user/sven/linux.git/include/linux, branch v6.1.129

x86/i8253: Disable PIT timer 0 when not in use

2025-02-21T12:50:12Z

commit 70e6b7d9ae3c63df90a7bba7700e8d5c300c3c60 upstream. Leaving the PIT interrupt running can cause noticeable steal time for virtual guests. The VMM generally has a timer which toggles the IRQ input to the PIC and I/O APIC, which takes CPU time away from the guest. Even on real hardware, running the counter may use power needlessly (albeit not much). Make sure it's turned off if it isn't going to be used. Signed-off-by: David Woodhouse Signed-off-by: Thomas Gleixner Tested-by: Michael Kelley Link: https://lore.kernel.org/all/20240802135555.564941-1-dwmw2@infradead.org Signed-off-by: Greg Kroah-Hartman

can: ems_pci: move ASIX AX99100 ids to pci_ids.h

2025-02-21T12:50:11Z

commit 3029ad91335353a70feb42acd24d580d70ab258b upstream. Move PCI Vendor and Device ID of ASIX AX99100 PCIe to Multi I/O Controller to pci_ids.h for its serial and parallel port driver support in subsequent patches. Signed-off-by: Jiaqing Zhao Reviewed-by: Andy Shevchenko Acked-by: Bjorn Helgaas Acked-by: Marc Kleine-Budde Link: https://lore.kernel.org/r/20230724083933.3173513-3-jiaqing.zhao@linux.intel.com [Moeko: Drop changes in drivers/net/can/sja1000/ems_pci.c] Signed-off-by: Tomita Moeko Signed-off-by: Greg Kroah-Hartman

iommu: Return right value in iommu_sva_bind_device()

2025-02-21T12:50:09Z

commit 89e8a2366e3bce584b6c01549d5019c5cda1205e upstream. iommu_sva_bind_device() should return either a sva bond handle or an ERR_PTR value in error cases. Existing drivers (idxd and uacce) only check the return value with IS_ERR(). This could potentially lead to a kernel NULL pointer dereference issue if the function returns NULL instead of an error pointer. In reality, this doesn't cause any problems because iommu_sva_bind_device() only returns NULL when the kernel is not configured with CONFIG_IOMMU_SVA. In this case, iommu_dev_enable_feature(dev, IOMMU_DEV_FEAT_SVA) will return an error, and the device drivers won't call iommu_sva_bind_device() at all. Fixes: 26b25a2b98e4 ("iommu: Bind process address spaces to devices") Signed-off-by: Lu Baolu Reviewed-by: Jean-Philippe Brucker Reviewed-by: Kevin Tian Reviewed-by: Vasant Hegde Link: https://lore.kernel.org/r/20240528042528.71396-1-baolu.lu@linux.intel.com Signed-off-by: Joerg Roedel Signed-off-by: Bin Lan Signed-off-by: Greg Kroah-Hartman

net: add dev_net_rcu() helper

2025-02-21T12:50:06Z

[ Upstream commit 482ad2a4ace2740ca0ff1cbc8f3c7f862f3ab507 ] dev->nd_net can change, readers should either use rcu_read_lock() or RTNL. We currently use a generic helper, dev_net() with no debugging support. We probably have many hidden bugs. Add dev_net_rcu() helper for callers using rcu_read_lock() protection. Signed-off-by: Eric Dumazet Reviewed-by: Kuniyuki Iwashima Link: https://patch.msgid.link/20250205155120.1676781-2-edumazet@google.com Signed-off-by: Jakub Kicinski Stable-dep-of: 71b8471c93fa ("ipv4: use RCU protection in ipv4_default_advmss()") Signed-off-by: Sasha Levin

