From ece6b0a2b25652d684a7ced4ae680a863af041e0 Mon Sep 17 00:00:00 2001 From: Cong Wang Date: Sun, 3 Mar 2013 16:18:11 +0000 Subject: rds: limit the size allocated by rds_message_alloc() Dave Jones reported the following bug: "When fed mangled socket data, rds will trust what userspace gives it, and tries to allocate enormous amounts of memory larger than what kmalloc can satisfy." WARNING: at mm/page_alloc.c:2393 __alloc_pages_nodemask+0xa0d/0xbe0() Hardware name: GA-MA78GM-S2H Modules linked in: vmw_vsock_vmci_transport vmw_vmci vsock fuse bnep dlci bridge 8021q garp stp mrp binfmt_misc l2tp_ppp l2tp_core rfcomm s Pid: 24652, comm: trinity-child2 Not tainted 3.8.0+ #65 Call Trace: [] warn_slowpath_common+0x75/0xa0 [] warn_slowpath_null+0x1a/0x20 [] __alloc_pages_nodemask+0xa0d/0xbe0 [] ? native_sched_clock+0x26/0x90 [] ? trace_hardirqs_off_caller+0x28/0xc0 [] ? trace_hardirqs_off+0xd/0x10 [] alloc_pages_current+0xb8/0x180 [] __get_free_pages+0x2a/0x80 [] kmalloc_order_trace+0x3e/0x1a0 [] __kmalloc+0x2f5/0x3a0 [] ? local_bh_enable_ip+0x7c/0xf0 [] rds_message_alloc+0x23/0xb0 [rds] [] rds_sendmsg+0x2b1/0x990 [rds] [] ? trace_hardirqs_off+0xd/0x10 [] sock_sendmsg+0xb0/0xe0 [] ? get_lock_stats+0x22/0x70 [] ? put_lock_stats.isra.23+0xe/0x40 [] sys_sendto+0x130/0x180 [] ? trace_hardirqs_on+0xd/0x10 [] ? _raw_spin_unlock_irq+0x3b/0x60 [] ? sysret_check+0x1b/0x56 [] ? trace_hardirqs_on_caller+0x115/0x1a0 [] ? trace_hardirqs_on_thunk+0x3a/0x3f [] system_call_fastpath+0x16/0x1b ---[ end trace eed6ae990d018c8b ]--- Reported-by: Dave Jones Cc: Dave Jones Cc: David S. Miller Cc: Venkat Venkatsubra Signed-off-by: Cong Wang Acked-by: Venkat Venkatsubra Signed-off-by: David S. Miller --- net/rds/message.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/net/rds/message.c b/net/rds/message.c index f0a4658f3273..aff589cc022e 100644 --- a/net/rds/message.c +++ b/net/rds/message.c @@ -197,6 +197,9 @@ struct rds_message *rds_message_alloc(unsigned int extra_len, gfp_t gfp) { struct rds_message *rm; + if (extra_len > KMALLOC_MAX_SIZE - sizeof(struct rds_message)) + return NULL; + rm = kzalloc(sizeof(struct rds_message) + extra_len, gfp); if (!rm) goto out; -- cgit v1.2.1