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[PATCH] vfs: Don't leak disconnected dentries on umount

by Jan Kara

When user calls open_by_handle_at() on some inode that is not cached, we will create disconnected dentry for it. If such dentry is a directory, exportfs_decode_fh_raw() will then try to connect this dentry to the dentry tree through reconnect_path(). It may happen for various reasons (such as corrupted fs or race with rename) that the call to lookup_one_unlocked() in reconnect_one() will fail to find the dentry we are trying to reconnect and instead create a new dentry under the parent. Now this dentry will not be marked as disconnected although the parent still may well be disconnected (at least in case this inconsistency happened because the fs is corrupted and .. doesn't point to the real parent directory). This creates inconsistency in disconnected flags but AFAICS it was mostly harmless. At least until commit f1ee616214cb ("VFS: don't keep disconnected dentries on d_anon") which removed adding of most disconnected dentries to sb->s_anon list. Thus after this commit cleanup of disconnected dentries implicitely relies on the fact that dput() will immediately reclaim such dentries. However when some leaf dentry isn't marked as disconnected, as in the scenario described above, the reclaim doesn't happen and the dentries are "leaked". Memory reclaim can eventually reclaim them but otherwise they stay in memory and if umount comes first, we hit infamous "Busy inodes after unmount" bug. Make sure all dentries created under a disconnected parent are marked as disconnected as well. Reported-by: syzbot+1d79ebe5383fc016cf07(a)syzkaller.appspotmail.com Fixes: f1ee616214cb ("VFS: don't keep disconnected dentries on d_anon") CC: stable(a)vger.kernel.org Signed-off-by: Jan Kara <jack(a)suse.cz> --- fs/dcache.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/fs/dcache.c b/fs/dcache.c index 65cc11939654..3ec21f9cedba 100644 --- a/fs/dcache.c +++ b/fs/dcache.c @@ -2557,6 +2557,8 @@ struct dentry *d_alloc_parallel(struct dentry *parent, spin_lock(&parent->d_lock); new->d_parent = dget_dlock(parent); hlist_add_head(&new->d_sib, &parent->d_children); + if (parent->d_flags & DCACHE_DISCONNECTED) + new->d_flags |= DCACHE_DISCONNECTED; spin_unlock(&parent->d_lock); retry: -- 2.51.0

1 week, 4 days

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[PATCH net v3 1/1] net: usb: asix: hold PM usage ref to avoid PM/MDIO + RTNL deadlock