cgroup: fix race between fork and cgroup.kill

2025-02-21T12:50:04Z

commit b69bb476dee99d564d65d418e9a20acca6f32c3f upstream. Tejun reported the following race between fork() and cgroup.kill at [1]. Tejun: I was looking at cgroup.kill implementation and wondering whether there could be a race window. So, __cgroup_kill() does the following: k1. Set CGRP_KILL. k2. Iterate tasks and deliver SIGKILL. k3. Clear CGRP_KILL. The copy_process() does the following: c1. Copy a bunch of stuff. c2. Grab siglock. c3. Check fatal_signal_pending(). c4. Commit to forking. c5. Release siglock. c6. Call cgroup_post_fork() which puts the task on the css_set and tests CGRP_KILL. The intention seems to be that either a forking task gets SIGKILL and terminates on c3 or it sees CGRP_KILL on c6 and kills the child. However, I don't see what guarantees that k3 can't happen before c6. ie. After a forking task passes c5, k2 can take place and then before the forking task reaches c6, k3 can happen. Then, nobody would send SIGKILL to the child. What am I missing? This is indeed a race. One way to fix this race is by taking cgroup_threadgroup_rwsem in write mode in __cgroup_kill() as the fork() side takes cgroup_threadgroup_rwsem in read mode from cgroup_can_fork() to cgroup_post_fork(). However that would be heavy handed as this adds one more potential stall scenario for cgroup.kill which is usually called under extreme situation like memory pressure. To fix this race, let's maintain a sequence number per cgroup which gets incremented on __cgroup_kill() call. On the fork() side, the cgroup_can_fork() will cache the sequence number locally and recheck it against the cgroup's sequence number at cgroup_post_fork() site. If the sequence numbers mismatch, it means __cgroup_kill() can been called and we should send SIGKILL to the newly created task. Reported-by: Tejun Heo Closes: https://lore.kernel.org/all/Z5QHE2Qn-QZ6M-KW@slm.duckdns.org/ [1] Fixes: 661ee6280931 ("cgroup: introduce cgroup.kill") Cc: stable@vger.kernel.org # v5.14+ Signed-off-by: Shakeel Butt Reviewed-by: Michal Koutný Signed-off-by: Tejun Heo Signed-off-by: Greg Kroah-Hartman

efi: Avoid cold plugged memory for placing the kernel

2025-02-21T12:50:04Z

commit ba69e0750b0362870294adab09339a0c39c3beaf upstream. UEFI 2.11 introduced EFI_MEMORY_HOT_PLUGGABLE to annotate system memory regions that are 'cold plugged' at boot, i.e., hot pluggable memory that is available from early boot, and described as system RAM by the firmware. Existing loaders and EFI applications running in the boot context will happily use this memory for allocating data structures that cannot be freed or moved at runtime, and this prevents the memory from being unplugged. Going forward, the new EFI_MEMORY_HOT_PLUGGABLE attribute should be tested, and memory annotated as such should be avoided for such allocations. In the EFI stub, there are a couple of occurrences where, instead of the high-level AllocatePages() UEFI boot service, a low-level code sequence is used that traverses the EFI memory map and carves out the requested number of pages from a free region. This is needed, e.g., for allocating as low as possible, or for allocating pages at random. While AllocatePages() should presumably avoid special purpose memory and cold plugged regions, this manual approach needs to incorporate this logic itself, in order to prevent the kernel itself from ending up in a hot unpluggable region, preventing it from being unplugged. So add the EFI_MEMORY_HOTPLUGGABLE macro definition, and check for it where appropriate. Cc: stable@vger.kernel.org Signed-off-by: Ard Biesheuvel Signed-off-by: Greg Kroah-Hartman

