kernel/linux.git/Documentation/admin-guide, branch v6.19.11

usb: core: new quirk to handle devices with zero configurations

2026-04-02T11:25:22+00:00

[ Upstream commit 9f6a983cfa22ac662c86e60816d3a357d4b551e9 ] Some USB devices incorrectly report bNumConfigurations as 0 in their device descriptor, which causes the USB core to reject them during enumeration. logs: usb 1-2: device descriptor read/64, error -71 usb 1-2: no configurations usb 1-2: can't read configurations, error -22 However, these devices actually work correctly when treated as having a single configuration. Add a new quirk USB_QUIRK_FORCE_ONE_CONFIG to handle such devices. When this quirk is set, assume the device has 1 configuration instead of failing with -EINVAL. This quirk is applied to the device with VID:PID 5131:2007 which exhibits this behavior. Signed-off-by: Jie Deng Link: https://patch.msgid.link/20260227084931.1527461-1-dengjie03@kylinos.cn Signed-off-by: Greg Kroah-Hartman Signed-off-by: Sasha Levin

cgroup/cpuset: Don't fail cpuset.cpus change in v2

2026-03-04T12:20:00+00:00

[ Upstream commit 6e6f13f6d5095f3a432da421e78f4d7d51ef39c8 ] Commit fe8cd2736e75 ("cgroup/cpuset: Delay setting of CS_CPU_EXCLUSIVE until valid partition") introduced a new check to disallow the setting of a new cpuset.cpus.exclusive value that is a superset of a sibling's cpuset.cpus value so that there will at least be one CPU left in the sibling in case the cpuset becomes a valid partition root. This new check does have the side effect of failing a cpuset.cpus change that make it a subset of a sibling's cpuset.cpus.exclusive value. With v2, users are supposed to be allowed to set whatever value they want in cpuset.cpus without failure. To maintain this rule, the check is now restricted to only when cpuset.cpus.exclusive is being changed not when cpuset.cpus is changed. The cgroup-v2.rst doc file is also updated to reflect this change. Signed-off-by: Waiman Long Reviewed-by: Chen Ridong Signed-off-by: Tejun Heo Signed-off-by: Sasha Levin

Merge tag 'mm-hotfixes-stable-2026-02-04-15-55' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

2026-02-05T00:04:00+00:00

Pull misc fixes from Andrew Morton: "Five hotfixes. Two are cc:stable, two are for MM. All are singletons - please see the changelogs for details" * tag 'mm-hotfixes-stable-2026-02-04-15-55' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: Documentation: document liveupdate cmdline parameter mm, shmem: prevent infinite loop on truncate race mailmap: update Alexander Mikhalitsyn's emails liveupdate: luo_file: do not clear serialized_data on unfreeze x86/kfence: fix booting on 32bit non-PAE systems

Documentation: document liveupdate cmdline parameter

2026-02-03T02:43:56+00:00

liveupdate is used to enable Live Update Orchestrator (LUO) early during boot. Add it to kernel-parameters.txt so users can discover and use it. Link: https://lkml.kernel.org/r/20260130112036.359806-1-me@linux.beauty Signed-off-by: Li Chen Acked-by: Mike Rapoport (Microsoft) Cc: Arnd Bergmann Cc: "Borislav Petkov (AMD)" Cc: Frank van der Linden Cc: Ingo Molnar Cc: Jonathan Corbet Cc: Kees Cook Cc: Li RongQing Cc: Pawan Gupta Cc: Randy Dunlap Cc: Pratyush Yadav Cc: Pasha Tatashin Signed-off-by: Andrew Morton

