4.11-stable review patch. If anyone has any objections, please let me know. ------------------ From: Alban Browaeys <alban.browaeys@xxxxxxxxx> [ Upstream commit 9af9959e142c274f4a30fefb71d97d2b028b337f ] commit 9256645af098 ("net/core: relax BUILD_BUG_ON in netdev_stats_to_stats64") made an attempt to read beyond the size of the source a possibility. Fix to only copy src size to dest. As dest might be bigger than src. ================================================================== BUG: KASAN: slab-out-of-bounds in netdev_stats_to_stats64+0xe/0x30 at addr ffff8801be248b20 Read of size 192 by task VBoxNetAdpCtl/6734 CPU: 1 PID: 6734 Comm: VBoxNetAdpCtl Tainted: G O 4.11.4prahal+intel+ #118 Hardware name: LENOVO 20CDCTO1WW/20CDCTO1WW, BIOS GQET52WW (1.32 ) 05/04/2017 Call Trace: dump_stack+0x63/0x86 kasan_object_err+0x1c/0x70 kasan_report+0x270/0x520 ? netdev_stats_to_stats64+0xe/0x30 ? sched_clock_cpu+0x1b/0x190 ? __module_address+0x3e/0x3b0 ? unwind_next_frame+0x1ea/0xb00 check_memory_region+0x13c/0x1a0 memcpy+0x23/0x50 netdev_stats_to_stats64+0xe/0x30 dev_get_stats+0x1b9/0x230 rtnl_fill_stats+0x44/0xc00 ? nla_put+0xc6/0x130 rtnl_fill_ifinfo+0xe9e/0x3700 ? rtnl_fill_vfinfo+0xde0/0xde0 ? sched_clock+0x9/0x10 ? sched_clock+0x9/0x10 ? sched_clock_local+0x120/0x130 ? __module_address+0x3e/0x3b0 ? unwind_next_frame+0x1ea/0xb00 ? sched_clock+0x9/0x10 ? sched_clock+0x9/0x10 ? sched_clock_cpu+0x1b/0x190 ? VBoxNetAdpLinuxIOCtlUnlocked+0x14b/0x280 [vboxnetadp] ? depot_save_stack+0x1d8/0x4a0 ? depot_save_stack+0x34f/0x4a0 ? depot_save_stack+0x34f/0x4a0 ? save_stack+0xb1/0xd0 ? save_stack_trace+0x16/0x20 ? save_stack+0x46/0xd0 ? kasan_slab_alloc+0x12/0x20 ? __kmalloc_node_track_caller+0x10d/0x350 ? __kmalloc_reserve.isra.36+0x2c/0xc0 ? __alloc_skb+0xd0/0x560 ? rtmsg_ifinfo_build_skb+0x61/0x120 ? rtmsg_ifinfo.part.25+0x16/0xb0 ? rtmsg_ifinfo+0x47/0x70 ? register_netdev+0x15/0x30 ? vboxNetAdpOsCreate+0xc0/0x1c0 [vboxnetadp] ? vboxNetAdpCreate+0x210/0x400 [vboxnetadp] ? VBoxNetAdpLinuxIOCtlUnlocked+0x14b/0x280 [vboxnetadp] ? do_vfs_ioctl+0x17f/0xff0 ? SyS_ioctl+0x74/0x80 ? do_syscall_64+0x182/0x390 ? __alloc_skb+0xd0/0x560 ? __alloc_skb+0xd0/0x560 ? save_stack_trace+0x16/0x20 ? init_object+0x64/0xa0 ? ___slab_alloc+0x1ae/0x5c0 ? ___slab_alloc+0x1ae/0x5c0 ? __alloc_skb+0xd0/0x560 ? sched_clock+0x9/0x10 ? kasan_unpoison_shadow+0x35/0x50 ? kasan_kmalloc+0xad/0xe0 ? __kmalloc_node_track_caller+0x246/0x350 ? __alloc_skb+0xd0/0x560 ? kasan_unpoison_shadow+0x35/0x50 ? memset+0x31/0x40 ? __alloc_skb+0x31f/0x560 ? napi_consume_skb+0x320/0x320 ? br_get_link_af_size_filtered+0xb7/0x120 [bridge] ? if_nlmsg_size+0x440/0x630 rtmsg_ifinfo_build_skb+0x83/0x120 rtmsg_ifinfo.part.25+0x16/0xb0 rtmsg_ifinfo+0x47/0x70 register_netdevice+0xa2b/0xe50 ? __kmalloc+0x171/0x2d0 ? netdev_change_features+0x80/0x80 register_netdev+0x15/0x30 vboxNetAdpOsCreate+0xc0/0x1c0 [vboxnetadp] vboxNetAdpCreate+0x210/0x400 [vboxnetadp] ? vboxNetAdpComposeMACAddress+0x1d0/0x1d0 [vboxnetadp] ? kasan_check_write+0x14/0x20 VBoxNetAdpLinuxIOCtlUnlocked+0x14b/0x280 [vboxnetadp] ? VBoxNetAdpLinuxOpen+0x20/0x20 [vboxnetadp] ? lock_acquire+0x11c/0x270 ? __audit_syscall_entry+0x2fb/0x660 do_vfs_ioctl+0x17f/0xff0 ? __audit_syscall_entry+0x2fb/0x660 ? ioctl_preallocate+0x1d0/0x1d0 ? __audit_syscall_entry+0x2fb/0x660 ? kmem_cache_free+0xb2/0x250 ? syscall_trace_enter+0x537/0xd00 ? exit_to_usermode_loop+0x100/0x100 SyS_ioctl+0x74/0x80 ? do_sys_open+0x350/0x350 ? do_vfs_ioctl+0xff0/0xff0 do_syscall_64+0x182/0x390 entry_SYSCALL64_slow_path+0x25/0x25 RIP: 0033:0x7f7e39a1ae07 RSP: 002b:00007ffc6f04c6d8 EFLAGS: 00000206 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00007ffc6f04c730 RCX: 00007f7e39a1ae07 RDX: 00007ffc6f04c730 RSI: 00000000c0207601 RDI: 0000000000000007 RBP: 00007ffc6f04c700 R08: 00007ffc6f04c780 R09: 0000000000000008 R10: 0000000000000541 R11: 0000000000000206 R12: 0000000000000007 R13: 00000000c0207601 R14: 00007ffc6f04c730 R15: 0000000000000012 Object at ffff8801be248008, in cache kmalloc-4096 size: 4096 Allocated: PID = 6734 save_stack_trace+0x16/0x20 save_stack+0x46/0xd0 kasan_kmalloc+0xad/0xe0 __kmalloc+0x171/0x2d0 alloc_netdev_mqs+0x8a7/0xbe0 vboxNetAdpOsCreate+0x65/0x1c0 [vboxnetadp] vboxNetAdpCreate+0x210/0x400 [vboxnetadp] VBoxNetAdpLinuxIOCtlUnlocked+0x14b/0x280 [vboxnetadp] do_vfs_ioctl+0x17f/0xff0 SyS_ioctl+0x74/0x80 do_syscall_64+0x182/0x390 return_from_SYSCALL_64+0x0/0x6a Freed: PID = 5600 save_stack_trace+0x16/0x20 save_stack+0x46/0xd0 kasan_slab_free+0x73/0xc0 kfree+0xe4/0x220 kvfree+0x25/0x30 single_release+0x74/0xb0 __fput+0x265/0x6b0 ____fput+0x9/0x10 task_work_run+0xd5/0x150 exit_to_usermode_loop+0xe2/0x100 do_syscall_64+0x26c/0x390 return_from_SYSCALL_64+0x0/0x6a Memory state around the buggy address: ffff8801be248a80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ffff8801be248b00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 >ffff8801be248b80: 00 00 00 00 00 00 00 00 00 00 00 07 fc fc fc fc ^ ffff8801be248c00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff8801be248c80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ================================================================== Signed-off-by: Alban Browaeys <alban.browaeys@xxxxxxxxx> Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- net/core/dev.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- a/net/core/dev.c +++ b/net/core/dev.c @@ -7591,7 +7591,7 @@ void netdev_stats_to_stats64(struct rtnl { #if BITS_PER_LONG == 64 BUILD_BUG_ON(sizeof(*stats64) < sizeof(*netdev_stats)); - memcpy(stats64, netdev_stats, sizeof(*stats64)); + memcpy(stats64, netdev_stats, sizeof(*netdev_stats)); /* zero out counters that only exist in rtnl_link_stats64 */ memset((char *)stats64 + sizeof(*netdev_stats), 0, sizeof(*stats64) - sizeof(*netdev_stats));