From 660aabbf7d7004810eebde534df4ecdb182846c3 Mon Sep 17 00:00:00 2001 From: Taehee Yoo Date: Wed, 11 Dec 2019 08:23:17 +0000 Subject: [PATCH] gtp: fix wrong condition in gtp_genl_dump_pdp() BugLink: https://bugs.launchpad.net/bugs/1860816 [ Upstream commit 94a6d9fb88df43f92d943c32b84ce398d50bf49f ] gtp_genl_dump_pdp() is ->dumpit() callback of GTP module and it is used to dump pdp contexts. it would be re-executed because of dump packet size. If dump packet size is too big, it saves current dump pointer (gtp interface pointer, bucket, TID value) then it restarts dump from last pointer. Current GTP code allows adding zero TID pdp context but dump code ignores zero TID value. So, last dump pointer will not be found. In addition, this patch adds missing rcu_read_lock() in gtp_genl_dump_pdp(). Fixes: 459aa660eb1d ("gtp: add initial driver for datapath of GPRS Tunneling Protocol (GTP-U)") Signed-off-by: Taehee Yoo Signed-off-by: Jakub Kicinski Signed-off-by: Greg Kroah-Hartman Signed-off-by: Kamal Mostafa Signed-off-by: Khalid Elmously --- drivers/net/gtp.c | 36 +++++++++++++++++++----------------- 1 file changed, 19 insertions(+), 17 deletions(-) diff --git a/drivers/net/gtp.c b/drivers/net/gtp.c index 1f754e30baf2..a0595b67ad47 100644 --- a/drivers/net/gtp.c +++ b/drivers/net/gtp.c @@ -38,7 +38,6 @@ struct pdp_ctx { struct hlist_node hlist_addr; union { - u64 tid; struct { u64 tid; u16 flow; @@ -1244,43 +1243,46 @@ static int gtp_genl_dump_pdp(struct sk_buff *skb, struct netlink_callback *cb) { struct gtp_dev *last_gtp = (struct gtp_dev *)cb->args[2], *gtp; + int i, j, bucket = cb->args[0], skip = cb->args[1]; struct net *net = sock_net(skb->sk); - struct gtp_net *gn = net_generic(net, gtp_net_id); - unsigned long tid = cb->args[1]; - int i, k = cb->args[0], ret; struct pdp_ctx *pctx; + struct gtp_net *gn; + + gn = net_generic(net, gtp_net_id); if (cb->args[4]) return 0; + rcu_read_lock(); list_for_each_entry_rcu(gtp, &gn->gtp_dev_list, list) { if (last_gtp && last_gtp != gtp) continue; else last_gtp = NULL; - for (i = k; i < gtp->hash_size; i++) { - hlist_for_each_entry_rcu(pctx, >p->tid_hash[i], hlist_tid) { - if (tid && tid != pctx->u.tid) - continue; - else - tid = 0; - - ret = gtp_genl_fill_info(skb, - NETLINK_CB(cb->skb).portid, - cb->nlh->nlmsg_seq, - cb->nlh->nlmsg_type, pctx); - if (ret < 0) { + for (i = bucket; i < gtp->hash_size; i++) { + j = 0; + hlist_for_each_entry_rcu(pctx, >p->tid_hash[i], + hlist_tid) { + if (j >= skip && + gtp_genl_fill_info(skb, + NETLINK_CB(cb->skb).portid, + cb->nlh->nlmsg_seq, + cb->nlh->nlmsg_type, pctx)) { cb->args[0] = i; - cb->args[1] = pctx->u.tid; + cb->args[1] = j; cb->args[2] = (unsigned long)gtp; goto out; } + j++; } + skip = 0; } + bucket = 0; } cb->args[4] = 1; out: + rcu_read_unlock(); return skb->len; } -- 2.39.2