Описание
In the Linux kernel, the following vulnerability has been resolved:
gpio: sloppy-logic-analyzer: fix use-after-free via debugfs trigger on unbind
The "trigger" debugfs file has a hand-rolled ->write handler (trigger_write()) that dereferences the per-device gpio_la_poll_priv. The file is created with debugfs_create_file_unsafe(), and the handler never takes a debugfs reference. Nothing keeps the object alive while the handler runs.
priv is allocated with devm_kzalloc(). devres frees it when the platform device is unbound. debugfs_create_file_unsafe() installs no full_proxy wrapper, so debugfs_remove_recursive() in gpio_la_poll_remove() does not wait for an in-flight trigger_write(). The blob_lock taken there does not help, because trigger_write() never takes it. A write that races an unbind therefore writes into freed memory:
trigger_write() gpio_la_poll_remove() priv = m->private buf = memdup_user() [may sleep] mutex
EPSS
Дефекты
Связанные уязвимости
In the Linux kernel, the following vulnerability has been resolved: gpio: sloppy-logic-analyzer: fix use-after-free via debugfs trigger on unbind The "trigger" debugfs file has a hand-rolled ->write handler (trigger_write()) that dereferences the per-device gpio_la_poll_priv. The file is created with debugfs_create_file_unsafe(), and the handler never takes a debugfs reference. Nothing keeps the object alive while the handler runs. priv is allocated with devm_kzalloc(). devres frees it when the platform device is unbound. debugfs_create_file_unsafe() installs no full_proxy wrapper, so debugfs_remove_recursive() in gpio_la_poll_remove() does not wait for an in-flight trigger_write(). The blob_lock taken there does not help, because trigger_write() never takes it. A write that races an unbind therefore writes into freed memory: trigger_write() gpio_la_poll_remove() priv = m->private buf = memdup_user() [may sleep] mutex_lock(&priv->blob_lock) debugfs_remove_recursive...
In the Linux kernel, the following vulnerability has been resolved: gpio: sloppy-logic-analyzer: fix use-after-free via debugfs trigger on unbind The "trigger" debugfs file has a hand-rolled ->write handler (trigger_write()) that dereferences the per-device gpio_la_poll_priv. The file is created with debugfs_create_file_unsafe(), and the handler never takes a debugfs reference. Nothing keeps the object alive while the handler runs. priv is allocated with devm_kzalloc(). devres frees it when the platform device is unbound. debugfs_create_file_unsafe() installs no full_proxy wrapper, so debugfs_remove_recursive() in gpio_la_poll_remove() does not wait for an in-flight trigger_write(). The blob_lock taken there does not help, because trigger_write() never takes it. A write that races an unbind therefore writes into freed memory: trigger_write() gpio_la_poll_remove() priv = m->private buf = memdup_user() [may sleep] mutex_lock(&priv->blob_lock) debugfs_remove_recursive...
In the Linux kernel, the following vulnerability has been resolved: g ...
EPSS