{"id":"AZL-89115","summary":"CVE-2026-46114 affecting package kernel for versions less than 6.6.141.1-1","details":"In the Linux kernel, the following vulnerability has been resolved:\n\nRDMA/rxe: Reject non-8-byte ATOMIC_WRITE payloads\n\natomic_write_reply() at drivers/infiniband/sw/rxe/rxe_resp.c\nunconditionally dereferences 8 bytes at payload_addr(pkt):\n\n    value = *(u64 *)payload_addr(pkt);\n\ncheck_rkey() previously accepted an ATOMIC_WRITE request with pktlen ==\nresid == 0 because the length validation only compared pktlen against\nresid. A remote initiator that sets the RETH length to 0 therefore reaches\natomic_write_reply() with a zero-byte logical payload, and the responder\nreads sizeof(u64) bytes from past the logical end of the packet into\nskb-\u003ehead tailroom, then writes those 8 bytes into the attacker's MR via\nrxe_mr_do_atomic_write(). That is a remote disclosure of 4 bytes of kernel\ntailroom per probe (the other 4 bytes are the packet's own trailing ICRC).\n\nIBA oA19-28 defines ATOMIC_WRITE as exactly 8 bytes. Anything else is\nprotocol-invalid. Hoist a strict length check into check_rkey() so the\nresponder never reaches the unchecked dereference, and keep the existing\nWRITE-family length logic for the normal RDMA WRITE path.\n\nReproduced on mainline with an unmodified rxe driver: a sustained\nzero-length ATOMIC_WRITE probe repeatedly leaks adjacent skb head-buffer\nbytes into the attacker's MR, including recognisable kernel strings and\npartial kernel-direct-map pointer words.  With this patch applied the\nresponder rejects the PDU and the MR stays all-zero.","modified":"2026-08-28T17:48:10.282501201Z","published":"2026-05-28T10:16:26Z","upstream":["CVE-2026-46114"],"references":[{"type":"WEB","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-46114"}],"affected":[{"package":{"name":"kernel","ecosystem":"Azure Linux:3","purl":"pkg:rpm/azure-linux/kernel"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"6.6.141.1-1"}]}],"database_specific":{"source":"https://github.com/microsoft/AzureLinuxVulnerabilityData/blob/main/osv/AZL-89115.json"}}],"schema_version":"1.9.0"}