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CVE-2026-74394
RDMA/srpt: fix integer overflow in immediate data length check
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-2026-74394 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
imm_buf->len is a user-controlled uint32_t received from the network. Adding it to imm_data_offset without overflow checking allows a malicious initiator to send len=0xFFFFFFFF, causing req_size to wrap around to a small value, bypassing the bounds check, and subsequently passing a ~4GB length to sg_init_one(). Use check_add_overflow() to detect wrapping before the comparison.
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/ulp/srpt/ib_srpt.c
- What this is
- SCSI RDMA PROTOCOL (SRP) TARGETMAINTAINERS section matched on drivers/infiniband/ulp/srpt/ · linux-rdma@vger.kernel.org · Supported
- Kernel module
- ib_srpt
Check it on the machine
grep -wE 'CONFIG_INFINIBAND|CONFIG_INFINIBAND_SRPT' /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 ib_srptPrints 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.
- bookworm, trixie, forky, sidMnot 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_INFINIBAND, CONFIG_INFINIBAND_SRPT
- 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
- 9.8 critical
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:Hsource recompute it - Attack vector
- network (AV:N)source
- EPSS
- 0.54%, higher than 44.2% 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 |
|---|---|---|
| 5.0 | 5.10.261 | c82c860f8c8e |
| 5.0 | 5.15.212 | 3efa53011371 |
| 5.0 | 6.1.178 | 067b9556eeb0 |
| 5.0 | 6.6.145 | dcf7a986f377 |
| 5.0 | 6.12.97 | 07dec3f6dcb6 |
| 5.0 | 6.18.40 | 65572fbd8603 |
| 5.0 | 7.1.5 | 72497172a479 |
| 5.0 | 7.2 | eb4ecdf631fe |
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
- SRPT is an in-kernel SCSI RDMA target reached by remote initiators over InfiniBand/RoCE via RDMA/IB CM; malicious SRP_CMD IUs are delivered through `srpt_recv_done()` without any local syscall or physical access.
- AC:LAttack complexity, low
- Once connected on an immediate-data SRPT target (use_srq=0), a malicious initiator deterministically sets `imm_buf->len=0xFFFFFFFF` to wrap `req_size` and bypass checks; no race or attacker-uncontrollable condition is required.
- PR:NPrivileges required, none
- SRPT enables LIO demo mode (`srpt_check_true`), so any remote initiator that completes SRP login on an enabled target gets a dynamic ACL without target-local credentials, root, or CAP_NET_ADMIN on the victim host.
- UI:NUser interaction, none
- Exploitation requires only attacker-initiated RDMA connection, SRP login, and crafted SRP_CMD traffic; no administrator or other user must mount storage or perform any action on the target.
- S:UScope, unchanged
- The integer overflow corrupts kernel heap memory and SCSI-target processing within the host kernel's own security authority; it does not cross VM, IOMMU, or container sandbox boundaries.
- C:HConfidentiality impact, high
- Passing a ~4GB length to `sg_init_one()` on a small receive buffer creates a massive out-of-bounds scatterlist; subsequent target-core DMA/map operations can read far beyond the buffer, enabling arbitrary kernel memory disclosure.
- I:HIntegrity impact, high
- The bogus scatterlist gives the block/SCSI target path an attacker-controlled ~4GB kernel memory write/read primitive over adjacent heap objects, exploitable for control-flow hijacking and privilege escalation.
- A:HAvailability impact, high
- Out-of-bounds access from a ~4GB scatterlist on a kilobyte-scale receive buffer readily triggers kernel oops, KASAN faults, or panic, denying availability even before full exploitation.