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CVE-2026-98029
eth: nfp: bound the ntuple rule dump by the caller's buffer size
Published 2026-09-25 (24 days ago) by the Linux kernel CNA. Subsystem drivers/net. Debian urgency: unimportant.
What to do, per Debian release
Debian's own status for CVE-2026-98029 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 | fixedDSA-6528-1 · 2026-09-29 · text | 6.12.111-1 | Update the kernel and reboot. DSA-6528-1 shipped the fix on 2026-09-29, in 6.12.111-1. A running kernel keeps the old code until the machine restarts. |
| Debian 14forky | fixed | 7.2.7-1 | Update the kernel and reboot. Fixed in 7.2.7-1. A running kernel keeps the old code until the machine restarts. |
| Debian unstablesid | fixed | 7.2.7-1 | Update the kernel and reboot. Fixed in 7.2.7-1. A running kernel keeps the old code until the machine restarts. |
| Debian 12bookworm · linux-6.12 | fixedDLA-4817-1 · 2026-10-04 · text | 6.12.111-1~deb12u1 | Update the kernel and reboot. DLA-4817-1 shipped the fix on 2026-10-04, in 6.12.111-1~deb12u1. A running kernel keeps the old code until the machine restarts. |
The vulnerability
What the bug is
nfp_net_get_fs_loc() dumps every entry of nn->fs.list into rule_locs[] without consulting cmd->rule_cnt, which is how many entries the caller had room for. ETHTOOL_GRXCLSRLALL requires no CAP_NET_ADMIN and the ioctl sizes the buffer from the rule_cnt userspace passes in, so once an admin has installed flow steering rules any user can ask for fewer slots than there are rules and run off the end of the allocation. A rule_cnt of 0 leaves the buffer pointer NULL and the walk dereferences it. Bail out with -EMSGSIZE when the buffer fills up, the way the other ntuple capable drivers do, and report how many locations were filled so a shrinking rule list does not leave the caller reading stale slots.
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/netronome/nfp/nfp_net_ethtool.c
- What this is
- NETRONOME ETHERNET DRIVERSMAINTAINERS section matched on drivers/net/ethernet/netronome/ · oss-drivers@corigine.com · Odd Fixes
- Kernel module
- nfp
Check it on the machine
grep -wE 'CONFIG_ETHERNET|CONFIG_NET_VENDOR_NETRONOME|CONFIG_NFP' /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.
lsmod | grep -w nfpPrints a line if that module is loaded right now, and nothing if it is not. One that is not loaded can still be loaded later by anything that needs it.
Show whether Debian builds this, per release
Debian builds this, but not on every flavour. At least one release below builds the code on some of its kernel flavours and not on others, so the answer depends on the architecture and flavour installed.
- bookwormMnot built on amd64/cloud-amd64, arm64/cloud-arm64
- trixieMnot built on amd64/cloud-amd64, arm64/cloud-arm64, armel/rpi
- forky, sid, bookworm · linux-6.12Mnot built on amd64/cloud-amd64, arm64/cloud-arm64
- M
- a module where it is built at all; some flavours do not build it
- Build switches
- CONFIG_ETHERNET, CONFIG_NET_VENDOR_NETRONOME, CONFIG_NFP
- 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
- 2026-09-25 (24 days ago)source
- CVSS
- 7.0 high
CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:Hsource recompute it - Attack vector
- local (AV:L)source
- EPSS
- 0.12%, higher than 1.8% 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 |
|---|---|---|
| 6.8 | 6.12.111 | 82812583b9c6 |
| 6.8 | 6.18.53 | a7e023c63e85 |
| 6.8 | 7.2.7 | ecebfdaab72a |
| 6.8 | 7.3 | f1986bf87b07 |
Debian advisories
| Advisory | Date | Shipped to | Debian |
|---|---|---|---|
| DLA-4817-1 | 2026-10-04 | bookworm 6.12.111-1~deb12u1 | tracker |
| DSA-6528-1 | 2026-09-29 | trixie 6.12.111-1 | tracker |
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:LAttack vector, local
- The trigger is a local SIOCETHTOOL ioctl (ETHTOOL_GRXCLSRLALL) on a socket, reaching ethtool_get_rxnfc() -> nfp_net_get_rxnfc() -> nfp_net_get_fs_loc(). The rule_cnt that sizes the buffer comes from the local caller, not from any packet off the wire.
- AC:HAttack complexity, high
- The overflow needs a non-empty nn->fs.list on an NFP NIC with NFP_NET_CFG_CTRL_FLOW_STEER. Only an admin can create those rules, via set_rxnfc/nfp_net_fs_add with CAP_NET_ADMIN on a physical init-netns device. The unprivileged attacker cannot create this state and must wait for it to exist.
- PR:LPrivileges required, low
- dev_ethtool() lists ETHTOOL_GRXCLSRLALL among the commands anyone may run and skips the ns_capable(CAP_NET_ADMIN) check for it. Any local unprivileged user can call it with a small rule_cnt.
- UI:NUser interaction, none
- No victim action is needed. The attacker issues the ioctl whenever they like, once the rules exist as a standing configuration.
- S:UScope, unchanged
- Kernel heap corruption leading to local privilege escalation or a crash stays within the kernel's own security authority.
- C:HConfidentiality impact, high
- ethtool_get_rxnfc() sizes rule_buf with kcalloc(rule_cnt), so the attacker chooses the slab cache. nfp_net_get_fs_loc() then writes up to ~4KB of u32 rule locations past it. That corrupts adjacent kmalloc objects, which can be leveraged into an information leak.
- I:HIntegrity impact, high
- This is an out-of-bounds heap write into neighbouring slab objects in a cache the attacker chooses, with an attacker-chosen overflow length (rule count minus rule_cnt). It is a memory corruption primitive usable against adjacent object fields.
- A:HAvailability impact, high
- With rule_cnt=0, rule_buf stays NULL and rule_locs[0] = entry->loc writes through the NULL pointer, oopsing the kernel. Larger overflows corrupt the slab and can panic the kernel. Either can be repeated at will by an unprivileged user.