH OLK-6.6] platform/x86: classmate-laptop: Add missing NULL pointer checks
by Zeng Heng 07 Mar '26

07 Mar '26

From: "Rafael J. Wysocki" <rafael.j.wysocki(a)intel.com> mainline inclusion from mainline-v6.19 commit fe747d7112283f47169e9c16e751179a9b38611e category: bugfix bugzilla: https://atomgit.com/openeuler/kernel/issues/13842 Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id… -------------------------------- In a few places in the Classmate laptop driver, code using the accel object may run before that object's address is stored in the driver data of the input device using it. For example, cmpc_accel_sensitivity_store_v4() is the "show" method of cmpc_accel_sensitivity_attr_v4 which is added in cmpc_accel_add_v4(), before calling dev_set_drvdata() for inputdev->dev. If the sysfs attribute is accessed prematurely, the dev_get_drvdata(&inputdev->dev) call in in cmpc_accel_sensitivity_store_v4() returns NULL which leads to a NULL pointer dereference going forward. Moreover, sysfs attributes using the input device are added before initializing that device by cmpc_add_acpi_notify_device() and if one of them is accessed before running that function, a NULL pointer dereference will occur. For example, cmpc_accel_sensitivity_attr_v4 is added before calling cmpc_add_acpi_notify_device() and if it is read prematurely, the dev_get_drvdata(&acpi->dev) call in cmpc_accel_sensitivity_show_v4() returns NULL which leads to a NULL pointer dereference going forward. Fix this by adding NULL pointer checks in all of the relevant places. Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki(a)intel.com> Link: https://patch.msgid.link/12825381.O9o76ZdvQC@rafael.j.wysocki Reviewed-by: Ilpo Järvinen <ilpo.jarvinen(a)linux.intel.com> Signed-off-by: Ilpo Järvinen <ilpo.jarvinen(a)linux.intel.com> Conflicts: drivers/platform/x86/classmate-laptop.c [Context conflicts.] Signed-off-by: Zeng Heng <zengheng4(a)huawei.com> --- drivers/platform/x86/classmate-laptop.c | 32 +++++++++++++++++++++++++ 1 file changed, 32 insertions(+) diff --git a/drivers/platform/x86/classmate-laptop.c b/drivers/platform/x86/classmate-laptop.c index 2edaea2492df..053c8a86d5ec 100644 --- a/drivers/platform/x86/classmate-laptop.c +++ b/drivers/platform/x86/classmate-laptop.c @@ -208,7 +208,12 @@ static ssize_t cmpc_accel_sensitivity_show_v4(struct device *dev, acpi = to_acpi_device(dev); inputdev = dev_get_drvdata(&acpi->dev); + if (!inputdev) + return -ENXIO; + accel = dev_get_drvdata(&inputdev->dev); + if (!accel) + return -ENXIO; return sprintf(buf, "%d\n", accel->sensitivity); } @@ -225,7 +230,12 @@ static ssize_t cmpc_accel_sensitivity_store_v4(struct device *dev, acpi = to_acpi_device(dev); inputdev = dev_get_drvdata(&acpi->dev); + if (!inputdev) + return -ENXIO; + accel = dev_get_drvdata(&inputdev->dev); + if (!accel) + return -ENXIO; r = kstrtoul(buf, 0, &sensitivity); if (r) @@ -257,7 +267,12 @@ static ssize_t cmpc_accel_g_select_show_v4(struct device *dev, acpi = to_acpi_device(dev); inputdev = dev_get_drvdata(&acpi->dev); + if (!inputdev) + return -ENXIO; + accel = dev_get_drvdata(&inputdev->dev); + if (!accel) + return -ENXIO; return sprintf(buf, "%d\n", accel->g_select); } @@ -274,7 +289,12 @@ static ssize_t cmpc_accel_g_select_store_v4(struct device *dev, acpi = to_acpi_device(dev); inputdev = dev_get_drvdata(&acpi->dev); + if (!inputdev) + return -ENXIO; + accel = dev_get_drvdata(&inputdev->dev); + if (!accel) + return -ENXIO; r = kstrtoul(buf, 0, &g_select); if (r) @@ -303,6 +323,8 @@ static int cmpc_accel_open_v4(struct input_dev *input) acpi = to_acpi_device(input->dev.parent); accel = dev_get_drvdata(&input->dev); + if (!accel) + return -ENXIO; cmpc_accel_set_sensitivity_v4(acpi->handle, accel->sensitivity); cmpc_accel_set_g_select_v4(acpi->handle, accel->g_select); @@ -551,7 +573,12 @@ static ssize_t cmpc_accel_sensitivity_show(struct device *dev, acpi = to_acpi_device(dev); inputdev = dev_get_drvdata(&acpi->dev); + if (!inputdev) + return -ENXIO; + accel = dev_get_drvdata(&inputdev->dev); + if (!accel) + return -ENXIO; return sprintf(buf, "%d\n", accel->sensitivity); } @@ -568,7 +595,12 @@ static ssize_t cmpc_accel_sensitivity_store(struct device *dev, acpi = to_acpi_device(dev); inputdev = dev_get_drvdata(&acpi->dev); + if (!inputdev) + return -ENXIO; + accel = dev_get_drvdata(&inputdev->dev); + if (!accel) + return -ENXIO; r = kstrtoul(buf, 0, &sensitivity); if (r) -- 2.25.1

