Vulnerabilidades do Linux Linux Kernel

In the Linux kernel, the following vulnerability has been resolved: drm/amd/display: Fix dc_link NULL handling in HPD init amdgpu_dm_hpd_init() may see connectors without a valid dc_link. The code already checks dc_link for the polling decision, but later unconditionally dereferences it when setting up HPD interrupts. Assign dc_link early and skip connectors where it is NULL. Fixes the below: drivers/gpu/drm/amd/amdgpu/../display/amdgpu_dm/amdgpu_dm_irq.c:940 amdgpu_dm_hpd_init() error: we previously assumed 'dc_link' could be null (see line 931) drivers/gpu/drm/amd/amdgpu/../display/amdgpu_dm/amdgpu_dm_irq.c 923 /* 924 * Analog connectors may be hot-plugged unlike other connector 925 * types that don't support HPD. Only poll analog connectors. 926 */ 927 use_polling |= 928 amdgpu_dm_connector->dc_link && ^^^^^^^^^^^^^^^^^^^^^^^^^^^^ The patch adds this NULL check but hopefully it can be removed 929 dc_connector_supports_analog(amdgpu_dm_connector->dc_link->link_id.id); 930 931 dc_link = amdgpu_dm_connector->dc_link; dc_link assigned here. 932 933 /* 934 * Get a base driver irq reference for hpd ints for the lifetime 935 * of dm. Note that only hpd interrupt types are registered with 936 * base driver; hpd_rx types aren't. IOW, amdgpu_irq_get/put on 937 * hpd_rx isn't available. DM currently controls hpd_rx 938 * explicitly with dc_interrupt_set() 939 */ --> 940 if (dc_link->irq_source_hpd != DC_IRQ_SOURCE_INVALID) { ^^^^^^^^^^^^^^^^^^^^^^^ If it's NULL then we are trouble because we dereference it here. 941 irq_type = dc_link->irq_source_hpd - DC_IRQ_SOURCE_HPD1; 942 /* 943 * TODO: There's a mismatch between mode_info.num_hpd 944 * and what bios reports as the # of connectors with hpd

In the Linux kernel, the following vulnerability has been resolved: drm/panthor: Recover from panthor_gpu_flush_caches() failures We have seen a few cases where the whole memory subsystem is blocked and flush operations never complete. When that happens, we want to: - schedule a reset, so we can recover from this situation - in the reset path, we need to reset the pending_reqs so we can send new commands after the reset - if more panthor_gpu_flush_caches() operations are queued after the timeout, we skip them and return -EIO directly to avoid needless waits (the memory block won't miraculously work again) Note that we drop the WARN_ON()s because these hangs can be triggered with buggy GPU jobs created by the UMD, and there's no way we can prevent it. We do keep the error messages though. v2: - New patch v3: - Collect R-b - Explicitly mention the fact we dropped the WARN_ON()s in the commit message v4: - No changes

In the Linux kernel, the following vulnerability has been resolved: PCI: endpoint: Add missing NULL check for alloc_workqueue() alloc_workqueue() can return NULL on memory allocation failure. Without proper error checking, this may lead to a NULL pointer dereference when queue_work() is later called with the NULL workqueue pointer in epf_ntb_epc_init(). Add a NULL check immediately after alloc_workqueue() and return -ENOMEM on failure to prevent the driver from loading with an invalid workqueue pointer.

In the Linux kernel, the following vulnerability has been resolved: media: i2c: ov5647: Fix runtime PM refcount leak in s_ctrl Three control cases (AUTOGAIN, EXPOSURE_AUTO, ANALOGUE_GAIN) directly return without calling pm_runtime_put(), causing runtime PM reference count leaks. Change these cases from 'return' to 'ret = ... break' pattern to ensure pm_runtime_put() is always called before function exit.

In the Linux kernel, the following vulnerability has been resolved: media: rc: xbox_remote: heed DMA restrictions The buffer for IO must not be part of the device structure because that violates the DMA coherency rules.

