| From 3a1cccf56f48bf5642ddfbf86bb069d9836fb7f0 Mon Sep 17 00:00:00 2001 |
| From: Sasha Levin <sashal@kernel.org> |
| Date: Sun, 16 May 2021 14:44:42 +0000 |
| Subject: mld: fix panic in mld_newpack() |
| |
| From: Taehee Yoo <ap420073@gmail.com> |
| |
| [ Upstream commit 020ef930b826d21c5446fdc9db80fd72a791bc21 ] |
| |
| 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 <ap420073@gmail.com> |
| Signed-off-by: David S. Miller <davem@davemloft.net> |
| Signed-off-by: Sasha Levin <sashal@kernel.org> |
| --- |
| net/ipv6/mcast.c | 3 --- |
| 1 file changed, 3 deletions(-) |
| |
| diff --git a/net/ipv6/mcast.c b/net/ipv6/mcast.c |
| index f904b9b24027..9a78b89690bd 100644 |
| --- a/net/ipv6/mcast.c |
| +++ b/net/ipv6/mcast.c |
| @@ -1580,10 +1580,7 @@ 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; |
| |
| -- |
| 2.30.2 |
| |