| 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-2021-47341: KVM: mmio: Fix use-after-free Read in kvm_vm_ioctl_unregister_coalesced_mmio |
| |
| Description |
| =========== |
| |
| In the Linux kernel, the following vulnerability has been resolved: |
| |
| KVM: mmio: Fix use-after-free Read in kvm_vm_ioctl_unregister_coalesced_mmio |
| |
| BUG: KASAN: use-after-free in kvm_vm_ioctl_unregister_coalesced_mmio+0x7c/0x1ec arch/arm64/kvm/../../../virt/kvm/coalesced_mmio.c:183 |
| Read of size 8 at addr ffff0000c03a2500 by task syz-executor083/4269 |
| |
| CPU: 5 PID: 4269 Comm: syz-executor083 Not tainted 5.10.0 #7 |
| Hardware name: linux,dummy-virt (DT) |
| Call trace: |
| dump_backtrace+0x0/0x2d0 arch/arm64/kernel/stacktrace.c:132 |
| show_stack+0x28/0x34 arch/arm64/kernel/stacktrace.c:196 |
| __dump_stack lib/dump_stack.c:77 [inline] |
| dump_stack+0x110/0x164 lib/dump_stack.c:118 |
| print_address_description+0x78/0x5c8 mm/kasan/report.c:385 |
| __kasan_report mm/kasan/report.c:545 [inline] |
| kasan_report+0x148/0x1e4 mm/kasan/report.c:562 |
| check_memory_region_inline mm/kasan/generic.c:183 [inline] |
| __asan_load8+0xb4/0xbc mm/kasan/generic.c:252 |
| kvm_vm_ioctl_unregister_coalesced_mmio+0x7c/0x1ec arch/arm64/kvm/../../../virt/kvm/coalesced_mmio.c:183 |
| kvm_vm_ioctl+0xe30/0x14c4 arch/arm64/kvm/../../../virt/kvm/kvm_main.c:3755 |
| vfs_ioctl fs/ioctl.c:48 [inline] |
| __do_sys_ioctl fs/ioctl.c:753 [inline] |
| __se_sys_ioctl fs/ioctl.c:739 [inline] |
| __arm64_sys_ioctl+0xf88/0x131c fs/ioctl.c:739 |
| __invoke_syscall arch/arm64/kernel/syscall.c:36 [inline] |
| invoke_syscall arch/arm64/kernel/syscall.c:48 [inline] |
| el0_svc_common arch/arm64/kernel/syscall.c:158 [inline] |
| do_el0_svc+0x120/0x290 arch/arm64/kernel/syscall.c:220 |
| el0_svc+0x1c/0x28 arch/arm64/kernel/entry-common.c:367 |
| el0_sync_handler+0x98/0x170 arch/arm64/kernel/entry-common.c:383 |
| el0_sync+0x140/0x180 arch/arm64/kernel/entry.S:670 |
| |
| Allocated by task 4269: |
| stack_trace_save+0x80/0xb8 kernel/stacktrace.c:121 |
| kasan_save_stack mm/kasan/common.c:48 [inline] |
| kasan_set_track mm/kasan/common.c:56 [inline] |
| __kasan_kmalloc+0xdc/0x120 mm/kasan/common.c:461 |
| kasan_kmalloc+0xc/0x14 mm/kasan/common.c:475 |
| kmem_cache_alloc_trace include/linux/slab.h:450 [inline] |
| kmalloc include/linux/slab.h:552 [inline] |
| kzalloc include/linux/slab.h:664 [inline] |
| kvm_vm_ioctl_register_coalesced_mmio+0x78/0x1cc arch/arm64/kvm/../../../virt/kvm/coalesced_mmio.c:146 |
| kvm_vm_ioctl+0x7e8/0x14c4 arch/arm64/kvm/../../../virt/kvm/kvm_main.c:3746 |
| vfs_ioctl fs/ioctl.c:48 [inline] |
| __do_sys_ioctl fs/ioctl.c:753 [inline] |
| __se_sys_ioctl fs/ioctl.c:739 [inline] |
| __arm64_sys_ioctl+0xf88/0x131c fs/ioctl.c:739 |
| __invoke_syscall arch/arm64/kernel/syscall.c:36 [inline] |
| invoke_syscall arch/arm64/kernel/syscall.c:48 [inline] |
| el0_svc_common arch/arm64/kernel/syscall.c:158 [inline] |
| do_el0_svc+0x120/0x290 arch/arm64/kernel/syscall.c:220 |
| el0_svc+0x1c/0x28 arch/arm64/kernel/entry-common.c:367 |
| el0_sync_handler+0x98/0x170 arch/arm64/kernel/entry-common.c:383 |
| el0_sync+0x140/0x180 arch/arm64/kernel/entry.S:670 |
| |
| Freed by task 4269: |
| stack_trace_save+0x80/0xb8 kernel/stacktrace.c:121 |
| kasan_save_stack mm/kasan/common.c:48 [inline] |
| kasan_set_track+0x38/0x6c mm/kasan/common.c:56 |
