| From bippy-5f407fcff5a0 Mon Sep 17 00:00:00 2001 |
| From: Greg Kroah-Hartman <gregkh@linuxfoundation.org> |
| To: <linux-cve-announce@vger.kernel.org> |
| Reply-to: <cve@kernel.org>, <linux-kernel@vger.kernel.org> |
| Subject: CVE-2022-48819: tcp: take care of mixed splice()/sendmsg(MSG_ZEROCOPY) case |
| |
| 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 9b65b17db72313b7a4fe9bc9502928c88be57986 and fixed in 5.16.10 with commit 47f3860c4931175f112f28dcac66eacca9b1040f |
| Issue introduced in 5.16 with commit 9b65b17db72313b7a4fe9bc9502928c88be57986 and fixed in 5.17 with commit f8d9d938514f46c4892aff6bfe32f425e84d81cc |
| |
| 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 |
