diff options
| author | Dmitry Vyukov <dvyukov@google.com> | 2017-12-28 09:48:54 +0100 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2018-02-25 11:05:42 +0100 |
| commit | 1099c708d7b7bcb701ac9f892d8f26811842abdd (patch) | |
| tree | 854b87876ef6c11435c72aadd5cd704b51f6139a /net | |
| parent | c33f9272eefe349fed598999943e626fcef8a708 (diff) | |
netfilter: x_tables: fix int overflow in xt_alloc_table_info()
commit 889c604fd0b5f6d3b8694ade229ee44124de1127 upstream.
syzkaller triggered OOM kills by passing ipt_replace.size = -1
to IPT_SO_SET_REPLACE. The root cause is that SMP_ALIGN() in
xt_alloc_table_info() causes int overflow and the size check passes
when it should not. SMP_ALIGN() is no longer needed leftover.
Remove SMP_ALIGN() call in xt_alloc_table_info().
Reported-by: syzbot+4396883fa8c4f64e0175@syzkaller.appspotmail.com
Signed-off-by: Dmitry Vyukov <dvyukov@google.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'net')
| -rw-r--r-- | net/netfilter/x_tables.c | 4 |
1 files changed, 1 insertions, 3 deletions
diff --git a/net/netfilter/x_tables.c b/net/netfilter/x_tables.c index fc4977456c30..3de763aa143d 100644 --- a/net/netfilter/x_tables.c +++ b/net/netfilter/x_tables.c @@ -39,8 +39,6 @@ MODULE_LICENSE("GPL"); MODULE_AUTHOR("Harald Welte <laforge@netfilter.org>"); MODULE_DESCRIPTION("{ip,ip6,arp,eb}_tables backend module"); -#define SMP_ALIGN(x) (((x) + SMP_CACHE_BYTES-1) & ~(SMP_CACHE_BYTES-1)) - struct compat_delta { unsigned int offset; /* offset in kernel */ int delta; /* delta in 32bit user land */ @@ -952,7 +950,7 @@ struct xt_table_info *xt_alloc_table_info(unsigned int size) return NULL; /* Pedantry: prevent them from hitting BUG() in vmalloc.c --RR */ - if ((SMP_ALIGN(size) >> PAGE_SHIFT) + 2 > totalram_pages) + if ((size >> PAGE_SHIFT) + 2 > totalram_pages) return NULL; if (sz <= (PAGE_SIZE << PAGE_ALLOC_COSTLY_ORDER)) |