CVE-2026-89511

Published Sep 11, 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.

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References

Frequently Asked Questions

What is CVE-2026-89511? +
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.
How do I check if I'm vulnerable to CVE-2026-89511? +
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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