by Oleksij Rempel

Prevent USB runtime PM (autosuspend) for AX88772* in bind. usbnet enables runtime PM (autosuspend) by default, so disabling it via the usb_driver flag is ineffective. On AX88772B, autosuspend shows no measurable power saving with current driver (no link partner, admin up/down). The ~0.453 W -> ~0.248 W drop on v6.1 comes from phylib powering the PHY off on admin-down, not from USB autosuspend. The real hazard is that with runtime PM enabled, ndo_open() (under RTNL) may synchronously trigger autoresume (usb_autopm_get_interface()) into asix_resume() while the USB PM lock is held. Resume paths then invoke phylink/phylib and MDIO, which also expect RTNL, leading to possible deadlocks or PM lock vs MDIO wake issues. To avoid this, keep the device runtime-PM active by taking a usage reference in ax88772_bind() and dropping it in unbind(). A non-zero PM usage count blocks runtime suspend regardless of userspace policy (.../power/control - pm_runtime_allow/forbid), making this approach robust against sysfs overrides. Holding a runtime-PM usage ref does not affect system-wide suspend; system sleep/resume callbacks continue to run as before. Fixes: 4a2c7217cd5a ("net: usb: asix: ax88772: manage PHY PM from MAC") Reported-by: Hubert Wiśniewski <hubert.wisniewski.25632(a)gmail.com> Closes: https://lore.kernel.org/all/DCGHG5UJT9G3.2K1GHFZ3H87T0@gmail.com Tested-by: Hubert Wiśniewski <hubert.wisniewski.25632(a)gmail.com> Reported-by: Marek Szyprowski <m.szyprowski(a)samsung.com> Closes: https://lore.kernel.org/all/b5ea8296-f981-445d-a09a-2f389d7f6fdd@samsung.com Cc: stable(a)vger.kernel.org Signed-off-by: Oleksij Rempel <o.rempel(a)pengutronix.de> --- changes v3 - update comments and commit message changes v2: - Switch from pm_runtime_forbid()/allow() to pm_runtime_get_noresume()/put() as suggested by Alan Stern, to block autosuspend robustly. - Reword commit message to clarify the actual deadlock condition (autoresume under RTNL) as pointed out by Oliver Neukum. - Keep explanation in commit message, shorten in-code comment. Link to the measurement results: https://lore.kernel.org/all/aMkPMa650kfKfmF4@pengutronix.de/ --- drivers/net/usb/asix_devices.c | 29 +++++++++++++++++++++++++++++ 1 file changed, 29 insertions(+) diff --git a/drivers/net/usb/asix_devices.c b/drivers/net/usb/asix_devices.c index 792ddda1ad49..85bd5d845409 100644 --- a/drivers/net/usb/asix_devices.c +++ b/drivers/net/usb/asix_devices.c @@ -625,6 +625,21 @@ static void ax88772_suspend(struct usbnet *dev) asix_read_medium_status(dev, 1)); } +/* Notes on PM callbacks and locking context: + * + * - asix_suspend()/asix_resume() are invoked for both runtime PM and + * system-wide suspend/resume. For struct usb_driver the ->resume() + * callback does not receive pm_message_t, so the resume type cannot + * be distinguished here. + * + * - The MAC driver must hold RTNL when calling phylink interfaces such as + * phylink_suspend()/resume(). Those calls will also perform MDIO I/O. + * + * - Taking RTNL and doing MDIO from a runtime-PM resume callback (while + * the USB PM lock is held) is fragile. Since autosuspend brings no + * measurable power saving here, we block it by holding a PM usage + * reference in ax88772_bind(). + */ static int asix_suspend(struct usb_interface *intf, pm_message_t message) { struct usbnet *dev = usb_get_intfdata(intf); @@ -919,6 +934,13 @@ static int ax88772_bind(struct usbnet *dev, struct usb_interface *intf) if (ret) goto initphy_err; + /* Keep this interface runtime-PM active by taking a usage ref. + * Prevents runtime suspend while bound and avoids resume paths + * that could deadlock (autoresume under RTNL while USB PM lock + * is held, phylink/MDIO wants RTNL). + */ + pm_runtime_get_noresume(&intf->dev); + return 0; initphy_err: @@ -948,6 +970,8 @@ static void ax88772_unbind(struct usbnet *dev, struct usb_interface *intf) phylink_destroy(priv->phylink); ax88772_mdio_unregister(priv); asix_rx_fixup_common_free(dev->driver_priv); + /* Drop the PM usage ref taken in bind() */ + pm_runtime_put(&intf->dev); } static void ax88178_unbind(struct usbnet *dev, struct usb_interface *intf) @@ -1600,6 +1624,11 @@ static struct usb_driver asix_driver = { .resume = asix_resume, .reset_resume = asix_resume, .disconnect = usbnet_disconnect, + /* usbnet enables autosuspend by default (supports_autosuspend=1). + * We keep runtime-PM active for AX88772* by taking a PM usage + * reference in ax88772_bind() (pm_runtime_get_noresume()) and + * dropping it in unbind(), which effectively blocks autosuspend. + */ .supports_autosuspend = 1, .disable_hub_initiated_lpm = 1, }; -- 2.47.3

