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…
Does this matter?
High impact if exploited, but EPSS currently rates exploitation as unlikely (0.27%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.
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.
- CVSS 3.1
- 7.8 HIGHCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
- EPSS
- 0.27% probability · 20th percentile
- CISA KEV
- Not listed
- Weakness
- CWE-416
- Affected
- linux/linux kernel
- Source
- 416baaa9-dc9f-4396-8d5f-8c081fb06d67
References
- https://git.kernel.org/stable/c/46963e2e0629cb31c96b1d47ddd89dc3d8990b34Patch
- https://git.kernel.org/stable/c/4e6fd2b5fcf8e7119305a6042bd92e7f2b9ed215Patch
- https://git.kernel.org/stable/c/76f85c307ef9f10aa2cef1b1d5ee654c1f3345fcPatch
- https://git.kernel.org/stable/c/a5ce7ee5fcc07583159f54ab4af5164de00148f5Patch
- https://git.kernel.org/stable/c/e4382d0a39f9a1e260d62fdc079ddae5293c037dPatch
- https://git.kernel.org/stable/c/46963e2e0629cb31c96b1d47ddd89dc3d8990b34Patch
- https://git.kernel.org/stable/c/4e6fd2b5fcf8e7119305a6042bd92e7f2b9ed215Patch
- https://git.kernel.org/stable/c/76f85c307ef9f10aa2cef1b1d5ee654c1f3345fcPatch
- https://git.kernel.org/stable/c/a5ce7ee5fcc07583159f54ab4af5164de00148f5Patch
- https://git.kernel.org/stable/c/e4382d0a39f9a1e260d62fdc079ddae5293c037dPatch
Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.