Vulnerabilidades de Linux

In the Linux kernel, the following vulnerability has been resolved: mac802154: fix use-after-free of sdata via queued RX frames The RX softirq producer ieee802154_subif_frame() queues received beacon and MAC-command frames onto local->rx_beacon_list / rx_mac_cmd_list and schedules a process-context worker, storing a raw mac_pkt->sdata (and skb->dev == sdata->dev) with neither a reference nor any locking: - the lists have no lock: the softirq producer list_add_tail()s while the mac_wq worker list_del()s, so sibling interfaces on the same phy corrupt the list; - the workers dereference the interface after it may have been freed. mac802154_rx_mac_cmd_worker() touches mac_pkt->sdata directly, and mac802154_rx_beacon_worker() -> mac802154_process_beacon() dereferences skb->dev (== sdata->dev). Removing an interface frees its sdata (netdev_priv) while a queued frame still points at it, so a later worker run is a use-after-free. Reproduced under KASAN by flooding a victim interface with MAC command frames and removing it (the beacon path is the same class via skb->dev): BUG: KASAN: slab-use-after-free in mac802154_rx_mac_cmd_worker+0x463/0x630 [mac802154] Read of size 4 at addr ffff888002f9ea18 by task kworker/u8:1/31 Workqueue: phy0-mac-cmds mac802154_rx_mac_cmd_worker [mac802154] Call Trace: mac802154_rx_mac_cmd_worker+0x463/0x630 [mac802154] process_one_work+0x611/0xe80 worker_thread+0x52e/0xdc0 kthread+0x30c/0x630 ret_from_fork+0x2fd/0x3e0 Fix both lists together: - add local->rx_lock and take it around every list access: the softirq producer (plain spin_lock, softirq context) and the workers and flush (spin_lock_bh, process context); - pin the interface for the lifetime of a queued frame with netdev_hold()/netdev_put(), so the worker can safely dereference sdata / skb->dev even while the interface is being removed; - dequeue under the lock at the head and loop-drain the whole list in the workers (they previously processed one frame per run and relied on a later enqueue to drain the rest); - drop not-yet-started frames of an interface before it is unregistered, from ieee802154_if_remove() (after the RCU grace period) and from the ieee802154_remove_interfaces() loop -- the latter is the whole-phy teardown path, which does not go through ieee802154_if_remove(). An in-flight worker that already dequeued a frame keeps its own netdev reference; unregister_netdevice() then waits it out in netdev_run_todo(), which runs at rtnl_unlock() (rtnl released) and after the interface has been closed, so it does not pin rtnl. A worker blocked in an association TX only delays that one interface's unregister (the usual "waiting for %s to become free"), it does not hold rtnl. netdev_hold() is used for this reason instead of a cancel_work_sync() under rtnl, which would block on the worker's unbounded MLME TX wait via ieee802154_sync_queue(). The mac-command worker additionally skips processing for a stopped interface (ieee802154_sdata_running()), avoiding a needless association response during teardown.

In the Linux kernel, the following vulnerability has been resolved: landlock: Fix use-after-free of the source's parent directory current_check_refer_path() reads old_dentry->d_parent without holding a reference nor a lock on it, and then dereferences it in collect_domain_accesses() and in the audit record. A reference on a child does not pin its parent: __d_move() reassigns dentry->d_parent and drops the reference the child held on its former parent. hook_path_rename() is not affected because the rename path calls lock_rename() before the hook, so the source cannot be reparented under it. hook_path_link() has no such protection: filename_linkat() holds a reference on the source dentry but neither locks nor references its parent, so a concurrent rename(2) can reparent the source while security_path_link() runs, and the former parent can then be removed and freed while the hook walks it. A process can trigger this after entering a Landlock domain that handles at least one filesystem access right. The process can then race a linkat(2) loop against rename(2) and rmdir(2): BUG: KASAN: slab-use-after-free in collect_domain_accesses+0x278/0x290 Read of size 4 at addr ffff888160bd53f4 by task llrepro2/549 collect_domain_accesses+0x278/0x290 current_check_refer_path+0x952/0x1120 security_path_link+0x1be/0x320 filename_linkat+0x342/0x6d0 __x64_sys_linkat+0xfa/0x150 Freed by task 562: kmem_cache_free+0x139/0x4c0 i_callback+0x4b/0x80 rcu_core+0x7dc/0x10a0 Take a reference on the dentry selected as the source parent, using dget() for the common-mount-root case and dget_parent() otherwise. Release it after the hierarchy walk and synchronous audit logging. [mic: Clarify the caller, reachability, and reference handling]

In the Linux kernel, the following vulnerability has been resolved: s390/crypto: Fix wrong return code to engine in asynch callbacks When crypto_finalize_hash_request() or crypto_finalize_skcipher_request() explicitly completes a request, the do_one_request callback must return 0 to indicate successful handling. Returning a negative error code causes the crypto engine to assume the driver failed to take ownership and triggers a second completion via crypto_request_complete(), resulting in a double completion. This pattern occurs in paes_s390.c 4 times and once in phmac_s390.c. Fixed in phmac_do_one_request() and all four paes do_one_request callbacks (ecb, cbc, ctr, xts) by returning 0 after explicit finalization instead of propagating the error code.

In the Linux kernel, the following vulnerability has been resolved: afs: Fix incorrect free in candidate cleanup in afs_lookup_server() Fix afs_lookup_server() to not free an existing server's endpoint state when cleaning up a candidate server. The candidate record doesn't have an endpoint state yet at this point, so the free for that can just be removed.

