Linux Linux vulnerabilities

In the Linux kernel, the following vulnerability has been resolved: cxl/features: Reject Set Features output buffer smaller than the header cxlctl_set_feature() sizes its output buffer from the user's fwctl_rpc.out_len but never checks it is large enough to hold even the fwctl_rpc_cxl_out header. With out_len == 0 , kvzalloc() returns ZERO_SIZE_PTR, which passes the !rpc_out check, the subsequent rpc_out->size = 0 then writes through the poison pointer. Reject requests whose output buffer can't hold the response header, before allocating. The Set Feature reply carries no payload, so the header is all that is required.

In the Linux kernel, the following vulnerability has been resolved: cxl/features: Clamp Get Feature output size to the remaining buffer cxl_get_feature() reads a feature in a loop but passes a fixed size_out as the output capacity every iteration. On the last partial iteration the buffer has less room left, so a device that returns more than asked can overflow feat_out. Use the per-iter size data_to_rd_size, which already tracks the remaining room, as the output capacity.

In the Linux kernel, the following vulnerability has been resolved: dax/fsdev: clear vmemmap_shift when binding static pgmap Clear pgmap->vmemmap_shift for static DAX devices. When rebinding a static device from device_dax (which may set vmemmap_shift based on alignment) to fsdev_dax, the stale vmemmap_shift persists on the shared pgmap. Explicitly zero it before devm_memremap_pages() so the vmemmap is built for order-0 folios as fsdev requires.

In the Linux kernel, the following vulnerability has been resolved: dax/fsdev: clear pgmap ops and owner on unbind fsdev_dax_probe() sets pgmap->ops = &fsdev_pagemap_ops and pgmap->owner = dev_dax, but nothing ever clears them. For a dynamic device the pgmap is devm-allocated and freed on unbind, so this is harmless. For a static device the pgmap is the shared, long-lived one owned by the dax bus (kill_dev_dax() only NULLs dev_dax->pgmap for the non-static case), and device.c's probe sets only pgmap->type, never clearing ops/owner. So after fsdev unbinds a static device the stale fsdev_pagemap_ops survives on the shared pgmap. If the device is then rebound to device_dax (MEMORY_DEVICE_GENERIC, which installs no ->memory_failure), or the fsdev_dax module is unloaded, a subsequent memory_failure on that pgmap dispatches through the stale -- and possibly freed -- handler. Register a devm action that clears pgmap->ops and pgmap->owner on unbind, symmetric with setting them at probe, so the pgmap carries no fsdev state once fsdev is detached.

In the Linux kernel, the following vulnerability has been resolved: dax: read holder_ops once in dax_holder_notify_failure() dax_holder_notify_failure() reads dax_dev->holder_ops twice without READ_ONCE() -- once for the NULL check and once for the indirect notify_failure() call. A concurrent fs_put_dax() can clear holder_ops between the two reads, so the check can observe a non-NULL pointer while the call dereferences NULL. (kill_dax() also clears holder_ops, but only after synchronize_srcu(), so it cannot race a reader that is inside dax_read_lock(); fs_put_dax() does no such synchronization.) Fetch holder_ops once into a local with READ_ONCE() so the NULL check and the indirect call observe the same value.

In the Linux kernel, the following vulnerability has been resolved: irqchip/renesas-irqc: Fix generic interrupt chip leak on remove The driver allocates domain generic chips probe. However, on driver removal, the generic chips are not automatically freed when the interrupt domain is removed because the domain flags do not include IRQ_DOMAIN_FLAG_DESTROY_GC. This causes both the domain generic chips structure and the associated generic chips to be leaked. Additionally, the generic chips remain on the global list and may later be accessed by generic interrupt chip suspend, resume, or shutdown callbacks after the driver has been removed, potentially resulting in a use-after-free and kernel crash. Fix the resource leak by setting IRQ_DOMAIN_FLAG_DESTROY_GC on the interrupt domain; this lets the interrupt domain core automatically release all generic chips when irq_domain_remove() is invoked, removing the need for manual cleanup calls in error paths and remove callback.

In the Linux kernel, the following vulnerability has been resolved: media: bcm2835-unicam: Fix asc leaked in error/remove path v4l2_async_nf_add_fwnode_remote() allocates the asc, which is freed when v4l2_async_nf_cleanup() is called. Call v4l2_async_nf_cleanup() properly in the driver paths. Discovered with kmemleak after rmmod: unreferenced object 0xffff000084526b80 (size 64): comm "modprobe", pid 185, jiffies 4295013512 hex dump (first 32 bytes): 01 00 00 00 00 00 00 00 e8 0d ff bf 00 00 ff ff ................ 40 83 bc 84 00 00 ff ff 60 83 bc 84 00 00 ff ff @.......`....... backtrace (crc ac584083): [<00000000ffb081a7>] kmemleak_alloc+0x38/0x44 [<00000000d2fd9301>] __kmalloc+0x1b0/0x250 [<000000004dd5354d>] __v4l2_async_nf_add_fwnode+0x28/0x9c [<0000000067587657>] __v4l2_async_nf_add_fwnode_remote+0x3c/0x64

