Linux Linux vulnerabilities

In the Linux kernel, the following vulnerability has been resolved: vdpa_sim: fix cleanup after worker creation failure vdpasim_create() leaves vdpasim->worker as an ERR_PTR when kthread_run_worker() fails. The error path then drops the device reference, which releases the partially initialized simulator. vdpasim_free() unconditionally passes the worker pointer to kthread_destroy_worker(), so the ERR_PTR is dereferenced and can trigger a general protection fault. Store the worker error, clear the pointer, and only clean up the worker when it was successfully initialized. Also make the release path tolerate partially initialized objects by guarding virtqueue and IOTLB cleanup, since the same release path can be reached from other initialization failures. I found this bug myself, though the patch was written with AI assistance.

In the Linux kernel, the following vulnerability has been resolved: virtio_balloon: quiesce balloon work before device shutdown Commit 8bd2fa086a04 ("virtio: break and reset virtio devices on device_shutdown()") added a generic virtio bus .shutdown handler that breaks and resets every virtio device during device_shutdown(), i.e. on reboot and kexec. virtio_balloon provides no .shutdown of its own, so that generic path runs while the balloon's asynchronous work is still armed. Once the device has been broken, virtqueue_add_inbuf() in virtballoon_free_page_report() returns -EIO and trips its WARN_ON_ONCE(). On a kernel booted with panic_on_warn that turns an ordinary reboot, for example a kexec based upgrade, into a fatal panic in the middle of device_shutdown(), so the machine never reaches the new kernel. Relaxing that single WARN_ON_ONCE() would only hide the symptom: the inflate/deflate and OOM paths do not warn, they call wait_event(vb->acked, ...) and would instead block forever on a broken queue that can no longer complete. The device has to be quiesced, not just kept quiet. Add a .shutdown handler that quiesces the balloon via the shared virtballoon_quiesce() helper while the device is still alive, and only then breaks and resets it via virtio_device_shutdown(). Unlike virtballoon_remove() the balloon workqueue is not destroyed, as shutdown does not free the device and cancel_work_sync() together with stop_update already prevent any further work from being queued.

In the Linux kernel, the following vulnerability has been resolved: vdpa/mlx5: fix wrong list iterated in add_direct_chain error path In add_direct_chain(), newly allocated direct MR entries are added to the local list 'tmp', which is spliced into mr->head only on success. On the error path, the cleanup loop was incorrectly iterating over mr->head instead of tmp. Fix by iterating over 'tmp' in the err_alloc cleanup path.

In the Linux kernel, the following vulnerability has been resolved: virtio: rtc: time out alarm requests RTC class operations run with rtc_device.ops_lock held. The virtio RTC alarm requests currently wait without a timeout for the device to return their requestq buffers. On surprise removal, virtio-pci marks the virtqueues broken before unregistering the virtio device. If an alarm request is waiting when the device stops responding, viortc_remove() blocks in viortc_class_stop() while trying to acquire ops_lock. The request cannot complete and device removal hangs until the waiting task is signalled. Use the same 60-second timeout as clock read requests for alarm reads, alarm programming, and alarm interrupt enable requests. The existing message reference counting keeps a timed-out request alive until a late response or device teardown.

In the Linux kernel, the following vulnerability has been resolved: rtc: pcf8563: fix clock provider leak on unbind pcf8563_clkout_register_clk() registers the CLKOUT clock provider with of_clk_add_provider(), but nothing ever unwinds it: there is no of_clk_del_provider() call and the driver has no remove callback. Each of_clk_add_provider() allocates a struct of_clk_provider, takes a reference on the OF node and adds an entry to the global of_clk_providers list, none of which is released when the device is unbound. Every bind/unbind (or module reload) therefore leaks a provider structure and an of_node reference. The clock itself is already device-managed (devm_clk_register()); only the provider registration was not. Use devm_of_clk_add_hw_provider() so the provider is removed automatically on unbind. Tie it to the parent i2c device, whose OF node carries the #clock-cells and clock-output-names properties (the RTC class device has no OF node of its own).