In the Linux kernel, the following vulnerability has been resolved: media: saa7164: add ioremap return checks and cleanups Add checks for ioremap return values in saa7164_dev_setup(). If ioremap for BAR0 or BAR2 fails, release the already allocated PCI memory regions, remove the device from the global list, decrement the device count, and return -ENODEV. This prevents potential null pointer dereferences and ensures proper cleanup on memory mapping failures.

In the Linux kernel, the following vulnerability has been resolved: batman-adv: bla: only purge non-released claims When batadv_bla_purge_claims() goes through the list of claims, it is only traversing the hash list with an rcu_read_lock(). Due to a potential parallel batadv_claim_put(), it can happen that it encounters a claim which was actually in the process of being released+freed by batadv_claim_release(). In this case, backbone_gw is set to NULL before the delayed RCU kfree is started. Calling batadv_bla_claim_get_backbone_gw() is then no longer allowed because it would cause a NULL-ptr derefence. To avoid this, only claims with a valid reference counter must be purged. All others are already taken care of.

In the Linux kernel, the following vulnerability has been resolved: batman-adv: bla: put backbone reference on failed claim hash insert When batadv_bla_add_claim() fails to insert a new claim into the hash, it leaked a reference to the backbone_gw for which the claim was intended. Call batadv_backbone_gw_put() on the error path to release the reference and avoid leaking the backbone_gw object.

In the Linux kernel, the following vulnerability has been resolved: drm/amdkfd: Clear VRAM on allocation to prevent stale data exposure KFD VRAM allocations set AMDGPU_GEM_CREATE_VRAM_WIPE_ON_RELEASE but not AMDGPU_GEM_CREATE_VRAM_CLEARED, leaving freshly allocated VRAM with stale data from prior use observable by compute kernels. The GEM ioctl path already sets VRAM_CLEARED for all userspace allocations via amdgpu_gem_create_ioctl() and amdgpu_mode_dumb_create(). The KFD path was missing this flag, allowing stale page table remnants to leak into user buffers. This causes crashes in RCCL P2P transport where non-zero data in ptrExchange/head/tail fields corrupts the protocol handshake.

In the Linux kernel, the following vulnerability has been resolved: spi: ch341: fix devres lifetime USB drivers bind to USB interfaces and any device managed resources should have their lifetime tied to the interface rather than parent USB device. This avoids issues like memory leaks when drivers are unbound without their devices being physically disconnected (e.g. on probe deferral or configuration changes). Fix the controller and driver data lifetime so that they are released on driver unbind. Note that this also makes sure that the SPI controller is placed correctly under the USB interface in the device tree.

In the Linux kernel, the following vulnerability has been resolved: spi: fsl: fix controller deregistration Make sure to deregister the controller before releasing underlying resources like DMA during driver unbind.

In the Linux kernel, the following vulnerability has been resolved: spi: rspi: fix controller deregistration Make sure to deregister the controller before releasing underlying resources like DMA during driver unbind.

In the Linux kernel, the following vulnerability has been resolved: drm/xe: Fix bo leak in xe_dma_buf_init_obj() on allocation failure When drm_gpuvm_resv_object_alloc() fails, the pre-allocated storage bo is not freed. Add xe_bo_free(storage) before returning the error. xe_dma_buf_init_obj() calls xe_bo_init_locked(), which frees the bo on error. Therefore, xe_dma_buf_init_obj() must also free the bo on its own error paths. Otherwise, since xe_gem_prime_import() cannot distinguish whether the failure originated from xe_dma_buf_init_obj() or from xe_bo_init_locked(), it cannot safely decide whether the bo should be freed. Add comments documenting the ownership semantics: on success, ownership of storage is transferred to the returned drm_gem_object; on failure, storage is freed before returning. v2: Add comments to explain the free logic. (cherry picked from commit 78a6c5f899f22338bbf48b44fb8950409c5a69b9)