In the Linux kernel, the following vulnerability has been resolved: OPP: Fix cleanup ordering Commit 173e02d67494 ("OPP: Initialize scope-based pointers inline") added initialization for all pointers. In some cases, the ordering was changed so that *opp_table was initialized after *opp. This also changes the order of the registered cleanup functions. When the cleanup happens, this can cause use-after-free errors when the last reference is released and the release function _opp_kref_release tries to access the already freed opp->opp_table. Initialize *opp_table before *opp again to fix this and ensure the correct cleanup order.

In the Linux kernel, the following vulnerability has been resolved: drm/amd/display: Fix DM I2C teardown race DM I2C adapters can remain visible to userspace while DM teardown is already in progress. A concurrent i2c-dev transfer may then enter amdgpu_dm_i2c_xfer() after the backing DM state has been torn down, leading to a NULL pointer dereference. Create a devres group around the DM I2C adapter lifetime and release it at the start of dm_hw_fini(), before HPD, IRQ, and DM state are torn down. This removes the I2C adapters first and waits for in-flight users to drain before the structures used by amdgpu_dm_i2c_xfer() disappear. This fixes a teardown ordering race seen during device removal: BUG: kernel NULL pointer dereference RIP: amdgpu_dm_i2c_xfer+0x122/0x1c0 [amdgpu] Call Trace: __i2c_transfer i2c_transfer i2cdev_ioctl_rdwr

In the Linux kernel, the following vulnerability has been resolved: drm/bridge: tc358767: clamp the reported AUX read size to the request tc_aux_transfer() clamps an AUX read to the payload limit: size_t size = min_t(size_t, DP_AUX_MAX_PAYLOAD_BYTES - 1, msg->size); After the transfer it replaces size with the byte count the controller reports in AUX_BYTES: if (size) size = FIELD_GET(AUX_BYTES, auxstatus); AUX_BYTES is GENMASK(15, 8), so it can be up to 255. Nothing clamps it back to the request. tc_aux_read_data() reads that many bytes into the 16-byte auxrdata stack buffer, then copies them into the caller buffer. A reported count of 255 makes the read run to 256 bytes and overruns both. The controller should never report more than it was asked to transfer, so this is defense in depth rather than a live hole. The reported count is only lightly trusted, and the check is cheap. Clamp it back to the request, the same way ti-sn65dsi86 does in commit aca58eac52b8 ("drm/bridge: ti-sn65dsi86: Never store more than msg->size bytes in AUX xfer").

In the Linux kernel, the following vulnerability has been resolved: x86/mm/pat: Take cpa_lock around large-page collapse Loading and unloading modules concurrently on several CPUs on a KASAN build, with a short delay injected at the CPA page-table lookup to widen the window, faults within minutes: BUG: KASAN: use-after-free in __change_page_attr+0x7cc/0x7e0 Write of size 8 at addr ffff888181139718 by task modprobe ... The buggy address belongs to the physical page: pfn:0x181139 ... page_type: f2(table) cpa_collapse_large_pages() rebuilds a leaf PMD from its 4K PTEs and frees the old PTE-table pages, while __change_page_attr() fetches a PTE pointer from a lockless lookup_address_in_pgd_attr() and writes it with set_pte_atomic() only later. When module text is served from a shared large ROX mapping the two run on the same PMD: CPU A (module load) CPU B (module finalize) ------------------- ----------------------- execmem_make_temp_rw set_memory_nx __change_page_attr split 2M -> 4K table P kpte = &P[i] (lockless) execmem_restore_rox set_memory_rox (CPA_COLLAPSE) cpa_collapse_large_pages rebuild leaf PMD flush_tlb_all pagetable_free(P) set_pte_atomic(kpte, ...) -> writes into freed P P is a page-table page (page_type: table), reused at once, so the write corrupts whatever got the page next: a bad-pte or bad-page splat, or a fatal fault once P has been turned into read-only text. The flush_tlb_all() before the free does not close this: its IPI only serializes against page-table walkers that run with interrupts off (e.g. GUP-fast); the walk in __change_page_attr() runs with interrupts on, so nothing stops it from holding a stale pointer into P. Serialize the collapse - the PMD rebuild, TLB flush and PTE-table free - under cpa_lock, the same lock __change_page_attr() now takes unconditionally since commit ("x86/mm/pat: stop gating cpa_lock on debug_pagealloc_enabled()"), so a concurrent walker can no longer hold a pointer into a table the collapse is about to free.

In the Linux kernel, the following vulnerability has been resolved: wifi: iwlwifi: fix counter type in iwl_fwrt_dump_error_logs The loop counter 'count' was declared as u8 while num_pc is u32. If firmware advertises more than 255 PC entries the counter wraps back to zero and the loop never terminates potentially causing an infinite loop or reading past the allocated pc_data array. Change the declaration to u32 to match num_pc.

