UBUNTU-CVE-2026-46114
In the Linux kernel, the following vulnerability has been resolved: RDMA/rxe: Reject non-8-byte ATOMIC_WRITE payloads atomic_write_reply() at drivers/infiniband/sw/rxe/rxe_resp.c unconditionally dereferences 8 bytes at payload_addr(pkt): value = *(u64 *)payload_addr(pkt); check_rkey() previously accepted an ATOMIC_WRITE request with pktlen == resid == 0 because the length validation only compared pktlen against resid. A remote initiator that sets the RETH length to 0 therefore reaches atomic_write_reply() with a zero-byte logical payload, and the responder reads sizeof(u64) bytes from past the logical end of the packet into skb->head tailroom, then writes those 8 bytes into the attacker's MR via rxe_mr_do_atomic_write(). That is a remote disclosure of 4 bytes of kernel tailroom per probe (the other 4 bytes are the packet's own trailing ICRC). IBA oA19-28 defines ATOMIC_WRITE as exactly 8 bytes. Anything else is protocol-invalid. Hoist a strict length check into check_rkey() so the responder never reaches the unchecked dereference, and keep the existing WRITE-family length logic for the normal RDMA WRITE path. Reproduced on mainline with an unmodified rxe driver: a sustained zero-length ATOMIC_WRITE probe repeatedly leaks adjacent skb head-buffer bytes into the attacker's MR, including recognisable kernel strings and partial kernel-direct-map pointer words. With this patch applied the responder rejects the PDU and the MR stays all-zero.
02 / AFFECTED SOFTWARE
Affected packages
39 explicit affected versions
18 explicit affected versions
14 explicit affected versions
6 explicit affected versions
7 explicit affected versions
4 explicit affected versions
10 explicit affected versions
1 explicit affected versions
7 explicit affected versions
13 explicit affected versions
43 explicit affected versions
16 explicit affected versions
10 explicit affected versions
8 explicit affected versions
45 explicit affected versions
14 explicit affected versions
4 explicit affected versions
78 explicit affected versions
14 explicit affected versions
11 explicit affected versions
1 explicit affected versions
19 explicit affected versions
6 explicit affected versions
11 explicit affected versions
4 explicit affected versions
50 explicit affected versions
6 explicit affected versions
39 explicit affected versions
12 explicit affected versions
19 explicit affected versions
10 explicit affected versions
6 explicit affected versions
24 explicit affected versions
2 explicit affected versions
10 explicit affected versions
37 explicit affected versions
26 explicit affected versions
7 explicit affected versions
40 explicit affected versions
13 explicit affected versions
44 explicit affected versions
35 explicit affected versions
1 explicit affected versions
18 explicit affected versions
1 explicit affected versions
45 explicit affected versions
13 explicit affected versions
4 explicit affected versions
23 explicit affected versions
52 explicit affected versions
1 explicit affected versions
21 explicit affected versions
7 explicit affected versions
16 explicit affected versions
10 explicit affected versions
20 explicit affected versions
7 explicit affected versions
48 explicit affected versions
8 explicit affected versions
7 explicit affected versions
12 explicit affected versions
11 explicit affected versions
7 explicit affected versions
12 explicit affected versions
14 explicit affected versions
10 explicit affected versions
1 explicit affected versions
7 explicit affected versions
17 explicit affected versions
12 explicit affected versions
10 explicit affected versions
12 explicit affected versions
41 explicit affected versions
9 explicit affected versions
9 explicit affected versions
16 explicit affected versions
6 explicit affected versions
17 explicit affected versions
27 explicit affected versions
34 explicit affected versions
10 explicit affected versions
37 explicit affected versions
10 explicit affected versions
11 explicit affected versions
13 explicit affected versions
39 explicit affected versions
3 explicit affected versions
10 explicit affected versions
11 explicit affected versions
26 explicit affected versions
10 explicit affected versions
13 explicit affected versions
29 explicit affected versions
13 explicit affected versions
12 explicit affected versions
41 explicit affected versions
40 explicit affected versions
8 explicit affected versions
33 explicit affected versions
23 explicit affected versions
10 explicit affected versions
20 explicit affected versions
19 explicit affected versions
11 explicit affected versions
5 explicit affected versions
12 explicit affected versions
11 explicit affected versions
7 explicit affected versions
