CVE-2026-31753auxdisplay: line-display: fix NULL dereference in linedisp_release

Official description

In the Linux kernel, the following vulnerability has been resolved: auxdisplay: line-display: fix NULL dereference in linedisp_release linedisp_release() currently retrieves the enclosing struct linedisp via to_linedisp(). That lookup depends on the attachment list, but the attachment may already have been removed before put_device() invokes the release callback. This can happen in linedisp_unregister(), and can also be reached from some linedisp_register() error paths. In that case, to_linedisp() returns NULL and linedisp_release() dereferences it while freeing the display resources. The struct device released here is the embedded linedisp->dev used by linedisp_register(), so retrieve the enclosing object directly with container_of() instead.

Affected packages & fixed versions

Affected products (as reported)

References

• https://git.kernel.org/stable/c/625fdac41cfc4ca9e1774a0d31d7985aec2c1d66
• https://git.kernel.org/stable/c/7f138de156b20d9f9da6f72f90b63c01941d97d3