| 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-2022-49196: powerpc/pseries: Fix use after free in remove_phb_dynamic() |
| |
| Description |
| =========== |
| |
| In the Linux kernel, the following vulnerability has been resolved: |
| |
| powerpc/pseries: Fix use after free in remove_phb_dynamic() |
| |
| In remove_phb_dynamic() we use &phb->io_resource, after we've called |
| device_unregister(&host_bridge->dev). But the unregister may have freed |
| phb, because pcibios_free_controller_deferred() is the release function |
| for the host_bridge. |
| |
| If there are no outstanding references when we call device_unregister() |
| then phb will be freed out from under us. |
| |
| This has gone mainly unnoticed, but with slub_debug and page_poison |
| enabled it can lead to a crash: |
| |
| PID: 7574 TASK: c0000000d492cb80 CPU: 13 COMMAND: "drmgr" |
| #0 [c0000000e4f075a0] crash_kexec at c00000000027d7dc |
| #1 [c0000000e4f075d0] oops_end at c000000000029608 |
| #2 [c0000000e4f07650] __bad_page_fault at c0000000000904b4 |
| #3 [c0000000e4f076c0] do_bad_slb_fault at c00000000009a5a8 |
| #4 [c0000000e4f076f0] data_access_slb_common_virt at c000000000008b30 |
| Data SLB Access [380] exception frame: |
| R0: c000000000167250 R1: c0000000e4f07a00 R2: c000000002a46100 |
| R3: c000000002b39ce8 R4: 00000000000000c0 R5: 00000000000000a9 |
| R6: 3894674d000000c0 R7: 0000000000000000 R8: 00000000000000ff |
| R9: 0000000000000100 R10: 6b6b6b6b6b6b6b6b R11: 0000000000008000 |
| R12: c00000000023da80 R13: c0000009ffd38b00 R14: 0000000000000000 |
| R15: 000000011c87f0f0 R16: 0000000000000006 R17: 0000000000000003 |
| R18: 0000000000000002 R19: 0000000000000004 R20: 0000000000000005 |
| R21: 000000011c87ede8 R22: 000000011c87c5a8 R23: 000000011c87d3a0 |
| R24: 0000000000000000 R25: 0000000000000001 R26: c0000000e4f07cc8 |
| R27: c00000004d1cc400 R28: c0080000031d00e8 R29: c00000004d23d800 |
| R30: c00000004d1d2400 R31: c00000004d1d2540 |
| NIP: c000000000167258 MSR: 8000000000009033 OR3: c000000000e9f474 |
| CTR: 0000000000000000 LR: c000000000167250 XER: 0000000020040003 |
| CCR: 0000000024088420 MQ: 0000000000000000 DAR: 6b6b6b6b6b6b6ba3 |
| DSISR: c0000000e4f07920 Syscall Result: fffffffffffffff2 |
| [NIP : release_resource+56] |
| [LR : release_resource+48] |
| #5 [c0000000e4f07a00] release_resource at c000000000167258 (unreliable) |
| #6 [c0000000e4f07a30] remove_phb_dynamic at c000000000105648 |
| #7 [c0000000e4f07ab0] dlpar_remove_slot at c0080000031a09e8 [rpadlpar_io] |
| #8 [c0000000e4f07b50] remove_slot_store at c0080000031a0b9c [rpadlpar_io] |
| #9 [c0000000e4f07be0] kobj_attr_store at c000000000817d8c |
| #10 [c0000000e4f07c00] sysfs_kf_write at c00000000063e504 |
| #11 [c0000000e4f07c20] kernfs_fop_write_iter at c00000000063d868 |
| #12 [c0000000e4f07c70] new_sync_write at c00000000054339c |
| #13 [c0000000e4f07d10] vfs_write at c000000000546624 |
| #14 [c0000000e4f07d60] ksys_write at c0000000005469f4 |
| #15 [c0000000e4f07db0] system_call_exception at c000000000030840 |
| #16 [c0000000e4f07e10] system_call_vectored_common at c00000000000c168 |
| |
| To avoid it, we can take a reference to the host_bridge->dev until we're |
| done using phb. Then when we drop the reference the phb will be freed. |
| |
| The Linux kernel CVE team has assigned CVE-2022-49196 to this issue. |
| |
| |
| Affected and fixed versions |
| =========================== |
| |
| Issue introduced in 4.8 with commit 2dd9c11b9d4dfbd6c070eab7b81197f65e82f1a0 and fixed in 5.15.33 with commit 33d39efb61a84e055ca2386157d39ebbdf6b7d31 |
| Issue introduced in 4.8 with commit 2dd9c11b9d4dfbd6c070eab7b81197f65e82f1a0 and fixed in 5.16.19 with commit 403f9e0bc5535a0a5184d1352fa3a70e6ffacb6f |
| Issue introduced in 4.8 with commit 2dd9c11b9d4dfbd6c070eab7b81197f65e82f1a0 and fixed in 5.17.2 with commit 895ca4ae1f72e0a0160ab162723e59c9f265ec93 |
| Issue introduced in 4.8 with commit 2dd9c11b9d4dfbd6c070eab7b81197f65e82f1a0 and fixed in 5.18 with commit fe2640bd7a62f1f7c3f55fbda31084085075bc30 |
| Issue introduced in 3.16.39 with commit c3e740838fe3117413425c956ac56a5724ccd9f9 |
| Issue introduced in 4.7.8 with commit 83573addff2b4e16df9fad9a561a0d77d554b370 |
| |
| 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-2022-49196 |
| 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: |
| arch/powerpc/platforms/pseries/pci_dlpar.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/33d39efb61a84e055ca2386157d39ebbdf6b7d31 |
| https://git.kernel.org/stable/c/403f9e0bc5535a0a5184d1352fa3a70e6ffacb6f |
| https://git.kernel.org/stable/c/895ca4ae1f72e0a0160ab162723e59c9f265ec93 |
| https://git.kernel.org/stable/c/fe2640bd7a62f1f7c3f55fbda31084085075bc30 |
