[PATCH 4.4 39/41] netfilter: ipset: Fix oversized kvmalloc() calls

Greg Kroah-Hartman
2021-10-04T12:55:57Z

From: Jozsef Kadlecsik <kadlec@netfilter.org>

commit 7bbc3d385bd813077acaf0e6fdb2a86a901f5382 upstream.

The commit

commit 7661809d493b426e979f39ab512e3adf41fbcc69
Author: Linus Torvalds <torvalds@linux-foundation.org>
Date: Wed Jul 14 09:45:49 2021 -0700

mm: don't allow oversized kvmalloc() calls

limits the max allocatable memory via kvmalloc() to MAX_INT. Apply the
same limit in ipset.

Reported-by: syzbot+3493b1873fb3ea827986@syzkaller.appspotmail.com
Reported-by: syzbot+2b8443c35458a617c904@syzkaller.appspotmail.com
Reported-by: syzbot+ee5cb15f4a0e85e0d54e@syzkaller.appspotmail.com
Signed-off-by: Jozsef Kadlecsik <kadlec@netfilter.org>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
net/netfilter/ipset/ip_set_hash_gen.h | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)

--- a/net/netfilter/ipset/ip_set_hash_gen.h
+++ b/net/netfilter/ipset/ip_set_hash_gen.h
@@ -102,11 +102,11 @@ htable_size(u8 hbits)
{
size_t hsize;

- /* We must fit both into u32 in jhash and size_t */
+ /* We must fit both into u32 in jhash and INT_MAX in kvmalloc_node() */
if (hbits > 31)
return 0;
hsize = jhash_size(hbits);
- if ((((size_t)-1) - sizeof(struct htable)) / sizeof(struct hbucket *)
+ if ((INT_MAX - sizeof(struct htable)) / sizeof(struct hbucket *)
< hsize)
return 0;