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Commit 764f2162 authored by Florian Westphal's avatar Florian Westphal Committed by Greg Kroah-Hartman
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netfilter: compat: reject huge allocation requests 



commit 7d7d7e02 upstream.

no need to bother even trying to allocating huge compat offset arrays,
such ruleset is rejected later on anyway becaus we refuse to allocate
overly large rule blobs.

However, compat translation happens before blob allocation, so we should
add a check there too.

This is supposed to help with fuzzing by avoiding oom-killer.

Signed-off-by: default avatarFlorian Westphal <fw@strlen.de>
Signed-off-by: default avatarPablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent 8d92d533

net/netfilter/x_tables.c

+18 −8
Original line number Diff line number Diff line
@@ -555,14 +555,8 @@ int xt_compat_add_offset(u_int8_t af, unsigned int offset, int delta) 
{

	struct xt_af *xp = &xt[af];



	if (!xp->compat_tab) {

		if (!xp->number)

			return -EINVAL;

		xp->compat_tab = vmalloc(sizeof(struct compat_delta) * xp->number);

		if (!xp->compat_tab)

	if (WARN_ON(!xp->compat_tab))

		return -ENOMEM;

		xp->cur = 0;

	}



	if (xp->cur >= xp->number)

		return -EINVAL;
@@ -607,6 +601,22 @@ EXPORT_SYMBOL_GPL(xt_compat_calc_jump); 


int xt_compat_init_offsets(u8 af, unsigned int number)

{

	size_t mem;



	if (!number || number > (INT_MAX / sizeof(struct compat_delta)))

		return -EINVAL;



	if (WARN_ON(xt[af].compat_tab))

		return -EINVAL;



	mem = sizeof(struct compat_delta) * number;

	if (mem > XT_MAX_TABLE_SIZE)

		return -ENOMEM;



	xt[af].compat_tab = vmalloc(mem);

	if (!xt[af].compat_tab)

		return -ENOMEM;



	xt[af].number = number;

	xt[af].cur = 0;