ipmr: properly check rhltable_init() return value

edumazet · gregkh · commit f1409a73b6f4 · 2018-06-11T22:49:19.000+02:00
[ Upstream commit 66fb332 ] commit 8fb472c ("ipmr: improve hash scalability") added a call to rhltable_init() without checking its return value. This problem was then later copied to IPv6 and factorized in commit 0bbbf0e ("ipmr, ip6mr: Unite creation of new mr_table") kasan: CONFIG_KASAN_INLINE enabled kasan: GPF could be caused by NULL-ptr deref or user memory access general protection fault: 0000 [#1] SMP KASAN Dumping ftrace buffer: (ftrace buffer empty) Modules linked in: CPU: 1 PID: 31552 Comm: syz-executor7 Not tainted 4.17.0-rc5+ #60 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:rht_key_hashfn include/linux/rhashtable.h:277 [inline] RIP: 0010:__rhashtable_lookup include/linux/rhashtable.h:630 [inline] RIP: 0010:rhltable_lookup include/linux/rhashtable.h:716 [inline] RIP: 0010:mr_mfc_find_parent+0x2ad/0xbb0 net/ipv4/ipmr_base.c:63 RSP: 0018:ffff8801826aef70 EFLAGS: 00010203 RAX: 0000000000000001 RBX: 0000000000000001 RCX: ffffc90001ea0000 RDX: 0000000000000079 RSI: ffffffff8661e859 RDI: 000000000000000c RBP: ffff8801826af1c0 R08: ffff8801b2212000 R09: ffffed003b5e46c2 R10: ffffed003b5e46c2 R11: ffff8801daf23613 R12: dffffc0000000000 R13: ffff8801826af198 R14: ffff8801cf8225c0 R15: ffff8801826af658 FS: 00007ff7fa732700(0000) GS:ffff8801daf00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00000003ffffff9c CR3: 00000001b0210000 CR4: 00000000001406e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: ip6mr_cache_find_parent net/ipv6/ip6mr.c:981 [inline] ip6mr_mfc_delete+0x1fe/0x6b0 net/ipv6/ip6mr.c:1221 ip6_mroute_setsockopt+0x15c6/0x1d70 net/ipv6/ip6mr.c:1698 do_ipv6_setsockopt.isra.9+0x422/0x4660 net/ipv6/ipv6_sockglue.c:163 ipv6_setsockopt+0xbd/0x170 net/ipv6/ipv6_sockglue.c:922 rawv6_setsockopt+0x59/0x140 net/ipv6/raw.c:1060 sock_common_setsockopt+0x9a/0xe0 net/core/sock.c:3039 __sys_setsockopt+0x1bd/0x390 net/socket.c:1903 __do_sys_setsockopt net/socket.c:1914 [inline] __se_sys_setsockopt net/socket.c:1911 [inline] __x64_sys_setsockopt+0xbe/0x150 net/socket.c:1911 do_syscall_64+0x1b1/0x800 arch/x86/entry/common.c:287 entry_SYSCALL_64_after_hwframe+0x49/0xbe Fixes: 8fb472c ("ipmr: improve hash scalability") Fixes: 0bbbf0e ("ipmr, ip6mr: Unite creation of new mr_table") Signed-off-by: Eric Dumazet <edumazet@google.com> Cc: Nikolay Aleksandrov <nikolay@cumulusnetworks.com> Cc: Yuval Mintz <yuvalm@mellanox.com> Reported-by: syzbot <syzkaller@googlegroups.com> Acked-by: Nikolay Aleksandrov <nikolay@cumulusnetworks.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
diff --git a/net/ipv4/ipmr.c b/net/ipv4/ipmr.c
@@ -323,6 +323,7 @@ static const struct rhashtable_params ipmr_rht_params = {
 static struct mr_table *ipmr_new_table(struct net *net, u32 id)
 {
 	struct mr_table *mrt;
+	int err;
 
 	/* "pimreg%u" should not exceed 16 bytes (IFNAMSIZ) */
 	if (id != RT_TABLE_DEFAULT && id >= 1000000000)
@@ -338,7 +339,11 @@ static struct mr_table *ipmr_new_table(struct net *net, u32 id)
 	write_pnet(&mrt->net, net);
 	mrt->id = id;
 
-	rhltable_init(&mrt->mfc_hash, &ipmr_rht_params);
+	err = rhltable_init(&mrt->mfc_hash, &ipmr_rht_params);
+	if (err) {
+		kfree(mrt);
+		return ERR_PTR(err);
+	}
 	INIT_LIST_HEAD(&mrt->mfc_cache_list);
 	INIT_LIST_HEAD(&mrt->mfc_unres_queue);
 
