CVE-2022-48821

Summary

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.

Affected Software

VendorProductVersion RangeStatus
LinuxLinux6cffd79504ce040f460831030d3069fa1c99bb71 < 4e6fd2b5fcf8e7119305a6042bd92e7f2b9ed215affected
LinuxLinux6cffd79504ce040f460831030d3069fa1c99bb71 < a5ce7ee5fcc07583159f54ab4af5164de00148f5affected
LinuxLinux6cffd79504ce040f460831030d3069fa1c99bb71 < e4382d0a39f9a1e260d62fdc079ddae5293c037daffected
LinuxLinux6cffd79504ce040f460831030d3069fa1c99bb71 < 76f85c307ef9f10aa2cef1b1d5ee654c1f3345fcaffected
LinuxLinux6cffd79504ce040f460831030d3069fa1c99bb71 < 46963e2e0629cb31c96b1d47ddd89dc3d8990b34affected
LinuxLinux5.1affected
LinuxLinux0 < 5.1unaffected
LinuxLinux5.4.180 <= 5.4.*unaffected
LinuxLinux5.10.101 <= 5.10.*unaffected
LinuxLinux5.15.24 <= 5.15.*unaffected
LinuxLinux5.16.10 <= 5.16.*unaffected
LinuxLinux5.17 <= *unaffected

Weaknesses

ADP Enrichment

CVE Program Container

Additional References

CISA ADP Vulnrichment

  • SSVC:
  • Exploitation: none
    • Automatable: no
    • Technical Impact: partial

References