In the Linux kernel, the following vulnerability has been resolved: smb: client: fix request buffer leak in smb2_new_read_req() smb2_new_read_req() allocates the request buffer with smb2_plain_req_init() but only publishes it to the caller with *buf = req at the very end of the function. Two error returns sit in between: rc = smb2_plain_req_init(SMB2_READ, io_parms->tcon, server, (void **) &req, total_len); if (rc) return rc; if (server == NULL) return -ECONNABORTED; [...] rdata->mr = smbd_register_mr(server->smbd_conn, &rdata->subreq.io_iter, true, need_invalidate); if (!rdata->mr) return -EAGAIN; On either of them the buffer is neither released nor handed back, so it is leaked. The caller cannot clean up after it: smb2_async_readv() does 'goto out' on a non-zero return, which skips the cifs_small_buf_release(buf) at async_readv_out, and buf has not been assigned at that point in any case. The write path has never had this problem. smb2_async_writev() registers the memory region inline and jumps to its release label instead of returning: wdata->mr = smbd_register_mr(...); if (!wdata->mr) { rc = -EAGAIN; goto async_writev_out; } Commit b7972092199f ("cifs: smbd: Retry on memory registration failure") changed both sides from -ENOBUFS to -EAGAIN in a single patch, which puts the two shapes next to each other. Only the -EAGAIN return is reachable in practice, because smb2_plain_req_init() calls smb2_reconnect() first and that already fails with -EIO when server is NULL, before anything is allocated. Both returns are given the same treatment here rather than leaving one of them correct only by accident. Because -EAGAIN is a replayable error, the failure also reaches the retry block at the end of smb2_async_readv(), which marks the subrequest NETFS_SREQ_NEED_RETRY, so a failing registration can be retried rather than ending the I/O, and every attempt that reaches it leaks another buffer. smb2_should_replay() short-circuits on tcon->retry, so on a hard mount the attempt count is not bounded by the retrans setting. Only the asynchronous read path is affected. The synchronous SMB2_read() caller passes rdata == NULL and the memory registration block is guarded on rdata. The memory registration failure path was pointed out by the Sashiko AI reviewer while it was reviewing an unrelated patch to smb2_async_readv().

In the Linux kernel, the following vulnerability has been resolved: irqchip/renesas-rzg2l: Fix loss of interrupt rzg2l_clear_irq_int() and rzg2l_clear_tint_int() perform a read-modify-write on the ISCR/TSCR status registers to clear the bit for the interrupt just handled. Since these registers are write-0-to-clear per bit, this is racy: If another interrupt's status bit gets set between the read and the write, that bit is written back as 0 by the software-constructed value, clearing an interrupt that hasn't been serviced yet and losing it. This can be reproduced by triggering multiple interrupts at once, e.g.: gpioset -c gpiochip0 355=0 353=0 328=0 352=0 Fix this by writing back only the bit being cleared, with all other bits set to 1, instead of read-modify-writing the whole register. Since 1-bits are left unchanged by hardware, concurrently-set status bits for other interrupts are preserved.

In the Linux kernel, the following vulnerability has been resolved: irqchip/ast2700-intc: Avoid allocating in the irq_domain activate() callback The interrupt core calls the irq_domain_activate() callback from __setup_irq() with desc->lock held and interrupts disabled. Both aspeed_intc1_irq_domain_activate() and aspeed_intc0_resolve_route() test a compatible string with fwnode_device_is_compatible(). fwnode_device_is_compatible() invokes fwnode_property_match_string(), which allocates with GFP_KERNEL. That's obviously not possible with interrupts disabled and a raw spinlock held. Both call sites are only ever handed OF nodes, so use of_device_is_compatible() instead: it walks the property in place and does not allocate.

