From 3ddc5b46a8e90f3c9251338b60191d0a804b0d92 Mon Sep 17 00:00:00 2001 From: Mathieu Desnoyers Date: Wed, 11 Sep 2013 14:23:18 -0700 Subject: kernel-wide: fix missing validations on __get/__put/__copy_to/__copy_from_user() I found the following pattern that leads in to interesting findings: grep -r "ret.*|=.*__put_user" * grep -r "ret.*|=.*__get_user" * grep -r "ret.*|=.*__copy" * The __put_user() calls in compat_ioctl.c, ptrace compat, signal compat, since those appear in compat code, we could probably expect the kernel addresses not to be reachable in the lower 32-bit range, so I think they might not be exploitable. For the "__get_user" cases, I don't think those are exploitable: the worse that can happen is that the kernel will copy kernel memory into in-kernel buffers, and will fail immediately afterward. The alpha csum_partial_copy_from_user() seems to be missing the access_ok() check entirely. The fix is inspired from x86. This could lead to information leak on alpha. I also noticed that many architectures map csum_partial_copy_from_user() to csum_partial_copy_generic(), but I wonder if the latter is performing the access checks on every architectures. Signed-off-by: Mathieu Desnoyers Cc: Richard Henderson Cc: Ivan Kokshaysky Cc: Matt Turner Cc: Jens Axboe Cc: Oleg Nesterov Cc: David Miller Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- net/socket.c | 50 +++++++++++++++++++++++++------------------------- 1 file changed, 25 insertions(+), 25 deletions(-) (limited to 'net') diff --git a/net/socket.c b/net/socket.c index b2d7c629eeb..0ceaa5cb9ea 100644 --- a/net/socket.c +++ b/net/socket.c @@ -3072,12 +3072,12 @@ static int compat_sioc_ifmap(struct net *net, unsigned int cmd, uifmap32 = &uifr32->ifr_ifru.ifru_map; err = copy_from_user(&ifr, uifr32, sizeof(ifr.ifr_name)); - err |= __get_user(ifr.ifr_map.mem_start, &uifmap32->mem_start); - err |= __get_user(ifr.ifr_map.mem_end, &uifmap32->mem_end); - err |= __get_user(ifr.ifr_map.base_addr, &uifmap32->base_addr); - err |= __get_user(ifr.ifr_map.irq, &uifmap32->irq); - err |= __get_user(ifr.ifr_map.dma, &uifmap32->dma); - err |= __get_user(ifr.ifr_map.port, &uifmap32->port); + err |= get_user(ifr.ifr_map.mem_start, &uifmap32->mem_start); + err |= get_user(ifr.ifr_map.mem_end, &uifmap32->mem_end); + err |= get_user(ifr.ifr_map.base_addr, &uifmap32->base_addr); + err |= get_user(ifr.ifr_map.irq, &uifmap32->irq); + err |= get_user(ifr.ifr_map.dma, &uifmap32->dma); + err |= get_user(ifr.ifr_map.port, &uifmap32->port); if (err) return -EFAULT; @@ -3088,12 +3088,12 @@ static int compat_sioc_ifmap(struct net *net, unsigned int cmd, if (cmd == SIOCGIFMAP && !err) { err = copy_to_user(uifr32, &ifr, sizeof(ifr.ifr_name)); - err |= __put_user(ifr.ifr_map.mem_start, &uifmap32->mem_start); - err |= __put_user(ifr.ifr_map.mem_end, &uifmap32->mem_end); - err |= __put_user(ifr.ifr_map.base_addr, &uifmap32->base_addr); - err |= __put_user(ifr.ifr_map.irq, &uifmap32->irq); - err |= __put_user(ifr.ifr_map.dma, &uifmap32->dma); - err |= __put_user(ifr.ifr_map.port, &uifmap32->port); + err |= put_user(ifr.ifr_map.mem_start, &uifmap32->mem_start); + err |= put_user(ifr.ifr_map.mem_end, &uifmap32->mem_end); + err |= put_user(ifr.ifr_map.base_addr, &uifmap32->base_addr); + err |= put_user(ifr.ifr_map.irq, &uifmap32->irq); + err |= put_user(ifr.ifr_map.dma, &uifmap32->dma); + err |= put_user(ifr.ifr_map.port, &uifmap32->port); if (err) err = -EFAULT; } @@ -3167,25 +3167,25 @@ static int routing_ioctl(struct net *net, struct socket *sock, struct in6_rtmsg32 __user *ur6 = argp; ret = copy_from_user(&r6.rtmsg_dst, &(ur6->rtmsg_dst), 3 * sizeof(struct in6_addr)); - ret |= __get_user(r6.rtmsg_type, &(ur6->rtmsg_type)); - ret |= __get_user(r6.rtmsg_dst_len, &(ur6->rtmsg_dst_len)); - ret |= __get_user(r6.rtmsg_src_len, &(ur6->rtmsg_src_len)); - ret |= __get_user(r6.rtmsg_metric, &(ur6->rtmsg_metric)); - ret |= __get_user(r6.rtmsg_info, &(ur6->rtmsg_info)); - ret |= __get_user(r6.rtmsg_flags, &(ur6->rtmsg_flags)); - ret |= __get_user(r6.rtmsg_ifindex, &(ur6->rtmsg_ifindex)); + ret |= get_user(r6.rtmsg_type, &(ur6->rtmsg_type)); + ret |= get_user(r6.rtmsg_dst_len, &(ur6->rtmsg_dst_len)); + ret |= get_user(r6.rtmsg_src_len, &(ur6->rtmsg_src_len)); + ret |= get_user(r6.rtmsg_metric, &(ur6->rtmsg_metric)); + ret |= get_user(r6.rtmsg_info, &(ur6->rtmsg_info)); + ret |= get_user(r6.rtmsg_flags, &(ur6->rtmsg_flags)); + ret |= get_user(r6.rtmsg_ifindex, &(ur6->rtmsg_ifindex)); r = (void *) &r6; } else { /* ipv4 */ struct rtentry32 __user *ur4 = argp; ret = copy_from_user(&r4.rt_dst, &(ur4->rt_dst), 3 * sizeof(struct sockaddr)); - ret |= __get_user(r4.rt_flags, &(ur4->rt_flags)); - ret |= __get_user(r4.rt_metric, &(ur4->rt_metric)); - ret |= __get_user(r4.rt_mtu, &(ur4->rt_mtu)); - ret |= __get_user(r4.rt_window, &(ur4->rt_window)); - ret |= __get_user(r4.rt_irtt, &(ur4->rt_irtt)); - ret |= __get_user(rtdev, &(ur4->rt_dev)); + ret |= get_user(r4.rt_flags, &(ur4->rt_flags)); + ret |= get_user(r4.rt_metric, &(ur4->rt_metric)); + ret |= get_user(r4.rt_mtu, &(ur4->rt_mtu)); + ret |= get_user(r4.rt_window, &(ur4->rt_window)); + ret |= get_user(r4.rt_irtt, &(ur4->rt_irtt)); + ret |= get_user(rtdev, &(ur4->rt_dev)); if (rtdev) { ret |= copy_from_user(devname, compat_ptr(rtdev), 15); r4.rt_dev = (char __user __force *)devname; -- cgit v1.2.3