In the Linux kernel, the following vulnerability has been resolved: wifi: iwlwifi: mvm: fix off-by-one in TXF key sanitiser iwl_mvm_frob_txf_key_iter() tracks the last matched byte position in loop variable 'i'. When a full key match is found (match == keylen), 'i' points at the last byte of the matched key. The memset start offset should therefore be i + 1 - keylen, not i - keylen; the current code zeroes one byte before the match and leaves the final key byte un-sanitised.

In the Linux kernel, the following vulnerability has been resolved: wifi: iwlwifi: guard against division by zero in iwl_dbg_tlv_alloc_fragments Make sure we don't end-up with a num_frags = 0 situation. For that, check that the required size is not 0 and put a checker on num_frags as well.

In the Linux kernel, the following vulnerability has been resolved: gpu: host1x: Avoid stack over-read in debug output helpers host1x_debug_output() and host1x_debug_cont() used vsnprintf(), which returns the length the formatted string would have reached with an unbounded buffer. That return value was passed straight to o->fn as the number of bytes to emit. This could cause a read past end of the output buffer if a call to host1x_debug_* produced a string longer than 256 bytes. This only affected the debugfs files as the printk debug sink ignores the number of bytes. In practice, this is very unlikely to occur. Fix by switching to vscnprintf(), which returns the number of bytes actually written.

In the Linux kernel, the following vulnerability has been resolved: drm/msm/adreno: fix use after free on error path in a6xx_gpu_init() The a6xx_destroy() function frees "a6xx_gpu" and so "adreno_gpu" points to freed memory. Preserve the error code before freeing the memory to avoid a use after free. Patchwork: https://patchwork.freedesktop.org/patch/732275/

In the Linux kernel, the following vulnerability has been resolved: drm/msm: Fix task_struct reference leak in recover_worker get_pid_task() increments the task reference count, but the corresponding put_task_struct() was missing in the else branch, leaking a reference on every GPU hang recovery. Patchwork: https://patchwork.freedesktop.org/patch/730662/

In the Linux kernel, the following vulnerability has been resolved: drm/msm: Only fini scheduler after successful init msm_ringbuffer_new() destroys a partially initialized ring through msm_ringbuffer_destroy() when an allocation or scheduler setup step fails. If drm_sched_init() fails before it finishes initializing the scheduler, the failure path still calls drm_sched_fini(). That teardown path assumes the scheduler work items, lists, and workqueue state were initialized. Track successful scheduler initialization and call drm_sched_fini() only after drm_sched_init() returned 0. This issue was found by a static analysis checker and confirmed by manual source review. Patchwork: https://patchwork.freedesktop.org/patch/738905/

In the Linux kernel, the following vulnerability has been resolved: scsi: ufs: core: Avoid possible memory reclaim deadlock in TX EQTR context TX EQTR may run while devfreq gear scaling has quiesced the UFS tagset. In that context, functions ufshcd_tx_eqtr(), __ufshcd_tx_eqtr() and ufs_qcom_get_rx_fom() allocate memory with GFP_KERNEL. If direct reclaim is triggered, reclaim/writeback can depend on I/O to UFS device. Because the queue is quiesced, this can cause deadlock. Use memalloc_noio_save/restore() in ufshcd_tx_eqtr() to cover all allocations in the TX EQTR call tree, including: - params->eqtr_record in ufshcd_tx_eqtr() - eqtr_data in __ufshcd_tx_eqtr() - params in ufs_qcom_get_rx_fom() This is preferred over tagging individual call sites with GFP_NOIO, as it automatically covers any future allocations added anywhere in the call tree without requiring each caller to be aware of this constraint. [mkp: fix label as suggested by Bart]

In the Linux kernel, the following vulnerability has been resolved: usb: gadget: f_uac1_legacy: remove broken string configfs attributes The UAC1_STR_ATTRIBUTE macro defines configfs show/store handlers for the fn_play, fn_cap, and fn_cntl string options. The store function contains an inverted null check on the kstrndup() return value. This means every write attempt returns -ENOMEM on success and dereferences a NULL pointer on allocation failure. The attributes have been broken and unused for many years. Remove the UAC1_STR_ATTRIBUTE macro and the three attributes it generated. The internal defaults (FILE_PCM_PLAYBACK, FILE_PCM_CAPTURE, FILE_CONTROL) set in f_audio_alloc_inst() are unaffected.

In the Linux kernel, the following vulnerability has been resolved: UDF symlink pathComponent header OOB read udf_symlink_filler() can enter udf_pc_to_char() with a partial pathComponent header. Validate that enough input remains for a complete pathComponent header before accessing it. Reject malformed symlink data that would otherwise make udf_pc_to_char() perform an out-of-bounds read.