12 explicit affected versions
10 explicit affected versions
16 explicit affected versions
17 explicit affected versions
5 explicit affected versions
10 explicit affected versions
26 explicit affected versions
39 explicit affected versions
35 explicit affected versions
48 explicit affected versions
11 explicit affected versions
10 explicit affected versions
13 explicit affected versions
46 explicit affected versions
16 explicit affected versions
50 explicit affected versions
10 explicit affected versions
3 explicit affected versions
7 explicit affected versions
15 explicit affected versions
51 explicit affected versions
16 explicit affected versions
18 explicit affected versions
43 explicit affected versions
12 explicit affected versions
7 explicit affected versions
27 explicit affected versions
3 explicit affected versions
8 explicit affected versions
43 explicit affected versions
8 explicit affected versions
3 explicit affected versions
5 explicit affected versions
8 explicit affected versions
6 explicit affected versions
10 explicit affected versions
7 explicit affected versions
46 explicit affected versions
13 explicit affected versions
13 explicit affected versions
7 explicit affected versions
8 explicit affected versions
10 explicit affected versions
12 explicit affected versions
9 explicit affected versions
44 explicit affected versions
16 explicit affected versions
3 explicit affected versions
13 explicit affected versions
26 explicit affected versions
45 explicit affected versions
37 explicit affected versions
50 explicit affected versions
14 explicit affected versions
38 explicit affected versions
9 explicit affected versions
17 explicit affected versions
11 explicit affected versions
03 / CONNECTIONS
Connected vulnerabilities
04 / EVIDENCE
Source records
In the Linux kernel, the following vulnerability has been resolved: RDMA/rxe: Reject non-8-byte ATOMIC_WRITE payloads atomic_write_reply() at drivers/infiniband/sw/rxe/rxe_resp.c unconditionally dereferences 8 bytes at payload_addr(pkt): value = *(u64 *)payload_addr(pkt); check_rkey() previously accepted an ATOMIC_WRITE request with pktlen == resid == 0 because the length validation only compared pktlen against resid. A remote initiator that sets the RETH length to 0 therefore reaches atomic_write_reply() with a zero-byte logical payload, and the responder reads sizeof(u64) bytes from past the logical end of the packet into skb->head tailroom, then writes those 8 bytes into the attacker's MR via rxe_mr_do_atomic_write(). That is a remote disclosure of 4 bytes of kernel tailroom per probe (the other 4 bytes are the packet's own trailing ICRC). IBA oA19-28 defines ATOMIC_WRITE as exactly 8 bytes. Anything else is protocol-invalid. Hoist a strict length check into check_rkey() so the responder never reaches the unchecked dereference, and keep the existing WRITE-family length logic for the normal RDMA WRITE path. Reproduced on mainline with an unmodified rxe driver: a sustained zero-length ATOMIC_WRITE probe repeatedly leaks adjacent skb head-buffer bytes into the attacker's MR, including recognisable kernel strings and partial kernel-direct-map pointer words. With this patch applied the responder rejects the PDU and the MR stays all-zero.
05 / REFERENCES
Further evidence
- https://git.kernel.org/linus/1114c87aa6f195cf07da55a27b2122ae26557b26
- https://git.kernel.org/stable/c/105bf79a23b85cf3a761d18a4f3e10ce88526bc1
- https://git.kernel.org/stable/c/1114c87aa6f195cf07da55a27b2122ae26557b26
- https://git.kernel.org/stable/c/539cabb7b2d8ba70f55bba91db55faef11c2a6d7
- https://git.kernel.org/stable/c/7ec1ed4747f5f99f8b797bb438c5efd36079fad5
- https://git.kernel.org/stable/c/d415fce3fcde6d7aeea6c25362a395b905811452
- https://ubuntu.com/security/CVE-2026-46114
- https://ubuntu.com/security/notices/USN-8566-1
- https://ubuntu.com/security/notices/USN-8567-1
- https://ubuntu.com/security/notices/USN-8568-1
- https://ubuntu.com/security/notices/USN-8569-1
- https://ubuntu.com/security/notices/USN-8574-1
- https://ubuntu.com/security/notices/USN-8574-2
- https://ubuntu.com/security/notices/USN-8574-3
- https://ubuntu.com/security/notices/USN-8593-1
- https://ubuntu.com/security/notices/USN-8595-1
- https://ubuntu.com/security/notices/USN-8595-2
- https://ubuntu.com/security/notices/USN-8595-3
- https://ubuntu.com/security/notices/USN-8596-1
- https://ubuntu.com/security/notices/USN-8603-1
- https://ubuntu.com/security/notices/USN-8606-1
- https://ubuntu.com/security/notices/USN-8607-1
- https://ubuntu.com/security/notices/USN-8608-1
- https://ubuntu.com/security/notices/USN-8609-1
- https://ubuntu.com/security/notices/USN-8618-1
- https://ubuntu.com/security/notices/USN-8619-1
- https://www.cve.org/CVERecord?id=CVE-2026-46114