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| author | Dmitry Vyukov <dvyukov@google.com> | 2017-12-28 11:48:54 +0300 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2018-02-25 13:07:50 +0300 |
| commit | 6609d112229fff5dbccf57bbc31facffc1ba06dd (patch) | |
| tree | c49991057b87c0d844e34d31b50236711013fa85 /net | |
| parent | 4249e8af8108afadc6316d9e4815f3333c9770d0 (diff) | |
| download | linux-6609d112229fff5dbccf57bbc31facffc1ba06dd.tar.xz | |
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 | 3 |
1 files changed, 1 insertions, 2 deletions
diff --git a/net/netfilter/x_tables.c b/net/netfilter/x_tables.c index d8571f414208..20f7856fec16 100644 --- a/net/netfilter/x_tables.c +++ b/net/netfilter/x_tables.c @@ -39,7 +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)) #define XT_PCPU_BLOCK_SIZE 4096 struct compat_delta { @@ -1000,7 +999,7 @@ 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; info = kvmalloc(sz, GFP_KERNEL); |