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netfilter: nft_set_pipapo: prevent overflow in lookup table allocation

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[ Upstream commit 4c5c6aa9967dbe55bd017bb509885928d0f31206 ]

When calculating the lookup table size, ensure the following
multiplication does not overflow:

- desc->field_len[] maximum value is U8_MAX multiplied by
  NFT_PIPAPO_GROUPS_PER_BYTE(f) that can be 2, worst case.
- NFT_PIPAPO_BUCKETS(f->bb) is 2^8, worst case.
- sizeof(unsigned long), from sizeof(*f->lt), lt in
  struct nft_pipapo_field.

Then, use check_mul_overflow() to multiply by bucket size and then use
check_add_overflow() to the alignment for avx2 (if needed). Finally, add
lt_size_check_overflow() helper and use it to consolidate this.

While at it, replace leftover allocation using the GFP_KERNEL to
GFP_KERNEL_ACCOUNT for consistency, in pipapo_resize().

Fixes: 3c4287f620 ("nf_tables: Add set type for arbitrary concatenation of ranges")
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Reviewed-by: Stefano Brivio <sbrivio@redhat.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
This commit is contained in:
Pablo Neira Ayuso
2025-04-22 21:52:43 +02:00
committed by Greg Kroah-Hartman
parent c7b7d63a33
commit c1360ac815
1 changed files with 44 additions and 14 deletions
Download Patch File Download Diff File Expand all files Collapse all files

58
net/netfilter/nft_set_pipapo.c
View File

@@ -683,6 +683,30 @@ out_free:
return 0;
}
/**
* lt_calculate_size() - Get storage size for lookup table with overflow check
* @groups: Amount of bit groups
* @bb: Number of bits grouped together in lookup table buckets
* @bsize: Size of each bucket in lookup table, in longs
*
* Return: allocation size including alignment overhead, negative on overflow
*/
static ssize_t lt_calculate_size(unsigned int groups, unsigned int bb,
unsigned int bsize)
{
ssize_t ret = groups * NFT_PIPAPO_BUCKETS(bb) * sizeof(long);
if (check_mul_overflow(ret, bsize, &ret))
return -1;
if (check_add_overflow(ret, NFT_PIPAPO_ALIGN_HEADROOM, &ret))
return -1;
if (ret > INT_MAX)
return -1;
return ret;
}
/**
* pipapo_resize() - Resize lookup or mapping table, or both
* @f: Field containing lookup and mapping tables
@@ -701,6 +725,7 @@ static int pipapo_resize(struct nft_pipapo_field *f,
long *new_lt = NULL, *new_p, *old_lt = f->lt, *old_p;
unsigned int new_bucket_size, copy;
int group, bucket, err;
ssize_t lt_size;
if (rules >= NFT_PIPAPO_RULE0_MAX)
return -ENOSPC;
@@ -719,10 +744,11 @@ static int pipapo_resize(struct nft_pipapo_field *f,
else
copy = new_bucket_size;
new_lt = kvzalloc(f->groups * NFT_PIPAPO_BUCKETS(f->bb) *
new_bucket_size * sizeof(*new_lt) +
NFT_PIPAPO_ALIGN_HEADROOM,
GFP_KERNEL);
lt_size = lt_calculate_size(f->groups, f->bb, new_bucket_size);
if (lt_size < 0)
return -ENOMEM;
new_lt = kvzalloc(lt_size, GFP_KERNEL_ACCOUNT);
if (!new_lt)
return -ENOMEM;
@@ -907,7 +933,7 @@ static void pipapo_lt_bits_adjust(struct nft_pipapo_field *f)
{
unsigned int groups, bb;
unsigned long *new_lt;
size_t lt_size;
ssize_t lt_size;
lt_size = f->groups * NFT_PIPAPO_BUCKETS(f->bb) * f->bsize *
sizeof(*f->lt);
@@ -917,15 +943,17 @@ static void pipapo_lt_bits_adjust(struct nft_pipapo_field *f)
groups = f->groups * 2;
bb = NFT_PIPAPO_GROUP_BITS_LARGE_SET;
lt_size = groups * NFT_PIPAPO_BUCKETS(bb) * f->bsize *
sizeof(*f->lt);
lt_size = lt_calculate_size(groups, bb, f->bsize);
if (lt_size < 0)
return;
} else if (f->bb == NFT_PIPAPO_GROUP_BITS_LARGE_SET &&
lt_size < NFT_PIPAPO_LT_SIZE_LOW) {
groups = f->groups / 2;
bb = NFT_PIPAPO_GROUP_BITS_SMALL_SET;
lt_size = groups * NFT_PIPAPO_BUCKETS(bb) * f->bsize *
sizeof(*f->lt);
lt_size = lt_calculate_size(groups, bb, f->bsize);
if (lt_size < 0)
return;
/* Don't increase group width if the resulting lookup table size
* would exceed the upper size threshold for a "small" set.
@@ -936,7 +964,7 @@ static void pipapo_lt_bits_adjust(struct nft_pipapo_field *f)
return;
}
new_lt = kvzalloc(lt_size + NFT_PIPAPO_ALIGN_HEADROOM, GFP_KERNEL_ACCOUNT);
new_lt = kvzalloc(lt_size, GFP_KERNEL_ACCOUNT);
if (!new_lt)
return;
@@ -1451,13 +1479,15 @@ static struct nft_pipapo_match *pipapo_clone(struct nft_pipapo_match *old)
for (i = 0; i < old->field_count; i++) {
unsigned long *new_lt;
ssize_t lt_size;
memcpy(dst, src, offsetof(struct nft_pipapo_field, lt));
new_lt = kvzalloc(src->groups * NFT_PIPAPO_BUCKETS(src->bb) *
src->bsize * sizeof(*dst->lt) +
NFT_PIPAPO_ALIGN_HEADROOM,
GFP_KERNEL_ACCOUNT);
lt_size = lt_calculate_size(src->groups, src->bb, src->bsize);
if (lt_size < 0)
goto out_lt;
new_lt = kvzalloc(lt_size, GFP_KERNEL_ACCOUNT);
if (!new_lt)
goto out_lt;