| 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-2022-48658: mm: slub: fix flush_cpu_slab()/__free_slab() invocations in task context. |
| |
| Description |
| =========== |
| |
| In the Linux kernel, the following vulnerability has been resolved: |
| |
| mm: slub: fix flush_cpu_slab()/__free_slab() invocations in task context. |
| |
| Commit 5a836bf6b09f ("mm: slub: move flush_cpu_slab() invocations |
| __free_slab() invocations out of IRQ context") moved all flush_cpu_slab() |
| invocations to the global workqueue to avoid a problem related |
| with deactivate_slab()/__free_slab() being called from an IRQ context |
| on PREEMPT_RT kernels. |
| |
| When the flush_all_cpu_locked() function is called from a task context |
| it may happen that a workqueue with WQ_MEM_RECLAIM bit set ends up |
| flushing the global workqueue, this will cause a dependency issue. |
| |
| workqueue: WQ_MEM_RECLAIM nvme-delete-wq:nvme_delete_ctrl_work [nvme_core] |
| is flushing !WQ_MEM_RECLAIM events:flush_cpu_slab |
| WARNING: CPU: 37 PID: 410 at kernel/workqueue.c:2637 |
| check_flush_dependency+0x10a/0x120 |
| Workqueue: nvme-delete-wq nvme_delete_ctrl_work [nvme_core] |
| RIP: 0010:check_flush_dependency+0x10a/0x120[ 453.262125] Call Trace: |
| __flush_work.isra.0+0xbf/0x220 |
| ? __queue_work+0x1dc/0x420 |
| flush_all_cpus_locked+0xfb/0x120 |
| __kmem_cache_shutdown+0x2b/0x320 |
| kmem_cache_destroy+0x49/0x100 |
| bioset_exit+0x143/0x190 |
| blk_release_queue+0xb9/0x100 |
| kobject_cleanup+0x37/0x130 |
| nvme_fc_ctrl_free+0xc6/0x150 [nvme_fc] |
| nvme_free_ctrl+0x1ac/0x2b0 [nvme_core] |
| |
| Fix this bug by creating a workqueue for the flush operation with |
| the WQ_MEM_RECLAIM bit set. |
| |
| The Linux kernel CVE team has assigned CVE-2022-48658 to this issue. |
| |
| |
| Affected and fixed versions |
| =========================== |
| |
| Issue introduced in 5.15 with commit 5a836bf6b09f99ead1b69457ff39ab3011ece57b and fixed in 5.15.71 with commit 61703b248be993eb4997b00ae5d3318e6d8f3c5b |
| Issue introduced in 5.15 with commit 5a836bf6b09f99ead1b69457ff39ab3011ece57b and fixed in 5.19.12 with commit df6cb39335cf5a1b918e8dbd8ba7cd9f1d00e45a |
| Issue introduced in 5.15 with commit 5a836bf6b09f99ead1b69457ff39ab3011ece57b and fixed in 6.0 with commit e45cc288724f0cfd497bb5920bcfa60caa335729 |
| |
| 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-2022-48658 |
| 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: |
| mm/slub.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/61703b248be993eb4997b00ae5d3318e6d8f3c5b |
| https://git.kernel.org/stable/c/df6cb39335cf5a1b918e8dbd8ba7cd9f1d00e45a |
| https://git.kernel.org/stable/c/e45cc288724f0cfd497bb5920bcfa60caa335729 |
