# CVE-2026-89511

## Summary

- **CVE ID:** CVE-2026-89511
- **Severity:** HIGH
- **CVSS Score:** 7.5 (CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H)
- **CWE:** N/A
- **Published:** Sep 11, 2026
- **Last Modified:** Sep 14, 2026

## Description

In the Linux kernel, the following vulnerability has been resolved:

qede: Fix NULL pointer dereference in TPA fragment processing

Under memory pressure, the qede driver encounters NULL pointer
dereferences when processing TPA continuation fragments.

Commit 8a8633978b84 ("qede: Add build_skb() support.") accidentally
dropped the assignment of tpa_info->buffer.data in qede_tpa_start().

When memory pressure causes an SKB allocation failure in qede_tpa_start(),
the driver sets tpa_start_fail = true and attempts to recycle the physical
page later in qede_tpa_end() via qede_reuse_page(). However, because
buffer.data was left uninitialized (NULL), qede_reuse_page() pushes a
"ghost" BD (valid DMA mapping but NULL data pointer) back into the
active Rx ring.

The next time the hardware uses this ring slot, it passes a NULL page
to qede_fill_frag_skb(), causing a kernel panic.

Example crash from production system:
 BUG: unable to handle kernel NULL pointer dereference at 0x8
 RIP: qede_fill_frag_skb+0x96/0x430 [qede]
 Call Trace:
   qede_rx_int+0xb06/0x1de0
   qede_poll+0x2f4/0x6c0
   __napi_poll+0x2d/0x130

Fix the root cause by restoring the tpa_info->buffer.data assignment
in qede_tpa_start(), ensuring valid pages are correctly tracked and
recycled. Additionally, update the stale comment for
struct qede_agg_info::buffer to reflect its current usage.

## Affected Products

- Linux — Linux (8a8633978b842c88fbcfe00d4e5dde96048f630e)
- Linux — Linux (4.18)
- Linux — Linux (0)
- Linux — Linux (6.12.109)
- Linux — Linux (6.18.50)
- Linux — Linux (7.2.4)
- Linux — Linux (7.3-rc1)
- Linux — Linux (5.10.270)
- Linux — Linux (5.15.221)
- Linux — Linux (6.1.188)
- Linux — Linux (6.6.157)

## References

- [CNA](https://git.kernel.org/stable/c/7f911e208b3ca2c76d9f2bbba1f54b9403568c10)
- [CNA](https://git.kernel.org/stable/c/2a952fb1b20d83e83ca852773e6188511f7d2191)
- [CNA](https://git.kernel.org/stable/c/f5c8619ccbd70102642120c4c6fda1c048a555fd)
- [CNA](https://git.kernel.org/stable/c/06aa3d26327f24edd039ff249672fdf6f2ba5695)
- [CNA](https://git.kernel.org/stable/c/e2214e2793154b745436e46c6a9a7985d9b3781d)
- [CNA](https://git.kernel.org/stable/c/dd8bc0a9d87d2b048711edd17ba7286432edd285)
- [CNA](https://git.kernel.org/stable/c/fa7c9bd2c4a8de167e2fb32968ca4d91dd774375)
- [CNA](https://git.kernel.org/stable/c/a5e1fdc126ab337d601d1a00cc4b47910679d005)

## Exploitation Prediction (EPSS)

- **EPSS Score:** 0.72%
- **EPSS Percentile:** 52.1

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_Exported from OnDuty AI Vulnerability Intelligence on 2026-09-17._