Vulnerabilidades do Linux Linux Kernel

In the Linux kernel, the following vulnerability has been resolved: eventpoll: Fix semi-unbounded recursion Ensure that epoll instances can never form a graph deeper than EP_MAX_NESTS+1 links. Currently, ep_loop_check_proc() ensures that the graph is loop-free and does some recursion depth checks, but those recursion depth checks don't limit the depth of the resulting tree for two reasons: - They don't look upwards in the tree. - If there are multiple downwards paths of different lengths, only one of the paths is actually considered for the depth check since commit 28d82dc1c4ed ("epoll: limit paths"). Essentially, the current recursion depth check in ep_loop_check_proc() just serves to prevent it from recursing too deeply while checking for loops. A more thorough check is done in reverse_path_check() after the new graph edge has already been created; this checks, among other things, that no paths going upwards from any non-epoll file with a length of more than 5 edges exist. However, this check does not apply to non-epoll files. As a result, it is possible to recurse to a depth of at least roughly 500, tested on v6.15. (I am unsure if deeper recursion is possible; and this may have changed with commit 8c44dac8add7 ("eventpoll: Fix priority inversion problem").) To fix it: 1. In ep_loop_check_proc(), note the subtree depth of each visited node, and use subtree depths for the total depth calculation even when a subtree has already been visited. 2. Add ep_get_upwards_depth_proc() for similarly determining the maximum depth of an upwards walk. 3. In ep_loop_check(), use these values to limit the total path length between epoll nodes to EP_MAX_NESTS edges.

In the Linux kernel, the following vulnerability has been resolved: bpf, ktls: Fix data corruption when using bpf_msg_pop_data() in ktls When sending plaintext data, we initially calculated the corresponding ciphertext length. However, if we later reduced the plaintext data length via socket policy, we failed to recalculate the ciphertext length. This results in transmitting buffers containing uninitialized data during ciphertext transmission. This causes uninitialized bytes to be appended after a complete "Application Data" packet, leading to errors on the receiving end when parsing TLS record.

In the Linux kernel, the following vulnerability has been resolved: wifi: ath12k: Pass ab pointer directly to ath12k_dp_tx_get_encap_type() In ath12k_dp_tx_get_encap_type(), the arvif parameter is only used to retrieve the ab pointer. In vdev delete sequence the arvif->ar could become NULL and that would trigger kernel panic. Since the caller ath12k_dp_tx() already has a valid ab pointer, pass it directly to avoid panic and unnecessary dereferencing. PC points to "ath12k_dp_tx+0x228/0x988 [ath12k]" LR points to "ath12k_dp_tx+0xc8/0x988 [ath12k]". The Backtrace obtained is as follows: ath12k_dp_tx+0x228/0x988 [ath12k] ath12k_mac_tx_check_max_limit+0x608/0x920 [ath12k] ieee80211_process_measurement_req+0x320/0x348 [mac80211] ieee80211_tx_dequeue+0x9ac/0x1518 [mac80211] ieee80211_tx_dequeue+0xb14/0x1518 [mac80211] ieee80211_tx_prepare_skb+0x224/0x254 [mac80211] ieee80211_xmit+0xec/0x100 [mac80211] __ieee80211_subif_start_xmit+0xc50/0xf40 [mac80211] ieee80211_subif_start_xmit+0x2e8/0x308 [mac80211] netdev_start_xmit+0x150/0x18c dev_hard_start_xmit+0x74/0xc0 Tested-on: QCN9274 hw2.0 PCI WLAN.WBE.1.3.1-00173-QCAHKSWPL_SILICONZ-1

