CVE-2023-52438 SUSE CVE security@suse.de SUSE Security Team SUSE CVE-2023-52438 Interim 1 7 2025-02-16T01:59:55Z current 2024-02-22T00:10:01Z 2025-02-16T01:59:55Z cve-database/bin/generate-cvrf-cve.pl 2020-12-27T01:00:00Z CVE-2023-52438 In the Linux kernel, the following vulnerability has been resolved: binder: fix use-after-free in shinker's callback The mmap read lock is used during the shrinker's callback, which means that using alloc->vma pointer isn't safe as it can race with munmap(). As of commit dd2283f2605e ("mm: mmap: zap pages with read mmap_sem in munmap") the mmap lock is downgraded after the vma has been isolated. I was able to reproduce this issue by manually adding some delays and triggering page reclaiming through the shrinker's debug sysfs. The following KASAN report confirms the UAF: ================================================================== BUG: KASAN: slab-use-after-free in zap_page_range_single+0x470/0x4b8 Read of size 8 at addr ffff356ed50e50f0 by task bash/478 CPU: 1 PID: 478 Comm: bash Not tainted 6.6.0-rc5-00055-g1c8b86a3799f-dirty #70 Hardware name: linux,dummy-virt (DT) Call trace: zap_page_range_single+0x470/0x4b8 binder_alloc_free_page+0x608/0xadc __list_lru_walk_one+0x130/0x3b0 list_lru_walk_node+0xc4/0x22c binder_shrink_scan+0x108/0x1dc shrinker_debugfs_scan_write+0x2b4/0x500 full_proxy_write+0xd4/0x140 vfs_write+0x1ac/0x758 ksys_write+0xf0/0x1dc __arm64_sys_write+0x6c/0x9c Allocated by task 492: kmem_cache_alloc+0x130/0x368 vm_area_alloc+0x2c/0x190 mmap_region+0x258/0x18bc do_mmap+0x694/0xa60 vm_mmap_pgoff+0x170/0x29c ksys_mmap_pgoff+0x290/0x3a0 __arm64_sys_mmap+0xcc/0x144 Freed by task 491: kmem_cache_free+0x17c/0x3c8 vm_area_free_rcu_cb+0x74/0x98 rcu_core+0xa38/0x26d4 rcu_core_si+0x10/0x1c __do_softirq+0x2fc/0xd24 Last potentially related work creation: __call_rcu_common.constprop.0+0x6c/0xba0 call_rcu+0x10/0x1c vm_area_free+0x18/0x24 remove_vma+0xe4/0x118 do_vmi_align_munmap.isra.0+0x718/0xb5c do_vmi_munmap+0xdc/0x1fc __vm_munmap+0x10c/0x278 __arm64_sys_munmap+0x58/0x7c Fix this issue by performing instead a vma_lookup() which will fail to find the vma that was isolated before the mmap lock downgrade. Note that this option has better performance than upgrading to a mmap write lock which would increase contention. Plus, mmap_write_trylock() has been recently removed anyway. The CVRF data is provided by SUSE under the Creative Commons License 4.0 with Attribution (CC-BY-4.0). https://www.suse.com/support/security/rating/ SUSE Security Ratings SUSE CaaS Platform 4.0 SUSE Linux Enterprise Module for Public Cloud 15 SP2 SUSE Enterprise Storage 7.1 SUSE Linux Enterprise Module for Public Cloud 15 SP3 SUSE Linux Enterprise Module for Basesystem 15 SP5 SUSE Linux Enterprise Module for Development Tools 15 SP5 SUSE Linux Enterprise High Performance Computing 12 SP5 SUSE Linux Enterprise High Performance Computing 15 SP1-LTSS SUSE Linux Enterprise Module for Public Cloud 15 SP2 SUSE Linux Enterprise High Performance Computing 15 SP2-LTSS SUSE Linux Enterprise Module for Public Cloud 15 SP3 SUSE Linux Enterprise High Performance Computing 15 SP3-LTSS SUSE Linux Enterprise Module for Public Cloud 15 SP4 SUSE Linux Enterprise High Performance Computing 15 SP4-ESPOS SUSE Linux Enterprise High Performance Computing 15 SP4-LTSS SUSE Linux Enterprise Module for Basesystem 15 SP5 SUSE Linux Enterprise Module for Development Tools 15 SP5 SUSE Linux Enterprise Module for Public