Merge tag 'vfs-6.19-rc8.fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs

2026-01-26T17:30:48+00:00

Pull vfs fixes from Christian Brauner: - Fix the the buggy conversion of fuse_reverse_inval_entry() introduced during the creation rework - Disallow nfs delegation requests for directories by setting simple_nosetlease() - Require an opt-in for getting readdir flag bits outside of S_DT_MASK set in d_type - Fix scheduling delayed writeback work by only scheduling when the dirty time expiry interval is non-zero and cancel the delayed work if the interval is set to zero - Use rounded_jiffies_interval for dirty time work - Check the return value of sb_set_blocksize() for romfs - Wait for batched folios to be stable in __iomap_get_folio() - Use private naming for fuse hash size - Fix the stale dentry cleanup to prevent a race that causes a UAF * tag 'vfs-6.19-rc8.fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs: vfs: document d_dispose_if_unused() fuse: shrink once after all buckets have been scanned fuse: clean up fuse_dentry_tree_work() fuse: add need_resched() before unlocking bucket fuse: make sure dentry is evicted if stale fuse: fix race when disposing stale dentries fuse: use private naming for fuse hash size writeback: use round_jiffies_relative for dirtytime_work iomap: wait for batched folios to be stable in __iomap_get_folio romfs: check sb_set_blocksize() return value docs: clarify that dirtytime_expire_seconds=0 disables writeback writeback: fix 100% CPU usage when dirtytime_expire_interval is 0 readdir: require opt-in for d_type flags vboxsf: don't allow delegations to be set on directories ceph: don't allow delegations to be set on directories gfs2: don't allow delegations to be set on directories 9p: don't allow delegations to be set on directories smb/client: properly disallow delegations on directories nfs: properly disallow delegation requests on directories fuse: fix conversion of fuse_reverse_inval_entry() to start_removing()

Merge tag 'platform-drivers-x86-v6.19-3' of git://git.kernel.org/pub/scm/linux/kernel/git/pdx86/platform-drivers-x86

2026-01-23T21:16:26+00:00

Pull x86 platform driver fixes from Ilpo Järvinen: - acer-wmi: - Extend support for Acer Nitro AN515-58 - Fix missing capability check - amd/wbrf: Fix memory leak in wbrf_record() - asus-armoury: - Fix GA403U* matching - Fix FA608UM TDP data - Add many models - asus-wmi: Move OOBE presence check outside deprecation ifdef - hp-bioscfg: - Fix kernel panic in GET_INSTANCE_ID macro - Fix kobject warnings for empty attribute names - Correct GUID to uppercase (lowercase letter prevented autoloading the module) - mellanox: Fix SN5640/SN5610 LED platform data - docs: - alienware-wmi: Typo fix - amd_hsmp: Fix document link * tag 'platform-drivers-x86-v6.19-3' of git://git.kernel.org/pub/scm/linux/kernel/git/pdx86/platform-drivers-x86: (21 commits) platform/x86: acer-wmi: Fix missing capability check platform/x86: acer-wmi: Extend support for Acer Nitro AN515-58 platform/x86: asus-armoury: add support for GA403WW platform/x86: asus-armoury: keep the list ordered alphabetically platform/x86: asus-armoury: add support for G835L platform/x86: asus-armoury: fix ppt data for FA608UM platform/x86: hp-bioscfg: Fix automatic module loading platform/x86: hp-bioscfg: Fix kernel panic in GET_INSTANCE_ID macro platform/x86: hp-bioscfg: Fix kobject warnings for empty attribute names platform/x86: asus-wmi: fix sending OOBE at probe platform/x86: asus-armoury: add support for FA617XT platform/x86: asus-armoury: add support for FA401UV platform/x86: asus-armoury: add support for GV302XV platform/x86: asus-armoury: Add power limits for Asus G513QY platform/x86/amd: Fix memory leak in wbrf_record() platform/mellanox: Fix SN5640/SN5610 LED platform data docs: fix PPR for AMD EPYC broken link docs: alienware-wmi: fix typo platform/x86: asus-armoury: add support for GA403UV asus-armoury: fix ppt data for GA403U* renaming to GA403UI ...

