tcp: reject non zerocopy devmem tx
- Published
- Last modified
- Where the record stands: published, rejected by its publisher, or superseded by another id.What do these mean? →
- published
- Whether CISA lists it in its Known Exploited Vulnerabilities catalog: proof that attackers are using it.What do these mean? →
- Not listed in CISA KEV
- Fix
- Fixed in 6.18.52, 7.2.6
- Whether working attack code is public (Exploit-DB, Metasploit, Nuclei or GitHub). Public code makes attacks easier.What do these mean? →
- None on Exploit-DB, Metasploit or GitHub
Summary
In the Linux kernel, the following vulnerability has been resolved: tcp: reject non zerocopy devmem tx Devmem tcp tx doesn't work without zero-copy, however it's not currently enforced if NETIF_F_SG isn't present. In this case, tcp_sendmsg_locked() will try the copy path and try to copy data from an iovec which consists of offsets into the dma-buf and would normally fail. Moreover, d9c56501c72fd ("net: tcp: block mixing readable and unreadable frags") relies on that and assumes that the devmem binding is present IFF we're using the zero-copy path, which can be used to mix net-iov and pages in a single skb, and break invariants. Let's reject devmem tx without zero-copy. Note, the parameter check the patch is modifying is too loose, we can create an io_uring request with dmabuf_id and all ZC flags, but which won't have the binding. We replace it with stricter validation.
Timeline
- CVE published
- Record last updated
Affected versions
- Linux Linux
From bd61848900bff597764238f3a8ec67c815cd316e · fixed in 2151b2bcf6fcec52665f606eed20da068447f0b7; From bd61848900bff597764238f3a8ec67c815cd316e · fixed in b04326c7927af7048fd4e730f5770cca350d0a60; From bd61848900bff597764238f3a8ec67c815cd316e · fixed in 125755776bc6d4dd53eaf551c87e3d460625d638
- Linux Linux
6.16
- KernelLinux
From 6.16.0 · fixed in 6.18.52; From 6.19.0 · fixed in 7.2.6