In the Linux kernel, the following vulnerability has been resolved: cgroup: Defer css percpu_ref kill on rmdir until cgroup is depopulated A chain of commits going back to v7.0 reworked rmdir to satisfy the controller invariant that a subsystem's ->css_offline() must not run while tasks are still doing kernel-side work in the cgroup. [1] d245698d727a ("cgroup: Defer task cgroup unlink until after the task is done switching out") [2] a72f73c4dd9b ("cgroup: Don't expose dead tasks in cgroup") [3] 1b164b876c36 ("cgroup: Wait for dying tasks to leave on rmdir") [4] 4c56a8ac6869 ("cgroup: Fix cgroup_drain_dying() testing the wrong condition") [5] 13e786b64bd3 ("cgroup: Increment nr_dying_subsys_* from rmdir context") [1] moved task cset unlink from do_exit() to finish_task_switch() so a task's cset link drops only after the task has fully stopped scheduling. That made tasks past exit_signals() linger on cset->tasks until their final context switch, which led to a series of problems as what userspace expected to see after rmdir diverged from what the kernel needs to wait for. [2]-[5] tried to bridge that divergence: [2] filtered the exiting tasks from cgroup.procs; [3] had rmdir(2) sleep in TASK_UNINTERRUPTIBLE for them; [4] fixed the wait's condition; [5] made nr_dying_subsys_* visible synchronously. The cgroup_drain_dying() wait in [3] turned out to be a dead end. When the rmdir caller is also the reaper of a zombie that pins a pidns teardown (e.g. host PID 1 systemd reaping orphan pids that were re-parented to it during the same teardown), rmdir blocks in TASK_UNINTERRUPTIBLE waiting for those pids to free, the pids can't free because PID 1 is the reaper and it's stuck in rmdir, and the system A-A deadlocks. No internal lock ordering breaks this; the wait itself is the bug. The css killing side that drove the original reorder, however, can be made cleanly asynchronous: ->css_offline() is already async, run from css_killed_work_fn() driven by percpu_ref_kill_and_confirm(). The fix is to make that chain start only after all tasks have left the cgroup. rmdir's user-visible side then returns as soon as cgroup.procs and friends are empty, while ->css_offline() still runs only after the cgroup is fully drained. Verified by the original reproducer (pidns teardown + zombie reaper, runs under vng) which hangs vanilla and succeeds here, and by per-commit deterministic repros for [2], [3], [4], [5] with a boot parameter that widens the post-exit_signals() window so each state is reliably reachable. Some stress tests on top of that. cgroup_apply_control_disable() has the same shape of pre-existing race: when a controller is disabled via subtree_control, kill_css() ran synchronously while tasks past exit_signals() could still be linked to the cgroup's csets, and ->css_offline() could fire before they drained. This patch preserves the existing synchronous behavior at that call site (kill_css_sync() + kill_css_finish() back-to-back) and a follow-up patch will defer kill_css_finish() there using a per-css trigger. This seems like the right approach and I don't see problems with it. The changes are somewhat invasive but not excessively so, so backporting to -stable should be okay. If something does turn out to be wrong, the fallback is to revert the entire chain ([1]-[5]) and rework in the development branch instead. v2: Pin cgrp across the deferred destroy work with explicit cgroup_get()/cgroup_put() around queue_work() and the work_fn. v1 wasn't actually broken (ordered cgroup_offline_wq + queue_work order in cgroup_task_dead() saved it) but the explicit ref removes the dependency on those non-obvious invariants. Also note the pre-existing cgroup_apply_control_disable() race in the description; a follow-up will defer kill_css_finish() there.

In the Linux kernel, the following vulnerability has been resolved: media: rockchip: rkcif: Add missing MUST_CONNECT flag to pads The pads missed checks for connected devices which may a null dereference when the stream is enabled. Unable to handle kernel NULL pointer dereference at virtual address 0000000000000020 pc : rkcif_interface_enable_streams+0x48/0xf0 lr : rkcif_interface_enable_streams+0x44/0xf0 Call trace: rkcif_interface_enable_streams+0x48/0xf0 v4l2_subdev_enable_streams+0x26c/0x3f0 rkcif_stream_start_streaming+0x140/0x278 vb2_start_streaming+0x74/0x188 vb2_core_streamon+0xe0/0x1d8 vb2_ioctl_streamon+0x60/0xa8 v4l_streamon+0x2c/0x40 __video_do_ioctl+0x34c/0x400 video_usercopy+0x2d0/0x800 video_ioctl2+0x20/0x60 v4l2_ioctl+0x48/0x78