perf hists browser: Fix seg fault when annotate null symbol

[pandora-kernel.git] / fs / namei.c

diff --git a/fs/namei.c b/fs/namei.c
index 5a9a6c3..e6cd611 100644 (file)
--- a/fs/namei.c
+++ b/fs/namei.c
@@ -70,7 +70,7 @@
  * name indicated by the symlink. The old code always complained that the
  * name already exists, due to not following the symlink even if its target
  * is nonexistent.  The new semantics affects also mknod() and link() when
- * the name is a symlink pointing to a non-existant name.
+ * the name is a symlink pointing to a non-existent name.
  *
  * I don't know which semantics is the right one, since I have no access
  * to standards. But I found by trial that HP-UX 9.0 has the full "new"
@@ -183,6 +183,9 @@ static int acl_permission_check(struct inode *inode, int mask, unsigned int flag
 
        mask &= MAY_READ | MAY_WRITE | MAY_EXEC;
 
+       if (current_user_ns() != inode_userns(inode))
+               goto other_perms;
+
        if (current_fsuid() == inode->i_uid)
                mode >>= 6;
        else {
@@ -196,6 +199,7 @@ static int acl_permission_check(struct inode *inode, int mask, unsigned int flag
                        mode >>= 3;
        }
 
+other_perms:
        /*
         * If the DACs are ok we don't need any capability check.
         */
@@ -237,7 +241,7 @@ int generic_permission(struct inode *inode, int mask, unsigned int flags,
         * Executable DACs are overridable if at least one exec bit is set.
         */
        if (!(mask & MAY_EXEC) || execute_ok(inode))
-               if (capable(CAP_DAC_OVERRIDE))
+               if (ns_capable(inode_userns(inode), CAP_DAC_OVERRIDE))
                        return 0;
 
        /*
@@ -245,7 +249,7 @@ int generic_permission(struct inode *inode, int mask, unsigned int flags,
         */
        mask &= MAY_READ | MAY_WRITE | MAY_EXEC;
        if (mask == MAY_READ || (S_ISDIR(inode->i_mode) && !(mask & MAY_WRITE)))
-               if (capable(CAP_DAC_READ_SEARCH))
+               if (ns_capable(inode_userns(inode), CAP_DAC_READ_SEARCH))
                        return 0;
 
        return -EACCES;
@@ -654,6 +658,7 @@ static inline int handle_reval_path(struct nameidata *nd)
 static inline int exec_permission(struct inode *inode, unsigned int flags)
 {
        int ret;
+       struct user_namespace *ns = inode_userns(inode);
 
        if (inode->i_op->permission) {
                ret = inode->i_op->permission(inode, MAY_EXEC, flags);
@@ -666,7 +671,8 @@ static inline int exec_permission(struct inode *inode, unsigned int flags)
        if (ret == -ECHILD)
                return ret;
 
-       if (capable(CAP_DAC_OVERRIDE) || capable(CAP_DAC_READ_SEARCH))
+       if (ns_capable(ns, CAP_DAC_OVERRIDE) ||
+                       ns_capable(ns, CAP_DAC_READ_SEARCH))
                goto ok;
 
        return ret;
@@ -986,6 +992,12 @@ int follow_down_one(struct path *path)
        return 0;
 }
 
+static inline bool managed_dentry_might_block(struct dentry *dentry)
+{
+       return (dentry->d_flags & DCACHE_MANAGE_TRANSIT &&
+               dentry->d_op->d_manage(dentry, true) < 0);
+}
+
 /*
  * Skip to top of mountpoint pile in rcuwalk mode.  We abort the rcu-walk if we
  * meet a managed dentry and we're not walking to "..".  True is returned to
@@ -994,19 +1006,26 @@ int follow_down_one(struct path *path)
 static bool __follow_mount_rcu(struct nameidata *nd, struct path *path,
                               struct inode **inode, bool reverse_transit)
 {
-       while (d_mountpoint(path->dentry)) {
+       for (;;) {
                struct vfsmount *mounted;
-               if (unlikely(path->dentry->d_flags & DCACHE_MANAGE_TRANSIT) &&
-                   !reverse_transit &&
-                   path->dentry->d_op->d_manage(path->dentry, true) < 0)
+               /*
+                * Don't forget we might have a non-mountpoint managed dentry
+                * that wants to block transit.
+                */
+               *inode = path->dentry->d_inode;
+               if (!reverse_transit &&
+                    unlikely(managed_dentry_might_block(path->dentry)))
                        return false;
+
+               if (!d_mountpoint(path->dentry))
+                       break;
+
                mounted = __lookup_mnt(path->mnt, path->dentry, 1);
                if (!mounted)
                        break;
                path->mnt = mounted;
                path->dentry = mounted->mnt_root;
                nd->seq = read_seqcount_begin(&path->dentry->d_seq);
-               *inode = path->dentry->d_inode;
        }
 
        if (unlikely(path->dentry->d_flags & DCACHE_NEED_AUTOMOUNT))
@@ -1644,13 +1663,16 @@ static int path_lookupat(int dfd, const char *name,
                        err = -ECHILD;
        }
 
-       if (!err)
+       if (!err) {
                err = handle_reval_path(nd);
+               if (err)
+                       path_put(&nd->path);
+       }
 
        if (!err && nd->flags & LOOKUP_DIRECTORY) {
                if (!nd->inode->i_op->lookup) {
                        path_put(&nd->path);
-                       return -ENOTDIR;
+                       err = -ENOTDIR;
                }
        }
 
@@ -1842,11 +1864,15 @@ static inline int check_sticky(struct inode *dir, struct inode *inode)
 
        if (!(dir->i_mode & S_ISVTX))
                return 0;
+       if (current_user_ns() != inode_userns(inode))
+               goto other_userns;
        if (inode->i_uid == fsuid)
                return 0;
        if (dir->i_uid == fsuid)
                return 0;
-       return !capable(CAP_FOWNER);
+
+other_userns:
+       return !ns_capable(inode_userns(inode), CAP_FOWNER);
 }
 
 /*
@@ -2026,7 +2052,7 @@ static int may_open(struct path *path, int acc_mode, int flag)
        }
 
        /* O_NOATIME can only be set by the owner or superuser */
-       if (flag & O_NOATIME && !is_owner_or_cap(inode))
+       if (flag & O_NOATIME && !inode_owner_or_capable(inode))
                return -EPERM;
 
        /*
@@ -2440,7 +2466,8 @@ int vfs_mknod(struct inode *dir, struct dentry *dentry, int mode, dev_t dev)
        if (error)
                return error;
 
-       if ((S_ISCHR(mode) || S_ISBLK(mode)) && !capable(CAP_MKNOD))
+       if ((S_ISCHR(mode) || S_ISBLK(mode)) &&
+           !ns_capable(inode_userns(dir), CAP_MKNOD))
                return -EPERM;
 
        if (!dir->i_op->mknod)