Overview
About vulnerability
In the Linux kernel, the following vulnerability has been resolved:
drbd: reject data replies with an out-of-range payload size
recv_dless_read() receives a P_DATA_REPLY from a peer into the bio of an outstanding read request. The peer-supplied payload length reaches it as the signed int data_size, and two peer-controlled inputs can make it negative. With a negotiated data-integrity-alg the digest length is subtracted first, so a reply whose payload is smaller than the digest underflows data_size. With no integrity algorithm (the default) data_size is assigned from the unsigned h95/h100 wire length and drbdd() never bounds it for a payload-carrying command, so a length above INT_MAX casts it negative; this path needs no non-default feature. The bio receive loop then computes expect = min_t(int, data_size, bv_len), which is negative, and drbd_recv_all_warn(mapped, expect) receives with a size_t of SIZE_MAX into the first mapped page.
The sibling receive path read_in_block() is not affected: it uses an unsigned size and rejects it against DRBD_MAX_BIO_SIZE before receiving. Reject a data reply whose size is negative after the optional digest subtraction, covering both triggers.
Impact: a malicious or man-in-the-middle DRBD peer copies attacker-chosen bytes past a bio page in the receiver, corrupting kernel memory. A node that reads from its peer (a diskless node, or read-balancing to the peer) is exposed in the default configuration; data-integrity-alg is not required.
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 @ 4.19.0 (+17 more)
Fixes
KernelCare state
Live-patch status from KernelCare for each operating system.
| Operating system | Status | Covered kernels |
|---|---|---|
| Amazon Linux 2023 | Planned | — |
| Debian 12 | Released |
42 kernels
|
| Debian 13 | Released |
13 kernels
|
| Oracle Linux 8 UEK 7 | Released |
112 kernels
|
| Oracle Linux 9 UEK 7 | Released |
112 kernels
|
| Ubuntu 22.04 | Planned | — |
| Ubuntu 22.04 AWS | Planned | — |
| Ubuntu 22.04 Azure | Planned | — |
| Ubuntu 24.04 | Planned | — |
| Ubuntu 24.04 AWS | Planned | — |
| Ubuntu 26.04 | Released |
1 kernel
|