| 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-2021-47649: udmabuf: validate ubuf->pagecount |
| |
| Description |
| =========== |
| |
| In the Linux kernel, the following vulnerability has been resolved: |
| |
| udmabuf: validate ubuf->pagecount |
| |
| Syzbot has reported GPF in sg_alloc_append_table_from_pages(). The |
| problem was in ubuf->pages == ZERO_PTR. |
| |
| ubuf->pagecount is calculated from arguments passed from user-space. If |
| user creates udmabuf with list.size == 0 then ubuf->pagecount will be |
| also equal to zero; it causes kmalloc_array() to return ZERO_PTR. |
| |
| Fix it by validating ubuf->pagecount before passing it to |
| kmalloc_array(). |
| |
| The Linux kernel CVE team has assigned CVE-2021-47649 to this issue. |
| |
| |
| Affected and fixed versions |
| =========================== |
| |
| Issue introduced in 4.20 with commit fbb0de795078190a9834b3409e4b009cfb18a6d4 and fixed in 5.4.189 with commit 5d50f851dd307c07ca5591297093f19967c834a9 |
| Issue introduced in 4.20 with commit fbb0de795078190a9834b3409e4b009cfb18a6d4 and fixed in 5.10.110 with commit b267a8118c2b171bf7d67b90ed64154eeab9fae0 |
| Issue introduced in 4.20 with commit fbb0de795078190a9834b3409e4b009cfb18a6d4 and fixed in 5.15.33 with commit 811b667cefbea9cb7511a874b169d6a92907137e |
| Issue introduced in 4.20 with commit fbb0de795078190a9834b3409e4b009cfb18a6d4 and fixed in 5.16.19 with commit a3728d32fc61eb0fe283cb8ff60b2c8f751e2202 |
| Issue introduced in 4.20 with commit fbb0de795078190a9834b3409e4b009cfb18a6d4 and fixed in 5.17.2 with commit 9e9b4a269f84d3230f2af84ff42322db676440d9 |
| Issue introduced in 4.20 with commit fbb0de795078190a9834b3409e4b009cfb18a6d4 and fixed in 5.18 with commit 2b6dd600dd72573c23ea180b5b0b2f1813405882 |
| |
| 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-2021-47649 |
| 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/dma-buf/udmabuf.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/5d50f851dd307c07ca5591297093f19967c834a9 |
| https://git.kernel.org/stable/c/b267a8118c2b171bf7d67b90ed64154eeab9fae0 |
| https://git.kernel.org/stable/c/811b667cefbea9cb7511a874b169d6a92907137e |
| https://git.kernel.org/stable/c/a3728d32fc61eb0fe283cb8ff60b2c8f751e2202 |
| https://git.kernel.org/stable/c/9e9b4a269f84d3230f2af84ff42322db676440d9 |
| https://git.kernel.org/stable/c/2b6dd600dd72573c23ea180b5b0b2f1813405882 |
