UBUNTU-CVE-2026-89511: Null Pointer Dereference
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 buildskb() support.") accidentally dropped the assignment of tpainfo->buffer.data in qedetpastart(). When memory pressure causes an SKB allocation failure in qedetpastart(), the driver sets tpastartfail = true and attempts to recycle the physical page later in qedetpaend() via qedereusepage(). However, because buffer.data was left uninitialized (NULL), qedereusepage() 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 qedefillfragskb(), causing a kernel panic. Example crash from production system: BUG: unable to handle kernel NULL pointer dereference at 0x8 RIP: qedefillfragskb+0x96/0x430 [qede] Call Trace: qederxint+0xb06/0x1de0 qedepoll+0x2f4/0x6c0 napipoll+0x2d/0x130 Fix the root cause by restoring the tpainfo->buffer.data assignment in qedetpastart(), ensuring valid pages are correctly tracked and recycled. Additionally, update the stale comment for struct qedeagginfo::buffer to reflect its current usage.
Affected Software
Remediation
Recommended actions to resolve this vulnerability, in priority order.
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ubuntu/linux-aws-5.15to a version that resolves this vulnerability.Fixed in 5.15.0-1119.126~20.04.1 - Upgrade
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ubuntu/linux-azure-5.15to a version that resolves this vulnerability.Fixed in 5.15.0-1125.134~20.04.1 - Upgrade
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ubuntu/linux-azure-fde-5.15to a version that resolves this vulnerability.Fixed in 5.15.0-1124.133~20.04.1 - Upgrade
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ubuntu/linux-gcp-5.15to a version that resolves this vulnerability.Fixed in 5.15.0-1120.130~20.04.1 - Upgrade
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ubuntu/linux-hwe-5.15to a version that resolves this vulnerability.Fixed in 5.15.0-202.212~20.04.1 - Upgrade
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ubuntu/linux-ibm-5.15to a version that resolves this vulnerability.Fixed in 5.15.0-1113.117~20.04.1 - Upgrade
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ubuntu/linux-intel-iotg-5.15to a version that resolves this vulnerability.Fixed in 5.15.0-1114.120~20.04.1 - Upgrade
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ubuntu/linux-lowlatency-hwe-5.15to a version that resolves this vulnerability.Fixed in 5.15.0-197.207~20.04.1 - Upgrade
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ubuntu/linux-nvidia-tegra-5.15to a version that resolves this vulnerability.Fixed in 5.15.0-1070.72~20.04.1 - Upgrade
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ubuntu/linux-oracle-5.15to a version that resolves this vulnerability.Fixed in 5.15.0-1116.122~20.04.1 - Upgrade
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ubuntu/linux-riscv-5.15to a version that resolves this vulnerability.Fixed in 5.15.0-1113.117~20.04.2 - Upgrade
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ubuntu/linuxto a version that resolves this vulnerability.Fixed in 5.15.0-202.212 - Upgrade
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ubuntu/linux-awsto a version that resolves this vulnerability.Fixed in 5.15.0-1119.126 - Upgrade
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ubuntu/linux-azureto a version that resolves this vulnerability.Fixed in 5.15.0-1125.134 - Upgrade
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ubuntu/linux-azure-fdeto a version that resolves this vulnerability.Fixed in 5.15.0-1124.133 - Upgrade
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ubuntu/linux-gcpto a version that resolves this vulnerability.Fixed in 5.15.0-1120.130 - Upgrade
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ubuntu/linux-kvmto a version that resolves this vulnerability.Fixed in 5.15.0-1111.116 - Upgrade
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ubuntu/linux-lowlatencyto a version that resolves this vulnerability.Fixed in 5.15.0-197.207 - Upgrade
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ubuntu/linux-nvidiato a version that resolves this vulnerability.Fixed in 5.15.0-1114.115 - Upgrade
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ubuntu/linux-nvidia-tegra-igxto a version that resolves this vulnerability.Fixed in 5.15.0-1059.59 - Upgrade
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ubuntu/linux-oracleto a version that resolves this vulnerability.Fixed in 5.15.0-1116.122 - Upgrade
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ubuntu/linux-bluefieldto a version that resolves this vulnerability.Fixed in 5.15.0-1103.105 - Upgrade
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ubuntu/linux-aws-fipsto a version that resolves this vulnerability.Fixed in 5.15.0-1119.126+fips1 - Upgrade
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ubuntu/linux-azure-fipsto a version that resolves this vulnerability.Fixed in 5.15.0-1125.134+fips1 - Upgrade
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ubuntu/linux-fipsto a version that resolves this vulnerability.Fixed in 5.15.0-202.212+fips1 - Upgrade
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ubuntu/linux-gcp-fipsto a version that resolves this vulnerability.Fixed in 5.15.0-1120.130+fips1 - Upgrade
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ubuntu/linux-hwe-7.0to a version that resolves this vulnerability.Fixed in 7.0.0-42.42~24.04.1 - Upgrade
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ubuntu/linux-riscv-7.0to a version that resolves this vulnerability.Fixed in 7.0.0-42.42.1~24.04.1 - Upgrade
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ubuntu/linuxto a version that resolves this vulnerability.Fixed in 7.0.0-42.42 - Upgrade
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ubuntu/linux-awsto a version that resolves this vulnerability.Fixed in 7.0.0-1016.17 - Upgrade
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ubuntu/linux-gcpto a version that resolves this vulnerability.Fixed in 7.0.0-1016.18 - Upgrade
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ubuntu/linux-ibmto a version that resolves this vulnerability.Fixed in 7.0.0-1017.17 - Upgrade
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ubuntu/linux-oem-7.0to a version that resolves this vulnerability.Fixed in 7.0.0-1017.17 - Upgrade
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ubuntu/linux-oracleto a version that resolves this vulnerability.Fixed in 7.0.0-1015.16 - Upgrade
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ubuntu/linux-riscvto a version that resolves this vulnerability.Fixed in 7.0.0-42.42.1 - Compensating control
In the qede driver, restore the tpa_info->buffer.data assignment in qede_tpa_start() so valid pages are tracked and recycled correctly, and update the stale comment for struct qede_agg_info::buffer to reflect its current usage.
Event History
Frequently Asked Questions
Which systems are exposed to this issue?
Systems running one of the listed Ubuntu kernel packages are affected when the qede driver processes TPA continuation fragments. The failure is triggered under memory pressure.
What does an attacker need to do to trigger the vulnerability?
The advisory provides a network attack vector with low attack complexity and no required privileges or user interaction. It does not specify the exact network traffic or conditions needed beyond TPA fragment processing during memory pressure.
What is the operational impact if the issue is triggered?
A NULL page can be returned to the active receive ring, and later fragment processing can dereference it, causing a kernel panic. The stated impact is denial of service through system unavailability.
How can I identify a likely occurrence?
Affected systems may panic with a NULL pointer dereference in qede_fill_frag_skb, with qede_rx_int and qede_poll appearing in the call trace. The example fault address is 0x8.