CVE-2024-42071

MEDIUM
Published Jul 29, 2024 Modified Nov 21, 2024 CWE-834

Description

In the Linux kernel, the following vulnerability has been resolved: ionic: use dev_consume_skb_any outside of napi If we're not in a NAPI softirq context, we need to be careful about how we call napi_consume_skb(), specifically we need to call it with budget==0 to signal to it that we're not in a safe context. This was found while running some configuration stress testing of traffic and a change queue config loop running, and this curious note popped out: [ 4371.402645] BUG: using smp_processor_id() in preemptible [00000000] code: ethtool/20545 [ 4371.402897] caller is napi_skb_cache_put+0x16/0x80 [ 4371.403120] CPU: 25 PID: 20545 Comm: ethtool Kdump: loaded Tainted: G OE 6.10.0-rc3-netnext+ #8 [ 4371.403302] Hardware name: HPE ProLiant DL360 Gen10/ProLiant DL360 Gen10, BIOS U32 01/23/2021 [ 4371.403460] Call Trace: [ 4371.403613] <TASK> [ 4371.403758] dump_stack_lvl+0x4f/0x70 [ 4371.403904] check_preemption_disabled+0xc1/0xe0 [ 4371.404051] napi_skb_cache_put+0x16/0x80 [ 4371.404199] ionic_tx_clean+0x18a/0x240 [ionic] [ 4371.404354] ionic_tx_cq_service+0xc4/0x200 [ionic] [ 4371.404505] ionic_tx_flush+0x15/0x70 [ionic] [ 4371.404653] ? ionic_lif_qcq_deinit.isra.23+0x5b/0x70 [ionic] [ 4371.404805] ionic_txrx_deinit+0x71/0x190 [ionic] [ 4371.404956] ionic_reconfigure_queues+0x5f5/0xff0 [ionic] [ 4371.405111] ionic_set_ringparam+0x2e8/0x3e0 [ionic] [ 4371.405265] ethnl_set_rings+0x1f1/0x300 [ 4371.405418] ethnl_default_set_doit+0xbb/0x160 [ 4371.405571] genl_family_rcv_msg_doit+0xff/0x130 [...] I found that ionic_tx_clean() calls napi_consume_skb() which calls napi_skb_cache_put(), but before that last call is the note /* Zero budget indicate non-NAPI context called us, like netpoll */ and DEBUG_NET_WARN_ON_ONCE(!in_softirq()); Those are pretty big hints that we're doing it wrong. We can pass a context hint down through the calls to let ionic_tx_clean() know what we're doing so it can call napi_consume_skb() correctly.

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CVSS v3.1 Score

5.5
MEDIUM
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

Weakness Type (CWE)

CWE-834 CWE-834

Affected Products

Vendor Product
linux linux_kernel
linux linux_kernel

References

Frequently Asked Questions

What is CVE-2024-42071? +
In the Linux kernel, the following vulnerability has been resolved: ionic: use dev_consume_skb_any outside of napi If we're not in a NAPI softirq context, we need to be careful about how we call napi_consume_skb(), specifically we need to call it with budget==0 to signal to it that we're not in a safe context. This was found while running some configuration stress testing of traffic and a change queue config loop running, and this curious note popped out: [ 4371.402645] BUG: using smp_processor_id() in preemptible [00000000] code: ethtool/20545 [ 4371.402897] caller is napi_skb_cache_put+0x16/0x80 [ 4371.403120] CPU: 25 PID: 20545 Comm: ethtool Kdump: loaded Tainted: G OE 6.10.0-rc3-netnext+ #8 [ 4371.403302] Hardware name: HPE ProLiant DL360 Gen10/ProLiant DL360 Gen10, BIOS U32 01/23/2021 [ 4371.403460] Call Trace: [ 4371.403613] <TASK> [ 4371.403758] dump_stack_lvl+0x4f/0x70 [ 4371.403904] check_preemption_disabled+0xc1/0xe0 [ 4371.404051] napi_skb_cache_put+0x16/0x80 [ 4371.404199] ionic_tx_clean+0x18a/0x240 [ionic] [ 4371.404354] ionic_tx_cq_service+0xc4/0x200 [ionic] [ 4371.404505] ionic_tx_flush+0x15/0x70 [ionic] [ 4371.404653] ? ionic_lif_qcq_deinit.isra.23+0x5b/0x70 [ionic] [ 4371.404805] ionic_txrx_deinit+0x71/0x190 [ionic] [ 4371.404956] ionic_reconfigure_queues+0x5f5/0xff0 [ionic] [ 4371.405111] ionic_set_ringparam+0x2e8/0x3e0 [ionic] [ 4371.405265] ethnl_set_rings+0x1f1/0x300 [ 4371.405418] ethnl_default_set_doit+0xbb/0x160 [ 4371.405571] genl_family_rcv_msg_doit+0xff/0x130 [...] I found that ionic_tx_clean() calls napi_consume_skb() which calls napi_skb_cache_put(), but before that last call is the note /* Zero budget indicate non-NAPI context called us, like netpoll */ and DEBUG_NET_WARN_ON_ONCE(!in_softirq()); Those are pretty big hints that we're doing it wrong. We can pass a context hint down through the calls to let ionic_tx_clean() know what we're doing so it can call napi_consume_skb() correctly. It has a CVSS v3.1 base score of 5.5 (MEDIUM).
How severe is CVE-2024-42071? +
CVE-2024-42071 has a CVSS v3.1 score of 5.5 out of 10, rated MEDIUM. This is a medium-severity vulnerability that should be remediated as part of regular maintenance.
What products are affected by CVE-2024-42071? +
CVE-2024-42071 affects products from linux, specifically: linux_kernel. Check the affected products table above for specific version ranges.
How do I check if I'm vulnerable to CVE-2024-42071? +
You can use Secably's free Website Scanner to check your website for known vulnerabilities. For infrastructure scanning, use the Port Scanner to identify exposed services that may be affected. Check the vendor advisories linked above for specific patch and version information.

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