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[PATCH v2 OLK-6.6] vsock/virtio: cap TX credit to local buffer size
by Ze Zuo 07 Mar '26

07 Mar '26

From: Melbin K Mathew <mlbnkm1(a)gmail.com> stable inclusion from stable-v6.6.122 commit d9d5f222558b42f6277eafaaa6080966faf37676 category: feature bugzilla: https://atomgit.com/src-openeuler/kernel/issues/13619 CVE: CVE-2026-23086 Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id… -------------------------------- [ Upstream commit 8ee784fdf006cbe8739cfa093f54d326cbf54037 ] The virtio transports derives its TX credit directly from peer_buf_alloc, which is set from the remote endpoint's SO_VM_SOCKETS_BUFFER_SIZE value. On the host side this means that the amount of data we are willing to queue for a connection is scaled by a guest-chosen buffer size, rather than the host's own vsock configuration. A malicious guest can advertise a large buffer and read slowly, causing the host to allocate a correspondingly large amount of sk_buff memory. The same thing would happen in the guest with a malicious host, since virtio transports share the same code base. Introduce a small helper, virtio_transport_tx_buf_size(), that returns min(peer_buf_alloc, buf_alloc), and use it wherever we consume peer_buf_alloc. This ensures the effective TX window is bounded by both the peer's advertised buffer and our own buf_alloc (already clamped to buffer_max_size via SO_VM_SOCKETS_BUFFER_MAX_SIZE), so a remote peer cannot force the other to queue more data than allowed by its own vsock settings. On an unpatched Ubuntu 22.04 host (~64 GiB RAM), running a PoC with 32 guest vsock connections advertising 2 GiB each and reading slowly drove Slab/SUnreclaim from ~0.5 GiB to ~57 GiB; the system only recovered after killing the QEMU process. That said, if QEMU memory is limited with cgroups, the maximum memory used will be limited. With this patch applied: Before: MemFree: ~61.6 GiB Slab: ~142 MiB SUnreclaim: ~117 MiB After 32 high-credit connections: MemFree: ~61.5 GiB Slab: ~178 MiB SUnreclaim: ~152 MiB Only ~35 MiB increase in Slab/SUnreclaim, no host OOM, and the guest remains responsive. Compatibility with non-virtio transports: - VMCI uses the AF_VSOCK buffer knobs to size its queue pairs per socket based on the local vsk->buffer_* values; the remote side cannot enlarge those queues beyond what the local endpoint configured. - Hyper-V's vsock transport uses fixed-size VMBus ring buffers and an MTU bound; there is no peer-controlled credit field comparable to peer_buf_alloc, and the remote endpoint cannot drive in-flight kernel memory above those ring sizes. - The loopback path reuses virtio_transport_common.c, so it naturally follows the same semantics as the virtio transport. This change is limited to virtio_transport_common.c and thus affects virtio-vsock, vhost-vsock, and loopback, bringing them in line with the "remote window intersected with local policy" behaviour that VMCI and Hyper-V already effectively have. Fixes: 06a8fc78367d ("VSOCK: Introduce virtio_vsock_common.ko") Suggested-by: Stefano Garzarella <sgarzare(a)redhat.com> Signed-off-by: Melbin K Mathew <mlbnkm1(a)gmail.com> [Stefano: small adjustments after changing the previous patch] [Stefano: tweak the commit message] Signed-off-by: Stefano Garzarella <sgarzare(a)redhat.com> Reviewed-by: Luigi Leonardi <leonardi(a)redhat.com> Link: https://patch.msgid.link/20260121093628.9941-4-sgarzare@redhat.com Acked-by: Michael S. Tsirkin <mst(a)redhat.com> Signed-off-by: Paolo Abeni <pabeni(a)redhat.com> Signed-off-by: Sasha Levin <sashal(a)kernel.org> Conflicts: net/vmw_vsock/virtio_transport_common.c [Conflicts due to context.] Signed-off-by: Ze Zuo <zuoze1(a)huawei.com> --- change since v1: -- fix patch merge conflict. --- net/vmw_vsock/virtio_transport_common.c | 14 ++++++++++++-- 1 file changed, 12 insertions(+), 2 deletions(-) diff --git a/net/vmw_vsock/virtio_transport_common.c b/net/vmw_vsock/virtio_transport_common.c index 1401177e2622..4c374c36c29d 100644 --- a/net/vmw_vsock/virtio_transport_common.c +++ b/net/vmw_vsock/virtio_transport_common.c @@ -628,6 +628,15 @@ virtio_transport_seqpacket_dequeue(struct vsock_sock *vsk, } EXPORT_SYMBOL_GPL(virtio_transport_seqpacket_dequeue); +static u32 virtio_transport_tx_buf_size(struct virtio_vsock_sock *vvs) +{ + /* The peer advertises its receive buffer via peer_buf_alloc, but we + * cap it to our local buf_alloc so a remote peer cannot force us to + * queue more data than our own buffer configuration allows. + */ + return min(vvs->peer_buf_alloc, vvs->buf_alloc); +} + int virtio_transport_seqpacket_enqueue(struct vsock_sock *vsk, struct msghdr *msg, @@ -637,7 +646,7 @@ virtio_transport_seqpacket_enqueue(struct vsock_sock *vsk, spin_lock_bh(&vvs->tx_lock); - if (len > vvs->peer_buf_alloc) { + if (len > virtio_transport_tx_buf_size(vvs)) { spin_unlock_bh(&vvs->tx_lock); return -EMSGSIZE; } @@ -691,7 +700,8 @@ static s64 virtio_transport_has_space(struct virtio_vsock_sock *vvs) * we have bytes in flight (tx_cnt - peer_fwd_cnt), the subtraction * does not underflow. */ - bytes = (s64)vvs->peer_buf_alloc - (vvs->tx_cnt - vvs->peer_fwd_cnt); + bytes = (s64)virtio_transport_tx_buf_size(vvs) - + (vvs->tx_cnt - vvs->peer_fwd_cnt); if (bytes < 0) bytes = 0; -- 2.25.1

