Vulnerabilidades do Linux Linux Kernel

In the Linux kernel, the following vulnerability has been resolved: selinux: fix avdcache auditing The per-task avdcache was incorrectly saving and reusing the audited vector computed by avc_audit_required() rather than recomputing based on the currently requested permissions and distinguishing the denied versus allowed cases. As a result, some permission checks were not being audited, e.g. directory write checks after a previously cached directory search check. [PM: line wrap tweaks]

In the Linux kernel, the following vulnerability has been resolved: vsock/virtio: fix zerocopy completion for multi-skb sends When a large message is fragmented into multiple skbs, the zerocopy uarg is only allocated and attached to the last skb in the loop. Non-final skbs carry pinned user pages with no completion tracking, so the kernel has no way to notify userspace when those pages are safe to reuse. If the loop breaks early the uarg is never allocated at all, leaking pinned pages with no completion notification. Fix this by following the approach used by TCP: allocate the zerocopy uarg (if not provided by the caller) before the send loop and attach it to every skb via skb_zcopy_set(), which takes a reference per skb. Each skb's completion properly decrements the refcount, and the notification only fires after the last skb is freed. On failure, if no data was sent, the uarg is cleanly aborted via net_zcopy_put_abort(). This issue was initially discovered by sashiko while reviewing commit 1cb36e252211 ("vsock/virtio: fix MSG_ZEROCOPY pinned-pages accounting") but was pre-existing.

In the Linux kernel, the following vulnerability has been resolved: Bluetooth: hci_conn: Fix memory leak in hci_le_big_terminate() hci_le_big_terminate() allocates iso_list_data via kzalloc_obj but returns 0 without freeing it when neither pa_sync_term nor big_sync_term flags are set after evaluating the PA and BIG sync connection state. This early-return path was introduced when hci_le_big_terminate() was refactored to take struct hci_conn instead of raw u8 parameters, adding PA/BIG flag evaluation logic. The existing kfree() on hci_cmd_sync_queue failure does not cover this path.

