| 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-2022-49198: mptcp: Fix crash due to tcp_tsorted_anchor was initialized before release skb |
| |
| Description |
| =========== |
| |
| In the Linux kernel, the following vulnerability has been resolved: |
| |
| mptcp: Fix crash due to tcp_tsorted_anchor was initialized before release skb |
| |
| Got crash when doing pressure test of mptcp: |
| |
| =========================================================================== |
| dst_release: dst:ffffa06ce6e5c058 refcnt:-1 |
| kernel tried to execute NX-protected page - exploit attempt? (uid: 0) |
| BUG: unable to handle kernel paging request at ffffa06ce6e5c058 |
| PGD 190a01067 P4D 190a01067 PUD 43fffb067 PMD 22e403063 PTE 8000000226e5c063 |
| Oops: 0011 [#1] SMP PTI |
| CPU: 7 PID: 7823 Comm: kworker/7:0 Kdump: loaded Tainted: G E |
| Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.2.1 04/01/2014 |
| Call Trace: |
| ? skb_release_head_state+0x68/0x100 |
| ? skb_release_all+0xe/0x30 |
| ? kfree_skb+0x32/0xa0 |
| ? mptcp_sendmsg_frag+0x57e/0x750 |
| ? __mptcp_retrans+0x21b/0x3c0 |
| ? __switch_to_asm+0x35/0x70 |
| ? mptcp_worker+0x25e/0x320 |
| ? process_one_work+0x1a7/0x360 |
| ? worker_thread+0x30/0x390 |
| ? create_worker+0x1a0/0x1a0 |
| ? kthread+0x112/0x130 |
| ? kthread_flush_work_fn+0x10/0x10 |
| ? ret_from_fork+0x35/0x40 |
| =========================================================================== |
| |
| In __mptcp_alloc_tx_skb skb was allocated and skb->tcp_tsorted_anchor will |
| be initialized, in under memory pressure situation sk_wmem_schedule will |
| return false and then kfree_skb. In this case skb->_skb_refdst is not null |
| because_skb_refdst and tcp_tsorted_anchor are stored in the same mem, and |
| kfree_skb will try to release dst and cause crash. |
| |
| The Linux kernel CVE team has assigned CVE-2022-49198 to this issue. |
| |
| |
| Affected and fixed versions |
| =========================== |
| |
| Issue introduced in 5.16 with commit f70cad1085d1e01d3ec73c1078405f906237feee and fixed in 5.16.19 with commit 752add6f5ce5305e55d8bda4ac8d69be3a09f14d |
| Issue introduced in 5.16 with commit f70cad1085d1e01d3ec73c1078405f906237feee and fixed in 5.17.2 with commit 4d54181eba4b077fb74033a7186898ad4000a7a5 |
| Issue introduced in 5.16 with commit f70cad1085d1e01d3ec73c1078405f906237feee and fixed in 5.18 with commit 3ef3905aa3b5b3e222ee6eb0210bfd999417a8cc |
| |
| 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-2022-49198 |
| 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/mptcp/protocol.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/af61a8f7603926c26158153d0a0755764d82657c |
| https://git.kernel.org/stable/c/752add6f5ce5305e55d8bda4ac8d69be3a09f14d |
| https://git.kernel.org/stable/c/4d54181eba4b077fb74033a7186898ad4000a7a5 |
| https://git.kernel.org/stable/c/3ef3905aa3b5b3e222ee6eb0210bfd999417a8cc |
