In the Linux kernel, the following vulnerability has been resolved:
libceph: bound get_version reply decode to front len
handle_get_version_reply() uses msg->front_alloc_len as the decode boundary for MON_GET_VERSION_REPLY. That is the size of the reused reply buffer, not the number of bytes actually received.
A truncated reply can therefore pass ceph_decode_need() and decode the second u64 from stale tail bytes left in the buffer by an earlier message, causing an uninitialized memory read.
Use msg->front.iov_len as the receive-side decode boundary, matching other libceph reply handlers and limiting decoding to the bytes that were actually read from the wire.
References
- https://git.kernel.org/stable/c/0d934c934ec746d53fc7e4f53239792647bbae63
- https://git.kernel.org/stable/c/340e0386aa39da181015bee38f309018c335ce16
- https://git.kernel.org/stable/c/4e7ebfaa0d14cf50e44041bfde38070d6dbc019f
- https://git.kernel.org/stable/c/d3c32939fa0e3ee9b883b9a0fd1972c5c444e3d0
- https://git.kernel.org/stable/c/d60de8253c85a02d0e6194b0735e7a562981a04c