sysfs: only access bin file vm_ops with the active lock
bb->vm_ops is a cached copy of the vm_ops of the underlying
sysfs bin file, which means that after sysfs_bin_remove_file
completes it is only longer valid to deference bb->vm_ops.
So move all of the tests of bb->vm_ops inside of where
we hold the sysfs active lock.
Signed-off-by: Eric W. Biederman <ebiederm@aristanetworks.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
diff --git a/fs/sysfs/bin.c b/fs/sysfs/bin.c
index d31d7b7..a475983 100644
--- a/fs/sysfs/bin.c
+++ b/fs/sysfs/bin.c
@@ -179,13 +179,14 @@
struct bin_buffer *bb = file->private_data;
struct sysfs_dirent *attr_sd = file->f_path.dentry->d_fsdata;
- if (!bb->vm_ops || !bb->vm_ops->open)
+ if (!bb->vm_ops)
return;
if (!sysfs_get_active(attr_sd))
return;
- bb->vm_ops->open(vma);
+ if (bb->vm_ops->open)
+ bb->vm_ops->open(vma);
sysfs_put_active(attr_sd);
}
@@ -197,13 +198,15 @@
struct sysfs_dirent *attr_sd = file->f_path.dentry->d_fsdata;
int ret;
- if (!bb->vm_ops || !bb->vm_ops->fault)
+ if (!bb->vm_ops)
return VM_FAULT_SIGBUS;
if (!sysfs_get_active(attr_sd))
return VM_FAULT_SIGBUS;
- ret = bb->vm_ops->fault(vma, vmf);
+ ret = VM_FAULT_SIGBUS;
+ if (bb->vm_ops->fault)
+ ret = bb->vm_ops->fault(vma, vmf);
sysfs_put_active(attr_sd);
return ret;
@@ -219,13 +222,12 @@
if (!bb->vm_ops)
return VM_FAULT_SIGBUS;
- if (!bb->vm_ops->page_mkwrite)
- return 0;
-
if (!sysfs_get_active(attr_sd))
return VM_FAULT_SIGBUS;
- ret = bb->vm_ops->page_mkwrite(vma, vmf);
+ ret = 0;
+ if (bb->vm_ops->page_mkwrite)
+ ret = bb->vm_ops->page_mkwrite(vma, vmf);
sysfs_put_active(attr_sd);
return ret;
@@ -239,13 +241,15 @@
struct sysfs_dirent *attr_sd = file->f_path.dentry->d_fsdata;
int ret;
- if (!bb->vm_ops || !bb->vm_ops->access)
+ if (!bb->vm_ops)
return -EINVAL;
if (!sysfs_get_active(attr_sd))
return -EINVAL;
- ret = bb->vm_ops->access(vma, addr, buf, len, write);
+ ret = -EINVAL;
+ if (bb->vm_ops->access)
+ ret = bb->vm_ops->access(vma, addr, buf, len, write);
sysfs_put_active(attr_sd);
return ret;
@@ -259,13 +263,15 @@
struct sysfs_dirent *attr_sd = file->f_path.dentry->d_fsdata;
int ret;
- if (!bb->vm_ops || !bb->vm_ops->set_policy)
+ if (!bb->vm_ops)
return 0;
if (!sysfs_get_active(attr_sd))
return -EINVAL;
- ret = bb->vm_ops->set_policy(vma, new);
+ ret = 0;
+ if (bb->vm_ops->set_policy)
+ ret = bb->vm_ops->set_policy(vma, new);
sysfs_put_active(attr_sd);
return ret;
@@ -279,13 +285,15 @@
struct sysfs_dirent *attr_sd = file->f_path.dentry->d_fsdata;
struct mempolicy *pol;
- if (!bb->vm_ops || !bb->vm_ops->get_policy)
+ if (!bb->vm_ops)
return vma->vm_policy;
if (!sysfs_get_active(attr_sd))
return vma->vm_policy;
- pol = bb->vm_ops->get_policy(vma, addr);
+ pol = vma->vm_policy;
+ if (bb->vm_ops->get_policy)
+ pol = bb->vm_ops->get_policy(vma, addr);
sysfs_put_active(attr_sd);
return pol;
@@ -299,13 +307,15 @@
struct sysfs_dirent *attr_sd = file->f_path.dentry->d_fsdata;
int ret;
- if (!bb->vm_ops || !bb->vm_ops->migrate)
+ if (!bb->vm_ops)
return 0;
if (!sysfs_get_active(attr_sd))
return 0;
- ret = bb->vm_ops->migrate(vma, from, to, flags);
+ ret = 0;
+ if (bb->vm_ops->migrate)
+ ret = bb->vm_ops->migrate(vma, from, to, flags);
sysfs_put_active(attr_sd);
return ret;