[Linux-kernel-mentees] [PATCH net] tipc: Fix memory leak in tipc_group_create_member()
From: Peilin Ye <hidden>
Date: 2020-09-12 10:24:33
Also in:
linux-kernel-mentees, lkml
Subsystem:
networking [general], the rest, tipc network layer · Maintainers:
"David S. Miller", Eric Dumazet, Jakub Kicinski, Paolo Abeni, Linus Torvalds, Jon Maloy
tipc_group_add_to_tree() returns silently if `key` matches `nkey` of an
existing node, causing tipc_group_create_member() to leak memory. Let
tipc_group_add_to_tree() return an error in such a case, so that
tipc_group_create_member() can handle it properly.
Fixes: 75da2163dbb6 ("tipc: introduce communication groups")
Reported-and-tested-by: syzbot+f95d90c454864b3b5bc9@syzkaller.appspotmail.com
Cc: Hillf Danton <redacted>
Link: https://syzkaller.appspot.com/bug?id=048390604fe1b60df34150265479202f10e13aff
Signed-off-by: Peilin Ye <redacted>
---
Decoded syzbot reproducer in pseudo-C:
fd0 = socket(AF_TIPC, SOCK_DGRAM, 0);
sockaddr_tipc.family = AF_TIPC;
sockaddr_tipc.addrtype = TIPC_ADDR_NAMESEQ;
sockaddr_tipc.scope = 0;
sockaddr_tipc.addr.namesq.type = TIPC_RESERVED_TYPES + 1;
bind(fd0, &sockaddr_tipc, sizeof(sockaddr_tipc));
tipc_group_req0.type = TIPC_RESERVED_TYPES + 1;
setsockopt(fd0, SOL_TIPC, TIPC_GROUP_JOIN, &tipc_group_req0, sizeof(tipc_group_req0));
fd1 = socket(AF_TIPC, SOCK_STREAM, 0);
tipc_group_req1.type = TIPC_RESERVED_TYPES + 1;
tipc_group_req1.scope = TIPC_CLUSTER_SCOPE;
setsockopt(fd1, SOL_TIPC, TIPC_GROUP_JOIN, &tipc_group_req1, sizeof(tipc_group_req1));
net/tipc/group.c | 14 ++++++++++----
1 file changed, 10 insertions(+), 4 deletions(-)
diff --git a/net/tipc/group.c b/net/tipc/group.c
index 588c2d2b0c69..553cf08b4d76 100644
--- a/net/tipc/group.c
+++ b/net/tipc/group.c@@ -273,8 +273,8 @@ static struct tipc_member *tipc_group_find_node(struct tipc_group *grp, return NULL; } -static void tipc_group_add_to_tree(struct tipc_group *grp, - struct tipc_member *m) +static int tipc_group_add_to_tree(struct tipc_group *grp, + struct tipc_member *m) { u64 nkey, key = (u64)m->node << 32 | m->port; struct rb_node **n, *parent = NULL;
@@ -291,10 +291,11 @@ static void tipc_group_add_to_tree(struct tipc_group *grp, else if (key > nkey) n = &(*n)->rb_right; else - return; + return -1; } rb_link_node(&m->tree_node, parent, n); rb_insert_color(&m->tree_node, &grp->members); + return 0; } static struct tipc_member *tipc_group_create_member(struct tipc_group *grp,
@@ -302,6 +303,7 @@ static struct tipc_member *tipc_group_create_member(struct tipc_group *grp, u32 instance, int state) { struct tipc_member *m; + int ret; m = kzalloc(sizeof(*m), GFP_ATOMIC); if (!m)
@@ -314,8 +316,12 @@ static struct tipc_member *tipc_group_create_member(struct tipc_group *grp, m->port = port; m->instance = instance; m->bc_acked = grp->bc_snd_nxt - 1; + ret = tipc_group_add_to_tree(grp, m); + if (ret < 0) { + kfree(m); + return NULL; + } grp->member_cnt++; - tipc_group_add_to_tree(grp, m); tipc_nlist_add(&grp->dests, m->node); m->state = state; return m;
--
2.25.1