Cloud 15 SP5 SUSE Linux Enterprise Micro 5.0 SUSE Linux Enterprise Micro 5.1 SUSE Linux Enterprise Micro 5.2 SUSE Linux Enterprise Micro 5.3 SUSE Linux Enterprise Micro 5.4 SUSE Linux Enterprise Real Time 12 SP5 SUSE Real Time Module 15 SP5 SUSE Linux Enterprise Server 11 SP4 LTSS SUSE Linux Enterprise Server 11 SP4 LTSS EXTREME CORE SUSE Linux Enterprise Server 12 SP2-LTSS SUSE Linux Enterprise Server 12 SP4-LTSS SUSE Linux Enterprise Server 12 SP5 SUSE Linux Enterprise Server 15 SP1-LTSS SUSE Linux Enterprise Module for Public Cloud 15 SP2 SUSE Linux Enterprise Server 15 SP2-LTSS SUSE Linux Enterprise Module for Public Cloud 15 SP3 SUSE Linux Enterprise Server 15 SP3-LTSS SUSE Linux Enterprise Module for Public Cloud 15 SP4 SUSE Linux Enterprise Server 15 SP4-LTSS SUSE Linux Enterprise Module for Basesystem 15 SP5 SUSE Linux Enterprise Module for Development Tools 15 SP5 SUSE Linux Enterprise Module for Public Cloud 15 SP5 SUSE Linux Enterprise Server 15-LTSS SUSE Linux Enterprise Server Teradata 12 SP3 SUSE Linux Enterprise Server Teradata 12 SP3-LTSS SUSE Linux Enterprise Server for SAP Applications 12 SP2 SUSE Linux Enterprise Server for SAP Applications 12 SP4 SUSE Linux Enterprise Server for SAP Applications 12 SP5 SUSE Linux Enterprise Server for SAP Applications 15 SP1 SUSE Linux Enterprise Module for Public Cloud 15 SP2 SUSE Linux Enterprise Server for SAP Applications 15 SP2 SUSE Linux Enterprise Module for Public Cloud 15 SP3 SUSE Linux Enterprise Server for SAP Applications 15 SP3 SUSE Linux Enterprise Module for Public Cloud 15 SP4 SUSE Linux Enterprise Server for SAP Applications 15 SP4 SUSE Linux Enterprise Module for Basesystem 15 SP5 SUSE Linux Enterprise Module for Development Tools 15 SP5 SUSE Linux Enterprise Module for Public Cloud 15 SP5 SUSE Linux Enterprise Module for Public Cloud 15 SP2 SUSE Linux Enterprise Module for Public Cloud 15 SP3 SUSE Linux Enterprise Module for Public Cloud 15 SP4 SUSE Manager Proxy 4.3 SUSE Linux Enterprise Module for Public Cloud 15 SP2 SUSE Linux Enterprise Module for Public Cloud 15 SP3 SUSE Linux Enterprise Module for Public Cloud 15 SP4 SUSE Manager Retail Branch Server 4.3 SUSE Linux Enterprise Module for Public Cloud 15 SP2 SUSE Linux Enterprise Module for Public Cloud 15 SP3 SUSE Linux Enterprise Module for Public Cloud 15 SP4 SUSE Manager Server 4.3 SUSE OpenStack Cloud 9 SUSE OpenStack Cloud Crowbar 9 kernel-default kernel-default-base kernel-default-devel kernel-default-man kernel-devel kernel-devel-azure kernel-devel-rt kernel-macros kernel-source kernel-source-azure kernel-source-rt reiserfs-kmp-default kernel-default as a component of SUSE CaaS Platform 4.0 kernel-default-base as a component of SUSE CaaS Platform 4.0 kernel-default-devel as a component of SUSE CaaS Platform 4.0 reiserfs-kmp-default as a component of SUSE CaaS Platform 4.0 kernel-devel as a component of SUSE CaaS Platform 4.0 kernel-macros as a component of SUSE CaaS Platform 4.0 kernel-source as a component of SUSE CaaS Platform 4.0 kernel-default as a component of SUSE Enterprise Storage 7.1 kernel-default-devel as a component of SUSE Enterprise Storage 7.1 reiserfs-kmp-default as a component of SUSE Enterprise Storage 7.1 kernel-devel as a component of SUSE Enterprise Storage 7.1 kernel-macros as a component of SUSE Enterprise Storage 7.1 kernel-source as a component of SUSE Enterprise Storage 7.1 kernel-default as a component of SUSE Linux Enterprise High Performance