Description (CNA)
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.
Affected (CNA)
| Vendor / product | Versions |
|---|---|
| Linux / Linux | affected bd61848900bff597764238f3a8ec67c815cd316e before 2151b2bcf6fcec52665f606eed20da068447f0b7; affected bd61848900bff597764238f3a8ec67c815cd316e before b04326c7927af7048fd4e730f5770cca350d0a60; affected bd61848900bff597764238f3a8ec67c815cd316e before 125755776bc6d4dd53eaf551c87e3d460625d638 |
| Linux / Linux | affected 6.16; unaffected 0 before 6.16; unaffected 6.18.52 through 6.18.*; unaffected 7.2.6 through 7.2.*; unaffected 7.3 through * |
CWE
No CWE identifiers supplied.