1 week, 4 days

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[PATCH] ALSA: hda: Fix missing pointer check in hda_component_manager_init function

by Denis Arefev

The __component_match_add function may assign the 'matchptr' pointer the value ERR_PTR(-ENOMEM), which will subsequently be dereferenced. The call stack leading to the error looks like this: hda_component_manager_init |-> component_match_add |-> component_match_add_release |-> __component_match_add ( ... ,**matchptr, ... ) |-> *matchptr = ERR_PTR(-ENOMEM); // assign |-> component_master_add_with_match( ... match) |-> component_match_realloc(match, match->num); // dereference Add IS_ERR() check to prevent the crash. Found by Linux Verification Center (linuxtesting.org) with SVACE. Fixes: fd895a74dc1d ("ALSA: hda: realtek: Move hda_component implementation to module") Cc: stable(a)vger.kernel.org Signed-off-by: Denis Arefev <arefev(a)swemel.ru> --- sound/hda/codecs/side-codecs/hda_component.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/sound/hda/codecs/side-codecs/hda_component.c b/sound/hda/codecs/side-codecs/hda_component.c index 71860e2d6377..84ddbab660e3 100644 --- a/sound/hda/codecs/side-codecs/hda_component.c +++ b/sound/hda/codecs/side-codecs/hda_component.c @@ -181,6 +181,8 @@ int hda_component_manager_init(struct hda_codec *cdc, sm->match_str = match_str; sm->index = i; component_match_add(dev, &match, hda_comp_match_dev_name, sm); + if (IS_ERR(match)) + return PTR_ERR(match); } ret = component_master_add_with_match(dev, ops, match); -- 2.43.0

1 week, 4 days

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[PATCH v2 03/14] iommu/exynos: fix device leak on of_xlate()

by Johan Hovold

Make sure to drop the reference taken to the iommu platform device when looking up its driver data during of_xlate(). Note that commit 1a26044954a6 ("iommu/exynos: add missing put_device() call in exynos_iommu_of_xlate()") fixed the leak in a couple of error paths, but the reference is still leaking on success. Fixes: aa759fd376fb ("iommu/exynos: Add callback for initializing devices from device tree") Cc: stable(a)vger.kernel.org # 4.2: 1a26044954a6 Cc: Marek Szyprowski <m.szyprowski(a)samsung.com> Cc: Yu Kuai <yukuai3(a)huawei.com> Acked-by: Robin Murphy <robin.murphy(a)arm.com> Signed-off-by: Johan Hovold <johan(a)kernel.org> --- drivers/iommu/exynos-iommu.c | 9 +++------ 1 file changed, 3 insertions(+), 6 deletions(-) diff --git a/drivers/iommu/exynos-iommu.c b/drivers/iommu/exynos-iommu.c index b6edd178fe25..ce9e935cb84c 100644 --- a/drivers/iommu/exynos-iommu.c +++ b/drivers/iommu/exynos-iommu.c @@ -1446,17 +1446,14 @@ static int exynos_iommu_of_xlate(struct device *dev, return -ENODEV; data = platform_get_drvdata(sysmmu); - if (!data) { - put_device(&sysmmu->dev); + put_device(&sysmmu->dev); + if (!data) return -ENODEV; - } if (!owner) { owner = kzalloc(sizeof(*owner), GFP_KERNEL); - if (!owner) { - put_device(&sysmmu->dev); + if (!owner) return -ENOMEM; - } INIT_LIST_HEAD(&owner->controllers); mutex_init(&owner->rpm_lock); -- 2.49.1