Computing 12 SP5 kernel-source as a component of SUSE Linux Enterprise High Performance Computing 12 SP5 kernel-source-azure as a component of SUSE Linux Enterprise High Performance Computing 12 SP5 kernel-default as a component of SUSE Linux Enterprise High Performance Computing 15 SP1-LTSS kernel-default-base as a component of SUSE Linux Enterprise High Performance Computing 15 SP1-LTSS kernel-default-devel as a component of SUSE Linux Enterprise High Performance Computing 15 SP1-LTSS kernel-devel as a component of SUSE Linux Enterprise High Performance Computing 15 SP1-LTSS kernel-macros as a component of SUSE Linux Enterprise High Performance Computing 15 SP1-LTSS kernel-source as a component of SUSE Linux Enterprise High Performance Computing 15 SP1-LTSS kernel-default as a component of SUSE Linux Enterprise High Performance Computing 15 SP2-LTSS kernel-default-devel as a component of SUSE Linux Enterprise High Performance Computing 15 SP2-LTSS kernel-devel as a component of SUSE Linux Enterprise High Performance Computing 15 SP2-LTSS kernel-macros as a component of SUSE Linux Enterprise High Performance Computing 15 SP2-LTSS kernel-source as a component of SUSE Linux Enterprise High Performance Computing 15 SP2-LTSS kernel-default as a component of SUSE Linux Enterprise High Performance Computing 15 SP3-LTSS kernel-default-devel as a component of SUSE Linux Enterprise High Performance Computing 15 SP3-LTSS reiserfs-kmp-default as a component of SUSE Linux Enterprise High Performance Computing 15 SP3-LTSS kernel-devel as a component of SUSE Linux Enterprise High Performance Computing 15 SP3-LTSS kernel-macros as a component of SUSE Linux Enterprise High Performance Computing 15 SP3-LTSS kernel-source as a component of SUSE Linux Enterprise High Performance Computing 15 SP3-LTSS kernel-default as a component of SUSE Linux Enterprise High Performance Computing 15 SP4-ESPOS kernel-default-devel as a component of SUSE Linux Enterprise High Performance Computing 15 SP4-ESPOS reiserfs-kmp-default as a component of SUSE Linux Enterprise High Performance Computing 15 SP4-ESPOS kernel-devel as a component of SUSE Linux Enterprise High Performance Computing 15 SP4-ESPOS kernel-macros as a component of SUSE Linux Enterprise High Performance Computing 15 SP4-ESPOS kernel-source as a component of SUSE Linux Enterprise High Performance Computing 15 SP4-ESPOS kernel-default as a component of SUSE Linux Enterprise High Performance Computing 15 SP4-LTSS kernel-default-devel as a component of SUSE Linux Enterprise High Performance Computing 15 SP4-LTSS reiserfs-kmp-default as a component of SUSE Linux Enterprise High Performance Computing 15 SP4-LTSS kernel-devel as a component of SUSE Linux Enterprise High Performance Computing 15 SP4-LTSS kernel-macros as a component of SUSE Linux Enterprise High Performance Computing 15 SP4-LTSS kernel-source as a component of SUSE Linux Enterprise High Performance Computing 15 SP4-LTSS kernel-default as a component of SUSE Linux Enterprise Micro 5.0 kernel-default as a component of SUSE Linux Enterprise Micro 5.1 kernel-default as a component of SUSE Linux Enterprise Micro 5.2 kernel-default as a component of SUSE Linux Enterprise Micro 5.3 kernel-default as a component of SUSE Linux Enterprise Micro 5.4 kernel-default as a component of SUSE Linux Enterprise Module for Basesystem 15 SP5 kernel-default-devel as a component of SUSE Linux Enterprise Module for Basesystem 15 