CVE-2024-42110 net: ntb_netdev: Move ntb_netdev_rx_handler() to call netif_rx() from __netif_rx()
A kernel bug in the NTB network driver causes a crash when using threaded interrupt handlers, leading to denial of service.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2024-42110?
CVE-2024-42110 is a high-severity denial of service vulnerability in Linux kernel, published on 30 Jul 2024. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official description
In the Linux kernel, the following vulnerability has been resolved:
net: ntb_netdev: Move ntb_netdev_rx_handler() to call netif_rx() from __netif_rx()
The following is emitted when using idxd (DSA) dmanegine as the data mover for ntb_transport that ntb_netdev uses.
[74412.546922] BUG: using smp_processor_id() in preemptible [00000000] code: irq/52-idxd-por/14526 [74412.556784] caller is netif_rx_internal+0x42/0x130 [74412.562282] CPU: 6 PID: 14526 Comm: irq/52-idxd-por Not tainted 6.9.5 #5 [74412.569870] Hardware name: Intel Corporation ArcherCity/ArcherCity, BIOS EGSDCRB1.E9I.1752.P05.2402080856 02/08/2024 [74412.581699] Call Trace: [74412.584514] <TASK> [74412.586933] dump_stack_lvl+0x55/0x70 [74412.591129] check_preemption_disabled+0xc8/0xf0 [74412.596374] netif_rx_internal+0x42/0x130 [74412.600957] __netif_rx+0x20/0xd0 [74412.604743] ntb_netdev_rx_handler+0x66/0x150 [ntb_netdev] [74412.610985] ntb_complete_rxc+0xed/0x140 [ntb_transport] [74412.617010] ntb_rx_copy_callback+0x53/0x80 [ntb_transport] [74412.623332] idxd_dma_complete_txd+0xe3/0x160 [idxd] [74412.628963] idxd_wq_thread+0x1a6/0x2b0 [idxd] [74412.634046] irq_thread_fn+0x21/0x60 [74412.638134] ? irq_thread+0xa8/0x290 [74412.642218] irq_thread+0x1a0/0x290 [74412.646212] ? __pfx_irq_thread_fn+0x10/0x10 [74412.651071] ? __pfx_irq_thread_dtor+0x10/0x10 [74412.656117] ? __pfx_irq_thread+0x10/0x10 [74412.660686] kthread+0x100/0x130 [74412.664384] ? __pfx_kthread+0x10/0x10 [74412.668639] ret_from_fork+0x31/0x50 [74412.672716] ? __pfx_kthread+0x10/0x10 [74412.676978] ret_from_fork_asm+0x1a/0x30 [74412.681457] </TASK>
The cause is due to the idxd driver interrupt completion handler uses threaded interrupt and the threaded handler is not hard or soft interrupt context. However __netif_rx() can only be called from interrupt context. Change the call to netif_rx() in order to allow completion via normal context for dmaengine drivers that utilize threaded irq handling.
While the following commit changed from netif_rx() to __netif_rx(), baebdf48c360 ("net: dev: Makes sure netif_rx() can be invoked in any context."), the change should've been a noop instead. However, the code precedes this fix should've been using netif_rx_ni() or netif_rx_any_context().
Which versions are affected by CVE-2024-42110?
It affects 1 product.
Products include Linux kernel.
How do I fix CVE-2024-42110?
Apply the vendor's patch.
Upgrade, then put limits on request size, rate and nesting depth so one client cannot exhaust the service. More about Denial of service.
Is CVE-2024-42110 being exploited?
There is no known exploitation of CVE-2024-42110 in the wild and no public exploit code.
Other vulnerabilities in Linux kernel
Sources
Also known as BELL-CVE-2024-42110, DEBIAN-CVE-2024-42110, GHSA-fjfg-6xrv-2gqg, ROOT-OS-DEBIAN-11-CVE-2024-42110, ROOT-OS-UBUNTU-2204-CVE-2024-42110, UBUNTU-CVE-2024-42110.