Driver core fixes for 6.17-rc6

- Fix UAF in cgroup pressure polling by using kernfs_get_active_of()
     to prevent operations on released file descriptors.
 
   - Fix unresolved intra-doc link in the documentation of struct Device
     when CONFIG_DRM != y.
 
   - Update the DMA Rust MAINTAINERS entry.
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Merge tag 'driver-core-6.17-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/driver-core/driver-core

Pull driver core fixes from Danilo Krummrich:

 - Fix UAF in cgroup pressure polling by using kernfs_get_active_of()
   to prevent operations on released file descriptors

 - Fix unresolved intra-doc link in the documentation of struct Device
   when CONFIG_DRM != y

 - Update the DMA Rust MAINTAINERS entry

* tag 'driver-core-6.17-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/driver-core/driver-core:
  MAINTAINERS: Update the DMA Rust entry
  kernfs: Fix UAF in polling when open file is released
  rust: device: fix unresolved link to drm::Device
This commit is contained in:
Linus Torvalds 2025-09-13 10:36:06 -07:00
commit b891d11b74
3 changed files with 43 additions and 24 deletions

View File

@ -7238,15 +7238,15 @@ F: include/linux/swiotlb.h
F: kernel/dma/
DMA MAPPING HELPERS DEVICE DRIVER API [RUST]
M: Abdiel Janulgue <abdiel.janulgue@gmail.com>
M: Danilo Krummrich <dakr@kernel.org>
R: Abdiel Janulgue <abdiel.janulgue@gmail.com>
R: Daniel Almeida <daniel.almeida@collabora.com>
R: Robin Murphy <robin.murphy@arm.com>
R: Andreas Hindborg <a.hindborg@kernel.org>
L: rust-for-linux@vger.kernel.org
S: Supported
W: https://rust-for-linux.com
T: git https://github.com/Rust-for-Linux/linux.git alloc-next
T: git git://git.kernel.org/pub/scm/linux/kernel/git/driver-core/driver-core.git
F: rust/helpers/dma.c
F: rust/kernel/dma.rs
F: samples/rust/rust_dma.rs