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[PATCH OLK-6.6] Revert "mm: Move vm_cache_limit_mbytes check to page_cache_over_limit()"
by Ze Zuo 07 Mar '26

07 Mar '26

hulk inclusion category: bugfix bugzilla: https://atomgit.com/src-openeuler/kernel/issues/13853 -------------------------------- This reverts commit 00b50cbb31ad11c0896355e351f961b1b586797f. Before this patch commit 00b50cbb31ad ("mm: Move vm_cache_limit_mbytes check to page_cache_over_limit()") was merged, setting cache_limit_mbytes to 0 meant that periodic reclaim could reclaim page cache without limitation. After the patch was merged, page cache is no longer reclaimed when cache_limit_mbytes is set to 0. As a result, periodic reclaim becomes ineffective. Revert this patch. Fixes: 00b50cbb31ad ("mm: Move vm_cache_limit_mbytes check to page_cache_over_limit()") Signed-off-by: Ze Zuo <zuoze1(a)huawei.com> --- mm/page_cache_limit.c | 16 ++++++++++++---- 1 file changed, 12 insertions(+), 4 deletions(-) diff --git a/mm/page_cache_limit.c b/mm/page_cache_limit.c index 677ead24d27f..fe67b8b804f0 100644 --- a/mm/page_cache_limit.c +++ b/mm/page_cache_limit.c @@ -38,9 +38,6 @@ static bool page_cache_over_limit(void) unsigned long lru_file; unsigned long limit; - if (!vm_cache_limit_mbytes) - return false; - limit = vm_cache_limit_mbytes << (20 - PAGE_SHIFT); lru_file = global_node_page_state(NR_ACTIVE_FILE) + global_node_page_state(NR_INACTIVE_FILE); @@ -50,6 +47,17 @@ static bool page_cache_over_limit(void) return false; } +static bool should_reclaim_page_cache(void) +{ + if (!should_periodical_reclaim()) + return false; + + if (!vm_cache_limit_mbytes) + return false; + + return true; +} + int cache_reclaim_enable_handler(struct ctl_table *table, int write, void *buffer, size_t *length, loff_t *ppos) { @@ -102,7 +110,7 @@ int cache_limit_mbytes_sysctl_handler(struct ctl_table *table, int write, } if (write) { - while (should_periodical_reclaim() && page_cache_over_limit() && + while (should_reclaim_page_cache() && page_cache_over_limit() && nr_retries--) { if (signal_pending(current)) return -EINTR; -- 2.25.1

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