发布于3月6日3月6日 Members Ubuntu: (CVE-2023-52849): linux vulnerability Severity 5 CVSS (AV:L/AC:L/Au:S/C:N/I:N/A:C) Published 05/21/2024 Created 11/21/2024 Added 11/19/2024 Modified 02/11/2025 Description In the Linux kernel, the following vulnerability has been resolved: cxl/mem: Fix shutdown order Ira reports that removing cxl_mock_mem causes a crash with the following trace: BUG: kernel NULL pointer dereference, address: 0000000000000044 [..] RIP: 0010:cxl_region_decode_reset+0x7f/0x180 [cxl_core] [..] Call Trace: <TASK> cxl_region_detach+0xe8/0x210 [cxl_core] cxl_decoder_kill_region+0x27/0x40 [cxl_core] cxld_unregister+0x29/0x40 [cxl_core] devres_release_all+0xb8/0x110 device_unbind_cleanup+0xe/0x70 device_release_driver_internal+0x1d2/0x210 bus_remove_device+0xd7/0x150 device_del+0x155/0x3e0 device_unregister+0x13/0x60 devm_release_action+0x4d/0x90 ? __pfx_unregister_port+0x10/0x10 [cxl_core] delete_endpoint+0x121/0x130 [cxl_core] devres_release_all+0xb8/0x110 device_unbind_cleanup+0xe/0x70 device_release_driver_internal+0x1d2/0x210 bus_remove_device+0xd7/0x150 device_del+0x155/0x3e0 ? lock_release+0x142/0x290 cdev_device_del+0x15/0x50 cxl_memdev_unregister+0x54/0x70 [cxl_core] This crash is due to the clearing out the cxl_memdev's driver context (@cxlds) before the subsystem is done with it. This is ultimately due to the region(s), that this memdev is a member, being torn down and expecting to be able to de-reference @cxlds, like here: static int cxl_region_decode_reset(struct cxl_region *cxlr, int count) ... if (cxlds->rcd) goto endpoint_reset; ... Fix it by keeping the driver context valid until memdev-device unregistration, and subsequently the entire stack of related dependencies, unwinds. Solution(s) ubuntu-upgrade-linux ubuntu-upgrade-linux-aws ubuntu-upgrade-linux-aws-5-15 ubuntu-upgrade-linux-aws-fips ubuntu-upgrade-linux-azure ubuntu-upgrade-linux-azure-5-15 ubuntu-upgrade-linux-azure-fde ubuntu-upgrade-linux-azure-fde-5-15 ubuntu-upgrade-linux-bluefield ubuntu-upgrade-linux-fips ubuntu-upgrade-linux-gcp ubuntu-upgrade-linux-gcp-5-15 ubuntu-upgrade-linux-gcp-fips ubuntu-upgrade-linux-gke ubuntu-upgrade-linux-gkeop ubuntu-upgrade-linux-gkeop-5-15 ubuntu-upgrade-linux-hwe-5-15 ubuntu-upgrade-linux-ibm ubuntu-upgrade-linux-ibm-5-15 ubuntu-upgrade-linux-intel-iot-realtime ubuntu-upgrade-linux-intel-iotg ubuntu-upgrade-linux-intel-iotg-5-15 ubuntu-upgrade-linux-kvm ubuntu-upgrade-linux-lowlatency ubuntu-upgrade-linux-lowlatency-hwe-5-15 ubuntu-upgrade-linux-nvidia ubuntu-upgrade-linux-nvidia-6-5 ubuntu-upgrade-linux-oracle ubuntu-upgrade-linux-oracle-5-15 ubuntu-upgrade-linux-raspi ubuntu-upgrade-linux-realtime ubuntu-upgrade-linux-riscv-5-15 ubuntu-upgrade-linux-xilinx-zynqmp References https://attackerkb.com/topics/cve-2023-52849 CVE - 2023-52849 https://git.kernel.org/linus/88d3917f82ed4215a2154432c26de1480a61b209 https://git.kernel.org/stable/c/0ca074f7d788627a4e0b047ca5fbdb5fc567220c https://git.kernel.org/stable/c/20bd0198bebdd706bd4614b3933ef70d7c19618f https://git.kernel.org/stable/c/7c7371b41a14e86f53e7dbe5baa7b1d3e0ab324b https://git.kernel.org/stable/c/88d3917f82ed4215a2154432c26de1480a61b209 https://git.kernel.org/stable/c/cad22a757029c3a1985c221a2d4a6491ad4035ae https://www.cve.org/CVERecord?id=CVE-2023-52849 View more