pps: Fix a use-after-free

2025-02-21T12:49:55Z

commit c79a39dc8d060b9e64e8b0fa9d245d44befeefbe upstream. On a board running ntpd and gpsd, I'm seeing a consistent use-after-free in sys_exit() from gpsd when rebooting: pps pps1: removed ------------[ cut here ]------------ kobject: '(null)' (00000000db4bec24): is not initialized, yet kobject_put() is being called. WARNING: CPU: 2 PID: 440 at lib/kobject.c:734 kobject_put+0x120/0x150 CPU: 2 UID: 299 PID: 440 Comm: gpsd Not tainted 6.11.0-rc6-00308-gb31c44928842 #1 Hardware name: Raspberry Pi 4 Model B Rev 1.1 (DT) pstate: 60000005 (nZCv daif -PAN -UAO -TCO -DIT -SSBS BTYPE=--) pc : kobject_put+0x120/0x150 lr : kobject_put+0x120/0x150 sp : ffffffc0803d3ae0 x29: ffffffc0803d3ae0 x28: ffffff8042dc9738 x27: 0000000000000001 x26: 0000000000000000 x25: ffffff8042dc9040 x24: ffffff8042dc9440 x23: ffffff80402a4620 x22: ffffff8042ef4bd0 x21: ffffff80405cb600 x20: 000000000008001b x19: ffffff8040b3b6e0 x18: 0000000000000000 x17: 0000000000000000 x16: 0000000000000000 x15: 696e6920746f6e20 x14: 7369203a29343263 x13: 205d303434542020 x12: 0000000000000000 x11: 0000000000000000 x10: 0000000000000000 x9 : 0000000000000000 x8 : 0000000000000000 x7 : 0000000000000000 x6 : 0000000000000000 x5 : 0000000000000000 x4 : 0000000000000000 x3 : 0000000000000000 x2 : 0000000000000000 x1 : 0000000000000000 x0 : 0000000000000000 Call trace: kobject_put+0x120/0x150 cdev_put+0x20/0x3c __fput+0x2c4/0x2d8 ____fput+0x1c/0x38 task_work_run+0x70/0xfc do_exit+0x2a0/0x924 do_group_exit+0x34/0x90 get_signal+0x7fc/0x8c0 do_signal+0x128/0x13b4 do_notify_resume+0xdc/0x160 el0_svc+0xd4/0xf8 el0t_64_sync_handler+0x140/0x14c el0t_64_sync+0x190/0x194 ---[ end trace 0000000000000000 ]--- ...followed by more symptoms of corruption, with similar stacks: refcount_t: underflow; use-after-free. kernel BUG at lib/list_debug.c:62! Kernel panic - not syncing: Oops - BUG: Fatal exception This happens because pps_device_destruct() frees the pps_device with the embedded cdev immediately after calling cdev_del(), but, as the comment above cdev_del() notes, fops for previously opened cdevs are still callable even after cdev_del() returns. I think this bug has always been there: I can't explain why it suddenly started happening every time I reboot this particular board. In commit d953e0e837e6 ("pps: Fix a use-after free bug when unregistering a source."), George Spelvin suggested removing the embedded cdev. That seems like the simplest way to fix this, so I've implemented his suggestion, using __register_chrdev() with pps_idr becoming the source of truth for which minor corresponds to which device. But now that pps_idr defines userspace visibility instead of cdev_add(), we need to be sure the pps->dev refcount can't reach zero while userspace can still find it again. So, the idr_remove() call moves to pps_unregister_cdev(), and pps_idr now holds a reference to pps->dev. pps_core: source serial1 got cdev (251:1) <...> pps pps1: removed pps_core: unregistering pps1 pps_core: deallocating pps1 Fixes: d953e0e837e6 ("pps: Fix a use-after free bug when unregistering a source.") Cc: stable@vger.kernel.org Signed-off-by: Calvin Owens Reviewed-by: Michal Schmidt Link: https://lore.kernel.org/r/a17975fd5ae99385791929e563f72564edbcf28f.1731383727.git.calvin@wbinvd.org Signed-off-by: Calvin Owens Signed-off-by: Greg Kroah-Hartman

KVM: Explicitly verify target vCPU is online in kvm_get_vcpu()

