Linux

In the Linux kernel, the following vulnerability has been resolved: ksmbd: fix Preauh_HashValue race condition If client send multiple session setup requests to ksmbd, Preauh_HashValue race condition could happen. There is no need to free sess->Preauh_HashValue at session setup phase. It can be freed together with session at connection termination phase.Show less

In the Linux kernel, the following vulnerability has been resolved: x86/sev: Evict cache lines during SNP memory validation An SNP cache coherency vulnerability requires a cache line eviction mitigation when validating memory after a page state change to private. The specific mitigation is to touch the first and last byte of each 4K page that is being validated. There is no need to perform the mitigation when performing a page state change to shared and rescinding validation. CPUID bit Fn8000001F_EBX[31] defines the COHERENCY_SFW_NO CPUID bit that, when set, indicates that the software mitigation for this vulnerability is not needed. Implement the mitigation and invoke it when validating memory (making it private) and the COHERENCY_SFW_NO bit is not set, indicating the SNP guest is vulnerable.Show less

In the Linux kernel, the following vulnerability has been resolved: platform/x86/intel/pmt: fix a crashlog NULL pointer access Usage of the intel_pmt_read() for binary sysfs, requires a pcidev. The current use of the endpoint value is only valid for telemetry endpoint usage. Without the ep, the crashlog usage causes the following NULL pointer exception: BUG: kernel NULL pointer dereference, address: 0000000000000000 Oops: Oops: 0000 [#1] SMP NOPTI RIP: 0010:intel_pmt_read+0x3b/0x70 [pmt_class] Code: Call Trace: <TASK> ? sysfs_kf_bin_read+0xc0/0xe0 kernfs_fop_read_iter+0xac/0x1a0 vfs_read+0x26d/0x350 ksys_read+0x6b/0xe0 __x64_sys_read+0x1d/0x30 x64_sys_call+0x1bc8/0x1d70 do_syscall_64+0x6d/0x110 Augment struct intel_pmt_entry with a pointer to the pcidev to avoid the NULL pointer exception.Show less

In the Linux kernel, the following vulnerability has been resolved: usb: gadget: uvc: Initialize frame-based format color matching descriptor Fix NULL pointer crash in uvcg_framebased_make due to uninitialized color matching descriptor for frame-based format which was added in commit f5e7bdd34aca ("usb: gadget: uvc: Allow creating new color matching descriptors") that added handling for uncompressed and mjpeg format. Crash is seen when userspace configuration (via configfs) does not explicitly define the color matching descriptor. If color_matching is not found, config_group_find_item() returns NULL. The code then jumps to out_put_cm, where it calls config_item_put(color_matching);. If color_matching is NULL, this will dereference a null pointer, leading to a crash. [ 2.746440] Unable to handle kernel NULL pointer dereference at virtual address 000000000000008c [ 2.756273] Mem abort info: [ 2.760080] ESR = 0x0000000096000005 [ 2.764872] EC = 0x25: DABT (current EL), IL = 32 bits [ 2.771068] SET = 0, FnV = 0 [ 2.771069] EA = 0, S1PTW = 0 [ 2.771070] FSC = 0x05: level 1 translation fault [ 2.771071] Data abort info: [ 2.771072] ISV = 0, ISS = 0x00000005, ISS2 = 0x00000000 [ 2.771073] CM = 0, WnR = 0, TnD = 0, TagAccess = 0 [ 2.771074] GCS = 0, Overlay = 0, DirtyBit = 0, Xs = 0 [ 2.771075] user pgtable: 4k pages, 39-bit VAs, pgdp=00000000a3e59000 [ 2.771077] [000000000000008c] pgd=0000000000000000, p4d=0000000000000000, pud=0000000000000000 [ 2.771081] Internal error: Oops: 0000000096000005 [#1] PREEMPT SMP [ 2.771084] Dumping ftrace buffer: [ 2.771085] (ftrace buffer empty) [ 2.771138] CPU: 7 PID: 486 Comm: ln Tainted: G W E 6.6.58-android15 [ 2.771139] Hardware name: Qualcomm Technologies, Inc. SunP QRD HDK (DT) [ 2.771140] pstate: 61400005 (nZCv daif +PAN -UAO -TCO +DIT -SSBS BTYPE=--) [ 2.771141] pc : __uvcg_fill_strm+0x198/0x2cc [ 2.771145] lr : __uvcg_iter_strm_cls+0xc8/0x17c [ 2.771146] sp : ffffffc08140bbb0 [ 2.771146] x29: ffffffc08140bbb0 x28: ffffff803bc81380 x27: ffffff8023bbd250 [ 2.771147] x26: ffffff8023bbd250 x25: ffffff803c361348 x24: ffffff803d8e6768 [ 2.771148] x23: 0000000000000004 x22: 0000000000000003 x21: ffffffc08140bc48 [ 2.771149] x20: 0000000000000000 x19: ffffffc08140bc48 x18: ffffffe9f8cf4a00 [ 2.771150] x17: 000000001bf64ec3 x16: 000000001bf64ec3 x15: ffffff8023bbd250 [ 2.771151] x14: 000000000000000f x13: 004c4b40000f4240 x12: 000a2c2a00051615 [ 2.771152] x11: 000000000000004f x10: ffffffe9f76b40ec x9 : ffffffe9f7e389d0 [ 2.771153] x8 : ffffff803d0d31ce x7 : 000f4240000a2c2a x6 : 0005161500028b0a [ 2.771154] x5 : ffffff803d0d31ce x4 : 0000000000000003 x3 : 0000000000000000 [ 2.771155] x2 : ffffffc08140bc50 x1 : ffffffc08140bc48 x0 : 0000000000000000 [ 2.771156] Call trace: [ 2.771157] __uvcg_fill_strm+0x198/0x2cc [ 2.771157] __uvcg_iter_strm_cls+0xc8/0x17c [ 2.771158] uvcg_streaming_class_allow_link+0x240/0x290 [ 2.771159] configfs_symlink+0x1f8/0x630 [ 2.771161] vfs_symlink+0x114/0x1a0 [ 2.771163] do_symlinkat+0x94/0x28c [ 2.771164] __arm64_sys_symlinkat+0x54/0x70 [ 2.771164] invoke_syscall+0x58/0x114 [ 2.771166] el0_svc_common+0x80/0xe0 [ 2.771168] do_el0_svc+0x1c/0x28 [ 2.771169] el0_svc+0x3c/0x70 [ 2.771172] el0t_64_sync_handler+0x68/0xbc [ 2.771173] el0t_64_sync+0x1a8/0x1ac Initialize color matching descriptor for frame-based format to prevent NULL pointer crash by mirroring the handling done for uncompressed and mjpeg formats.Show less

