FKIE_CVE-2026-46031

Vulnerability from fkie_nvd - Published: 2026-05-27 14:17 - Updated: 2026-05-27 14:48
Severity
Summary
In the Linux kernel, the following vulnerability has been resolved: net: ks8851: Reinstate disabling of BHs around IRQ handler If the driver executes ks8851_irq() AND a TX packet has been sent, then the driver enables TX queue via netif_wake_queue() which schedules TX softirq to queue packets for this device. If CONFIG_PREEMPT_RT=y is set AND a packet has also been received by the MAC, then ks8851_rx_pkts() calls netdev_alloc_skb_ip_align() to allocate SKBs for the received packets. If netdev_alloc_skb_ip_align() is called with BH enabled, then local_bh_enable() at the end of netdev_alloc_skb_ip_align() will trigger the pending softirq processing, which may ultimately call the .xmit callback ks8851_start_xmit_par(). The ks8851_start_xmit_par() will try to lock struct ks8851_net_par .lock spinlock, which is already locked by ks8851_irq() from which ks8851_start_xmit_par() was called. This leads to a deadlock, which is reported by the kernel, including a trace listed below. If CONFIG_PREEMPT_RT is not set, then since commit 0913ec336a6c0 ("net: ks8851: Fix deadlock with the SPI chip variant") the deadlock can also be triggered without received packet in the RX FIFO. The pending softirqs will be processed on return from spin_unlock_bh(&ks->statelock) in ks8851_irq(), which triggers the deadlock as well. Fix the problem by disabling BH around critical sections, including the IRQ handler, thus preventing the net_tx_action() softirq from triggering during these critical sections. The net_tx_action() softirq is triggered once BH are re-enabled and at the end of the IRQ handler, once all the other IRQ handler actions have been completed. __schedule from schedule_rtlock+0x1c/0x34 schedule_rtlock from rtlock_slowlock_locked+0x548/0x904 rtlock_slowlock_locked from rt_spin_lock+0x60/0x9c rt_spin_lock from ks8851_start_xmit_par+0x74/0x1a8 ks8851_start_xmit_par from netdev_start_xmit+0x20/0x44 netdev_start_xmit from dev_hard_start_xmit+0xd0/0x188 dev_hard_start_xmit from sch_direct_xmit+0xb8/0x25c sch_direct_xmit from __qdisc_run+0x1f8/0x4ec __qdisc_run from qdisc_run+0x1c/0x28 qdisc_run from net_tx_action+0x1f0/0x268 net_tx_action from handle_softirqs+0x1a4/0x270 handle_softirqs from __local_bh_enable_ip+0xcc/0xe0 __local_bh_enable_ip from __alloc_skb+0xd8/0x128 __alloc_skb from __netdev_alloc_skb+0x3c/0x19c __netdev_alloc_skb from ks8851_irq+0x388/0x4d4 ks8851_irq from irq_thread_fn+0x24/0x64 irq_thread_fn from irq_thread+0x178/0x28c irq_thread from kthread+0x12c/0x138 kthread from ret_from_fork+0x14/0x28
References
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/21f1707a8e978558dcb11b053855521e32ac0eec
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/518040324067d8efaa2da1992297b7e7bf5640f4
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/5c9fcac3c872224316714d0d8914d9af16c76a6d
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/640a7631d31db87d5fa1b34cea44a99b6e78854b
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/be8aad558b4675f45b43080f81a9ffdeddea73a5
Impacted products
Vendor Product Version
To clipboard 

