Описание
In the Linux kernel, the following vulnerability has been resolved:
usb: gadget: f_fs: Fix Use-After-Free in AIO error path
In ffs_epfile_write_iter() and ffs_epfile_read_iter(), when ffs_epfile_io()
fails with an error other than -EIOCBQUEUED, the io_data structure (p) is
freed. However, for AIO operations, the kiocb cancel function was already
armed and kiocb->private was set to p.
If a concurrent cancel operation (such as sys_io_cancel()) executes after
ffs_epfile_io() fails but before the function frees p, a Use-After-Free
can occur when the cancellation handler accesses the freed pointer.
To securely fix this race condition, we must properly un-arm the
cancellation. Invoking kiocb->ki_complete() does exactly this by
acquiring ctx->ctx_lock and safely removing the kiocb from the active
sequence. In doing so, it ensures that a parallel io_cancel can no longer
discover the kiocb, effectively closing the race window.
We then return -EIOCBQUEUED to notify the VFS laye...
In the Linux kernel, the following vulnerability has been resolved:
usb: gadget: f_fs: Fix Use-After-Free in AIO error path
In ffs_epfile_write_iter() and ffs_epfile_read_iter(), when ffs_epfile_io()
fails with an error other than -EIOCBQUEUED, the io_data structure (p) is
freed. However, for AIO operations, the kiocb cancel function was already
armed and kiocb->private was set to p.
If a concurrent cancel operation (such as sys_io_cancel()) executes after
ffs_epfile_io() fails but before the function frees p, a Use-After-Free
can occur when the cancellation handler accesses the freed pointer.
To securely fix this race condition, we must properly un-arm the
cancellation. Invoking kiocb->ki_complete() does exactly this by
acquiring ctx->ctx_lock and safely removing the kiocb from the active
sequence. In doing so, it ensures that a parallel io_cancel can no longer
discover the kiocb, effectively closing the race window.
We then return -EIOCBQUEUED to notify the VFS layer that the kiocb has been consumed and it should avoid attempting to complete the request again or triggering subsequent completion handlers.
Связанные уязвимости
(In the Linux kernel, the following vulnerability has been resolved: u ...)
In the Linux kernel, the following vulnerability has been resolved: usb: gadget: f_fs: Fix Use-After-Free in AIO error path In ffs_epfile_write_iter() and ffs_epfile_read_iter(), when ffs_epfile_io() fails with an error other than -EIOCBQUEUED, the io_data structure (`p`) is freed. However, for AIO operations, the kiocb cancel function was already armed and kiocb->private was set to `p`. If a concurrent cancel operation (such as sys_io_cancel()) executes after ffs_epfile_io() fails but before the function frees `p`, a Use-After-Free can occur when the cancellation handler accesses the freed pointer. To securely fix this race condition, we must properly un-arm the cancellation. Invoking `kiocb->ki_complete()` does exactly this by acquiring `ctx->ctx_lock` and safely removing the kiocb from the active sequence. In doing so, it ensures that a parallel io_cancel can no longer discover the kiocb, effectively closing the race window. We then return -EIOCBQUEUED to notify the VFS layer t
In the Linux kernel, the following vulnerability has been resolved: u ...