CVE-2022-48821

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.

• linux linux kernel (>= 5.1 < 5.4.180) • linux linux kernel (>= 5.5 < 5.10.101) • linux linux kernel (>= 5.11 < 5.15.24) • linux linux kernel (>= 5.16 < 5.16.10) • linux linux kernel 5.17