SP5 kernel-devel as a component of SUSE Linux Enterprise Module for Basesystem 15 SP5 kernel-macros as a component of SUSE Linux Enterprise Module for Basesystem 15 SP5 kernel-source as a component of SUSE Linux Enterprise Module for Basesystem 15 SP5 kernel-default as a component of SUSE Linux Enterprise Module for Development Tools 15 SP5 kernel-source as a component of SUSE Linux Enterprise Module for Development Tools 15 SP5 kernel-source-azure as a component of SUSE Linux Enterprise Module for Public Cloud 15 SP2 kernel-source-azure as a component of SUSE Linux Enterprise Module for Public Cloud 15 SP3 kernel-source-azure as a component of SUSE Linux Enterprise Module for Public Cloud 15 SP4 kernel-devel-azure as a component of SUSE Linux Enterprise Module for Public Cloud 15 SP5 kernel-source-azure as a component of SUSE Linux Enterprise Module for Public Cloud 15 SP5 kernel-devel-rt as a component of SUSE Linux Enterprise Real Time 12 SP5 kernel-source-rt as a component of SUSE Linux Enterprise Real Time 12 SP5 kernel-default as a component of SUSE Linux Enterprise Server 11 SP4 LTSS kernel-source as a component of SUSE Linux Enterprise Server 11 SP4 LTSS kernel-default as a component of SUSE Linux Enterprise Server 11 SP4 LTSS EXTREME CORE kernel-default-base as a component of SUSE Linux Enterprise Server 11 SP4 LTSS EXTREME CORE kernel-default-devel as a component of SUSE Linux Enterprise Server 11 SP4 LTSS EXTREME CORE kernel-source as a component of SUSE Linux Enterprise Server 11 SP4 LTSS EXTREME CORE kernel-default as a component of SUSE Linux Enterprise Server 12 SP2-LTSS kernel-default-base as a component of SUSE Linux Enterprise Server 12 SP2-LTSS kernel-default-devel as a component of SUSE Linux Enterprise Server 12 SP2-LTSS kernel-default-man as a component of SUSE Linux Enterprise Server 12 SP2-LTSS kernel-devel as a component of SUSE Linux Enterprise Server 12 SP2-LTSS kernel-macros as a component of SUSE Linux Enterprise Server 12 SP2-LTSS kernel-source as a component of SUSE Linux Enterprise Server 12 SP2-LTSS kernel-default as a component of SUSE Linux Enterprise Server 12 SP4-LTSS kernel-default-base as a component of SUSE Linux Enterprise Server 12 SP4-LTSS kernel-default-devel as a component of SUSE Linux Enterprise Server 12 SP4-LTSS kernel-default-man as a component of SUSE Linux Enterprise Server 12 SP4-LTSS kernel-devel as a component of SUSE Linux Enterprise Server 12 SP4-LTSS kernel-macros as a component of SUSE Linux Enterprise Server 12 SP4-LTSS kernel-source as a component of SUSE Linux Enterprise Server 12 SP4-LTSS kernel-default as a component of SUSE Linux Enterprise Server 12 SP5 kernel-default-base as a component of SUSE Linux Enterprise Server 12 SP5 kernel-default-devel as a component of SUSE Linux Enterprise Server 12 SP5 kernel-default-man as a component of SUSE Linux Enterprise Server 12 SP5 kernel-devel as a component of SUSE Linux Enterprise Server 12 SP5 kernel-macros as a component of SUSE Linux Enterprise Server 12 SP5 kernel-source as a component of SUSE Linux Enterprise Server 12 SP5 kernel-devel-azure as a component of SUSE Linux Enterprise Server 12 SP5 kernel-source-azure as a component of SUSE Linux Enterprise Server 12 SP5 kernel-default as a component of SUSE Linux Enterprise Server 15 SP1-LTSS kernel-default-base as a component of SUSE Linux Enterprise Server 15 SP1-LTSS kernel-default-devel as a component of SUSE Linux Enterprise Server 15 