# CVE-2024-56656: bnxt_en: Fix aggregation ID mask to prevent oops on 5760X chips

> A flaw in the bnxt_en driver causes a kernel oops and denial of service on specific Broadcom chips due to incorrect aggregation ID masking.

- **Severity:** Critical 9.8 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 27 Dec 2024
- **Updated:** 5 Aug 2026
- **Also known as:** BELL-CVE-2024-56656, DEBIAN-CVE-2024-56656, GHSA-jm3q-3f7r-g7wc, UBUNTU-CVE-2024-56656

## What is CVE-2024-56656?

CVE-2024-56656 is a critical vulnerability in Linux kernel, published on 27 Dec 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:

bnxt_en: Fix aggregation ID mask to prevent oops on 5760X chips

The 5760X (P7) chip's HW GRO/LRO interface is very similar to that of
the previous generation (5750X or P5).  However, the aggregation ID
fields in the completion structures on P7 have been redefined from
16 bits to 12 bits.  The freed up 4 bits are redefined for part of the
metadata such as the VLAN ID.  The aggregation ID mask was not modified
when adding support for P7 chips.  Including the extra 4 bits for the
aggregation ID can potentially cause the driver to store or fetch the
packet header of GRO/LRO packets in the wrong TPA buffer.  It may hit
the BUG() condition in __skb_pull() because the SKB contains no valid
packet header:

kernel BUG at include/linux/skbuff.h:2766!
Oops: invalid opcode: 0000 1 PREEMPT SMP NOPTI
CPU: 4 UID: 0 PID: 0 Comm: swapper/4 Kdump: loaded Tainted: G           OE      6.12.0-rc2+ #7
Tainted: [O]=OOT_MODULE, [E]=UNSIGNED_MODULE
Hardware name: Dell Inc. PowerEdge R760/0VRV9X, BIOS 1.0.1 12/27/2022
RIP: 0010:eth_type_trans+0xda/0x140
Code: 80 00 00 00 eb c1 8b 47 70 2b 47 74 48 8b 97 d0 00 00 00 83 f8 01 7e 1b 48 85 d2 74 06 66 83 3a ff 74 09 b8 00 04 00 00 eb a5 <0f> 0b b8 00 01 00 00 eb 9c 48 85 ff 74 eb 31 f6 b9 02 00 00 00 48
RSP: 0018:ff615003803fcc28 EFLAGS: 00010283
RAX: 00000000000022d2 RBX: 0000000000000003 RCX: ff2e8c25da334040
RDX: 0000000000000040 RSI: ff2e8c25c1ce8000 RDI: ff2e8c25869f9000
RBP: ff2e8c258c31c000 R08: ff2e8c25da334000 R09: 0000000000000001
R10: ff2e8c25da3342c0 R11: ff2e8c25c1ce89c0 R12: ff2e8c258e0990b0
R13: ff2e8c25bb120000 R14: ff2e8c25c1ce89c0 R15: ff2e8c25869f9000
FS:  0000000000000000(0000) GS:ff2e8c34be300000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000055f05317e4c8 CR3: 000000108bac6006 CR4: 0000000000773ef0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe07f0 DR7: 0000000000000400
PKRU: 55555554
Call Trace:
 <IRQ>
 ? die+0x33/0x90
 ? do_trap+0xd9/0x100
 ? eth_type_trans+0xda/0x140
 ? do_error_trap+0x65/0x80
 ? eth_type_trans+0xda/0x140
 ? exc_invalid_op+0x4e/0x70
 ? eth_type_trans+0xda/0x140
 ? asm_exc_invalid_op+0x16/0x20
 ? eth_type_trans+0xda/0x140
 bnxt_tpa_end+0x10b/0x6b0 [bnxt_en]
 ? bnxt_tpa_start+0x195/0x320 [bnxt_en]
 bnxt_rx_pkt+0x902/0xd90 [bnxt_en]
 ? __bnxt_tx_int.constprop.0+0x89/0x300 [bnxt_en]
 ? kmem_cache_free+0x343/0x440
 ? __bnxt_tx_int.constprop.0+0x24f/0x300 [bnxt_en]
 __bnxt_poll_work+0x193/0x370 [bnxt_en]
 bnxt_poll_p5+0x9a/0x300 [bnxt_en]
 ? try_to_wake_up+0x209/0x670
 __napi_poll+0x29/0x1b0

Fix it by redefining the aggregation ID mask for P5_PLUS chips to be
12 bits.  This will work because the maximum aggregation ID is less
than 4096 on all P5_PLUS chips.

## Which versions are affected by CVE-2024-56656?

It affects 1 product.


Products: Linux kernel.

## How do I fix CVE-2024-56656?

Apply the vendor's patch.

## Is CVE-2024-56656 being exploited?

There is no known exploitation of CVE-2024-56656 in the wild and no public exploit code.

## Other vulnerabilities in Linux kernel

- [CVE-2026-53266](https://insights.sbomify.com/CVE-2026-53266/): Linux Kernel Out-of-Bounds Write (high 8.8, exploited in the wild)
- [CVE-2013-6282](https://insights.sbomify.com/CVE-2013-6282/): Linux Kernel Improper Input Validation (high 8.8, exploited in the wild)
- [CVE-2022-0185](https://insights.sbomify.com/CVE-2022-0185/): Linux Kernel Heap-Based Buffer Overflow (high 8.4, exploited in the wild)
- [CVE-2013-2094](https://insights.sbomify.com/CVE-2013-2094/): Linux Kernel Privilege Escalation (high 8.4, exploited in the wild)
- [CVE-2026-53362](https://insights.sbomify.com/CVE-2026-53362/): Linux Kernel Unspecified (high 7.8, exploited in the wild)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2024-56656 and fix it if it is affected.

What it is: CVE-2024-56656 is a critical vulnerability in Linux kernel, published on 27 Dec 2024. An attacker can exploit it over the internet without logging in, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2024-56656 in the wild and no public exploit code.

Affected product: Linux kernel. No package-level version data is available, so check the vendor advisory linked from the reference page.

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2024-56656/ (Markdown: https://insights.sbomify.com/CVE-2024-56656/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2024-56656
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2024-56656
- OSV: https://osv.dev/vulnerability/CVE-2024-56656

---
From sbomify Insights: https://insights.sbomify.com/CVE-2024-56656/
Summaries are generated and may contain mistakes; the official description above is the record.
