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.

CVSS

No CVSS.

References

Link	Resource
https://git.kernel.org/stable/c/46963e2e0629cb31c96b1d47ddd89dc3d8990b34
https://git.kernel.org/stable/c/4e6fd2b5fcf8e7119305a6042bd92e7f2b9ed215
https://git.kernel.org/stable/c/76f85c307ef9f10aa2cef1b1d5ee654c1f3345fc
https://git.kernel.org/stable/c/a5ce7ee5fcc07583159f54ab4af5164de00148f5
https://git.kernel.org/stable/c/e4382d0a39f9a1e260d62fdc079ddae5293c037d

Configurations

No configuration.

History

No history.

Information

Published : 2024-07-16 12:15

Updated : 2024-07-16 13:43

NVD link : CVE-2022-48821

Mitre link : CVE-2022-48821

CVE.ORG link : CVE-2022-48821

JSON object : View

Products Affected

No product.

CWE

No CWE.

{"id": "CVE-2022-48821", "cveTags": [], "metrics": {}, "published": "2024-07-16T12:15:06.010", "references": [{"url": "https://git.kernel.org/stable/c/46963e2e0629cb31c96b1d47ddd89dc3d8990b34", "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}, {"url": "https://git.kernel.org/stable/c/4e6fd2b5fcf8e7119305a6042bd92e7f2b9ed215", "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}, {"url": "https://git.kernel.org/stable/c/76f85c307ef9f10aa2cef1b1d5ee654c1f3345fc", "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}, {"url": "https://git.kernel.org/stable/c/a5ce7ee5fcc07583159f54ab4af5164de00148f5", "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}, {"url": "https://git.kernel.org/stable/c/e4382d0a39f9a1e260d62fdc079ddae5293c037d", "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}], "vulnStatus": "Awaiting Analysis", "descriptions": [{"lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nmisc: fastrpc: avoid double fput() on failed usercopy\n\nIf the copy back to userland fails for the FASTRPC_IOCTL_ALLOC_DMA_BUFF\nioctl(), we shouldn't assume that 'buf->dmabuf' is still valid. In fact,\ndma_buf_fd() called fd_install() before, i.e. \"consumed\" one reference,\nleaving us with none.\n\nCalling dma_buf_put() will therefore put a reference we no longer own,\nleading to a valid file descritor table entry for an already released\n'file' object which is a straight use-after-free.\n\nSimply avoid calling dma_buf_put() and rely on the process exit code to\ndo the necessary cleanup, if needed, i.e. if the file descriptor is\nstill valid."}, {"lang": "es", "value": "En el kernel de Linux, se ha resuelto la siguiente vulnerabilidad: misc: fastrpc: evitar doble fput() en copia de usuario fallida. Si la copia al \u00e1rea de usuario falla para FASTRPC_IOCTL_ALLOC_DMA_BUFF ioctl(), no debemos asumir que 'buf->dmabuf' aun es v\u00e1lido. De hecho, dma_buf_fd() llam\u00f3 a fd_install() antes, es decir, \"consumi\u00f3\" una referencia, dej\u00e1ndonos sin ninguna. Por lo tanto, llamar a dma_buf_put() colocar\u00e1 una referencia que ya no poseemos, lo que conducir\u00e1 a una entrada v\u00e1lida en la tabla de descripci\u00f3n de archivos para un objeto 'archivo' ya publicado que es un use-after-free directo. Simplemente evite llamar a dma_buf_put() y conf\u00ede en el c\u00f3digo de salida del proceso para realizar la limpieza necesaria, si es necesario, es decir, si el descriptor del archivo a\u00fan es v\u00e1lido."}], "lastModified": "2024-07-16T13:43:58.773", "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}