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CVE-2026-74741
net: ngbe: fix NULL pointer dereference in non-MSI-X interrupt enabling
Published 2026-08-26 (2 months ago) by the Linux kernel CNA. Subsystem drivers/net. Debian urgency: unimportant.
Debian does not build this code. The per-release build detail is under "Where it lives" below.
What to do, per Debian release
Debian's own status for CVE-2026-74741 in every release this site tracks, and what each one means in practice. Every status below is the one the Debian Security Team publishes for this CVE. source
| Release | Status | Version | What this means |
|---|---|---|---|
| Debian 12bookworm | not affected | 6.1.190-1 | Nothing to do. bookworm never shipped the vulnerable code. |
| Debian 13trixie | not affected | 6.12.113-1 | Nothing to do. trixie never shipped the vulnerable code. |
| Debian 14forky | fixed | 7.1.10-1 | Update the kernel and reboot. Fixed in 7.1.10-1. A running kernel keeps the old code until the machine restarts. |
| Debian unstablesid | fixed | 7.1.10-1 | Update the kernel and reboot. Fixed in 7.1.10-1. A running kernel keeps the old code until the machine restarts. |
The vulnerability
What the bug is
In non-MSI-X mode (such as legacy INTx or single MSI), wx->msix_entry is not allocated or initialized. Calling NGBE_INTR_MISC(wx) dereferences wx->msix_entry->entry, leading to a NULL pointer dereference crash. This issue was introduced by fixing the IRQ vector when the number of VFs is 7. Fix the issue by explicitly checking `pdev->msix_enabled` to determine the correct vector index. Additionally, as a side fix, set the interrupt mask to BIT(0) for the non-MSI-X fallback. In MSI/INTx mode, the MISC and queue interrupts share vector 0, and the WX_PX_MISC_IVAR register is only valid in the MSI-X case. Thus, BIT(0) is the correct mask for the miscellaneous cause when MSI-X is disabled.
Where it lives
The fix touches these files. If the subsystem is one you do not use, the practical exposure is lower, though the package is still the vulnerable one.
drivers/net/ethernet/wangxun/ngbe/ngbe_main.c
- What this is
- WANGXUN ETHERNET DRIVERMAINTAINERS section matched on drivers/net/ethernet/wangxun/ · netdev@vger.kernel.org · Maintained
- Kernel module
- none to look for. The file would have gone into ngbe, and Debian does not compile it into that module, so finding ngbe in lsmod would say nothing about this CVE.
Check it on the machine
grep -wE 'CONFIG_ETHERNET|CONFIG_NET_VENDOR_WANGXUN|CONFIG_NGBE' /boot/config-$(uname -r)Reads the booted kernel's own configuration, on the machine and nowhere else. =y is built in, =m is a module, and an is not set line means the code is not there.
Show whether Debian builds this, per release
Debian does not build this code. In 4 releases below, every kernel flavour Debian publishes has the switch off, so the vulnerable file is compiled into no kernel binary Debian ships.
- bookworm, trixie, forky, sidn
- n
- not enabled on any flavour - this release does not build the code
- Build switches
- CONFIG_ETHERNET, CONFIG_NET_VENDOR_WANGXUN, CONFIG_NGBE
- Reads as
- all on means the file is compiled; any one off means it is not.
From the configuration Debian publishes for every kernel flavour it builds. It covers only the architectures Debian ships a linux-config package for, and nothing about a kernel you built yourself. Debian's own status above stays authoritative about the source package.MAINTAINERS kbuild Makefiles Debian linux-config packages
Signals
- Published
- 2026-08-26 (2 months ago)source
- CVSS
- 7.5 high
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:Hsource recompute it - Attack vector
- network (AV:N)source
- EPSS
- 0.61%, higher than 48.1% of all CVEssource
- CISA KEV
- not listedthe KEV catalogue
- Debian urgency
- unimportantsource
- Subsystem
- drivers/net
Upstream fixes
The versions the CNA records as introducing and fixing this, and the commit for each. source
| Introduced | Fixed in | Commit |
|---|---|---|
| 6.16 | 6.18.46 | cef4c5b9aca2 |
| 6.16 | 7.1.10 | 0ab482b2195e |
| 6.16 | 7.2 | 5f3a13e0bb5e |
Why the CNA scored it this way
Quoted from the kernel CNA's own scoring file, word for word. A highlighted metric carries the most severe value CVSS v3.1 defines for it, which is what pushes the score up. source
- AV:NAttack vector, network
- The NULL dereference is in ngbe_intr(), the MSI/INTx hard-IRQ handler reached when the Wangxun ngbe NIC raises an interrupt from wire activity (RX/TX completion, link, or misc events); a remote peer sending traffic to an up interface drives this path with no local access.
- AC:LAttack complexity, low
- After the 4174c0c regression every non-MSI-X interrupt that reaches ngbe_irq_enable(wx,false) deterministically dereferences NULL msix_entry; MSI/INTx fallback is automatic on MSI-X allocation failure, VMs, and pci=nomsi, and each packet reliably retriggers the fault.
- PR:NPrivileges required, none
- No credentials or capabilities are needed on the target once the netdev is up; received frames are handled in hardirq before any socket, netfilter, or authentication gate, so any host that can send packets to the interface can trigger the crash.
- UI:NUser interaction, none
- Interrupt delivery and the faulty re-enable run automatically in hardirq context on normal NIC operation; no administrator or end-user action beyond the interface already being configured up at boot is required.
- S:UScope, unchanged
- The oops is confined to kernel hardirq context within the same security authority; it is not a VM escape, hypervisor bypass, IOMMU violation, or sandbox boundary crossing.
- C:NConfidentiality impact, none
- The fault is a NULL read of wx->msix_entry->entry while computing an interrupt mask; execution aborts immediately with no out-of-bounds read, use-after-free, or data returned to the attacker.
- I:NIntegrity impact, none
- This is a pure NULL pointer read, not memory corruption; no attacker-controlled write, heap spray, or control-flow hijack primitive exists before the kernel faults.
- A:HAvailability impact, high
- The NULL dereference occurs in hardirq context and causes a kernel oops or panic, fully denying availability; on internet-facing servers with ngbe in MSI/INTx mode an unauthenticated remote attacker can repeat the crash on every interrupt.