path: root/fs/orangefs/super.c
diff options
authorDavid Windsor <dave@nullcore.net>2017-06-10 22:50:39 -0400
committerKees Cook <keescook@chromium.org>2018-01-15 12:07:55 -0800
commit6b330623e56900db8db3634b782093289c8ad175 (patch)
treebdb9e06487b1f4c4657d7148ad1ac21bee3c5c3d /fs/orangefs/super.c
parent2b06a9e336170d7e3c807c21d5cd85cbc92fff4e (diff)
orangefs: Define usercopy region in orangefs_inode_cache slab cache
orangefs symlink pathnames, stored in struct orangefs_inode_s.link_target and therefore contained in the orangefs_inode_cache, need to be copied to/from userspace. cache object allocation: fs/orangefs/super.c: orangefs_alloc_inode(...): ... orangefs_inode = kmem_cache_alloc(orangefs_inode_cache, ...); ... return &orangefs_inode->vfs_inode; fs/orangefs/orangefs-utils.c: exofs_symlink(...): ... inode->i_link = orangefs_inode->link_target; example usage trace: readlink_copy+0x43/0x70 vfs_readlink+0x62/0x110 SyS_readlinkat+0x100/0x130 fs/namei.c: readlink_copy(..., link): ... copy_to_user(..., link, len); (inlined in vfs_readlink) generic_readlink(dentry, ...): struct inode *inode = d_inode(dentry); const char *link = inode->i_link; ... readlink_copy(..., link); In support of usercopy hardening, this patch defines a region in the orangefs_inode_cache slab cache in which userspace copy operations are allowed. This region is known as the slab cache's usercopy region. Slab caches can now check that each dynamically sized copy operation involving cache-managed memory falls entirely within the slab's usercopy region. This patch is modified from Brad Spengler/PaX Team's PAX_USERCOPY whitelisting code in the last public patch of grsecurity/PaX based on my understanding of the code. Changes or omissions from the original code are mine and don't reflect the original grsecurity/PaX code. Signed-off-by: David Windsor <dave@nullcore.net> [kees: adjust commit log, provide usage trace] Cc: Mike Marshall <hubcap@omnibond.com> Signed-off-by: Kees Cook <keescook@chromium.org>
Diffstat (limited to 'fs/orangefs/super.c')
1 files changed, 10 insertions, 5 deletions
diff --git a/fs/orangefs/super.c b/fs/orangefs/super.c
index 36f1390b5ed7..62d49e53061c 100644
--- a/fs/orangefs/super.c
+++ b/fs/orangefs/super.c
@@ -610,11 +610,16 @@ void orangefs_kill_sb(struct super_block *sb)
int orangefs_inode_cache_initialize(void)
- orangefs_inode_cache = kmem_cache_create("orangefs_inode_cache",
- sizeof(struct orangefs_inode_s),
- 0,
- orangefs_inode_cache_ctor);
+ orangefs_inode_cache = kmem_cache_create_usercopy(
+ "orangefs_inode_cache",
+ sizeof(struct orangefs_inode_s),
+ 0,
+ offsetof(struct orangefs_inode_s,
+ link_target),
+ sizeof_field(struct orangefs_inode_s,
+ link_target),
+ orangefs_inode_cache_ctor);
if (!orangefs_inode_cache) {
gossip_err("Cannot create orangefs_inode_cache\n");

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