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CVE-2026-74390
RDMA/irdma: Fix out-of-bounds write in irdma_copy_user_pgaddrs
Published 2026-08-15 (2 months ago) by the Linux kernel CNA. Subsystem drivers/infiniband. Debian urgency: not yet assigned.
What to do, per Debian release
Debian's own status for CVE-2026-74390 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 | fixed | 6.1.180-1 | Update the kernel and reboot. Fixed in 6.1.180-1. A running kernel keeps the old code until the machine restarts. |
| Debian 13trixie | fixed | 6.12.100-1 | Update the kernel and reboot. Fixed in 6.12.100-1. A running kernel keeps the old code until the machine restarts. |
| Debian 14forky | fixed | 7.1.5-1 | Update the kernel and reboot. Fixed in 7.1.5-1. A running kernel keeps the old code until the machine restarts. |
| Debian unstablesid | fixed | 7.1.5-1 | Update the kernel and reboot. Fixed in 7.1.5-1. A running kernel keeps the old code until the machine restarts. |
The vulnerability
What the bug is
The irdma_copy_user_pgaddrs function loops through all of the umem DMA blocks to populate the PBLEs and will stop when either the last DMA block is reached or palloc->total_cnt is reached. The issue is that the logic for checking palloc->total_cnt would only work for non-zero values. When irdma_setup_pbles is called with lvl==0, it calls irdma_copy_user_pgaddrs with palloc->total_cnt==0, which means the only way to break out of the loop is to reach the last umem DMA block, which means it could end up going beyond the fixed size of 4 iwmr->pgaddrmem array that is used in the lvl==0 case. In the case of QP/CQ/SRQ rings, the value of lvl is determined by a separate input (for example, req.cq_pages in the case of a CQ). So, we must perform explicit checking to ensure we don't overflow the pgaddrmem array if the user provides a umem that consists of more blocks than their provided req.cq_pages.
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/infiniband/hw/irdma/verbs.c
- What this is
- INTEL ETHERNET PROTOCOL DRIVER FOR RDMAMAINTAINERS section matched on drivers/infiniband/hw/irdma/ · linux-rdma@vger.kernel.org · Supported
- Kernel module
- irdma
Check it on the machine
grep -wE 'CONFIG_INFINIBAND|CONFIG_INFINIBAND_IRDMA' /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 irdmaPrints 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, sidMnot built on amd64/cloud-amd64, arm64/cloud-arm64, armhf/armmp, armhf/armmp-lpae, loong64/loong64, ppc64el/powerpc64le, ppc64el/powerpc64le-64k, riscv64/riscv64, s390x/s390x
- M
- a module where it is built at all; some flavours do not build it
- Build switches
- CONFIG_INFINIBAND, CONFIG_INFINIBAND_IRDMA
- 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
- 2026-08-15 (2 months ago)source
- CVSS
- 7.8 high
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:Hsource recompute it - Attack vector
- local (AV:L)source
- EPSS
- 0.13%, higher than 2.3% of all CVEssource
- CISA KEV
- not listedthe KEV catalogue
- Debian urgency
- not yet assignedsource
- Subsystem
- drivers/infiniband
Upstream fixes
The versions the CNA records as introducing and fixing this, and the commit for each. source
| Introduced | Fixed in | Commit |
|---|---|---|
| 5.14 | 5.15.212 | 4780f58672ee |
| 5.14 | 6.1.178 | 79a20a8e201a |
| 5.14 | 6.6.145 | 9f8f0d2099e3 |
| 5.14 | 6.12.97 | 192a3be0e375 |
| 5.14 | 6.18.40 | 424d51d33c75 |
| 5.14 | 7.1.5 | abd27a977b41 |
| 5.14 | 7.2 | 5ebb3ed757be |
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
- Exploitation requires a local ioctl on /dev/infiniband/uverbs to register CQ/QP/SRQ memory via irdma_reg_user_mr; the bug is not reachable from remote iWARP/RoCE packet handling.
- AC:LAttack complexity, low
- An attacker fully controls reg_type, cq_pages/sq_pages/rq_pages, and umem size; triggering lvl==0 with many DMA blocks is deterministic and needs no races or special memory layout.
- PR:LPrivileges required, low
- Any unprivileged local user who can open the uverbs device (mode 0666) and use the RDMA NIC—typical on cloud/HPC RDMA nodes—can invoke the vulnerable MR registration path without real root.
- UI:NUser interaction, none
- No victim interaction is required; the attacker triggers the overflow directly through their own RDMA verbs memory registration calls.
- S:UScope, unchanged
- Impact is kernel heap corruption and privilege escalation within the host kernel security boundary, not a cross-VM or cross-IOMMU sandbox escape.
- C:HConfidentiality impact, high
- The out-of-bounds write of attacker-influenced DMA addresses into adjacent irdma_mr/iwpbl heap metadata can be leveraged for arbitrary kernel memory read primitives, not merely a bounded leak.
- I:HIntegrity impact, high
- Controlled out-of-bounds u64 writes past pgaddrmem[4] corrupt adjacent kernel heap structures and are suitable for control-flow or arbitrary kernel write exploitation.
- A:HAvailability impact, high
- Heap corruption in a kzalloc'd irdma_mr can cause immediate kernel oops/panic during registration or on subsequent use of corrupted queue memory metadata.