2025-02-21T12:49:39Z

commit 1e7381f3617d14b3c11da80ff5f8a93ab14cfc46 upstream. Explicitly verify the target vCPU is fully online _prior_ to clamping the index in kvm_get_vcpu(). If the index is "bad", the nospec clamping will generate '0', i.e. KVM will return vCPU0 instead of NULL. In practice, the bug is unlikely to cause problems, as it will only come into play if userspace or the guest is buggy or misbehaving, e.g. KVM may send interrupts to vCPU0 instead of dropping them on the floor. However, returning vCPU0 when it shouldn't exist per online_vcpus is problematic now that KVM uses an xarray for the vCPUs array, as KVM needs to insert into the xarray before publishing the vCPU to userspace (see commit c5b077549136 ("KVM: Convert the kvm->vcpus array to a xarray")), i.e. before vCPU creation is guaranteed to succeed. As a result, incorrectly providing access to vCPU0 will trigger a use-after-free if vCPU0 is dereferenced and kvm_vm_ioctl_create_vcpu() bails out of vCPU creation due to an error and frees vCPU0. Commit afb2acb2e3a3 ("KVM: Fix vcpu_array[0] races") papered over that issue, but in doing so introduced an unsolvable teardown conundrum. Preventing accesses to vCPU0 before it's fully online will allow reverting commit afb2acb2e3a3, without re-introducing the vcpu_array[0] UAF race. Fixes: 1d487e9bf8ba ("KVM: fix spectrev1 gadgets") Cc: stable@vger.kernel.org Cc: Will Deacon Cc: Michal Luczaj Reviewed-by: Pankaj Gupta Acked-by: Will Deacon Link: https://lore.kernel.org/r/20241009150455.1057573-2-seanjc@google.com Signed-off-by: Sean Christopherson Signed-off-by: Greg Kroah-Hartman

net/mlx5: use do_aux_work for PHC overflow checks

2025-02-21T12:49:32Z

[ Upstream commit e61e6c415ba9ff2b32bb6780ce1b17d1d76238f1 ] The overflow_work is using system wq to do overflow checks and updates for PHC device timecounter, which might be overhelmed by other tasks. But there is dedicated kthread in PTP subsystem designed for such things. This patch changes the work queue to proper align with PTP subsystem and to avoid overloading system work queue. The adjfine() function acts the same way as overflow check worker, we can postpone ptp aux worker till the next overflow period after adjfine() was called. Reviewed-by: Dragos Tatulea Signed-off-by: Vadim Fedorenko Acked-by: Tariq Toukan Link: https://patch.msgid.link/20250107104812.380225-1-vadfed@meta.com Signed-off-by: Paolo Abeni Signed-off-by: Sasha Levin

exec: fix up /proc/pid/comm in the execveat(AT_EMPTY_PATH) case

2025-02-21T12:49:29Z

[ Upstream commit 543841d1806029889c2f69f040e88b247aba8e22 ] Zbigniew mentioned at Linux Plumber's that systemd is interested in switching to execveat() for service execution, but can't, because the contents of /proc/pid/comm are the file descriptor which was used, instead of the path to the binary[1]. This makes the output of tools like top and ps useless, especially in a world where most fds are opened CLOEXEC so the number is truly meaningless. When the filename passed in is empty (e.g. with AT_EMPTY_PATH), use the dentry's filename for "comm" instead of using the useless numeral from the synthetic fdpath construction. This way the actual exec machinery is unchanged, but cosmetically the comm looks reasonable to admins investigating things. Instead of adding TASK_COMM_LEN more bytes to bprm, use one of the unused flag bits to indicate that we need to set "comm" from the dentry. Suggested-by: Zbigniew Jędrzejewski-Szmek Suggested-by: Tycho Andersen Suggested-by: Al Viro Suggested-by: Linus Torvalds Link: https://github.com/uapi-group/kernel-features#set-comm-field-before-exec [1] Reviewed-by: Aleksa Sarai Tested-by: Zbigniew Jędrzejewski-Szmek Signed-off-by: Kees Cook Signed-off-by: Sasha Levin