In the Linux kernel, the following vulnerability has been resolved: clk: visconti: Make sure clk_init_data is fully initialized The clk_init_data structure contains several mutually-exclusive members for different methods to specify the possible parents of a clock, prompting drivers to initialize only the members they need. However, not initializing all members may cause subtle issues, which are only exposed when CONFIG_INIT_STACK_ALL_PATTERN or CONFIG_INIT_STACK_NONE is enabled. visconti_clk_register_gate() fills in init.parent_data, and assumes that init.parent_names is NULL. However, the latter in uninitialized, and thus may cause a crash. Make sure all members are fully initialized, to fix such bugs, and to avoid future breakage when converting drivers to a different method for specifying the parents.

In the Linux kernel, the following vulnerability has been resolved: ALSA: ice1712: Fix the card leak at probe error with the auto-cleanup snd_ice1712_probe() performs multiple initialization steps after snd_card_new(), but directly returns on failures from later steps without releasing the ALSA card, causing resource leaks when probing fails. Use snd_devm_card_new() together with scope-based cleanup via __free(snd_card_unref), and clear the card pointer after successful registration to keep it alive.

In the Linux kernel, the following vulnerability has been resolved: irqchip/gic-v5: Clear per-CPU IRS data on teardown IRS affinity setup publishes an IRS pointer and IAFFID state in the per-CPU data before the remaining IRS initialization can fail. The error path then frees the IRS data without clearing that published state, leaving CPUs associated with freed memory. On initialization failure and normal IRS teardown, clear the per-CPU IRS association by removing the stale pointer to irs_data. Also invalidate the per-CPU IAFFID state for any CPUs that were tied to the IRS before it was freed.

In the Linux kernel, the following vulnerability has been resolved: ntfs: validate usa_ofs before preserving the update sequence number When ntfs_mft_record_alloc() reuses a free mft record it reads the old update sequence number straight from the on-disk record: usn = *(__le16 *)((u8 *)m + le16_to_cpu(m->usa_ofs)); Here m points into the raw $MFT page-cache folio, which still holds unvalidated, MST-protected bytes: the folio is read by a plain iomap_read_folio() and neither post_read_mst_fixup() nor ntfs_mft_record_check() has run on it (both work on private copies). m->usa_ofs is therefore an untrusted u16, and a corrupted record can put it past the end of the record so the two-byte read lands outside the folio. Reading such a record while creating a file gives, under KASAN: BUG: KASAN: use-after-free in ntfs_mft_record_alloc+... Read of size 2 at addr ... ntfs_mft_record_alloc -> __ntfs_create -> ntfs_create -> path_openat Only preserve the old update sequence number when usa_ofs is even and in range, mirroring the check ntfs_mft_record_check() already applies; otherwise leave usn zero, which the existing restore below skips.

In the Linux kernel, the following vulnerability has been resolved: ALSA: mtpav: shut down output timer before card teardown snd_mtpav_output_timer() rearms chip->timer while holding chip->spinlock and accesses the card-private mtpav state. snd_mtpav_free() currently takes the same lock and calls timer_delete() when the timer is active. This only removes a pending timer; it does not wait for a callback that is already running and does not prevent the callback from rearming the timer. A callback running on another CPU can therefore continue after snd_mtpav_free() releases the lock and access the card-private state while the card is being torn down. It can also rearm the timer after timer_delete() has returned. Call timer_shutdown_sync() without holding chip->spinlock. This waits for any running callback to finish and prevents further rearming before the card-private mtpav state is released.