In the Linux kernel, the following vulnerability has been resolved: hsr: Remove WARN_ONCE() in hsr_addr_is_self(). syzbot reported the warning [0] in hsr_addr_is_self(), whose assumption is simply wrong. hsr->self_node is cleared in hsr_del_self_node(), which is called from hsr_dellink(). Since dev->rtnl_link_ops->dellink() is called before unregister_netdevice_many(), there is a window when user can find the device but without hsr->self_node. Let's remove WARN_ONCE() in hsr_addr_is_self(). [0]: HSR: No self node WARNING: net/hsr/hsr_framereg.c:39 at hsr_addr_is_self+0x211/0x3f0 net/hsr/hsr_framereg.c:39, CPU#0: syz.4.16848/17220 Modules linked in: CPU: 0 UID: 0 PID: 17220 Comm: syz.4.16848 Tainted: G L syzkaller #0 PREEMPT_{RT,(full)} Tainted: [L]=SOFTLOCKUP Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026 RIP: 0010:hsr_addr_is_self+0x211/0x3f0 net/hsr/hsr_framereg.c:39 Code: 33 2f 41 0f b7 dd 89 ee 09 de 31 ff e8 c8 b4 c6 f6 09 dd 74 54 e8 0f b0 c6 f6 31 ed eb 53 e8 06 b0 c6 f6 48 8d 3d 2f 50 9c 04 <67> 48 0f b9 3a 31 ed eb 42 e8 c1 13 1f 00 89 c5 31 ff 89 c6 e8 96 RSP: 0018:ffffc900041c70e0 EFLAGS: 00010283 RAX: ffffffff8afdc6ca RBX: ffffffff8afdc4e6 RCX: 0000000000080000 RDX: ffffc90010493000 RSI: 0000000000000948 RDI: ffffffff8f9a1700 RBP: 0000000000000001 R08: 0000000000000000 R09: 0000000000000000 R10: ffffc900041c71e8 R11: fffff52000838e3f R12: dffffc0000000000 R13: ffff888041f9e3c0 R14: ffff888086ee3802 R15: 0000000000000000 FS: 00007f6fe985d6c0(0000) GS:ffff888126176000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f80bd437dac CR3: 0000000025096000 CR4: 00000000003526f0 DR0: ffffffffffffffff DR1: 00000000000001f8 DR2: 0000000000000002 DR3: ffffffffefffff15 DR6: 00000000ffff0ff0 DR7: 0000000000000400 Call Trace: <TASK> check_local_dest net/hsr/hsr_forward.c:592 [inline] fill_frame_info net/hsr/hsr_forward.c:728 [inline] hsr_forward_skb+0xa11/0x2a80 net/hsr/hsr_forward.c:739 hsr_dev_xmit+0x253/0x370 net/hsr/hsr_device.c:236 __netdev_start_xmit include/linux/netdevice.h:5368 [inline] netdev_start_xmit include/linux/netdevice.h:5377 [inline] xmit_one net/core/dev.c:3888 [inline] dev_hard_start_xmit+0x2df/0x860 net/core/dev.c:3904 __dev_queue_xmit+0x1428/0x3900 net/core/dev.c:4870 neigh_output include/net/neighbour.h:556 [inline] ip_finish_output2+0xcec/0x10b0 net/ipv4/ip_output.c:237 ip_send_skb net/ipv4/ip_output.c:1510 [inline] ip_push_pending_frames+0x8b/0x110 net/ipv4/ip_output.c:1530 raw_sendmsg+0x1547/0x1a50 net/ipv4/raw.c:659 sock_sendmsg_nosec net/socket.c:787 [inline] __sock_sendmsg net/socket.c:802 [inline] ____sys_sendmsg+0x7da/0x9c0 net/socket.c:2698 ___sys_sendmsg+0x2a5/0x360 net/socket.c:2752 __sys_sendmsg net/socket.c:2784 [inline] __do_sys_sendmsg net/socket.c:2789 [inline] __se_sys_sendmsg net/socket.c:2787 [inline] __x64_sys_sendmsg+0x1c3/0x2a0 net/socket.c:2787 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x15f/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f6feb62ce59 Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 e8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f6fe985d028 EFLAGS: 00000246 ORIG_RAX: 000000000000002e RAX: ffffffffffffffda RBX: 00007f6feb8a6090 RCX: 00007f6feb62ce59 RDX: 0000000000000000 RSI: 0000200000000000 RDI: 0000000000000004 RBP: 00007f6feb6c2d6f R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f6feb8a6128 R14: 00007f6feb8a6090 R15: 00007ffcf01cc488 </TASK>

In the Linux kernel, the following vulnerability has been resolved: riscv/ptrace: Use USER_REGSET_NOTE_TYPE for REGSET_CFI Fixes a warning while dumping core: [54983.546369][ C7] WARNING: [!note_name] fs/binfmt_elf.c:1771 at elf_core_dump+0x910/0xf68, CPU#7: abort01/31982

In the Linux kernel, the following vulnerability has been resolved: signal: clear JOBCTL_PENDING_MASK for caller in zap_other_threads() When a multi-threaded process receives a stop signal (e.g., SIGSTOP), do_signal_stop() sets JOBCTL_STOP_PENDING and JOBCTL_STOP_CONSUME on all threads and sets signal->group_stop_count to the number of threads. If one of the threads concurrently calls execve(), de_thread() invokes zap_other_threads() to kill all other threads. zap_other_threads() aborts the pending group stop by resetting signal->group_stop_count to 0 and clears the JOBCTL_PENDING_MASK for all other threads. However, it fails to clear the job control flags for the calling thread. When execve() completes, the calling thread returns to user mode and checks for pending signals. Seeing the stale JOBCTL_STOP_PENDING flag, it calls do_signal_stop(), which invokes task_participate_group_stop(). Since JOBCTL_STOP_CONSUME is still set, it attempts to decrement the already-zero signal->group_stop_count, triggering a warning: sig->group_stop_count == 0 WARNING: CPU: 1 PID: 6475 at kernel/signal.c:373 task_participate_group_stop+0x215/0x2d0 Call Trace: <TASK> do_signal_stop+0x3be/0x5c0 kernel/signal.c:2619 get_signal+0xa8c/0x1330 kernel/signal.c:2884 arch_do_signal_or_restart+0xbc/0x840 arch/x86/kernel/signal.c:337 exit_to_user_mode_loop+0x8c/0x4d0 kernel/entry/common.c:98 do_syscall_64+0x33e/0xf80 arch/x86/entry/syscall_64.c:100 entry_SYSCALL_64_after_hwframe+0x77/0x7f </TASK> Fix this race condition by clearing the JOBCTL_PENDING_MASK for the calling thread in zap_other_threads(), ensuring it does not retain any stale job control state after the thread group is destroyed. This aligns with other functions that tear down a thread group and abort group stops, such as zap_process() and complete_signal(), which correctly clear these flags for all threads including the current one.

