| 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-2024-26983: bootconfig: use memblock_free_late to free xbc memory to buddy |
| |
| Description |
| =========== |
| |
| In the Linux kernel, the following vulnerability has been resolved: |
| |
| bootconfig: use memblock_free_late to free xbc memory to buddy |
| |
| On the time to free xbc memory in xbc_exit(), memblock may has handed |
| over memory to buddy allocator. So it doesn't make sense to free memory |
| back to memblock. memblock_free() called by xbc_exit() even causes UAF bugs |
| on architectures with CONFIG_ARCH_KEEP_MEMBLOCK disabled like x86. |
| Following KASAN logs shows this case. |
| |
| This patch fixes the xbc memory free problem by calling memblock_free() |
| in early xbc init error rewind path and calling memblock_free_late() in |
| xbc exit path to free memory to buddy allocator. |
| |
| [ 9.410890] ================================================================== |
| [ 9.418962] BUG: KASAN: use-after-free in memblock_isolate_range+0x12d/0x260 |
| [ 9.426850] Read of size 8 at addr ffff88845dd30000 by task swapper/0/1 |
| |
| [ 9.435901] CPU: 9 PID: 1 Comm: swapper/0 Tainted: G U 6.9.0-rc3-00208-g586b5dfb51b9 #5 |
| [ 9.446403] Hardware name: Intel Corporation RPLP LP5 (CPU:RaptorLake)/RPLP LP5 (ID:13), BIOS IRPPN02.01.01.00.00.19.015.D-00000000 Dec 28 2023 |
| [ 9.460789] Call Trace: |
| [ 9.463518] <TASK> |
| [ 9.465859] dump_stack_lvl+0x53/0x70 |
| [ 9.469949] print_report+0xce/0x610 |
| [ 9.473944] ? __virt_addr_valid+0xf5/0x1b0 |
| [ 9.478619] ? memblock_isolate_range+0x12d/0x260 |
| [ 9.483877] kasan_report+0xc6/0x100 |
| [ 9.487870] ? memblock_isolate_range+0x12d/0x260 |
| [ 9.493125] memblock_isolate_range+0x12d/0x260 |
| [ 9.498187] memblock_phys_free+0xb4/0x160 |
| [ 9.502762] ? __pfx_memblock_phys_free+0x10/0x10 |
| [ 9.508021] ? mutex_unlock+0x7e/0xd0 |
| [ 9.512111] ? __pfx_mutex_unlock+0x10/0x10 |
| [ 9.516786] ? kernel_init_freeable+0x2d4/0x430 |
| [ 9.521850] ? __pfx_kernel_init+0x10/0x10 |
| [ 9.526426] xbc_exit+0x17/0x70 |
| [ 9.529935] kernel_init+0x38/0x1e0 |
| [ 9.533829] ? _raw_spin_unlock_irq+0xd/0x30 |
| [ 9.538601] ret_from_fork+0x2c/0x50 |
| [ 9.542596] ? __pfx_kernel_init+0x10/0x10 |
| [ 9.547170] ret_from_fork_asm+0x1a/0x30 |
| [ 9.551552] </TASK> |
| |
| [ 9.555649] The buggy address belongs to the physical page: |
| [ 9.561875] page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x1 pfn:0x45dd30 |
| [ 9.570821] flags: 0x200000000000000(node=0|zone=2) |
| [ 9.576271] page_type: 0xffffffff() |
| [ 9.580167] raw: 0200000000000000 ffffea0011774c48 ffffea0012ba1848 0000000000000000 |
| [ 9.588823] raw: 0000000000000001 0000000000000000 00000000ffffffff 0000000000000000 |
| [ 9.597476] page dumped because: kasan: bad access detected |
| |
| [ 9.605362] Memory state around the buggy address: |
| [ 9.610714] ffff88845dd2ff00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 |
| [ 9.618786] ffff88845dd2ff80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 |
| [ 9.626857] >ffff88845dd30000: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff |
| [ 9.634930] ^ |
| [ 9.638534] ffff88845dd30080: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff |
| [ 9.646605] ffff88845dd30100: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff |
| [ 9.654675] ================================================================== |
| |
| The Linux kernel CVE team has assigned CVE-2024-26983 to this issue. |
| |
| |
| Affected and fixed versions |
| =========================== |
| |
| Issue introduced in 5.15 with commit 40caa127f3c7279c75cb0c9684559fa314ee3a66 and fixed in 6.1.88 with commit 1e7feb31a18c197d63a5e606025ed63c762f8918 |
| Issue introduced in 5.15 with commit 40caa127f3c7279c75cb0c9684559fa314ee3a66 and fixed in 6.6.29 with commit e46d3be714ad9652480c6db129ab8125e2d20ab7 |
| Issue introduced in 5.15 with commit 40caa127f3c7279c75cb0c9684559fa314ee3a66 and fixed in 6.8.8 with commit 5a7dfb8fcd3f29fc93161100179b27f24f3d5f35 |
| Issue introduced in 5.15 with commit 40caa127f3c7279c75cb0c9684559fa314ee3a66 and fixed in 6.9 with commit 89f9a1e876b5a7ad884918c03a46831af202c8a0 |
| |
| 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-2024-26983 |
| 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: |
| include/linux/bootconfig.h |
| lib/bootconfig.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/1e7feb31a18c197d63a5e606025ed63c762f8918 |
| https://git.kernel.org/stable/c/e46d3be714ad9652480c6db129ab8125e2d20ab7 |
| https://git.kernel.org/stable/c/5a7dfb8fcd3f29fc93161100179b27f24f3d5f35 |
| https://git.kernel.org/stable/c/89f9a1e876b5a7ad884918c03a46831af202c8a0 |