In the Linux kernel, the following vulnerability has been resolved: xsk: fix NULL pointer dereference in __xsk_rcv() In the __xsk_rcv() multi-buffer path, xsk_buff_alloc() is called in a loop without checking its return value. xsk_buff_can_alloc() only counts fill queue entries without validating their addresses, so it can succeed while xsk_buff_alloc() rejects all remaining entries and returns NULL. Oops: general protection fault, probably for non-canonical address 0xdffffc0000000000 KASAN: null-ptr-deref in range [0x0000000000000000-0x0000000000000007] RIP: 0010:__xsk_rcv+0x426/0xc20 (net/xdp/xsk.c:350) Call Trace: xsk_generic_rcv+0x26d/0x5f0 xdp_do_generic_redirect+0x3c5/0xcf0 do_xdp_generic+0x92f/0xe70 __netif_receive_skb_core.constprop.0+0xf7e/0x2b30 Fix this with a two-stage transaction. First allocate and stage all buffers required for the packet, recycling all staged buffers with xsk_buff_free() if any allocation fails. Only after this stage succeeds, copy the data, reserve the RX descriptors, and release the buffers in an error-free loop.

In the Linux kernel, the following vulnerability has been resolved: net: bridge: Reject descending VLAN tunnel ranges A pair of descending VLAN and tunnel IDs can pass the tunnel range span check. The VLAN subtraction produces a negative int, which is converted to unsigned when compared with the u32 tunnel ID subtraction. It can therefore equal the wrapped tunnel ID delta. The range loop then performs no iterations. Since the batched notification handling added a post-loop error check, this leaves err uninitialized and makes the request's return value unpredictable. Reject descending VLAN ranges before comparing the spans. Valid ascending and single-entry ranges remain unchanged, while malformed descending ranges consistently return -EINVAL. This issue was found by a static analysis checker and confirmed by manual source review.

In the Linux kernel, the following vulnerability has been resolved: netdevsim: update queue NAPI association on queue reset In netdevsim, receive queues (struct nsim_rq) embed their own struct napi_struct. When queue reset is performed (e.g. via queue_reset debugfs), nsim_queue_start() swaps in a newly allocated struct nsim_rq, and nsim_queue_mem_free() later deletes and frees the old one. However, nsim_queue_start() failed to update the queue-to-NAPI mapping via netif_queue_set_napi(). As a result, dev->_rx[idx].napi continued to point to the old NAPI struct. After the old queue was freed, a subsequent queue dump via Netlink (NETDEV_CMD_QUEUE_GET) triggered a KASAN slab-use-after-free read in nla_put_napi_id() when accessing rxq->napi->napi_id. Fix this by calling netif_queue_set_napi() in nsim_queue_start() to associate the new NAPI with the RX queue, and clear the association with netif_queue_set_napi(..., NULL) in nsim_del_napi() during teardown.

In the Linux kernel, the following vulnerability has been resolved: net: qlcnic: validate unified ROM sections before loading The unified ROM parser reads directory, product, and data-descriptor fields from the firmware file. Existing validation forms table and data ends with unchecked additions and multiplications. Malformed values can wrap before they are compared with the firmware size. The parser also dereferences typed pointers at firmware-controlled offsets. Valid descriptor extents alone are insufficient for the consumers. The loader reads a fixed-size bootloader regardless of its declared size, the version parser assumes a 17-byte tail, and a partial final firmware word is read as a full u64. A truncated image can therefore make the driver read beyond the firmware allocation during validation or loading. Replace the pointer-returning parser with bounded range helpers. Validate table entry sizes, descriptor indices, section ranges, the fixed bootloader load length, and the version tail before exposing any section. Read all file fields with unaligned little-endian accessors and assemble a partial final word from only the bytes that remain. Apply the same range checks to the legacy image before reading its fixed fields.

