Commit e7480a44 authored by Jakub Kicinski's avatar Jakub Kicinski
Browse files

Revert "net: Remove low_thresh in ip defrag" 



This reverts commit b2cbac9b.

We have multiple reports of obvious breakage from this patch.

Reported-by: default avatarIdo Schimmel <idosch@idosch.org>
Link: https://lore.kernel.org/all/ZGIRWjNcfqI8yY8W@shredder/
Link: https://lore.kernel.org/all/CADJHv_sDK=0RrMA2FTZQV5fw7UQ+qY=HG21Wu5qb0V9vvx5w6A@mail.gmail.com/


Reported-by: default avatar <syzbot+a5e719ac7c268e414c95@syzkaller.appspotmail.com>
Reported-by: default avatar <syzbot+a03fd670838d927d9cd8@syzkaller.appspotmail.com>
Fixes: b2cbac9b ("net: Remove low_thresh in ip defrag")
Link: https://lore.kernel.org/r/20230517034112.1261835-1-kuba@kernel.org


Signed-off-by: default avatarJakub Kicinski <kuba@kernel.org>
parent a0e35a64

Documentation/networking/nf_conntrack-sysctl.rst

+0 −1
Original line number Diff line number Diff line
@@ -55,7 +55,6 @@ nf_conntrack_frag6_high_thresh - INTEGER 
	nf_conntrack_frag6_low_thresh is reached.



nf_conntrack_frag6_low_thresh - INTEGER

	(Obsolete since linux-4.17)

	default 196608



	See nf_conntrack_frag6_low_thresh

include/net/inet_frag.h

+1 −0
Original line number Diff line number Diff line
@@ -13,6 +13,7 @@ 
struct fqdir {

	/* sysctls */

	long			high_thresh;

	long			low_thresh;

	int			timeout;

	int			max_dist;

	struct inet_frags	*f;

net/ieee802154/6lowpan/reassembly.c

+5 −4
Original line number Diff line number Diff line
@@ -318,7 +318,7 @@ int lowpan_frag_rcv(struct sk_buff *skb, u8 frag_type) 
}



#ifdef CONFIG_SYSCTL

static unsigned long lowpanfrag_low_thresh_unuesd = IPV6_FRAG_LOW_THRESH;



static struct ctl_table lowpan_frags_ns_ctl_table[] = {

	{

		.procname	= "6lowpanfrag_high_thresh",
@@ -374,8 +374,8 @@ static int __net_init lowpan_frags_ns_sysctl_register(struct net *net) 
	}



	table[0].data	= &ieee802154_lowpan->fqdir->high_thresh;

	table[0].extra1 = &lowpanfrag_low_thresh_unuesd;

	table[1].data   = &lowpanfrag_low_thresh_unuesd;

	table[0].extra1	= &ieee802154_lowpan->fqdir->low_thresh;

	table[1].data	= &ieee802154_lowpan->fqdir->low_thresh;

	table[1].extra2	= &ieee802154_lowpan->fqdir->high_thresh;

	table[2].data	= &ieee802154_lowpan->fqdir->timeout;
@@ -451,6 +451,7 @@ static int __net_init lowpan_frags_init_net(struct net *net) 
		return res;



	ieee802154_lowpan->fqdir->high_thresh = IPV6_FRAG_HIGH_THRESH;

	ieee802154_lowpan->fqdir->low_thresh = IPV6_FRAG_LOW_THRESH;

	ieee802154_lowpan->fqdir->timeout = IPV6_FRAG_TIMEOUT;



	res = lowpan_frags_ns_sysctl_register(net);

net/ipv4/ip_fragment.c

+8 −5
Original line number Diff line number Diff line
@@ -553,7 +553,7 @@ EXPORT_SYMBOL(ip_check_defrag); 


#ifdef CONFIG_SYSCTL

static int dist_min;

static unsigned long ipfrag_low_thresh_unused;



static struct ctl_table ip4_frags_ns_ctl_table[] = {

	{

		.procname	= "ipfrag_high_thresh",
@@ -609,8 +609,8 @@ static int __net_init ip4_frags_ns_ctl_register(struct net *net) 


	}

	table[0].data	= &net->ipv4.fqdir->high_thresh;

	table[0].extra1 = &ipfrag_low_thresh_unused;

	table[1].data	= &ipfrag_low_thresh_unused;

	table[0].extra1	= &net->ipv4.fqdir->low_thresh;

	table[1].data	= &net->ipv4.fqdir->low_thresh;

	table[1].extra2	= &net->ipv4.fqdir->high_thresh;

	table[2].data	= &net->ipv4.fqdir->timeout;

	table[3].data	= &net->ipv4.fqdir->max_dist;
@@ -674,9 +674,12 @@ static int __net_init ipv4_frags_init_net(struct net *net) 
	 * A 64K fragment consumes 129736 bytes (44*2944)+200

	 * (1500 truesize == 2944, sizeof(struct ipq) == 200)

	 *

	 * We will commit 4MB at one time. Should we cross that limit.

	 * We will commit 4MB at one time. Should we cross that limit

	 * we will prune down to 3MB, making room for approx 8 big 64K

	 * fragments 8x128k.

	 */

	net->ipv4.fqdir->high_thresh = 4 * 1024 * 1024;

	net->ipv4.fqdir->low_thresh  = 3 * 1024 * 1024;

	/*

	 * Important NOTE! Fragment queue must be destroyed before MSL expires.

	 * RFC791 is wrong proposing to prolongate timer each fragment arrival

net/ipv6/netfilter/nf_conntrack_reasm.c

+5 −4
Original line number Diff line number Diff line
@@ -42,7 +42,7 @@ static struct nft_ct_frag6_pernet *nf_frag_pernet(struct net *net) 
}



#ifdef CONFIG_SYSCTL

static unsigned long nf_conntrack_frag6_low_thresh_unused = IPV6_FRAG_LOW_THRESH;



static struct ctl_table nf_ct_frag6_sysctl_table[] = {

	{

		.procname	= "nf_conntrack_frag6_timeout",
@@ -82,10 +82,10 @@ static int nf_ct_frag6_sysctl_register(struct net *net) 
	nf_frag = nf_frag_pernet(net);



	table[0].data	= &nf_frag->fqdir->timeout;

	table[1].data	= &nf_conntrack_frag6_low_thresh_unused;

	table[1].data	= &nf_frag->fqdir->low_thresh;

	table[1].extra2	= &nf_frag->fqdir->high_thresh;

	table[2].data	= &nf_frag->fqdir->high_thresh;

	table[2].extra1 = &nf_conntrack_frag6_low_thresh_unused;

	table[2].extra1	= &nf_frag->fqdir->low_thresh;



	hdr = register_net_sysctl(net, "net/netfilter", table);

	if (hdr == NULL)
@@ -500,6 +500,7 @@ static int nf_ct_net_init(struct net *net) 
		return res;



	nf_frag->fqdir->high_thresh = IPV6_FRAG_HIGH_THRESH;

	nf_frag->fqdir->low_thresh = IPV6_FRAG_LOW_THRESH;

	nf_frag->fqdir->timeout = IPV6_FRAG_TIMEOUT;



	res = nf_ct_frag6_sysctl_register(net);