1 week, 4 days

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[PATCH v2 13/14] iommu/sun50i: fix device leak on of_xlate()

by Johan Hovold

Make sure to drop the reference taken to the iommu platform device when looking up its driver data during of_xlate(). Fixes: 4100b8c229b3 ("iommu: Add Allwinner H6 IOMMU driver") Cc: stable(a)vger.kernel.org # 5.8 Cc: Maxime Ripard <mripard(a)kernel.org> Acked-by: Robin Murphy <robin.murphy(a)arm.com> Signed-off-by: Johan Hovold <johan(a)kernel.org> --- drivers/iommu/sun50i-iommu.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/drivers/iommu/sun50i-iommu.c b/drivers/iommu/sun50i-iommu.c index de10b569d9a9..6306570d57db 100644 --- a/drivers/iommu/sun50i-iommu.c +++ b/drivers/iommu/sun50i-iommu.c @@ -839,6 +839,8 @@ static int sun50i_iommu_of_xlate(struct device *dev, dev_iommu_priv_set(dev, platform_get_drvdata(iommu_pdev)); + put_device(&iommu_pdev->dev); + return iommu_fwspec_add_ids(dev, &id, 1); } -- 2.49.1

1 week, 4 days

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[PATCH v2 11/14] iommu/omap: fix device leaks on probe_device()

by Johan Hovold

Make sure to drop the references taken to the iommu platform devices when looking up their driver data during probe_device(). Note that the arch data device pointer added by commit 604629bcb505 ("iommu/omap: add support for late attachment of iommu devices") has never been used. Remove it to underline that the references are not needed. Fixes: 9d5018deec86 ("iommu/omap: Add support to program multiple iommus") Fixes: 7d6827748d54 ("iommu/omap: Fix iommu archdata name for DT-based devices") Cc: stable(a)vger.kernel.org # 3.18 Cc: Suman Anna <s-anna(a)ti.com> Acked-by: Robin Murphy <robin.murphy(a)arm.com> Signed-off-by: Johan Hovold <johan(a)kernel.org> --- drivers/iommu/omap-iommu.c | 2 +- drivers/iommu/omap-iommu.h | 2 -- 2 files changed, 1 insertion(+), 3 deletions(-) diff --git a/drivers/iommu/omap-iommu.c b/drivers/iommu/omap-iommu.c index 6fb93927bdb9..b87ce129fb1f 100644 --- a/drivers/iommu/omap-iommu.c +++ b/drivers/iommu/omap-iommu.c @@ -1675,6 +1675,7 @@ static struct iommu_device *omap_iommu_probe_device(struct device *dev) } oiommu = platform_get_drvdata(pdev); + put_device(&pdev->dev); if (!oiommu) { of_node_put(np); kfree(arch_data); @@ -1682,7 +1683,6 @@ static struct iommu_device *omap_iommu_probe_device(struct device *dev) } tmp->iommu_dev = oiommu; - tmp->dev = &pdev->dev; of_node_put(np); } diff --git a/drivers/iommu/omap-iommu.h b/drivers/iommu/omap-iommu.h index 27697109ec79..50b39be61abc 100644 --- a/drivers/iommu/omap-iommu.h +++ b/drivers/iommu/omap-iommu.h @@ -88,7 +88,6 @@ struct omap_iommu { /** * struct omap_iommu_arch_data - omap iommu private data * @iommu_dev: handle of the OMAP iommu device - * @dev: handle of the iommu device * * This is an omap iommu private data object, which binds an iommu user * to its iommu device. This object should be placed at the iommu user's @@ -97,7 +96,6 @@ struct omap_iommu { */ struct omap_iommu_arch_data { struct omap_iommu *iommu_dev; - struct device *dev; }; struct cr_regs { -- 2.49.1

1 week, 4 days

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[PATCH v2 09/14] iommu/mediatek-v1: fix device leaks on probe()