In the Linux kernel, the following vulnerability has been resolved: HID: apple: validate feature-report field count to prevent NULL pointer dereference A malicious HID device with quirk APPLE_MAGIC_BACKLIGHT can trigger a NULL pointer dereference whilst the power feature-report is toggled and sent to the device in apple_magic_backlight_report_set(). The power feature-report is expected to have two data fields, but if the descriptor declares one field then accessing field[1] and dereferencing it in apple_magic_backlight_report_set() becomes invalid since field[1] will be NULL. An example of a minimal descriptor which can cause the crash is something like the following where the report with ID 3 (power report) only references a single 1-byte field. When hid core parses the descriptor it will encounter the final feature tag, allocate a hid_report (all members of field[] will be zeroed out), create field structure and populate it, increasing the maxfield to 1. The subsequent field[1] access and dereference causes the crash. Usage Page (Vendor Defined 0xFF00) Usage (0x0F) Collection (Application) Report ID (1) Usage (0x01) Logical Minimum (0) Logical Maximum (255) Report Size (8) Report Count (1) Feature (Data,Var,Abs) Usage (0x02) Logical Maximum (32767) Report Size (16) Report Count (1) Feature (Data,Var,Abs) Report ID (3) Usage (0x03) Logical Minimum (0) Logical Maximum (1) Report Size (8) Report Count (1) Feature (Data,Var,Abs) End Collection Here we see the KASAN splat when the kernel dereferences the NULL pointer and crashes: [ 15.164723] Oops: general protection fault, probably for non-canonical address 0xdffffc0000000006: 0000 [#1] SMP KASAN NOPTI [ 15.165691] KASAN: null-ptr-deref in range [0x0000000000000030-0x0000000000000037] [ 15.165691] CPU: 0 UID: 0 PID: 10 Comm: kworker/0:1 Not tainted 6.15.0 #31 PREEMPT(voluntary) [ 15.165691] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.16.2-debian-1.16.2-1 04/01/2014 [ 15.165691] RIP: 0010:apple_magic_backlight_report_set+0xbf/0x210 [ 15.165691] Call Trace: [ 15.165691] <TASK> [ 15.165691] apple_probe+0x571/0xa20 [ 15.165691] hid_device_probe+0x2e2/0x6f0 [ 15.165691] really_probe+0x1ca/0x5c0 [ 15.165691] __driver_probe_device+0x24f/0x310 [ 15.165691] driver_probe_device+0x4a/0xd0 [ 15.165691] __device_attach_driver+0x169/0x220 [ 15.165691] bus_for_each_drv+0x118/0x1b0 [ 15.165691] __device_attach+0x1d5/0x380 [ 15.165691] device_initial_probe+0x12/0x20 [ 15.165691] bus_probe_device+0x13d/0x180 [ 15.165691] device_add+0xd87/0x1510 [...] To fix this issue we should validate the number of fields that the backlight and power reports have and if they do not have the required number of fields then bail.Show less