View File

@ -70,6 +70,24 @@ static struct kernfs_open_node *of_on(struct kernfs_open_file *of)
!list_empty(&of->list));
}
/* Get active reference to kernfs node for an open file */
static struct kernfs_open_file *kernfs_get_active_of(struct kernfs_open_file *of)
{
/* Skip if file was already released */
if (unlikely(of->released))
return NULL;
if (!kernfs_get_active(of->kn))
return NULL;
return of;
}
static void kernfs_put_active_of(struct kernfs_open_file *of)
{
return kernfs_put_active(of->kn);
}
/**
* kernfs_deref_open_node_locked - Get kernfs_open_node corresponding to @kn
*
@ -139,7 +157,7 @@ static void kernfs_seq_stop_active(struct seq_file *sf, void *v)
if (ops->seq_stop)
ops->seq_stop(sf, v);
kernfs_put_active(of->kn);
kernfs_put_active_of(of);
}
static void *kernfs_seq_start(struct seq_file *sf, loff_t *ppos)
@ -152,7 +170,7 @@ static void *kernfs_seq_start(struct seq_file *sf, loff_t *ppos)
* the ops aren't called concurrently for the same open file.
*/
mutex_lock(&of->mutex);
if (!kernfs_get_active(of->kn))
if (!kernfs_get_active_of(of))
return ERR_PTR(-ENODEV);
ops = kernfs_ops(of->kn);
@ -238,7 +256,7 @@ static ssize_t kernfs_file_read_iter(struct kiocb *iocb, struct iov_iter *iter)
* the ops aren't called concurrently for the same open file.
*/
mutex_lock(&of->mutex);
if (!kernfs_get_active(of->kn)) {
if (!kernfs_get_active_of(of)) {
len = -ENODEV;
mutex_unlock(&of->mutex);
goto out_free;
@ -252,7 +270,7 @@ static ssize_t kernfs_file_read_iter(struct kiocb *iocb, struct iov_iter *iter)
else
len = -EINVAL;
kernfs_put_active(of->kn);
kernfs_put_active_of(of);
mutex_unlock(&of->mutex);
if (len < 0)
@ -323,7 +341,7 @@ static ssize_t kernfs_fop_write_iter(struct kiocb *iocb, struct iov_iter *iter)
* the ops aren't called concurrently for the same open file.
*/
mutex_lock(&of->mutex);
if (!kernfs_get_active(of->kn)) {
if (!kernfs_get_active_of(of)) {
mutex_unlock(&of->mutex);
len = -ENODEV;
goto out_free;
@ -335,7 +353,7 @@ static ssize_t kernfs_fop_write_iter(struct kiocb *iocb, struct iov_iter *iter)
else
len = -EINVAL;
kernfs_put_active(of->kn);
kernfs_put_active_of(of);
mutex_unlock(&of->mutex);
if (len > 0)
@ -357,13 +375,13 @@ static void kernfs_vma_open(struct vm_area_struct *vma)
if (!of->vm_ops)
return;
if (!kernfs_get_active(of->kn))
if (!kernfs_get_active_of(of))
return;
if (of->vm_ops->open)
of->vm_ops->open(vma);
kernfs_put_active(of->kn);
kernfs_put_active_of(of);
}
static vm_fault_t kernfs_vma_fault(struct vm_fault *vmf)
@ -375,14 +393,14 @@ static vm_fault_t kernfs_vma_fault(struct vm_fault *vmf)
if (!of->vm_ops)
return VM_FAULT_SIGBUS;
if (!kernfs_get_active(of->kn))
if (!kernfs_get_active_of(of))
return VM_FAULT_SIGBUS;
ret = VM_FAULT_SIGBUS;
if (of->vm_ops->fault)
ret = of->vm_ops->fault(vmf);
kernfs_put_active(of->kn);
kernfs_put_active_of(of);
return ret;
}
@ -395,7 +413,7 @@ static vm_fault_t kernfs_vma_page_mkwrite(struct vm_fault *vmf)
if (!of->vm_ops)
return VM_FAULT_SIGBUS;
if (!kernfs_get_active(of->kn))
if (!kernfs_get_active_of(of))
return VM_FAULT_SIGBUS;
ret = 0;
@ -404,7 +422,7 @@ static vm_fault_t kernfs_vma_page_mkwrite(struct vm_fault *vmf)
else
file_update_time(file);
kernfs_put_active(of->kn);
kernfs_put_active_of(of);
return ret;
}
@ -418,14 +436,14 @@ static int kernfs_vma_access(struct vm_area_struct *vma, unsigned long addr,
if (!of->vm_ops)
return -EINVAL;
if (!kernfs_get_active(of->kn))
if (!kernfs_get_active_of(of))
return -EINVAL;
ret = -EINVAL;
if (of->vm_ops->access)
ret = of->vm_ops->access(vma, addr, buf, len, write);
kernfs_put_active(of->kn);
kernfs_put_active_of(of);
return ret;
}
@ -455,7 +473,7 @@ static int kernfs_fop_mmap(struct file *file, struct vm_area_struct *vma)
mutex_lock(&of->mutex);
rc = -ENODEV;
if (!kernfs_get_active(of->kn))
if (!kernfs_get_active_of(of))
goto out_unlock;
ops = kernfs_ops(of->kn);
@ -490,7 +508,7 @@ static int kernfs_fop_mmap(struct file *file, struct vm_area_struct *vma)
}
vma->vm_ops = &kernfs_vm_ops;
out_put:
kernfs_put_active(of->kn);
kernfs_put_active_of(of);
out_unlock:
mutex_unlock(&of->mutex);
@ -852,7 +870,7 @@ static __poll_t kernfs_fop_poll(struct file *filp, poll_table *wait)
struct kernfs_node *kn = kernfs_dentry_node(filp->f_path.dentry);
__poll_t ret;
if (!kernfs_get_active(kn))
if (!kernfs_get_active_of(of))
return DEFAULT_POLLMASK|EPOLLERR|EPOLLPRI;
if (kn->attr.ops->poll)
@ -860,7 +878,7 @@ static __poll_t kernfs_fop_poll(struct file *filp, poll_table *wait)
else
ret = kernfs_generic_poll(of, wait);
kernfs_put_active(kn);
kernfs_put_active_of(of);
return ret;
}
@ -875,7 +893,7 @@ static loff_t kernfs_fop_llseek(struct file *file, loff_t offset, int whence)
* the ops aren't called concurrently for the same open file.
*/
mutex_lock(&of->mutex);
if (!kernfs_get_active(of->kn)) {
if (!kernfs_get_active_of(of)) {
mutex_unlock(&of->mutex);
return -ENODEV;
}
@ -886,7 +904,7 @@ static loff_t kernfs_fop_llseek(struct file *file, loff_t offset, int whence)
else
ret = generic_file_llseek(file, offset, whence);
kernfs_put_active(of->kn);
kernfs_put_active_of(of);
mutex_unlock(&of->mutex);
return ret;
}

View File

@ -138,7 +138,9 @@
/// }
/// ```
///
/// An example for a class device implementation is [`drm::Device`].
/// An example for a class device implementation is
#[cfg_attr(CONFIG_DRM = "y", doc = "[`drm::Device`](kernel::drm::Device).")]
#[cfg_attr(not(CONFIG_DRM = "y"), doc = "`drm::Device`.")]
///
/// # Invariants
///
@ -151,7 +153,6 @@
/// dropped from any thread.
///
/// [`AlwaysRefCounted`]: kernel::types::AlwaysRefCounted
/// [`drm::Device`]: kernel::drm::Device
/// [`impl_device_context_deref`]: kernel::impl_device_context_deref
/// [`pci::Device`]: kernel::pci::Device
/// [`platform::Device`]: kernel::platform::Device