CVE-2026-90307 RDMA/srp: fix heap information leak on a truncated SRP_CRED_REQ
A malicious RDMA target can leak kernel heap memory to the initiator by sending truncated SRP requests, exposing sensitive data.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Local or same network only
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-90307?
CVE-2026-90307 is a vulnerability in Linux, published on 17 Sep 2026. It can only be exploited from the same machine or local network, with no action from the victim.
Official description
In the Linux kernel, the following vulnerability has been resolved:
RDMA/srp: fix heap information leak on a truncated SRP_CRED_REQ
srp_recv_done() passes wc->byte_len to srp_process_rsp(). It passes nothing to srp_process_cred_req() and srp_process_aer_req(), which read fixed-size fields from the receive buffer without checking that those fields were received.
The buffer size is max_ti_iu_len, which comes from the login response and is not validated. A target that advertises 8 and then sends an 8-byte SRP_CRED_REQ makes the initiator read req->tag from beyond the end of the buffer. req->tag is copied into the SRP_CRED_RSP and sent back, so those bytes reach the target. SRP_AER_REQ behaves the same way and also reads req->lun.
The leak is 8 bytes per response. max_ti_iu_len also decides which slab cache the buffer comes from. With 8 the buffer is a kmalloc-8 object and the read is entirely outside it:
BUG: KASAN: slab-out-of-bounds in srp_recv_done+0x172b/0x1aa0 Read of size 8 at addr ffff888104714da8 by task kworker/u8:3/50 which belongs to the cache kmalloc-8 of size 8 The buggy address is located 0 bytes to the right of allocated 8-byte region [ffff888104714da0, ffff888104714da8)
Without KASAN the returned bytes are whatever is next in the slab. One run returned ".strtab".
rsp->data[3] in srp_process_rsp() has the same problem: only resp_data_len is checked before it is read.
Drop a request that is shorter than the structure being parsed, and check byte_len before the tsk_mgmt read.
Which versions are affected by CVE-2026-90307?
How do I fix CVE-2026-90307?
Apply the vendor's patch.
Is CVE-2026-90307 being exploited?
There is no known exploitation of CVE-2026-90307 in the wild and no public exploit code.
Sources
Also known as AZL-101903, BELL-CVE-2026-90307, DEBIAN-CVE-2026-90307, GHSA-24j7-gr38-qhjc, UBUNTU-CVE-2026-90307.