In the Linux kernel, the following vulnerability has been resolved: net: sched: fix 32-bit backlog wrap in gred, bfifo and plug enqueue gred_enqueue(), bfifo_enqueue() and plug_enqueue() admit a packet when the current backlog plus the packet length fits within the queue limit: sch->qstats.backlog + qdisc_pkt_len(skb) <= sch->limit (gred default VQ) gred_backlog+qdisc_pkt_len(skb) <= q->limit (gred configured VQ) sch->qstats.backlog + qdisc_pkt_len(skb) <= sch->limit (bfifo) sch->qstats.backlog + skb->len <= q->limit (plug) sch->qstats.backlog and q->backlog are u32, and qdisc_pkt_len()/skb->len are unsigned int, so all sums are computed in 32 bits and wrap at 2^32. Once the true backlog exceeds 4 GiB the wrapped sum becomes small and admission keeps succeeding, so the queue grows without bound and the kernel can be driven to OOM. Promote the sums to u64 so admission stops once the true backlog exceeds the limit. The limit is u32, so the bounded queue stays below 2^32 and the stored u32 backlog never wraps. The bug can only be reproduced as root (albeit with ridiculous setup): attach a gred (or bfifo/plug) qdisc with a limit near 4 GiB, leaving the default VQ unconfigured (for gred), and drive >4 GiB of queued traffic (e.g. via a size table / stab to inflate qdisc_pkt_len, or sustained high-rate traffic). The u32 backlog+len sum wraps at 2^32, admission keeps succeeding, and the queue grows unboundedly to OOM.

In the Linux kernel, the following vulnerability has been resolved: net/smc: free stashed qentry before overwrite in REQ_ADD_LINK to ADD_LINK transition When smc_llc_event_handler() transitions the local LLC flow from SMC_LLC_FLOW_REQ_ADD_LINK to SMC_LLC_FLOW_ADD_LINK on arrival of an ADD_LINK request, it calls smc_llc_flow_qentry_set() unconditionally: if (lgr->llc_flow_lcl.type == SMC_LLC_FLOW_REQ_ADD_LINK) { lgr->llc_flow_lcl.type = SMC_LLC_FLOW_ADD_LINK; smc_llc_flow_qentry_set(&lgr->llc_flow_lcl, qentry); ... } A CONFIRM_LINK or ADD_LINK_CONT arriving while flow->type is SMC_LLC_FLOW_REQ_ADD_LINK is stashed into flow->qentry via the SMC_LLC_CONFIRM_LINK / SMC_LLC_ADD_LINK_CONT handler (which stores into flow->qentry for any non-NONE flow type). When the subsequent ADD_LINK arrives, the REQ_ADD_LINK branch overwrites flow->qentry with the new pointer without first freeing the stashed allocation, leaking one kmalloc object. The stashed entry has no consumer: smc_llc_wait() is only called from llc_add_link_work, which is not yet scheduled while the flow type remains REQ_ADD_LINK. No waiter is sleeping on llc_msg_waiter at this point. It is safe to unconditionally free any stashed qentry before the overwrite. Call smc_llc_flow_qentry_del() before smc_llc_flow_qentry_set() in the REQ_ADD_LINK branch. smc_llc_flow_qentry_del() already checks flow->qentry before freeing, so the normal path where no entry is stashed is a no-op.

In the Linux kernel, the following vulnerability has been resolved: net/smc: free pending qentry in smc_llc_flow_stop() before memset smc_llc_flow_stop() resets a flow struct with a blind memset: spin_lock_bh(&lgr->llc_flow_lock); memset(flow, 0, sizeof(*flow)); flow->type = SMC_LLC_FLOW_NONE; spin_unlock_bh(&lgr->llc_flow_lock); If flow->qentry is non-NULL at this point the pointer is overwritten without the allocation being freed, leaking one kmalloc object. A late-arriving duplicate CONFIRM_LINK or ADD_LINK_CONT message can set flow->qentry after the legitimate message has been consumed by the waiter via smc_llc_flow_qentry_clr() (which NULLs the pointer but leaves flow->type non-zero) but before the flow completes and smc_llc_flow_stop() runs. In that window the duplicate is stashed into flow->qentry, and then lost when smc_llc_flow_stop() zeros the struct. Call smc_llc_flow_qentry_del() inside the lock before the memset. smc_llc_flow_qentry_del() already checks flow->qentry before freeing, so the normal case where no entry is pending is a no-op.