In the Linux kernel, the following vulnerability has been resolved: wifi: ath11k: clear initialized flag for deinit-ed srng lists In a number of cases we see kernel panics on resume due to ath11k kernel page fault, which happens under the following circumstances: 1) First ath11k_hal_dump_srng_stats() call Last interrupt received for each group: ath11k_pci 0000:01:00.0: group_id 0 22511ms before ath11k_pci 0000:01:00.0: group_id 1 14440788ms before [..] ath11k_pci 0000:01:00.0: failed to receive control response completion, polling.. ath11k_pci 0000:01:00.0: Service connect timeout ath11k_pci 0000:01:00.0: failed to connect to HTT: -110 ath11k_pci 0000:01:00.0: failed to start core: -110 ath11k_pci 0000:01:00.0: firmware crashed: MHI_CB_EE_RDDM ath11k_pci 0000:01:00.0: already resetting count 2 ath11k_pci 0000:01:00.0: failed to wait wlan mode request (mode 4): -110 ath11k_pci 0000:01:00.0: qmi failed to send wlan mode off: -110 ath11k_pci 0000:01:00.0: failed to reconfigure driver on crash recovery [..] 2) At this point reconfiguration fails (we have 2 resets) and ath11k_core_reconfigure_on_crash() calls ath11k_hal_srng_deinit() which destroys srng lists. However, it does not reset per-list ->initialized flag. 3) Second ath11k_hal_dump_srng_stats() call sees stale ->initialized flag and attempts to dump srng stats: Last interrupt received for each group: ath11k_pci 0000:01:00.0: group_id 0 66785ms before ath11k_pci 0000:01:00.0: group_id 1 14485062ms before ath11k_pci 0000:01:00.0: group_id 2 14485062ms before ath11k_pci 0000:01:00.0: group_id 3 14485062ms before ath11k_pci 0000:01:00.0: group_id 4 14780845ms before ath11k_pci 0000:01:00.0: group_id 5 14780845ms before ath11k_pci 0000:01:00.0: group_id 6 14485062ms before ath11k_pci 0000:01:00.0: group_id 7 66814ms before ath11k_pci 0000:01:00.0: group_id 8 68997ms before ath11k_pci 0000:01:00.0: group_id 9 67588ms before ath11k_pci 0000:01:00.0: group_id 10 69511ms before BUG: unable to handle page fault for address: ffffa007404eb010 #PF: supervisor read access in kernel mode #PF: error_code(0x0000) - not-present page PGD 100000067 P4D 100000067 PUD 10022d067 PMD 100b01067 PTE 0 Oops: 0000 [#1] PREEMPT SMP NOPTI RIP: 0010:ath11k_hal_dump_srng_stats+0x2b4/0x3b0 [ath11k] Call Trace: <TASK> ? __die_body+0xae/0xb0 ? page_fault_oops+0x381/0x3e0 ? exc_page_fault+0x69/0xa0 ? asm_exc_page_fault+0x22/0x30 ? ath11k_hal_dump_srng_stats+0x2b4/0x3b0 [ath11k (HASH:6cea 4)] ath11k_qmi_driver_event_work+0xbd/0x1050 [ath11k (HASH:6cea 4)] worker_thread+0x389/0x930 kthread+0x149/0x170 Clear per-list ->initialized flag in ath11k_hal_srng_deinit().

In the Linux kernel, the following vulnerability has been resolved: drm/rockchip: vop2: fail cleanly if missing a primary plane for a video-port Each window of a vop2 is usable by a specific set of video ports, so while binding the vop2, we look through the list of available windows trying to find one designated as primary-plane and usable by that specific port. The code later wants to use drm_crtc_init_with_planes with that found primary plane, but nothing has checked so far if a primary plane was actually found. For whatever reason, the rk3576 vp2 does not have a usable primary window (if vp0 is also in use) which brought the issue to light and ended in a null-pointer dereference further down. As we expect a primary-plane to exist for a video-port, add a check at the end of the window-iteration and fail probing if none was found.

In the Linux kernel, the following vulnerability has been resolved: bpf, arm64: Fix fp initialization for exception boundary In the ARM64 BPF JIT when prog->aux->exception_boundary is set for a BPF program, find_used_callee_regs() is not called because for a program acting as exception boundary, all callee saved registers are saved. find_used_callee_regs() sets `ctx->fp_used = true;` when it sees FP being used in any of the instructions. For programs acting as exception boundary, ctx->fp_used remains false even if frame pointer is used by the program and therefore, FP is not set-up for such programs in the prologue. This can cause the kernel to crash due to a pagefault. Fix it by setting ctx->fp_used = true for exception boundary programs as fp is always saved in such programs.

In the Linux kernel, the following vulnerability has been resolved: bpf: Reject narrower access to pointer ctx fields The following BPF program, simplified from a syzkaller repro, causes a kernel warning: r0 = *(u8 *)(r1 + 169); exit; With pointer field sk being at offset 168 in __sk_buff. This access is detected as a narrower read in bpf_skb_is_valid_access because it doesn't match offsetof(struct __sk_buff, sk). It is therefore allowed and later proceeds to bpf_convert_ctx_access. Note that for the "is_narrower_load" case in the convert_ctx_accesses(), the insn->off is aligned, so the cnt may not be 0 because it matches the offsetof(struct __sk_buff, sk) in the bpf_convert_ctx_access. However, the target_size stays 0 and the verifier errors with a kernel warning: verifier bug: error during ctx access conversion(1) This patch fixes that to return a proper "invalid bpf_context access off=X size=Y" error on the load instruction. The same issue affects multiple other fields in context structures that allow narrow access. Some other non-affected fields (for sk_msg, sk_lookup, and sockopt) were also changed to use bpf_ctx_range_ptr for consistency. Note this syzkaller crash was reported in the "Closes" link below, which used to be about a different bug, fixed in commit fce7bd8e385a ("bpf/verifier: Handle BPF_LOAD_ACQ instructions in insn_def_regno()"). Because syzbot somehow confused the two bugs, the new crash and repro didn't get reported to the mailing list.