SP1-LTSS kernel-default-man as a component of SUSE Linux Enterprise Server 15 SP1-LTSS reiserfs-kmp-default as a component of SUSE Linux Enterprise Server 15 SP1-LTSS kernel-devel as a component of SUSE Linux Enterprise Server 15 SP1-LTSS kernel-macros as a component of SUSE Linux Enterprise Server 15 SP1-LTSS kernel-source as a component of SUSE Linux Enterprise Server 15 SP1-LTSS kernel-default as a component of SUSE Linux Enterprise Server 15 SP2-LTSS kernel-default-devel as a component of SUSE Linux Enterprise Server 15 SP2-LTSS reiserfs-kmp-default as a component of SUSE Linux Enterprise Server 15 SP2-LTSS kernel-devel as a component of SUSE Linux Enterprise Server 15 SP2-LTSS kernel-macros as a component of SUSE Linux Enterprise Server 15 SP2-LTSS kernel-source as a component of SUSE Linux Enterprise Server 15 SP2-LTSS kernel-default as a component of SUSE Linux Enterprise Server 15 SP3-LTSS kernel-default-devel as a component of SUSE Linux Enterprise Server 15 SP3-LTSS reiserfs-kmp-default as a component of SUSE Linux Enterprise Server 15 SP3-LTSS kernel-devel as a component of SUSE Linux Enterprise Server 15 SP3-LTSS kernel-macros as a component of SUSE Linux Enterprise Server 15 SP3-LTSS kernel-source as a component of SUSE Linux Enterprise Server 15 SP3-LTSS kernel-default as a component of SUSE Linux Enterprise Server 15 SP4-LTSS kernel-default-devel as a component of SUSE Linux Enterprise Server 15 SP4-LTSS reiserfs-kmp-default as a component of SUSE Linux Enterprise Server 15 SP4-LTSS kernel-devel as a component of SUSE Linux Enterprise Server 15 SP4-LTSS kernel-macros as a component of SUSE Linux Enterprise Server 15 SP4-LTSS kernel-source as a component of SUSE Linux Enterprise Server 15 SP4-LTSS kernel-default as a component of SUSE Linux Enterprise Server 15-LTSS kernel-default-base as a component of SUSE Linux Enterprise Server 15-LTSS kernel-default-devel as a component of SUSE Linux Enterprise Server 15-LTSS kernel-default-man as a component of SUSE Linux Enterprise Server 15-LTSS reiserfs-kmp-default as a component of SUSE Linux Enterprise Server 15-LTSS kernel-devel as a component of SUSE Linux Enterprise Server 15-LTSS kernel-macros as a component of SUSE Linux Enterprise Server 15-LTSS kernel-source as a component of SUSE Linux Enterprise Server 15-LTSS kernel-default as a component of SUSE Linux Enterprise Server Teradata 12 SP3 kernel-source as a component of SUSE Linux Enterprise Server Teradata 12 SP3 kernel-default as a component of SUSE Linux Enterprise Server Teradata 12 SP3-LTSS kernel-source as a component of SUSE Linux Enterprise Server Teradata 12 SP3-LTSS kernel-default as a component of SUSE Linux Enterprise Server for SAP Applications 12 SP2 kernel-default-base as a component of SUSE Linux Enterprise Server for SAP Applications 12 SP2 kernel-default-devel as a component of SUSE Linux Enterprise Server for SAP Applications 12 SP2 kernel-devel as a component of SUSE Linux Enterprise Server for SAP Applications 12 SP2 kernel-macros as a component of SUSE Linux Enterprise Server for SAP Applications 12 SP2 kernel-source as a component of SUSE Linux Enterprise Server for SAP Applications 12 SP2 kernel-default as a component of SUSE Linux Enterprise Server for SAP Applications 12 SP4 kernel-default-base as a component of SUSE Linux Enterprise Server for SAP Applications 12 SP4 kernel-default-devel as a component of SUSE Linux Enterprise Server for SAP Applications 12 SP4 