by Johan Hovold

Make sure to drop the references taken to the larb devices during probe on probe failure (e.g. probe deferral) and on driver unbind. Fixes: b17336c55d89 ("iommu/mediatek: add support for mtk iommu generation one HW") Cc: stable(a)vger.kernel.org # 4.8 Cc: Honghui Zhang <honghui.zhang(a)mediatek.com> Acked-by: Robin Murphy <robin.murphy(a)arm.com> Signed-off-by: Johan Hovold <johan(a)kernel.org> --- drivers/iommu/mtk_iommu_v1.c | 23 ++++++++++++++++++----- 1 file changed, 18 insertions(+), 5 deletions(-) diff --git a/drivers/iommu/mtk_iommu_v1.c b/drivers/iommu/mtk_iommu_v1.c index de9153c0a82f..44b965a2db92 100644 --- a/drivers/iommu/mtk_iommu_v1.c +++ b/drivers/iommu/mtk_iommu_v1.c @@ -648,8 +648,10 @@ static int mtk_iommu_v1_probe(struct platform_device *pdev) struct platform_device *plarbdev; larbnode = of_parse_phandle(dev->of_node, "mediatek,larbs", i); - if (!larbnode) - return -EINVAL; + if (!larbnode) { + ret = -EINVAL; + goto out_put_larbs; + } if (!of_device_is_available(larbnode)) { of_node_put(larbnode); @@ -659,11 +661,14 @@ static int mtk_iommu_v1_probe(struct platform_device *pdev) plarbdev = of_find_device_by_node(larbnode); if (!plarbdev) { of_node_put(larbnode); - return -ENODEV; + ret = -ENODEV; + goto out_put_larbs; } if (!plarbdev->dev.driver) { of_node_put(larbnode); - return -EPROBE_DEFER; + put_device(&plarbdev->dev); + ret = -EPROBE_DEFER; + goto out_put_larbs; } data->larb_imu[i].dev = &plarbdev->dev; @@ -675,7 +680,7 @@ static int mtk_iommu_v1_probe(struct platform_device *pdev) ret = mtk_iommu_v1_hw_init(data); if (ret) - return ret; + goto out_put_larbs; ret = iommu_device_sysfs_add(&data->iommu, &pdev->dev, NULL, dev_name(&pdev->dev)); @@ -697,12 +702,17 @@ static int mtk_iommu_v1_probe(struct platform_device *pdev) iommu_device_sysfs_remove(&data->iommu); out_clk_unprepare: clk_disable_unprepare(data->bclk); +out_put_larbs: + for (i = 0; i < MTK_LARB_NR_MAX; i++) + put_device(data->larb_imu[i].dev); + return ret; } static void mtk_iommu_v1_remove(struct platform_device *pdev) { struct mtk_iommu_v1_data *data = platform_get_drvdata(pdev); + int i; iommu_device_sysfs_remove(&data->iommu); iommu_device_unregister(&data->iommu); @@ -710,6 +720,9 @@ static void mtk_iommu_v1_remove(struct platform_device *pdev) clk_disable_unprepare(data->bclk); devm_free_irq(&pdev->dev, data->irq, data); component_master_del(&pdev->dev, &mtk_iommu_v1_com_ops); + + for (i = 0; i < MTK_LARB_NR_MAX; i++) + put_device(data->larb_imu[i].dev); } static int __maybe_unused mtk_iommu_v1_suspend(struct device *dev) -- 2.49.1

1 week, 4 days

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[PATCH v2 04/14] iommu/ipmmu-vmsa: fix device leak on of_xlate()

by Johan Hovold

Make sure to drop the reference taken to the iommu platform device when looking up its driver data during of_xlate(). Fixes: 7b2d59611fef ("iommu/ipmmu-vmsa: Replace local utlb code with fwspec ids") Cc: stable(a)vger.kernel.org # 4.14 Cc: Magnus Damm <damm+renesas(a)opensource.se> Acked-by: Robin Murphy <robin.murphy(a)arm.com> Signed-off-by: Johan Hovold <johan(a)kernel.org> --- drivers/iommu/ipmmu-vmsa.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/drivers/iommu/ipmmu-vmsa.c b/drivers/iommu/ipmmu-vmsa.c index ffa892f65714..02a2a55ffa0a 100644 --- a/drivers/iommu/ipmmu-vmsa.c +++ b/drivers/iommu/ipmmu-vmsa.c @@ -720,6 +720,8 @@ static int ipmmu_init_platform_device(struct device *dev, dev_iommu_priv_set(dev, platform_get_drvdata(ipmmu_pdev)); + put_device(&ipmmu_pdev->dev); + return 0; } -- 2.49.1