Docs/mm/allocation-profiling: describe sysctrl limitations in debug mode

2026-01-20T17:34:26+00:00

When CONFIG_MEM_ALLOC_PROFILING_DEBUG=y, /proc/sys/vm/mem_profiling is read-only to avoid debug warnings in a scenario when an allocation is made while profiling is disabled (allocation does not get an allocation tag), then profiling gets enabled and allocation gets freed (warning due to the allocation missing allocation tag). Link: https://lkml.kernel.org/r/20260116184423.2708363-1-surenb@google.com Fixes: ebdf9ad4ca98 ("memprofiling: documentation") Reported-by: Andrew Morton Signed-off-by: Suren Baghdasaryan Acked-by: SeongJae Park Cc: Jonathan Corbet Cc: Kent Overstreet Cc: Matthew Wilcox (Oracle) Cc: Ran Xiaokai Cc: SeongJae Park Signed-off-by: Andrew Morton

Merge tag 'mm-hotfixes-stable-2026-01-15-08-03' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

2026-01-15T18:47:14+00:00

Pull misc fixes from Andrew Morton: - kerneldoc fixes from Bagas Sanjaya - DAMON fixes from SeongJae - mremap VMA-related fixes from Lorenzo - various singletons - please see the changelogs for details * tag 'mm-hotfixes-stable-2026-01-15-08-03' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (30 commits) drivers/dax: add some missing kerneldoc comment fields for struct dev_dax mm: numa,memblock: include for 'numa_nodes_parsed' mailmap: add entry for Daniel Thompson tools/testing/selftests: fix gup_longterm for unknown fs mm/page_alloc: prevent pcp corruption with SMP=n iommu/sva: include mmu_notifier.h header mm: kmsan: fix poisoning of high-order non-compound pages tools/testing/selftests: add forked (un)/faulted VMA merge tests mm/vma: enforce VMA fork limit on unfaulted,faulted mremap merge too tools/testing/selftests: add tests for !tgt, src mremap() merges mm/vma: fix anon_vma UAF on mremap() faulted, unfaulted merge mm/zswap: fix error pointer free in zswap_cpu_comp_prepare() mm/damon/sysfs-scheme: cleanup access_pattern subdirs on scheme dir setup failure mm/damon/sysfs-scheme: cleanup quotas subdirs on scheme dir setup failure mm/damon/sysfs: cleanup attrs subdirs on context dir setup failure mm/damon/sysfs: cleanup intervals subdirs on attrs dir setup failure mm/damon/core: remove call_control in inactive contexts powerpc/watchdog: add support for hardlockup_sys_info sysctl mips: fix HIGHMEM initialization mm/hugetlb: ignore hugepage kernel args if hugepages are unsupported ...

docs: kernel-parameters: add kfence parameters

2026-01-15T06:16:20+00:00

Add a brief summary for KFENCE's kernel command-line parameters in admin-guide/kernel-parameters. Link: https://lkml.kernel.org/r/20251222150018.1349672-1-elver@google.com Signed-off-by: Marco Elver Cc: Alexander Potapenko Cc: Dmitriy Vyukov Cc: Jonathan Corbet Signed-off-by: Andrew Morton

net: add net.core.qdisc_max_burst

2026-01-13T09:12:11+00:00

In blamed commit, I added a check against the temporary queue built in __dev_xmit_skb(). Idea was to drop packets early, before any spinlock was acquired. if (unlikely(defer_count > READ_ONCE(q->limit))) { kfree_skb_reason(skb, SKB_DROP_REASON_QDISC_DROP); return NET_XMIT_DROP; } It turned out that HTB Qdisc has a zero q->limit. HTB limits packets on a per-class basis. Some of our tests became flaky. Add a new sysctl : net.core.qdisc_max_burst to control how many packets can be stored in the temporary lockless queue. Also add a new QDISC_BURST_DROP drop reason to better diagnose future issues. Thanks Neal ! Fixes: 100dfa74cad9 ("net: dev_queue_xmit() llist adoption") Reported-and-bisected-by: Neal Cardwell Signed-off-by: Eric Dumazet Reviewed-by: Neal Cardwell Link: https://patch.msgid.link/20260107104159.3669285-1-edumazet@google.com Signed-off-by: Paolo Abeni