In the Linux kernel, the following vulnerability has been resolved: HID: core: Harden s32ton() against conversion to 0 bits Testing by the syzbot fuzzer showed that the HID core gets a shift-out-of-bounds exception when it tries to convert a 32-bit quantity to a 0-bit quantity. Ideally this should never occur, but there are buggy devices and some might have a report field with size set to zero; we shouldn't reject the report or the device just because of that. Instead, harden the s32ton() routine so that it returns a reasonable result instead of crashing when it is called with the number of bits set to 0 -- the same as what snto32() does.Show less

In the Linux kernel, the following vulnerability has been resolved: usb: gadget : fix use-after-free in composite_dev_cleanup() 1. In func configfs_composite_bind() -> composite_os_desc_req_prepare(): if kmalloc fails, the pointer cdev->os_desc_req will be freed but not set to NULL. Then it will return a failure to the upper-level function. 2. in func configfs_composite_bind() -> composite_dev_cleanup(): it will checks whether cdev->os_desc_req is NULL. If it is not NULL, it will attempt to use it.This will lead to a use-after-free issue. BUG: KASAN: use-after-free in composite_dev_cleanup+0xf4/0x2c0 Read of size 8 at addr 0000004827837a00 by task init/1 CPU: 10 PID: 1 Comm: init Tainted: G O 5.10.97-oh #1 kasan_report+0x188/0x1cc __asan_load8+0xb4/0xbc composite_dev_cleanup+0xf4/0x2c0 configfs_composite_bind+0x210/0x7ac udc_bind_to_driver+0xb4/0x1ec usb_gadget_probe_driver+0xec/0x21c gadget_dev_desc_UDC_store+0x264/0x27cShow less

In the Linux kernel, the following vulnerability has been resolved: mm: fix a UAF when vma->mm is freed after vma->vm_refcnt got dropped By inducing delays in the right places, Jann Horn created a reproducer for a hard to hit UAF issue that became possible after VMAs were allowed to be recycled by adding SLAB_TYPESAFE_BY_RCU to their cache. Race description is borrowed from Jann's discovery report: lock_vma_under_rcu() looks up a VMA locklessly with mas_walk() under rcu_read_lock(). At that point, the VMA may be concurrently freed, and it can be recycled by another process. vma_start_read() then increments the vma->vm_refcnt (if it is in an acceptable range), and if this succeeds, vma_start_read() can return a recycled VMA. In this scenario where the VMA has been recycled, lock_vma_under_rcu() will then detect the mismatching ->vm_mm pointer and drop the VMA through vma_end_read(), which calls vma_refcount_put(). vma_refcount_put() drops the refcount and then calls rcuwait_wake_up() using a copy of vma->vm_mm. This is wrong: It implicitly assumes that the caller is keeping the VMA's mm alive, but in this scenario the caller has no relation to the VMA's mm, so the rcuwait_wake_up() can cause UAF. The diagram depicting the race: T1 T2 T3 == == == lock_vma_under_rcu mas_walk <VMA gets removed from mm> mmap <the same VMA is reallocated> vma_start_read __refcount_inc_not_zero_limited_acquire munmap __vma_enter_locked refcount_add_not_zero vma_end_read vma_refcount_put __refcount_dec_and_test rcuwait_wait_event <finish operation> rcuwait_wake_up [UAF] Note that rcuwait_wait_event() in T3 does not block because refcount was already dropped by T1. At this point T3 can exit and free the mm causing UAF in T1. To avoid this we move vma->vm_mm verification into vma_start_read() and grab vma->vm_mm to stabilize it before vma_refcount_put() operation. [surenb@google.com: v3]Show less

