CVE-2026-89511

Public on 2026-09-11
Modified on 2026-09-18
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.
Severity
Medium severity
Medium
See what this means
CVSS v3 Base Score
5.9
See breakdown

Affected Packages

Platform Package Release Date Advisory Status
Amazon Linux 2 - Kernel-5.10 Extra kernel Pending Fix
Amazon Linux 2 - Kernel-5.4 Extra kernel Pending Fix
Amazon Linux 2 - Core kernel Not Affected
Amazon Linux 2 - Kernel-5.15 Extra kernel Not Affected
Amazon Linux 2023 kernel Not Affected
Amazon Linux 2023 kernel6.12 Not Affected
Amazon Linux 2023 kernel6.18 Not Affected

CVSS Scores

Score Type Score Vector
Amazon Linux CVSSv3 5.9 CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H