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Unrated severityNVD Advisory· Published Jul 16, 2024· Updated May 4, 2025

misc: fastrpc: avoid double fput() on failed usercopy

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.

Affected products

164

Patches

0

No patches discovered yet.

Vulnerability mechanics

AI mechanics synthesis has not run for this CVE yet.

References

5

News mentions

0

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