Bugzilla – Bug 1227934
VUL-0: CVE-2022-48819: kernel: tcp: take care of mixed splice()/sendmsg(MSG_ZEROCOPY) case
Last modified: 2024-07-18 15:46:45 UTC
Description =========== In the Linux kernel, the following vulnerability has been resolved: tcp: take care of mixed splice()/sendmsg(MSG_ZEROCOPY) case syzbot found that mixing sendpage() and sendmsg(MSG_ZEROCOPY) calls over the same TCP socket would again trigger the infamous warning in inet_sock_destruct() WARN_ON(sk_forward_alloc_get(sk)); While Talal took into account a mix of regular copied data and MSG_ZEROCOPY one in the same skb, the sendpage() path has been forgotten. We want the charging to happen for sendpage(), because pages could be coming from a pipe. What is missing is the downgrading of pure zerocopy status to make sure sk_forward_alloc will stay synced. Add tcp_downgrade_zcopy_pure() helper so that we can use it from the two callers. The Linux kernel CVE team has assigned CVE-2022-48819 to this issue. Affected and fixed versions =========================== Issue introduced in 5.16 with commit 9b65b17db723 and fixed in 5.16.10 with commit 47f3860c4931 Issue introduced in 5.16 with commit 9b65b17db723 and fixed in 5.17 with commit f8d9d938514f Please see https://www.kernel.org for a full list of currently supported kernel versions by the kernel community. Unaffected versions might change over time as fixes are backported to older supported kernel versions. The official CVE entry at https://cve.org/CVERecord/?id=CVE-2022-48819 will be updated if fixes are backported, please check that for the most up to date information about this issue. Affected files ============== The file(s) affected by this issue are: net/ipv4/tcp.c Mitigation ========== The Linux kernel CVE team recommends that you update to the latest stable kernel version for this, and many other bugfixes. Individual changes are never tested alone, but rather are part of a larger kernel release. Cherry-picking individual commits is not recommended or supported by the Linux kernel community at all. If however, updating to the latest release is impossible, the individual changes to resolve this issue can be found at these commits: https://git.kernel.org/stable/c/47f3860c4931175f112f28dcac66eacca9b1040f https://git.kernel.org/stable/c/f8d9d938514f46c4892aff6bfe32f425e84d81cc References: http://web.nvd.nist.gov/view/vuln/detail?vulnId=CVE-2022-48819 https://git.kernel.org/pub/scm/linux/security/vulns.git/plain/cve/published/2022/CVE-2022-48819.mbox https://git.kernel.org/stable/c/47f3860c4931175f112f28dcac66eacca9b1040f https://git.kernel.org/stable/c/f8d9d938514f46c4892aff6bfe32f425e84d81cc