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CVE-2026-53186
RDMA/srp: bound SRP_RSP sense copy by the received length
Published 2026-06-25 (4 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-2026-53186 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 | fixedDLA-4665-1 · 2026-07-03 · text | 6.1.176-1 | Update the kernel and reboot. DLA-4665-1 shipped the fix on 2026-07-03, in 6.1.176-1. A running kernel keeps the old code until the machine restarts. |
| Debian 13trixie | fixed | 6.12.94-1 | Update the kernel and reboot. Fixed in 6.12.94-1. A running kernel keeps the old code until the machine restarts. |
| Debian 14forky | fixed | 7.0.13-1 | Update the kernel and reboot. Fixed in 7.0.13-1. A running kernel keeps the old code until the machine restarts. |
| Debian unstablesid | fixed | 7.0.13-1 | Update the kernel and reboot. Fixed in 7.0.13-1. A running kernel keeps the old code until the machine restarts. |
The vulnerability
What the bug is
srp_process_rsp() copies sense data from rsp->data + resp_data_len, where resp_data_len is the full 32-bit value supplied by the SRP target and is never checked against the number of bytes actually received (wc->byte_len). The copy length is bounded to SCSI_SENSE_BUFFERSIZE, so at most 96 bytes are copied, but the source offset is not bounded. A malicious or compromised SRP target on the InfiniBand/RoCE fabric that the initiator has logged into can return an SRP_RSP with SRP_RSP_FLAG_SNSVALID set and a large resp_data_len. The receive buffer is allocated at the target-chosen max_ti_iu_len, so the source of the sense copy lands past the bytes actually received; with resp_data_len near 0xFFFFFFFF it is gigabytes past the buffer and the read faults. Copy the sense data only if it has not been truncated, that is, only if the response header, the response data, and the sense region fit within the bytes actually received; otherwise drop the sense and log. The in-tree iSER and NVMe-RDMA receive paths already bound their parse by wc->byte_len; this brings ib_srp into line with them.
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/srp/ib_srp.c
- What this is
- SCSI RDMA PROTOCOL (SRP) INITIATORMAINTAINERS section matched on drivers/infiniband/ulp/srp/ · linux-rdma@vger.kernel.org · Supported
- Kernel module
- ib_srp
Check it on the machine
grep -wE 'CONFIG_INFINIBAND|CONFIG_INFINIBAND_SRP' /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_srpPrints 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_SRP
- 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
- 2026-06-25 (4 months ago)source
- CVSS
- 9.1 critical
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:Hsource recompute it - Attack vector
- network (AV:N)source
- EPSS
- 0.51%, higher than 42.5% 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 |
|---|---|---|
| 2.6.15 | 5.10.259 | 3889517c2ec7 |
| 2.6.15 | 5.15.210 | ed77cc819ad6 |
| 2.6.15 | 6.1.176 | 0b9ee09d5e84 |
| 2.6.15 | 6.6.143 | 0d64bc200ebe |
| 2.6.15 | 6.12.94 | 201503819593 |
| 2.6.15 | 6.18.36 | f92a285db7ff |
| 2.6.15 | 7.0.13 | 3523e53ff95f |
| 2.6.15 | 7.1 | 13e91fd07630 |
Debian advisories
| Advisory | Date | Shipped to | Debian |
|---|---|---|---|
| DLA-4671-1 | 2026-07-05 | bullseye 6.1.176-1~deb11u1 | tracker |
| DLA-4665-1 | 2026-07-03 | bookworm 6.1.176-1 | tracker |
| DLA-4664-1 | 2026-07-03 | bullseye 5.10.259-1 | 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:NAttack vector, network
- A malicious or compromised SRP target can trigger this by sending an SRP_RSP over the established RDMA network session to the initiator. The vulnerable parsing is reached from remote peer-controlled RDMA receive completions, not from local or physical access.
- AC:LAttack complexity, low
- The target controls SRP_RSP flags and length fields and sees the command tag in each SRP_CMD, so it can craft a matching response with SRP_RSP_FLAG_SNSVALID and an oversized resp_data_len. No race or hard-to-control environmental condition is required.
- PR:NPrivileges required, none
- The attacker needs control of the remote SRP target or a compromised target on the fabric, but no privileges on the vulnerable initiator host. The vulnerable receive path processes target responses after the initiator is connected.
- UI:NUser interaction, none
- Once the initiator is logged into the target, the target can trigger the bug by responding to normal SCSI commands or scan traffic. No additional victim user action is needed for the malicious SRP_RSP to be processed.
- S:UScope, unchanged
- The impact is within the vulnerable kernel instance processing the SRP response. This is not a guest-to-host escape, IOMMU bypass, or other cross-authority boundary change.
- C:HConfidentiality impact, high
- The target-controlled offset can make the kernel read out of bounds from memory beyond the SRP receive buffer, with up to SCSI_SENSE_BUFFERSIZE bytes copied into sense data. Under the required higher-severity rule, this out-of-bounds kernel read is treated as high confidentiality impact.
- I:NIntegrity impact, none
- The bug is an out-of-bounds read source for a copy into the intended SCSI sense buffer, not an out-of-bounds write or control-flow overwrite. The target can already provide arbitrary valid sense data, so this flaw does not add a distinct kernel integrity primitive.
- A:HAvailability impact, high
- With a large resp_data_len, the copy source can land far beyond the receive buffer and fault in kernel context, causing an oops or panic. The malicious target can repeat this by sending crafted responses.