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| author | Dmitry Vyukov <dvyukov@google.com> | 2017-12-28 09:48:54 +0100 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2018-02-25 11:01:17 +0100 |
| commit | ab24a3d5b937e9fc9c162eff1690bc989581bf5f (patch) | |
| tree | 64ee0849727cb1f3012163d660184e548c4c7642 | |
| parent | e1f5f1cdb5b0e762281d0b8e19aea14a0fa2fe82 (diff) | |
| download | linux-stable-ab24a3d5b937e9fc9c162eff1690bc989581bf5f.tar.gz linux-stable-ab24a3d5b937e9fc9c162eff1690bc989581bf5f.tar.bz2 linux-stable-ab24a3d5b937e9fc9c162eff1690bc989581bf5f.zip | |
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>
| -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 489899325bf7..a6bdc4bc03ef 100644 --- a/net/netfilter/x_tables.c +++ b/net/netfilter/x_tables.c @@ -38,8 +38,6 @@ 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 */ @@ -951,7 +949,7 @@ struct xt_table_info *xt_alloc_table_info(unsigned int size) int cpu; /* 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; newinfo = kzalloc(XT_TABLE_INFO_SZ, GFP_KERNEL); |