From 7f78e0351394052e1a6293e175825eb5c7869507 Mon Sep 17 00:00:00 2001 From: "Eric W. Biederman" Date: Sat, 2 Mar 2013 19:39:14 -0800 Subject: fs: Limit sys_mount to only request filesystem modules. Modify the request_module to prefix the file system type with "fs-" and add aliases to all of the filesystems that can be built as modules to match. A common practice is to build all of the kernel code and leave code that is not commonly needed as modules, with the result that many users are exposed to any bug anywhere in the kernel. Looking for filesystems with a fs- prefix limits the pool of possible modules that can be loaded by mount to just filesystems trivially making things safer with no real cost. Using aliases means user space can control the policy of which filesystem modules are auto-loaded by editing /etc/modprobe.d/*.conf with blacklist and alias directives. Allowing simple, safe, well understood work-arounds to known problematic software. This also addresses a rare but unfortunate problem where the filesystem name is not the same as it's module name and module auto-loading would not work. While writing this patch I saw a handful of such cases. The most significant being autofs that lives in the module autofs4. This is relevant to user namespaces because we can reach the request module in get_fs_type() without having any special permissions, and people get uncomfortable when a user specified string (in this case the filesystem type) goes all of the way to request_module. After having looked at this issue I don't think there is any particular reason to perform any filtering or permission checks beyond making it clear in the module request that we want a filesystem module. The common pattern in the kernel is to call request_module() without regards to the users permissions. In general all a filesystem module does once loaded is call register_filesystem() and go to sleep. Which means there is not much attack surface exposed by loading a filesytem module unless the filesystem is mounted. In a user namespace filesystems are not mounted unless .fs_flags = FS_USERNS_MOUNT, which most filesystems do not set today. Acked-by: Serge Hallyn Acked-by: Kees Cook Reported-by: Kees Cook Signed-off-by: "Eric W. Biederman" --- drivers/infiniband/hw/ipath/ipath_fs.c | 1 + drivers/infiniband/hw/qib/qib_fs.c | 1 + 2 files changed, 2 insertions(+) (limited to 'drivers/infiniband') diff --git a/drivers/infiniband/hw/ipath/ipath_fs.c b/drivers/infiniband/hw/ipath/ipath_fs.c index a479375a8fd8..e0c404bdc4a8 100644 --- a/drivers/infiniband/hw/ipath/ipath_fs.c +++ b/drivers/infiniband/hw/ipath/ipath_fs.c @@ -410,6 +410,7 @@ static struct file_system_type ipathfs_fs_type = { .mount = ipathfs_mount, .kill_sb = ipathfs_kill_super, }; +MODULE_ALIAS_FS("ipathfs"); int __init ipath_init_ipathfs(void) { diff --git a/drivers/infiniband/hw/qib/qib_fs.c b/drivers/infiniband/hw/qib/qib_fs.c index 644bd6f6467c..f247fc6e6182 100644 --- a/drivers/infiniband/hw/qib/qib_fs.c +++ b/drivers/infiniband/hw/qib/qib_fs.c @@ -604,6 +604,7 @@ static struct file_system_type qibfs_fs_type = { .mount = qibfs_mount, .kill_sb = qibfs_kill_super, }; +MODULE_ALIAS_FS("ipathfs"); int __init qib_init_qibfs(void) { -- cgit v1.2.2 From 95e1b7145ed220a2124f9566ad97f4ccecdba063 Mon Sep 17 00:00:00 2001 From: Tejun Heo Date: Wed, 13 Mar 2013 14:59:39 -0700 Subject: mlx4: remove leftover idr_pre_get() call Commit 6a9200603d76 ("IB/mlx4: convert to idr_alloc()") forgot to remove idr_pre_get() call in mlx4_ib_cm_paravirt_init(). It's unnecessary and idr_pre_get() will soon be deprecated. Remove it. Signed-off-by: Tejun Heo Cc: Jack Morgenstein Cc: Or Gerlitz Cc: Roland Dreier Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- drivers/infiniband/hw/mlx4/cm.c | 1 - 1 file changed, 1 deletion(-) (limited to 'drivers/infiniband') diff --git a/drivers/infiniband/hw/mlx4/cm.c b/drivers/infiniband/hw/mlx4/cm.c index e0d79b2395e4..add98d01476c 100644 --- a/drivers/infiniband/hw/mlx4/cm.c +++ b/drivers/infiniband/hw/mlx4/cm.c @@ -362,7 +362,6 @@ void mlx4_ib_cm_paravirt_init(struct mlx4_ib_dev *dev) INIT_LIST_HEAD(&dev->sriov.cm_list); dev->sriov.sl_id_map = RB_ROOT; idr_init(&dev->sriov.pv_id_table); - idr_pre_get(&dev->sriov.pv_id_table, GFP_KERNEL); } /* slave = -1 ==> all slaves */ -- cgit v1.2.2 From aaa0c23cb90141309f5076ba5e3bfbd39544b985 Mon Sep 17 00:00:00 2001 From: Zhouyi Zhou Date: Thu, 14 Mar 2013 17:21:50 +0000 Subject: Fix dst_neigh_lookup/dst_neigh_lookup_skb return value handling bug When neighbour table is full, dst_neigh_lookup/dst_neigh_lookup_skb will return -ENOBUFS which is absolutely non zero, while all the code in kernel which use above functions assume failure only on zero return which will cause panic. (for example: : https://bugzilla.kernel.org/show_bug.cgi?id=54731). This patch corrects above error with smallest changes to kernel source code and also correct two return value check missing bugs in drivers/infiniband/hw/cxgb4/cm.c Tested on my x86_64 SMP machine Reported-by: Zhouyi Zhou Tested-by: Zhouyi Zhou Signed-off-by: Zhouyi Zhou Signed-off-by: David S. Miller --- drivers/infiniband/hw/cxgb4/cm.c | 12 ++++++++++++ 1 file changed, 12 insertions(+) (limited to 'drivers/infiniband') diff --git a/drivers/infiniband/hw/cxgb4/cm.c b/drivers/infiniband/hw/cxgb4/cm.c index 565bfb161c1a..a3fde52840ca 100644 --- a/drivers/infiniband/hw/cxgb4/cm.c +++ b/drivers/infiniband/hw/cxgb4/cm.c @@ -1575,6 +1575,12 @@ static int c4iw_reconnect(struct c4iw_ep *ep) neigh = dst_neigh_lookup(ep->dst, &ep->com.cm_id->remote_addr.sin_addr.s_addr); + if (!neigh) { + pr_err("%s - cannot alloc neigh.\n", __func__); + err = -ENOMEM; + goto fail4; + } + /* get a l2t entry */ if (neigh->dev->flags & IFF_LOOPBACK) { PDBG("%s LOOPBACK\n", __func__); @@ -3053,6 +3059,12 @@ static int rx_pkt(struct c4iw_dev *dev, struct sk_buff *skb) dst = &rt->dst; neigh = dst_neigh_lookup_skb(dst, skb); + if (!neigh) { + pr_err("%s - failed to allocate neigh!\n", + __func__); + goto free_dst; + } + if (neigh->dev->flags & IFF_LOOPBACK) { pdev = ip_dev_find(&init_net, iph->daddr); e = cxgb4_l2t_get(dev->rdev.lldi.l2t, neigh, -- cgit v1.2.2