In the Linux kernel, the following vulnerability has been resolved: afs: Clear stale peer app data after address list changes afs_fs_probe_fileserver() fetches the current endpoint state under server->fs_lock, but leaves old_alist as NULL. Consequently, afs_set_peer_appdata() treats every address list replacement as initial setup and only binds the new peers; it never unbinds peers removed from the old list. An address refresh can therefore proceed as follows. CPU 0 replaces server S's list and drops Pold without clearing Pold->app_data. The server destroyer then clears only S's current peers and lets S reach its RCU callback. After the callback frees S, CPU 1 handles a callback through an RxRPC connection that still pins Pold, reads Pold->app_data, and calls afs_use_server() on the freed object. KASAN reported: BUG: KASAN: slab-use-after-free in afs_find_server+0x3c/0xa0 Read of size 4 at addr ffff8881013e1af0 by task krxrpcio/7001/74 Call Trace: afs_find_server+0x3c/0xa0 afs_rx_new_call+0x15c/0x390 rxrpc_new_incoming_call+0x97c/0x1730 rxrpc_input_packet.constprop.0+0xd03/0xec0 rxrpc_io_thread+0x967/0x1640 Allocated by task 93: afs_lookup_server+0x1a7/0x14c0 afs_alloc_server_list+0x43f/0xb60 afs_create_volume+0x923/0x1490 afs_get_tree+0x1c6/0x10a0 Freed by task 0: kfree+0x131/0x3c0 rcu_core+0x50a/0x1850 Last potentially related work creation: __call_rcu_common.constprop.0+0x71/0xa10 afs_put_server+0x213/0x2b0 Preserve old->addresses for the peer app-data update so that removed peers are cleared before the endpoint state is replaced. Also advance both cursors when the old and new lists share a peer; activating the old/new comparison without this would otherwise loop forever on the shared entry.

In the Linux kernel, the following vulnerability has been resolved: media: rkvdec: bound HEVC tile loops and PPS id to the array capacity compute_tiles_uniform() and compute_tiles_non_uniform() loop over num_tile_columns_minus1 + 1 / num_tile_rows_minus1 + 1 entries, and assemble_hw_pps() writes one COLUMN_WIDTH / ROW_HEIGHT register per tile and indexes priv_tbl->param_set[] by pic_parameter_set_id, all taken from the untrusted PPS. Use the bounded v4l2_hevc_pps_num_tile_columns() / v4l2_hevc_pps_num_tile_rows() helpers for the tile loops, and bail out of assemble_hw_pps() before indexing priv_tbl->param_set[] with an out-of-range pic_parameter_set_id, so the writes stay within the hardware tables.

In the Linux kernel, the following vulnerability has been resolved: media: mediatek: vcodec: bound AV1 tile-start copy to the array capacity vdec_av1_slice_setup_tile() copies tile_cols + 1 / tile_rows + 1 entries into mi_col_starts[] / mi_row_starts[] from the bitstream tile_info. Bound the copy to the array capacity.

In the Linux kernel, the following vulnerability has been resolved: media: verisilicon: rockchip: guard VPU981 AV1 divisor and tile buffer rockchip_vpu981_av1_dec_set_tile_info() divides context_update_tile_id by tile_info->tile_cols and writes one descriptor per tile into the tile_info DMA buffer, which holds AV1_MAX_TILES entries; tile_cols and tile_rows come from the bitstream. Guard the division against a zero tile_cols by initialising the context-update values to zero and computing them only when tile_cols is non-zero, and stop the descriptor writes once the tile_info buffer is full. The tile geometry written to the hardware registers is left unmodified; the per-dimension and total tile bounds are enforced by the control validation.

In the Linux kernel, the following vulnerability has been resolved: media: verisilicon: rockchip: reject AV1 frames exceeding the tile capacity rockchip_vpu981_av1_dec_set_tile_info() indexes the tile group entry array by tile1 * tile_cols + tile0, reading up to tile_cols * tile_rows entries, lays out one descriptor per tile in the AV1_MAX_TILES tile_info buffer, and programs the real tile_cols / tile_rows into the hardware. The tile group entry control is a dynamic array sized to the number of entries userspace submitted, independent of tile_cols / tile_rows, so a frame that claims more tiles than entries reads past the array. A frame that claims more than AV1_MAX_TILES tiles also leaves the hardware programmed for more tiles than the descriptor buffer holds. Reject both in prepare_run(): tile_cols * tile_rows must not exceed the submitted entry count or AV1_MAX_TILES. The entry count is read via v4l2_ctrl_find() (ctrl->elems). This mirrors the bound the mediatek AV1 decoder already enforces.

In the Linux kernel, the following vulnerability has been resolved: media: v4l2-ctrls: validate HEVC tile counts The stateless HEVC decoders read num_tile_columns_minus1 + 1 entries from column_width_minus1[] and num_tile_rows_minus1 + 1 from row_height_minus1[] and use them as tile-loop bounds, but std_validate_compound() does not bound these u8 counts. Reject a V4L2_CTRL_TYPE_HEVC_PPS with tiling enabled whose tile counts exceed the uAPI array capacity, mirroring the existing compound-control range checks.

In the Linux kernel, the following vulnerability has been resolved: media: v4l2-ctrls: validate AV1 tile counts The stateless AV1 decoders use tile_info.tile_cols and tile_rows as loop bounds and as indices into the mi_*_starts[] and *_in_sbs_minus_1[] arrays, as the divisor for context_update_tile_id, and their product bounds the per-tile descriptor buffers, but std_validate_compound() does not bound these u8 fields. Reject a V4L2_CTRL_TYPE_AV1_FRAME whose tile_cols or tile_rows exceeds V4L2_AV1_MAX_TILE_COLS / _ROWS, or whose product exceeds V4L2_AV1_MAX_TILE_COUNT. A zero tile count is left to the consuming driver so the zero-initialised control that existing userspace submits is still accepted.