| 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-2021-47224: net: ll_temac: Make sure to free skb when it is completely used |
| |
| Description |
| =========== |
| |
| In the Linux kernel, the following vulnerability has been resolved: |
| |
| net: ll_temac: Make sure to free skb when it is completely used |
| |
| With the skb pointer piggy-backed on the TX BD, we have a simple and |
| efficient way to free the skb buffer when the frame has been transmitted. |
| But in order to avoid freeing the skb while there are still fragments from |
| the skb in use, we need to piggy-back on the TX BD of the skb, not the |
| first. |
| |
| Without this, we are doing use-after-free on the DMA side, when the first |
| BD of a multi TX BD packet is seen as completed in xmit_done, and the |
| remaining BDs are still being processed. |
| |
| The Linux kernel CVE team has assigned CVE-2021-47224 to this issue. |
| |
| |
| Affected and fixed versions |
| =========================== |
| |
| Fixed in 5.4.128 with commit 6d120ab4dc39a543c6b63361e1d0541c382900a3 |
| Fixed in 5.10.46 with commit 019ab7d044d0ebf97e1236bb8935b7809be92358 |
| Fixed in 5.12.13 with commit e8afe05bd359ebe12a61dbdc94c06c00ea3e8d4b |
| Fixed in 5.13 with commit 6aa32217a9a446275440ee8724b1ecaf1838df47 |
| |
| 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-2021-47224 |
| 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: |
| drivers/net/ethernet/xilinx/ll_temac_main.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/6d120ab4dc39a543c6b63361e1d0541c382900a3 |
| https://git.kernel.org/stable/c/019ab7d044d0ebf97e1236bb8935b7809be92358 |
| https://git.kernel.org/stable/c/e8afe05bd359ebe12a61dbdc94c06c00ea3e8d4b |
| https://git.kernel.org/stable/c/6aa32217a9a446275440ee8724b1ecaf1838df47 |