| kasan_set_free_info+0x20/0x40 mm/kasan/generic.c:355 |
| __kasan_slab_free+0x124/0x150 mm/kasan/common.c:422 |
| kasan_slab_free+0x10/0x1c mm/kasan/common.c:431 |
| slab_free_hook mm/slub.c:1544 [inline] |
| slab_free_freelist_hook mm/slub.c:1577 [inline] |
| slab_free mm/slub.c:3142 [inline] |
| kfree+0x104/0x38c mm/slub.c:4124 |
| coalesced_mmio_destructor+0x94/0xa4 arch/arm64/kvm/../../../virt/kvm/coalesced_mmio.c:102 |
| kvm_iodevice_destructor include/kvm/iodev.h:61 [inline] |
| kvm_io_bus_unregister_dev+0x248/0x280 arch/arm64/kvm/../../../virt/kvm/kvm_main.c:4374 |
| kvm_vm_ioctl_unregister_coalesced_mmio+0x158/0x1ec arch/arm64/kvm/../../../virt/kvm/coalesced_mmio.c:186 |
| kvm_vm_ioctl+0xe30/0x14c4 arch/arm64/kvm/../../../virt/kvm/kvm_main.c:3755 |
| vfs_ioctl fs/ioctl.c:48 [inline] |
| __do_sys_ioctl fs/ioctl.c:753 [inline] |
| __se_sys_ioctl fs/ioctl.c:739 [inline] |
| __arm64_sys_ioctl+0xf88/0x131c fs/ioctl.c:739 |
| __invoke_syscall arch/arm64/kernel/syscall.c:36 [inline] |
| invoke_syscall arch/arm64/kernel/syscall.c:48 [inline] |
| el0_svc_common arch/arm64/kernel/syscall.c:158 [inline] |
| do_el0_svc+0x120/0x290 arch/arm64/kernel/syscall.c:220 |
| el0_svc+0x1c/0x28 arch/arm64/kernel/entry-common.c:367 |
| el0_sync_handler+0x98/0x170 arch/arm64/kernel/entry-common.c:383 |
| el0_sync+0x140/0x180 arch/arm64/kernel/entry.S:670 |
| |
| If kvm_io_bus_unregister_dev() return -ENOMEM, we already call kvm_iodevice_destructor() |
| inside this function to delete 'struct kvm_coalesced_mmio_dev *dev' from list |
| and free the dev, but kvm_iodevice_destructor() is called again, it will lead |
| the above issue. |
| |
| Let's check the the return value of kvm_io_bus_unregister_dev(), only call |
| kvm_iodevice_destructor() if the return value is 0. |
| |
| The Linux kernel CVE team has assigned CVE-2021-47341 to this issue. |
| |
| |
| Affected and fixed versions |
| =========================== |
| |
| Issue introduced in 5.4.119 with commit 7d1bc32d6477ff96a32695ea4be8144e4513ab2d and fixed in 5.4.134 with commit f2ff9d03432fcb160e9f7d4be26174d89de2779a |
| Issue introduced in 5.10.37 with commit 2a20592baff59c5351c5200ec667e1a2aa22af85 and fixed in 5.10.52 with commit 679837dc0abaa2c6e2a7bcd86483e05eee1d5066 |
| Issue introduced in 5.12.4 with commit 50cbad42bfea8c052b7ca590bd4126cdc898713c and fixed in 5.12.19 with commit 8d7c539316d652d217e5e82b89ee204c812a7061 |
| Issue introduced in 5.13 with commit 5d3c4c79384af06e3c8e25b7770b6247496b4417 and fixed in 5.13.4 with commit 069d44a24c0ff8f85adf49233aae7a8ca16f5c7e |
| Issue introduced in 5.13 with commit 5d3c4c79384af06e3c8e25b7770b6247496b4417 and fixed in 5.14 with commit 23fa2e46a5556f787ce2ea1a315d3ab93cced204 |
| Issue introduced in 5.11.21 with commit 168e82f640ed1891a700bdb43e37da354b2ab63c |
| |
| 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-2021-47341 |
| 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: |
| virt/kvm/coalesced_mmio.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/f2ff9d03432fcb160e9f7d4be26174d89de2779a |
| https://git.kernel.org/stable/c/679837dc0abaa2c6e2a7bcd86483e05eee1d5066 |
| https://git.kernel.org/stable/c/8d7c539316d652d217e5e82b89ee204c812a7061 |
| https://git.kernel.org/stable/c/069d44a24c0ff8f85adf49233aae7a8ca16f5c7e |
| https://git.kernel.org/stable/c/23fa2e46a5556f787ce2ea1a315d3ab93cced204 |
