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CVE-2026-89784

SUNRPC: check rpc_sockaddr2uaddr() return value in rpcb_register_inet4/6

Published
Last modified
published
Not listed in CISA KEV
Fix
Fixed in 5.10.270, 5.15.221, 6.1.188, 6.6.157, 6.12.110, and 2 more
None on Exploit-DB, Metasploit or GitHub

Summary

In the Linux kernel, the following vulnerability has been resolved: SUNRPC: check rpc_sockaddr2uaddr() return value in rpcb_register_inet4/6 rpcb_register_inet4() and rpcb_register_inet6() store the result of rpc_sockaddr2uaddr() into map->r_addr without checking it for NULL. rpc_sockaddr2uaddr() returns NULL when its final kstrdup() fails, and the unchecked NULL is then carried into the synchronous RPCBPROC_SET encode path: rpcb_register_call() -> rpc_call_sync() -> rpcb_enc_getaddr() -> encode_rpcb_string(), whose first statement is strlen(string), dereferencing NULL and oopsing the kernel. The crash reproduces under failslab on v6.12; with KASAN the NULL dereference surfaces as a fault on the shadow of address zero: Oops: general protection fault, probably for non-canonical address 0xdffffc0000000000 [#1] PREEMPT SMP KASAN RIP: 0010:strlen (lib/string.c:409) Call Trace: encode_rpcb_string (net/sunrpc/rpcb_clnt.c:890) rpcb_enc_getaddr (net/sunrpc/rpcb_clnt.c:910) rpcauth_wrap_req_encode (net/sunrpc/auth.c:745) call_encode (net/sunrpc/clnt.c:1966) __rpc_execute (net/sunrpc/sched.c:952) rpc_run_task (net/sunrpc/clnt.c:1243) rpc_call_sync (net/sunrpc/clnt.c:1272) rpcb_v4_register (net/sunrpc/rpcb_clnt.c:500) svc_generic_rpcbind_set nfsd_rpcbind_set svc_register svc_setup_socket svc_addsock write_ports nfsctl_transaction_write vfs_write The crash is reachable when an in-kernel RPC service (nfsd, lockd, nfs-callback) registers with the local rpcbind under enough memory pressure for the small GFP_KERNEL kstrdup() in rpc_sockaddr2uaddr() to fail. The asynchronous getport path already handles this exact failure mode by returning -ENOMEM; only the two register helpers omit the check. Mirror that handling: bail out with -ENOMEM when rpc_sockaddr2uaddr() returns NULL, before the address is fed into the encoder.

Timeline

  1. CVE published
  2. Record last updated

Affected versions

  • Linux Linux

    From d77385f23830ee6c400569bac8b37e6eb3b7d360 · fixed in 04441b792ec40eb66349b5fab34b6a2090b5b2dd; From d77385f23830ee6c400569bac8b37e6eb3b7d360 · fixed in 5a51c49ddb37b883566874aecc66bc5a2e617a96; From d77385f23830ee6c400569bac8b37e6eb3b7d360 · fixed in 4a6095de8cb1858e05bdf70b3e7d6d7645c25041; From d77385f23830ee6c400569bac8b37e6eb3b7d360 · fixed in 12bf3e0182ccdaf3b412756a756d3944a7dacaa9; From d77385f23830ee6c400569bac8b37e6eb3b7d360 · fixed in 4e01022974355732e748ec8ebc97c558cb624ffe; From d77385f23830ee6c400569bac8b37e6eb3b7d360 · fixed in cda4aacfb0bbf5c0f90fd0b42c72c749635d1368; From d77385f23830ee6c400569bac8b37e6eb3b7d360 · fixed in eb476289c12cc22c8766f8a84eeb7ab46c4e8fb6; From d77385f23830ee6c400569bac8b37e6eb3b7d360 · fixed in fd22370226a0d8109045d0831fd5aaadee921693

  • Linux Linux

    3.2

  • KernelLinux

    From 3.2.0 · fixed in 5.10.270; From 5.11.0 · fixed in 5.15.221; From 5.16.0 · fixed in 6.1.188; From 6.2.0 · fixed in 6.6.157; From 6.7.0 · fixed in 6.12.110; From 6.13.0 · fixed in 6.18.52; From 6.19.0 · fixed in 7.2.6

References 8

git.kernel.org