In the Linux kernel, the following vulnerability has been resolved: ASoC: wm_adsp: Fix NULL dereference when removing firmware controls In wm_adsp_control_remove() check that the priv pointer is not NULL before attempting to cleanup what it points to. When cs_dsp creates a control it calls wm_adsp_control_add_cb() so that wm_adsp can create its own private control data. There are two cases where private data is not created: 1. The control is a SYSTEM control, so an ALSA control is not created. 2. The codec driver has registered a control_add() callback that hides the control, so wm_adsp_control_add() is not called. When cs_dsp_remove destroys its control list it calls wm_adsp_control_remove() for each control. But wm_adsp_control_remove() was attempting to cleanup the private data pointed to by cs_ctl->priv without checking the pointer for NULL.

In the Linux kernel, the following vulnerability has been resolved: netfilter: nf_conntrack: destroy stale expectfn expectations on unregister NAT helpers such as nf_nat_h323 store a raw pointer to module text in exp->expectfn (e.g. ip_nat_q931_expect). nf_ct_helper_expectfn_unregister() only unlinks the callback descriptor and never walks the expectation table, so an expectation pending at module removal survives with a dangling exp->expectfn into freed module text. When the expected connection arrives, init_conntrack() invokes exp->expectfn(), now a stale pointer into the unloaded module. Reproduced on a KASAN build by loading the H.323 helpers, creating a Q.931 expectation, unloading nf_nat_h323, then connecting to the expected port: Oops: int3: 0000 [#1] SMP KASAN NOPTI RIP: 0010:0xffffffffa06102d1 init_conntrack.isra.0 (net/netfilter/nf_conntrack_core.c:1862) nf_conntrack_in (net/netfilter/nf_conntrack_core.c:2049) ipv4_conntrack_local (net/netfilter/nf_conntrack_proto.c:223) nf_hook_slow (net/netfilter/core.c:619) __ip_local_out (net/ipv4/ip_output.c:120) __tcp_transmit_skb (net/ipv4/tcp_output.c:1715) tcp_connect (net/ipv4/tcp_output.c:4374) tcp_v4_connect (net/ipv4/tcp_ipv4.c:345) __sys_connect (net/socket.c:2167) Modules linked in: nf_conntrack_h323 [last unloaded: nf_nat_h323] Reaching the dangling state requires CAP_SYS_MODULE in the initial user namespace to remove a NAT helper that still has live expectations, so this is a robustness fix; leaving an expectation pointing at freed text is wrong regardless. Add nf_ct_helper_expectfn_destroy(), which walks the expectation table and drops every expectation whose ->expectfn matches the descriptor being torn down. Call it from each NAT helper's exit path after the existing RCU grace period, so no expectation outlives the code it points at and no extra synchronize_rcu() is introduced. With the fix, the same reproducer runs to completion without the Oops.

