| 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-2024-56544: udmabuf: change folios array from kmalloc to kvmalloc |
| |
| Description |
| =========== |
| |
| In the Linux kernel, the following vulnerability has been resolved: |
| |
| udmabuf: change folios array from kmalloc to kvmalloc |
| |
| When PAGE_SIZE 4096, MAX_PAGE_ORDER 10, 64bit machine, |
| page_alloc only support 4MB. |
| If above this, trigger this warn and return NULL. |
| |
| udmabuf can change size limit, if change it to 3072(3GB), and then alloc |
| 3GB udmabuf, will fail create. |
| |
| [ 4080.876581] ------------[ cut here ]------------ |
| [ 4080.876843] WARNING: CPU: 3 PID: 2015 at mm/page_alloc.c:4556 __alloc_pages+0x2c8/0x350 |
| [ 4080.878839] RIP: 0010:__alloc_pages+0x2c8/0x350 |
| [ 4080.879470] Call Trace: |
| [ 4080.879473] <TASK> |
| [ 4080.879473] ? __alloc_pages+0x2c8/0x350 |
| [ 4080.879475] ? __warn.cold+0x8e/0xe8 |
| [ 4080.880647] ? __alloc_pages+0x2c8/0x350 |
| [ 4080.880909] ? report_bug+0xff/0x140 |
| [ 4080.881175] ? handle_bug+0x3c/0x80 |
| [ 4080.881556] ? exc_invalid_op+0x17/0x70 |
| [ 4080.881559] ? asm_exc_invalid_op+0x1a/0x20 |
| [ 4080.882077] ? udmabuf_create+0x131/0x400 |
| |
| Because MAX_PAGE_ORDER, kmalloc can max alloc 4096 * (1 << 10), 4MB |
| memory, each array entry is pointer(8byte), so can save 524288 pages(2GB). |
| |
| Further more, costly order(order 3) may not be guaranteed that it can be |
| applied for, due to fragmentation. |
| |
| This patch change udmabuf array use kvmalloc_array, this can fallback |
| alloc into vmalloc, which can guarantee allocation for any size and does |
| not affect the performance of kmalloc allocations. |
| |
| The Linux kernel CVE team has assigned CVE-2024-56544 to this issue. |
| |
| |
| Affected and fixed versions |
| =========================== |
| |
| Issue introduced in 4.20 with commit fbb0de795078190a9834b3409e4b009cfb18a6d4 and fixed in 6.11.11 with commit 2acc6192aa8570661ed37868c02c03002b1dc290 |
| Issue introduced in 4.20 with commit fbb0de795078190a9834b3409e4b009cfb18a6d4 and fixed in 6.12.2 with commit 85bb72397cb63649fe493c96e27e1d0e4ed2ff63 |
| Issue introduced in 4.20 with commit fbb0de795078190a9834b3409e4b009cfb18a6d4 and fixed in 6.13 with commit 1c0844c6184e658064e14c4335885785ad3bf84b |
| |
| 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-2024-56544 |
| 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/2acc6192aa8570661ed37868c02c03002b1dc290 |
| https://git.kernel.org/stable/c/85bb72397cb63649fe493c96e27e1d0e4ed2ff63 |
| https://git.kernel.org/stable/c/1c0844c6184e658064e14c4335885785ad3bf84b |
