Overview
About vulnerability
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.
Details
- Affected product:
- AlmaLinux 9.2 ESU , Amazon Linux 2 ELS , CentOS 7 ELS , CentOS 8.4 ELS , CentOS 8.5 ELS , CentOS Stream 8 ELS , CloudLinux 7 ELS , Debian 10 ELS , Debian 11 ELS , Oracle Linux 7 ELS , RHEL 7 ELS , TuxCare 9.6 ESU , TuxCare 9.8 ESU , Ubuntu 16.04 ELS , Ubuntu 18.04 ELS , Ubuntu 20.04 ELS
- Affected packages:
- linux @ 5.4.0 (+17 more)
Fixes
KernelCare state
Live-patch status from KernelCare for each operating system.
| Operating system | Status | Covered kernels |
|---|---|---|
| Debian 12 | Planned | — |
| Debian 13 | In Rollout |
17 kernels
|