In the Linux kernel, the following vulnerability has been resolved: ksmbd: validate command request size In commit 2b9b8f3b68ed ("ksmbd: validate command payload size"), except for SMB2_OPLOCK_BREAK_HE command, the request size of other commands is not checked, it's not expected. Fix it by add check for request size of other commands.Show less

In the Linux kernel, the following vulnerability has been resolved: ksmbd: fix wrong next length validation of ea buffer in smb2_set_ea() There are multiple smb2_ea_info buffers in FILE_FULL_EA_INFORMATION request from client. ksmbd find next smb2_ea_info using ->NextEntryOffset of current smb2_ea_info. ksmbd need to validate buffer length Before accessing the next ea. ksmbd should check buffer length using buf_len, not next variable. next is the start offset of current ea that got from previous ea.Show less

In the Linux kernel, the following vulnerability has been resolved: ksmbd: fix out of bounds read in smb2_sess_setup ksmbd does not consider the case of that smb2 session setup is in compound request. If this is the second payload of the compound, OOB read issue occurs while processing the first payload in the smb2_sess_setup().Show less

In the Linux kernel, the following vulnerability has been resolved: ksmbd: validate session id and tree id in the compound request This patch validate session id and tree id in compound request. If first operation in the compound is SMB2 ECHO request, ksmbd bypass session and tree validation. So work->sess and work->tcon could be NULL. If secound request in the compound access work->sess or tcon, It cause NULL pointer dereferecing error.Show less

In the Linux kernel, the following vulnerability has been resolved: ksmbd: fix out-of-bound read in smb2_write ksmbd_smb2_check_message doesn't validate hdr->NextCommand. If ->NextCommand is bigger than Offset + Length of smb2 write, It will allow oversized smb2 write length. It will cause OOB read in smb2_write.Show less

In the Linux kernel, the following vulnerability has been resolved: ksmbd: call rcu_barrier() in ksmbd_server_exit() racy issue is triggered the bug by racing between closing a connection and rmmod. In ksmbd, rcu_barrier() is not called at module unload time, so nothing prevents ksmbd from getting unloaded while it still has RCU callbacks pending. It leads to trigger unintended execution of kernel code locally and use to defeat protections such as Kernel LockdownShow less

In the Linux kernel, the following vulnerability has been resolved: mptcp: plug races between subflow fail and subflow creation We have races similar to the one addressed by the previous patch between subflow failing and additional subflow creation. They are just harder to trigger. The solution is similar. Use a separate flag to track the condition 'socket state prevent any additional subflow creation' protected by the fallback lock. The socket fallback makes such flag true, and also receiving or sending an MP_FAIL option. The field 'allow_infinite_fallback' is now always touched under the relevant lock, we can drop the ONCE annotation on write.Show less

In the Linux kernel, the following vulnerability has been resolved: virtio-net: fix recursived rtnl_lock() during probe() The deadlock appears in a stack trace like: virtnet_probe() rtnl_lock() virtio_config_changed_work() netdev_notify_peers() rtnl_lock() It happens if the VMM sends a VIRTIO_NET_S_ANNOUNCE request while the virtio-net driver is still probing. The config_work in probe() will get scheduled until virtnet_open() enables the config change notification via virtio_config_driver_enable().Show less

In the Linux kernel, the following vulnerability has been resolved: ipv6: mcast: Delay put pmc->idev in mld_del_delrec() pmc->idev is still used in ip6_mc_clear_src(), so as mld_clear_delrec() does, the reference should be put after ip6_mc_clear_src() return.Show less

In the Linux kernel, the following vulnerability has been resolved: efivarfs: Fix memory leak of efivarfs_fs_info in fs_context error paths When processing mount options, efivarfs allocates efivarfs_fs_info (sfi) early in fs_context initialization. However, sfi is associated with the superblock and typically freed when the superblock is destroyed. If the fs_context is released (final put) before fill_super is called—such as on error paths or during reconfiguration—the sfi structure would leak, as ownership never transfers to the superblock. Implement the .free callback in efivarfs_context_ops to ensure any allocated sfi is properly freed if the fs_context is torn down before fill_super, preventing this memory leak.Show less

In the Linux kernel, the following vulnerability has been resolved: hwmon: (corsair-cpro) Validate the size of the received input buffer Add buffer_recv_size to store the size of the received bytes. Validate buffer_recv_size in send_usb_cmd().Show less