From 020ef930b826d21c5446fdc9db80fd72a791bc21 Mon Sep 17 00:00:00 2001 From: Taehee Yoo Date: Sun, 16 May 2021 14:44:42 +0000 Subject: mld: fix panic in mld_newpack() mld_newpack() doesn't allow to allocate high order page, only order-0 allocation is allowed. If headroom size is too large, a kernel panic could occur in skb_put(). Test commands: ip netns del A ip netns del B ip netns add A ip netns add B ip link add veth0 type veth peer name veth1 ip link set veth0 netns A ip link set veth1 netns B ip netns exec A ip link set lo up ip netns exec A ip link set veth0 up ip netns exec A ip -6 a a 2001:db8:0::1/64 dev veth0 ip netns exec B ip link set lo up ip netns exec B ip link set veth1 up ip netns exec B ip -6 a a 2001:db8:0::2/64 dev veth1 for i in {1..99} do let A=$i-1 ip netns exec A ip link add ip6gre$i type ip6gre \ local 2001:db8:$A::1 remote 2001:db8:$A::2 encaplimit 100 ip netns exec A ip -6 a a 2001:db8:$i::1/64 dev ip6gre$i ip netns exec A ip link set ip6gre$i up ip netns exec B ip link add ip6gre$i type ip6gre \ local 2001:db8:$A::2 remote 2001:db8:$A::1 encaplimit 100 ip netns exec B ip -6 a a 2001:db8:$i::2/64 dev ip6gre$i ip netns exec B ip link set ip6gre$i up done Splat looks like: kernel BUG at net/core/skbuff.c:110! invalid opcode: 0000 [#1] SMP DEBUG_PAGEALLOC KASAN PTI CPU: 0 PID: 7 Comm: kworker/0:1 Not tainted 5.12.0+ #891 Workqueue: ipv6_addrconf addrconf_dad_work RIP: 0010:skb_panic+0x15d/0x15f Code: 92 fe 4c 8b 4c 24 10 53 8b 4d 70 45 89 e0 48 c7 c7 00 ae 79 83 41 57 41 56 41 55 48 8b 54 24 a6 26 f9 ff <0f> 0b 48 8b 6c 24 20 89 34 24 e8 4a 4e 92 fe 8b 34 24 48 c7 c1 20 RSP: 0018:ffff88810091f820 EFLAGS: 00010282 RAX: 0000000000000089 RBX: ffff8881086e9000 RCX: 0000000000000000 RDX: 0000000000000089 RSI: 0000000000000008 RDI: ffffed1020123efb RBP: ffff888005f6eac0 R08: ffffed1022fc0031 R09: ffffed1022fc0031 R10: ffff888117e00187 R11: ffffed1022fc0030 R12: 0000000000000028 R13: ffff888008284eb0 R14: 0000000000000ed8 R15: 0000000000000ec0 FS: 0000000000000000(0000) GS:ffff888117c00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f8b801c5640 CR3: 0000000033c2c006 CR4: 00000000003706f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: ? ip6_mc_hdr.isra.26.constprop.46+0x12a/0x600 ? ip6_mc_hdr.isra.26.constprop.46+0x12a/0x600 skb_put.cold.104+0x22/0x22 ip6_mc_hdr.isra.26.constprop.46+0x12a/0x600 ? rcu_read_lock_sched_held+0x91/0xc0 mld_newpack+0x398/0x8f0 ? ip6_mc_hdr.isra.26.constprop.46+0x600/0x600 ? lock_contended+0xc40/0xc40 add_grhead.isra.33+0x280/0x380 add_grec+0x5ca/0xff0 ? mld_sendpack+0xf40/0xf40 ? lock_downgrade+0x690/0x690 mld_send_initial_cr.part.34+0xb9/0x180 ipv6_mc_dad_complete+0x15d/0x1b0 addrconf_dad_completed+0x8d2/0xbb0 ? lock_downgrade+0x690/0x690 ? addrconf_rs_timer+0x660/0x660 ? addrconf_dad_work+0x73c/0x10e0 addrconf_dad_work+0x73c/0x10e0 Allowing high order page allocation could fix this problem. Fixes: 72e09ad107e7 ("ipv6: avoid high order allocations") Signed-off-by: Taehee Yoo Signed-off-by: David S. Miller --- net/ipv6/mcast.c | 3 --- 1 file changed, 3 deletions(-) (limited to 'net/ipv6') diff --git a/net/ipv6/mcast.c b/net/ipv6/mcast.c index 0d59efb6b49e..d36ef9d25e73 100644 --- a/net/ipv6/mcast.c +++ b/net/ipv6/mcast.c @@ -1745,10 +1745,7 @@ static struct sk_buff *mld_newpack(struct inet6_dev *idev, unsigned int mtu) IPV6_TLV_PADN, 0 }; /* we assume size > sizeof(ra) here */ - /* limit our allocations to order-0 page */ - size = min_t(int, size, SKB_MAX_ORDER(0, 0)); skb = sock_alloc_send_skb(sk, size, 1, &err); - if (!skb) return NULL; -- cgit v1.2.3 From e29f011e8fc04b2cdc742a2b9bbfa1b62518381a Mon Sep 17 00:00:00 2001 From: Francesco Ruggeri Date: Fri, 21 May 2021 13:21:14 -0700 Subject: ipv6: record frag_max_size in atomic fragments in input path Commit dbd1759e6a9c ("ipv6: on reassembly, record frag_max_size") filled the frag_max_size field in IP6CB in the input path. The field should also be filled in case of atomic fragments. Fixes: dbd1759e6a9c ('ipv6: on reassembly, record frag_max_size') Signed-off-by: Francesco Ruggeri Signed-off-by: David S. Miller --- net/ipv6/reassembly.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) (limited to 'net/ipv6') diff --git a/net/ipv6/reassembly.c b/net/ipv6/reassembly.c index 47a0dc46cbdb..28e44782c94d 100644 --- a/net/ipv6/reassembly.c +++ b/net/ipv6/reassembly.c @@ -343,7 +343,7 @@ static int ipv6_frag_rcv(struct sk_buff *skb) hdr = ipv6_hdr(skb); fhdr = (struct frag_hdr *)skb_transport_header(skb); - if (!(fhdr->frag_off & htons(0xFFF9))) { + if (!(fhdr->frag_off & htons(IP6_OFFSET | IP6_MF))) { /* It is not a fragmented frame */ skb->transport_header += sizeof(struct frag_hdr); __IP6_INC_STATS(net, @@ -351,6 +351,8 @@ static int ipv6_frag_rcv(struct sk_buff *skb) IP6CB(skb)->nhoff = (u8 *)fhdr - skb_network_header(skb); IP6CB(skb)->flags |= IP6SKB_FRAGMENTED; + IP6CB(skb)->frag_max_size = ntohs(hdr->payload_len) + + sizeof(struct ipv6hdr); return 1; } -- cgit v1.2.3