CVE Published: 16/07/2024 |
CVE Updated: 04/11/2024 |
CVE Year: 2022 Source: Linux |
Vendor: Linux |
Product: Linux Status : PUBLISHED
CVE-2022-48821 Description
In the Linux kernel, the following vulnerability has been resolved:
misc: fastrpc: avoid double fput() on failed usercopy
If the copy back to userland fails for the FASTRPC_IOCTL_ALLOC_DMA_BUFF
ioctl(), we shouldn\'t assume that \'buf->dmabuf\' is still valid. In fact,
dma_buf_fd() called fd_install() before, i.e. "consumed" one reference,
leaving us with none.
Calling dma_buf_put() will therefore put a reference we no longer own,
leading to a valid file descritor table entry for an already released
\'file\' object which is a straight use-after-free.
Simply avoid calling dma_buf_put() and rely on the process exit code to
do the necessary cleanup, if needed, i.e. if the file descriptor is
still valid.