From: Marc Dionne marc.dionne@auristor.com
[ Upstream commit 9bd0160d12370a076e44f8d1320cde9c83f2c647 ]
afs_find_server tries to find a server that has an address that matches the transport address of an rxrpc peer. The code assumes that the transport address is always ipv6, with ipv4 represented as ipv4 mapped addresses, but that's not the case. If the transport family is AF_INET, srx->transport.sin6.sin6_addr.s6_addr32[] will be beyond the actual ipv4 address and will always be 0, and all ipv4 addresses will be seen as matching.
As a result, the first ipv4 address seen on any server will be considered a match, and the server returned may be the wrong one.
One of the consequences is that callbacks received over ipv4 will only be correctly applied for the server that happens to have the first ipv4 address on the fs_addresses4 list. Callbacks over ipv4 from all other servers are dropped, causing the client to serve stale data.
This is fixed by looking at the transport family, and comparing ipv4 addresses based on a sockaddr_in structure rather than a sockaddr_in6.
Fixes: d2ddc776a458 ("afs: Overhaul volume and server record caching and fileserver rotation") Signed-off-by: Marc Dionne marc.dionne@auristor.com Signed-off-by: David Howells dhowells@redhat.com Signed-off-by: Sasha Levin sashal@kernel.org --- fs/afs/server.c | 21 ++++++++------------- 1 file changed, 8 insertions(+), 13 deletions(-)
diff --git a/fs/afs/server.c b/fs/afs/server.c index 64d440aaabc0..ca8115ba1724 100644 --- a/fs/afs/server.c +++ b/fs/afs/server.c @@ -32,18 +32,11 @@ static void afs_dec_servers_outstanding(struct afs_net *net) struct afs_server *afs_find_server(struct afs_net *net, const struct sockaddr_rxrpc *srx) { - const struct sockaddr_in6 *a = &srx->transport.sin6, *b; const struct afs_addr_list *alist; struct afs_server *server = NULL; unsigned int i; - bool ipv6 = true; int seq = 0, diff;
- if (srx->transport.sin6.sin6_addr.s6_addr32[0] == 0 || - srx->transport.sin6.sin6_addr.s6_addr32[1] == 0 || - srx->transport.sin6.sin6_addr.s6_addr32[2] == htonl(0xffff)) - ipv6 = false; - rcu_read_lock();
do { @@ -52,7 +45,8 @@ struct afs_server *afs_find_server(struct afs_net *net, server = NULL; read_seqbegin_or_lock(&net->fs_addr_lock, &seq);
- if (ipv6) { + if (srx->transport.family == AF_INET6) { + const struct sockaddr_in6 *a = &srx->transport.sin6, *b; hlist_for_each_entry_rcu(server, &net->fs_addresses6, addr6_link) { alist = rcu_dereference(server->addresses); for (i = alist->nr_ipv4; i < alist->nr_addrs; i++) { @@ -68,15 +62,16 @@ struct afs_server *afs_find_server(struct afs_net *net, } } } else { + const struct sockaddr_in *a = &srx->transport.sin, *b; hlist_for_each_entry_rcu(server, &net->fs_addresses4, addr4_link) { alist = rcu_dereference(server->addresses); for (i = 0; i < alist->nr_ipv4; i++) { - b = &alist->addrs[i].transport.sin6; - diff = ((u16 __force)a->sin6_port - - (u16 __force)b->sin6_port); + b = &alist->addrs[i].transport.sin; + diff = ((u16 __force)a->sin_port - + (u16 __force)b->sin_port); if (diff == 0) - diff = ((u32 __force)a->sin6_addr.s6_addr32[3] - - (u32 __force)b->sin6_addr.s6_addr32[3]); + diff = ((u32 __force)a->sin_addr.s_addr - + (u32 __force)b->sin_addr.s_addr); if (diff == 0) goto found; }