In the Linux kernel, the following vulnerability has been resolved: ASoC: SDCA: fix NULL pointer dereference in sdca_dev_unregister_functions sdca_dev_unregister_functions() iterates over all SDCA function descriptors and calls sdca_dev_unregister() on each func_dev without checking for NULL. When a function registration has failed partway through, or the device cleanup races with probe deferral, func_dev entries may be NULL, leading to a kernel oops: BUG: kernel NULL pointer dereference, address: 0000000000000040 RIP: 0010:device_del+0x1e/0x3e0 Call Trace: sdca_dev_unregister_functions+0x37/0x60 [snd_soc_sdca] release_nodes+0x35/0xb0 devres_release_all+0x90/0x100 device_unbind_cleanup+0xe/0x80 device_release_driver_internal+0x1c1/0x200 bus_remove_device+0xc6/0x130 device_del+0x161/0x3e0 device_unregister+0x17/0x60 sdw_delete_slave+0xb6/0xd0 [soundwire_bus] sdw_bus_master_delete+0x1e/0x50 [soundwire_bus] ... sof_probe_work+0x19/0x30 [snd_sof] This was observed on a Lenovo ThinkPad X1 Carbon G14 (Panther Lake) with the SOF audio driver probe failing due to missing Panther Lake firmware, causing the subsequent cleanup of SoundWire devices to trigger the crash. Fix this with three changes: 1) Add a NULL guard in sdca_dev_unregister() so that callers do not need to pre-validate the pointer (defense in depth). 2) In sdca_dev_unregister_functions(), skip NULL func_dev entries and clear func_dev to NULL after unregistration, making the function idempotent and safe against double-invocation. 3) In sdca_dev_register_functions(), roll back all previously registered functions when a later one fails, so the function array is never left in a partially-populated state.

In the Linux kernel, the following vulnerability has been resolved: drm/virtio: Fix driver removal with disabled KMS DRM atomic and modesetting aren't initialized if virtio-gpu driver built with disabled KMS, leading to access of uninitialized data on driver removal/unbinding and crashing kernel. Fix it by skipping shutting down atomic core with unavailable KMS.

In the Linux kernel, the following vulnerability has been resolved: KVM: Don't WARN if memory is dirtied without a vCPU when the VM is dying When marking a page dirty, complain about not having a running/loaded vCPU if and only if the VM is still alive, i.e. its refcount is non-zero. This will allow fixing a memory leak for x86 SEV-ES guests without hitting what is effectively a false positive on the WARN. For some SEV-ES VM-Exits, KVM keeps a writable mapping of a guest page across an exit to userspace, and typically unmaps the page on the next KVM_RUN. But if userspace never calls KVM_RUN after such an exit, then KVM needs to unmap the page when the vCPU is destroyed, which in turn triggers the WARN about not having a running vCPU. Alternatively, SEV-ES could temporarily load the vCPU to suppress the WARN, as is done in nested_vmx_free_vcpu() (but for completely unrelated reasons; suppressing WARN from nested_put_vmcs12_pages() is pure happenstance). But loading a vCPU during destruction is gross (ideally nVMX code would be cleaned up), risks complicating the SEV-ES code (KVM would need to ensure the temporarily load()+put() only runs when the vCPU isn't already loaded), and is ultimately pointless. The motivation for the WARN is to guard against KVM dirtying guest memory without pushing the corresponding GFN to the active vCPU's dirty ring, e.g. to ensure userspace doesn't miss a dirty page. But for the VM's refcount to reach zero, there can't be _any_ userspace mappings to the dirty ring, as mapping the dirty ring requires doing mmap() on the vCPU FD. I.e. if userspace had a valid mapping for the dirty ring, then the vCPU file and thus the owning VM would still be alive. And so since userspace can't possibly reach the dirty ring, whether or not KVM technically "misses" a push to the dirty ring is irrelevant.

In the Linux kernel, the following vulnerability has been resolved: pinctrl: mcp23s08: Initialize mcp->dev and mcp->addr before regmap init Regmap initialization triggers regcache_maple_populate() which attempts SPI read to populate cache. SPI read requires mcp->dev and mcp->addr to be set, without them, NULL pointer dereference occurs during probe. Move initialization before mcp23s08_spi_regmap_init() call.

In the Linux kernel, the following vulnerability has been resolved: ARM: 9475/1: entry: use byte load for KASAN VMAP stack shadow Commit 44e9a3bb76e5 ("ARM: 9430/1: entry: Do a dummy read from VMAP shadow") added a dummy read from the KASAN VMAP stack shadow in __switch_to(). The read uses ldr, but the KASAN shadow address is byte-granular and is not guaranteed to be word aligned. ARMv5 faults unaligned word loads. With CONFIG_KASAN_VMALLOC and CONFIG_VMAP_STACK enabled, ARM926/VersatilePB crashes in __switch_to() with an alignment exception before reaching init. Use ldrb for the dummy shadow access. The code only needs to fault in the shadow mapping if the stack shadow is missing, so a byte load is sufficient and matches the granularity of KASAN shadow memory.