3.18-stable review patch. If anyone has any objections, please let me know.
------------------ From: Dmitry Vyukov <[email protected]> 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: [email protected] Signed-off-by: Dmitry Vyukov <[email protected]> Signed-off-by: Pablo Neira Ayuso <[email protected]> Signed-off-by: Greg Kroah-Hartman <[email protected]> --- net/netfilter/x_tables.c | 4 +--- 1 file changed, 1 insertion(+), 3 deletions(-) --- a/net/netfilter/x_tables.c +++ b/net/netfilter/x_tables.c @@ -38,8 +38,6 @@ MODULE_LICENSE("GPL"); MODULE_AUTHOR("Harald Welte <[email protected]>"); 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_inf 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);