kernel-devel as a component of SUSE Linux Enterprise Server for SAP Applications 12 SP4 kernel-macros as a component of SUSE Linux Enterprise Server for SAP Applications 12 SP4 kernel-source as a component of SUSE Linux Enterprise Server for SAP Applications 12 SP4 kernel-default as a component of SUSE Linux Enterprise Server for SAP Applications 12 SP5 kernel-source as a component of SUSE Linux Enterprise Server for SAP Applications 12 SP5 kernel-source-azure as a component of SUSE Linux Enterprise Server for SAP Applications 12 SP5 kernel-default as a component of SUSE Linux Enterprise Server for SAP Applications 15 SP1 kernel-default-base as a component of SUSE Linux Enterprise Server for SAP Applications 15 SP1 kernel-default-devel as a component of SUSE Linux Enterprise Server for SAP Applications 15 SP1 reiserfs-kmp-default as a component of SUSE Linux Enterprise Server for SAP Applications 15 SP1 kernel-devel as a component of SUSE Linux Enterprise Server for SAP Applications 15 SP1 kernel-macros as a component of SUSE Linux Enterprise Server for SAP Applications 15 SP1 kernel-source as a component of SUSE Linux Enterprise Server for SAP Applications 15 SP1 kernel-default as a component of SUSE Linux Enterprise Server for SAP Applications 15 SP2 kernel-default-devel as a component of SUSE Linux Enterprise Server for SAP Applications 15 SP2 reiserfs-kmp-default as a component of SUSE Linux Enterprise Server for SAP Applications 15 SP2 kernel-devel as a component of SUSE Linux Enterprise Server for SAP Applications 15 SP2 kernel-macros as a component of SUSE Linux Enterprise Server for SAP Applications 15 SP2 kernel-source as a component of SUSE Linux Enterprise Server for SAP Applications 15 SP2 kernel-default as a component of SUSE Linux Enterprise Server for SAP Applications 15 SP3 kernel-default-devel as a component of SUSE Linux Enterprise Server for SAP Applications 15 SP3 reiserfs-kmp-default as a component of SUSE Linux Enterprise Server for SAP Applications 15 SP3 kernel-devel as a component of SUSE Linux Enterprise Server for SAP Applications 15 SP3 kernel-macros as a component of SUSE Linux Enterprise Server for SAP Applications 15 SP3 kernel-source as a component of SUSE Linux Enterprise Server for SAP Applications 15 SP3 kernel-default as a component of SUSE Linux Enterprise Server for SAP Applications 15 SP4 kernel-default-devel as a component of SUSE Linux Enterprise Server for SAP Applications 15 SP4 reiserfs-kmp-default as a component of SUSE Linux Enterprise Server for SAP Applications 15 SP4 kernel-devel as a component of SUSE Linux Enterprise Server for SAP Applications 15 SP4 kernel-macros as a component of SUSE Linux Enterprise Server for SAP Applications 15 SP4 kernel-source as a component of SUSE Linux Enterprise Server for SAP Applications 15 SP4 kernel-default as a component of SUSE Manager Proxy 4.3 kernel-default-devel as a component of SUSE Manager Proxy 4.3 kernel-devel as a component of SUSE Manager Proxy 4.3 kernel-macros as a component of SUSE Manager Proxy 4.3 kernel-source as a component of SUSE Manager Proxy 4.3 kernel-default as a component of SUSE Manager Retail Branch Server 4.3 kernel-default-devel as a component of SUSE Manager Retail Branch Server 4.3 kernel-devel as a component of SUSE Manager Retail Branch Server 4.3 kernel-macros as a component of SUSE Manager Retail Branch Server 4.3 kernel-source as a component of SUSE Manager Retail Branch Server 4.3 