{
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nnet: ks8851: Reinstate disabling of BHs around IRQ handler\n\nIf the driver executes ks8851_irq() AND a TX packet has been sent, then\nthe driver enables TX queue via netif_wake_queue() which schedules TX\nsoftirq to queue packets for this device.\n\nIf CONFIG_PREEMPT_RT=y is set AND a packet has also been received by\nthe MAC, then ks8851_rx_pkts() calls netdev_alloc_skb_ip_align() to\nallocate SKBs for the received packets. If netdev_alloc_skb_ip_align()\nis called with BH enabled, then local_bh_enable() at the end of\nnetdev_alloc_skb_ip_align() will trigger the pending softirq processing,\nwhich may ultimately call the .xmit callback ks8851_start_xmit_par().\nThe ks8851_start_xmit_par() will try to lock struct ks8851_net_par\n.lock spinlock, which is already locked by ks8851_irq() from which\nks8851_start_xmit_par() was called. This leads to a deadlock, which\nis reported by the kernel, including a trace listed below.\n\nIf CONFIG_PREEMPT_RT is not set, then since commit 0913ec336a6c0\n(\"net: ks8851: Fix deadlock with the SPI chip variant\") the deadlock\ncan also be triggered without received packet in the RX FIFO. The\npending softirqs will be processed on return from\nspin_unlock_bh(\u0026ks-\u003estatelock) in ks8851_irq(), which triggers the\ndeadlock as well.\n\nFix the problem by disabling BH around critical sections, including the\nIRQ handler, thus preventing the net_tx_action() softirq from triggering\nduring these critical sections. The net_tx_action() softirq is triggered\nonce BH are re-enabled and at the end of the IRQ handler, once all the\nother IRQ handler actions have been completed.\n\n __schedule from schedule_rtlock+0x1c/0x34\n schedule_rtlock from rtlock_slowlock_locked+0x548/0x904\n rtlock_slowlock_locked from rt_spin_lock+0x60/0x9c\n rt_spin_lock from ks8851_start_xmit_par+0x74/0x1a8\n ks8851_start_xmit_par from netdev_start_xmit+0x20/0x44\n netdev_start_xmit from dev_hard_start_xmit+0xd0/0x188\n dev_hard_start_xmit from sch_direct_xmit+0xb8/0x25c\n sch_direct_xmit from __qdisc_run+0x1f8/0x4ec\n __qdisc_run from qdisc_run+0x1c/0x28\n qdisc_run from net_tx_action+0x1f0/0x268\n net_tx_action from handle_softirqs+0x1a4/0x270\n handle_softirqs from __local_bh_enable_ip+0xcc/0xe0\n __local_bh_enable_ip from __alloc_skb+0xd8/0x128\n __alloc_skb from __netdev_alloc_skb+0x3c/0x19c\n __netdev_alloc_skb from ks8851_irq+0x388/0x4d4\n ks8851_irq from irq_thread_fn+0x24/0x64\n irq_thread_fn from irq_thread+0x178/0x28c\n irq_thread from kthread+0x12c/0x138\n kthread from ret_from_fork+0x14/0x28"
    }
  ],
  "id": "CVE-2026-46031",
  "lastModified": "2026-05-27T14:48:03.013",
  "metrics": {},
  "published": "2026-05-27T14:17:22.057",
  "references": [
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/21f1707a8e978558dcb11b053855521e32ac0eec"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/518040324067d8efaa2da1992297b7e7bf5640f4"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/5c9fcac3c872224316714d0d8914d9af16c76a6d"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/640a7631d31db87d5fa1b34cea44a99b6e78854b"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/be8aad558b4675f45b43080f81a9ffdeddea73a5"
    }
  ],
  "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
  "vulnStatus": "Awaiting Analysis"
}


Log in or create an account to share your comment.




Tags
Taxonomy of the tags.





Forecast uses a logistic model when the trend is rising, or an exponential decay model when the trend is falling. Fitted via linearized least squares.

Sightings

Author Source Type Date Other

Nomenclature

  • Seen: The vulnerability was mentioned, discussed, or observed by the user.
  • Confirmed: The vulnerability has been validated from an analyst's perspective.
  • Published Proof of Concept: A public proof of concept is available for this vulnerability.
  • Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
  • Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
  • Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
  • Not confirmed: The user expressed doubt about the validity of the vulnerability.
  • Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.


Detection rules are retrieved from Rulezet.