1 week, 4 days

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[PATCH v2 02/14] iommu/qcom: fix device leak on of_xlate()

by Johan Hovold

Make sure to drop the reference taken to the iommu platform device when looking up its driver data during of_xlate(). Note that commit e2eae09939a8 ("iommu/qcom: add missing put_device() call in qcom_iommu_of_xlate()") fixed the leak in a couple of error paths, but the reference is still leaking on success and late failures. Fixes: 0ae349a0f33f ("iommu/qcom: Add qcom_iommu") Cc: stable(a)vger.kernel.org # 4.14: e2eae09939a8 Cc: Rob Clark <robin.clark(a)oss.qualcomm.com> Cc: Yu Kuai <yukuai3(a)huawei.com> Acked-by: Robin Murphy <robin.murphy(a)arm.com> Signed-off-by: Johan Hovold <johan(a)kernel.org> --- drivers/iommu/arm/arm-smmu/qcom_iommu.c | 10 ++++------ 1 file changed, 4 insertions(+), 6 deletions(-) diff --git a/drivers/iommu/arm/arm-smmu/qcom_iommu.c b/drivers/iommu/arm/arm-smmu/qcom_iommu.c index c5be95e56031..9c1166a3af6c 100644 --- a/drivers/iommu/arm/arm-smmu/qcom_iommu.c +++ b/drivers/iommu/arm/arm-smmu/qcom_iommu.c @@ -565,14 +565,14 @@ static int qcom_iommu_of_xlate(struct device *dev, qcom_iommu = platform_get_drvdata(iommu_pdev); + put_device(&iommu_pdev->dev); + /* make sure the asid specified in dt is valid, so we don't have * to sanity check this elsewhere: */ if (WARN_ON(asid > qcom_iommu->max_asid) || - WARN_ON(qcom_iommu->ctxs[asid] == NULL)) { - put_device(&iommu_pdev->dev); + WARN_ON(qcom_iommu->ctxs[asid] == NULL)) return -EINVAL; - } if (!dev_iommu_priv_get(dev)) { dev_iommu_priv_set(dev, qcom_iommu); @@ -581,10 +581,8 @@ static int qcom_iommu_of_xlate(struct device *dev, * multiple different iommu devices. Multiple context * banks are ok, but multiple devices are not: */ - if (WARN_ON(qcom_iommu != dev_iommu_priv_get(dev))) { - put_device(&iommu_pdev->dev); + if (WARN_ON(qcom_iommu != dev_iommu_priv_get(dev))) return -EINVAL; - } } return iommu_fwspec_add_ids(dev, &asid, 1); -- 2.49.1

1 week, 4 days

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[PATCH v2 01/14] iommu/apple-dart: fix device leak on of_xlate()

by Johan Hovold

Make sure to drop the reference taken to the iommu platform device when looking up its driver data during of_xlate(). Fixes: 46d1fb072e76 ("iommu/dart: Add DART iommu driver") Cc: stable(a)vger.kernel.org # 5.15 Cc: Sven Peter <sven(a)kernel.org> Acked-by: Robin Murphy <robin.murphy(a)arm.com> Signed-off-by: Johan Hovold <johan(a)kernel.org> --- drivers/iommu/apple-dart.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/drivers/iommu/apple-dart.c b/drivers/iommu/apple-dart.c index 190f28d76615..1aa7c10262a8 100644 --- a/drivers/iommu/apple-dart.c +++ b/drivers/iommu/apple-dart.c @@ -790,6 +790,8 @@ static int apple_dart_of_xlate(struct device *dev, struct apple_dart *cfg_dart; int i, sid; + put_device(&iommu_pdev->dev); + if (args->args_count != 1) return -EINVAL; sid = args->args[0]; -- 2.49.1

1 week, 4 days

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