Описание
In the Linux kernel, the following vulnerability has been resolved:
NFSD: Protect against send buffer overflow in NFSv3 READDIR
Since before the git era, NFSD has conserved the number of pages held by each nfsd thread by combining the RPC receive and send buffers into a single array of pages. This works because there are no cases where an operation needs a large RPC Call message and a large RPC Reply message at the same time.
Once an RPC Call has been received, svc_process() updates svc_rqst::rq_res to describe the part of rq_pages that can be used for constructing the Reply. This means that the send buffer (rq_res) shrinks when the received RPC record containing the RPC Call is large.
A client can force this shrinkage on TCP by sending a correctly- formed RPC Call header contained in an RPC record that is excessively large. The full maximum payload size cannot be constructed in that case.
Thanks to Aleksi Illikainen and Kari Hulkko for uncovering this issue.
In the Linux kernel, the following vulnerability has been resolved:
NFSD: Protect against send buffer overflow in NFSv3 READDIR
Since before the git era, NFSD has conserved the number of pages held by each nfsd thread by combining the RPC receive and send buffers into a single array of pages. This works because there are no cases where an operation needs a large RPC Call message and a large RPC Reply message at the same time.
Once an RPC Call has been received, svc_process() updates svc_rqst::rq_res to describe the part of rq_pages that can be used for constructing the Reply. This means that the send buffer (rq_res) shrinks when the received RPC record containing the RPC Call is large.
A client can force this shrinkage on TCP by sending a correctly- formed RPC Call header contained in an RPC record that is excessively large. The full maximum payload size cannot be constructed in that case.
Thanks to Aleksi Illikainen and Kari Hulkko for uncovering this issue.
Ссылки
- https://nvd.nist.gov/vuln/detail/CVE-2022-50487
- https://git.kernel.org/stable/c/071a076fd1b763aa6fe478efa047e0a549ba9c22
- https://git.kernel.org/stable/c/279274e31270c28b86feffe5e166d4088f22317b
- https://git.kernel.org/stable/c/57774b1526163766403167b7bf00b136fb103761
- https://git.kernel.org/stable/c/640f87c190e0d1b2a0fcb2ecf6d2cd53b1c41991
- https://git.kernel.org/stable/c/9c3224826ec17f14e8bdfc86cb7e82fe52d744a7
CVE ID
Связанные уязвимости
Rejected reason: This CVE ID has been rejected or withdrawn by its CVE Numbering Authority.
A buffer management flaw was found in the Linux kernel's NFS server implementation in the NFSv3 READDIR operation handling. A remote client can trigger this issue by crafting an RPC call with an oversized RPC record header, which forces the server to shrink its response buffer allocation. This causes the READDIR response construction to write beyond the available buffer space, resulting in a send buffer overflow that leads to memory corruption, denial of service via crash, or potential data integrity issues.
Rejected reason: This CVE ID has been rejected or withdrawn by its CVE Numbering Authority.
