diff options
| author | Jeff Layton <jlayton@kernel.org> | 2026-06-02 12:23:17 -0400 |
|---|---|---|
| committer | Chuck Lever <cel@kernel.org> | 2026-08-10 09:54:35 -0400 |
| commit | a99d720ed2a5258564e5e9d5f39f3184a030d354 (patch) | |
| tree | 13095d61796aa8422d4024587f85c03a6c66ae13 | |
| parent | 9f1ddfc8cb9076592401a611eb3a44d36186d014 (diff) | |
nfsd: widen nfsd_genl_rqstp address fields to sockaddr_storage
struct nfsd_genl_rqstp declares rq_daddr and rq_saddr as plain
"struct sockaddr" (16 bytes). When an IPv6 NFS client is connected,
nfsd_genl_rpc_status_compose_msg() casts these fields to
"struct sockaddr_in6 *" (28 bytes) and reads sin6_addr at offset 8..24,
which extends 8 bytes past the end of the 16-byte sockaddr field into
the adjacent rq_flags member. The 16-byte nla_put_in6_addr then ships 8
bytes of truncated IPv6 address followed by 8 bytes of rq_flags to
userspace via the NFSD_A_RPC_STATUS_SADDR6/DADDR6 netlink attributes.
This is reachable by any unprivileged process in the network namespace
because NFSD_CMD_RPC_STATUS_GET uses GENL_CMD_CAP_DUMP without
GENL_ADMIN_PERM.
Fix by widening rq_daddr and rq_saddr to struct sockaddr_storage so the
IPv6 casts operate within bounds, copying sizeof(struct sockaddr_storage)
bytes in the memcpy calls so the full address is captured, and
zero-initializing the genl_rqstp stack variable to prevent leaking
uninitialized tail bytes through netlink.
Fixes: bd9d6a3efa97 ("NFSD: add rpc_status netlink support")
Cc: stable@vger.kernel.org
Assisted-by: Claude:claude-opus-4-6
Signed-off-by: Jeff Layton <jlayton@kernel.org>
Link: https://patch.msgid.link/20260602-nfsd-testing-v2-5-e4ea62e3cd5c@kernel.org
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
| -rw-r--r-- | fs/nfsd/nfsctl.c | 12 |
1 files changed, 6 insertions, 6 deletions
diff --git a/fs/nfsd/nfsctl.c b/fs/nfsd/nfsctl.c index 5e3e60110ee6..c2ec30e6b51f 100644 --- a/fs/nfsd/nfsctl.c +++ b/fs/nfsd/nfsctl.c @@ -1414,8 +1414,8 @@ static int create_proc_exports_entry(void) unsigned int nfsd_net_id; struct nfsd_genl_rqstp { - struct sockaddr rq_daddr; - struct sockaddr rq_saddr; + struct sockaddr_storage rq_daddr; + struct sockaddr_storage rq_saddr; unsigned long rq_flags; ktime_t rq_stime; __be32 rq_xid; @@ -1450,7 +1450,7 @@ static int nfsd_genl_rpc_status_compose_msg(struct sk_buff *skb, NFSD_A_RPC_STATUS_PAD)) return -ENOBUFS; - switch (genl_rqstp->rq_saddr.sa_family) { + switch (genl_rqstp->rq_saddr.ss_family) { case AF_INET: { const struct sockaddr_in *s_in, *d_in; @@ -1527,7 +1527,7 @@ int nfsd_nl_rpc_status_get_dumpit(struct sk_buff *skb, list_for_each_entry_rcu(rqstp, &nn->nfsd_serv->sv_pools[i].sp_all_threads, rq_all) { - struct nfsd_genl_rqstp genl_rqstp; + struct nfsd_genl_rqstp genl_rqstp = {}; unsigned int status_counter; if (rqstp_index++ < cb->args[1]) /* already consumed */ @@ -1551,9 +1551,9 @@ int nfsd_nl_rpc_status_get_dumpit(struct sk_buff *skb, genl_rqstp.rq_stime = rqstp->rq_stime; genl_rqstp.rq_opcnt = 0; memcpy(&genl_rqstp.rq_daddr, svc_daddr(rqstp), - sizeof(struct sockaddr)); + sizeof(struct sockaddr_storage)); memcpy(&genl_rqstp.rq_saddr, svc_addr(rqstp), - sizeof(struct sockaddr)); + sizeof(struct sockaddr_storage)); #ifdef CONFIG_NFSD_V4 if (rqstp->rq_vers == NFS4_VERSION && |