In the Linux kernel, the following vulnerability has been resolved: sunrpc: fix client side handling of tls alerts A security exploit was discovered in NFS over TLS in tls_alert_recv due to its assumption that there is valid data in the msghdr's iterator's kvec. Instead, this patch proposes the rework how control messages are setup and used by sock_recvmsg(). If no control message structure is setup, kTLS layer will read and process TLS data record types. As soon as it encounters a TLS control message, it would return an error. At that point, NFS can setup a kvec backed control buffer and read in the control message such as a TLS alert. Scott found that a msg iterator can advance the kvec pointer as a part of the copy process thus we need to revert the iterator before calling into the tls_alert_recv.

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.

In the Linux kernel, the following vulnerability has been resolved: tracing: Add down_write(trace_event_sem) when adding trace event When a module is loaded, it adds trace events defined by the module. It may also need to modify the modules trace printk formats to replace enum names with their values. If two modules are loaded at the same time, the adding of the event to the ftrace_events list can corrupt the walking of the list in the code that is modifying the printk format strings and crash the kernel. The addition of the event should take the trace_event_sem for write while it adds the new event. Also add a lockdep_assert_held() on that semaphore in __trace_add_event_dirs() as it iterates the list.

In the Linux kernel, the following vulnerability has been resolved: bpf: Reject %p% format string in bprintf-like helpers static const char fmt[] = "%p%"; bpf_trace_printk(fmt, sizeof(fmt)); The above BPF program isn't rejected and causes a kernel warning at runtime: Please remove unsupported %\x00 in format string WARNING: CPU: 1 PID: 7244 at lib/vsprintf.c:2680 format_decode+0x49c/0x5d0 This happens because bpf_bprintf_prepare skips over the second %, detected as punctuation, while processing %p. This patch fixes it by not skipping over punctuation. %\x00 is then processed in the next iteration and rejected.

In the Linux kernel, the following vulnerability has been resolved: ice: add NULL check in eswitch lag check The function ice_lag_is_switchdev_running() is being called from outside of the LAG event handler code. This results in the lag->upper_netdev being NULL sometimes. To avoid a NULL-pointer dereference, there needs to be a check before it is dereferenced.

In the Linux kernel, the following vulnerability has been resolved: rxrpc: Fix recv-recv race of completed call If a call receives an event (such as incoming data), the call gets placed on the socket's queue and a thread in recvmsg can be awakened to go and process it. Once the thread has picked up the call off of the queue, further events will cause it to be requeued, and once the socket lock is dropped (recvmsg uses call->user_mutex to allow the socket to be used in parallel), a second thread can come in and its recvmsg can pop the call off the socket queue again. In such a case, the first thread will be receiving stuff from the call and the second thread will be blocked on call->user_mutex. The first thread can, at this point, process both the event that it picked call for and the event that the second thread picked the call for and may see the call terminate - in which case the call will be "released", decoupling the call from the user call ID assigned to it (RXRPC_USER_CALL_ID in the control message). The first thread will return okay, but then the second thread will wake up holding the user_mutex and, if it sees that the call has been released by the first thread, it will BUG thusly: kernel BUG at net/rxrpc/recvmsg.c:474! Fix this by just dequeuing the call and ignoring it if it is seen to be already released. We can't tell userspace about it anyway as the user call ID has become stale.

In the Linux kernel, the following vulnerability has been resolved: drm/xe/pf: Clear all LMTT pages on alloc Our LMEM buffer objects are not cleared by default on alloc and during VF provisioning we only setup LMTT PTEs for the actually provisioned LMEM range. But beyond that valid range we might leave some stale data that could either point to some other VFs allocations or even to the PF pages. Explicitly clear all new LMTT page to avoid the risk that a malicious VF would try to exploit that gap. While around add asserts to catch any undesired PTE overwrites and low-level debug traces to track LMTT PT life-cycle. (cherry picked from commit 3fae6918a3e27cce20ded2551f863fb05d4bef8d)

In the Linux kernel, the following vulnerability has been resolved: rxrpc: Fix oops due to non-existence of prealloc backlog struct If an AF_RXRPC service socket is opened and bound, but calls are preallocated, then rxrpc_alloc_incoming_call() will oops because the rxrpc_backlog struct doesn't get allocated until the first preallocation is made. Fix this by returning NULL from rxrpc_alloc_incoming_call() if there is no backlog struct. This will cause the incoming call to be aborted.

In the Linux kernel, the following vulnerability has been resolved: HID: nintendo: avoid bluetooth suspend/resume stalls Ensure we don't stall or panic the kernel when using bluetooth-connected controllers. This was reported as an issue on android devices using kernel 6.6 due to the resume hook which had been added for usb joycons. First, set a new state value to JOYCON_CTLR_STATE_SUSPENDED in a newly-added nintendo_hid_suspend. This makes sure we will not stall out the kernel waiting for input reports during led classdev suspend. The stalls could happen if connectivity is unreliable or lost to the controller prior to suspend. Second, since we lose connectivity during suspend, do not try joycon_init() for bluetooth controllers in the nintendo_hid_resume path. Tested via multiple suspend/resume flows when using the controller both in USB and bluetooth modes.