kernel-default as a component of SUSE Manager Server 4.3 kernel-default-devel as a component of SUSE Manager Server 4.3 kernel-devel as a component of SUSE Manager Server 4.3 kernel-macros as a component of SUSE Manager Server 4.3 kernel-source as a component of SUSE Manager Server 4.3 kernel-default as a component of SUSE OpenStack Cloud 9 kernel-default-base as a component of SUSE OpenStack Cloud 9 kernel-default-devel as a component of SUSE OpenStack Cloud 9 kernel-devel as a component of SUSE OpenStack Cloud 9 kernel-macros as a component of SUSE OpenStack Cloud 9 kernel-source as a component of SUSE OpenStack Cloud 9 kernel-default as a component of SUSE OpenStack Cloud Crowbar 9 kernel-default-base as a component of SUSE OpenStack Cloud Crowbar 9 kernel-default-devel as a component of SUSE OpenStack Cloud Crowbar 9 kernel-devel as a component of SUSE OpenStack Cloud Crowbar 9 kernel-macros as a component of SUSE OpenStack Cloud Crowbar 9 kernel-source as a component of SUSE OpenStack Cloud Crowbar 9 kernel-devel-rt as a component of SUSE Real Time Module 15 SP5 kernel-source-rt as a component of SUSE Real Time Module 15 SP5 In the Linux kernel, the following vulnerability has been resolved: binder: fix use-after-free in shinker's callback The mmap read lock is used during the shrinker's callback, which means that using alloc->vma pointer isn't safe as it can race with munmap(). As of commit dd2283f2605e ("mm: mmap: zap pages with read mmap_sem in munmap") the mmap lock is downgraded after the vma has been isolated. I was able to reproduce this issue by manually adding some delays and triggering page reclaiming through the shrinker's debug sysfs. The following KASAN report confirms the UAF: ================================================================== BUG: KASAN: slab-use-after-free in zap_page_range_single+0x470/0x4b8 Read of size 8 at addr ffff356ed50e50f0 by task bash/478 CPU: 1 PID: 478 Comm: bash Not tainted 6.6.0-rc5-00055-g1c8b86a3799f-dirty #70 Hardware name: linux,dummy-virt (DT) Call trace: zap_page_range_single+0x470/0x4b8 binder_alloc_free_page+0x608/0xadc __list_lru_walk_one+0x130/0x3b0 list_lru_walk_node+0xc4/0x22c binder_shrink_scan+0x108/0x1dc shrinker_debugfs_scan_write+0x2b4/0x500 full_proxy_write+0xd4/0x140 vfs_write+0x1ac/0x758 ksys_write+0xf0/0x1dc __arm64_sys_write+0x6c/0x9c Allocated by task 492: kmem_cache_alloc+0x130/0x368 vm_area_alloc+0x2c/0x190 mmap_region+0x258/0x18bc do_mmap+0x694/0xa60 vm_mmap_pgoff+0x170/0x29c ksys_mmap_pgoff+0x290/0x3a0 __arm64_sys_mmap+0xcc/0x144 Freed by task 491: kmem_cache_free+0x17c/0x3c8 vm_area_free_rcu_cb+0x74/0x98 rcu_core+0xa38/0x26d4 rcu_core_si+0x10/0x1c __do_softirq+0x2fc/0xd24 Last potentially related work creation: __call_rcu_common.constprop.0+0x6c/0xba0 call_rcu+0x10/0x1c vm_area_free+0x18/0x24 remove_vma+0xe4/0x118 do_vmi_align_munmap.isra.0+0x718/0xb5c do_vmi_munmap+0xdc/0x1fc __vm_munmap+0x10c/0x278 __arm64_sys_munmap+0x58/0x7c Fix this issue by performing instead a vma_lookup() which will fail to find the vma that was isolated before the mmap lock downgrade. Note that this option has better performance than upgrading to a mmap write lock which would increase contention. Plus, mmap_write_trylock() has been recently removed anyway. CVE-2023-52438 SUSE CaaS Platform 4.0:kernel-default SUSE CaaS Platform 4.0:kernel-default-base SUSE CaaS Platform 4.0:kernel-default-devel SUSE CaaS Platform 4.0:kernel-devel SUSE CaaS Platform 4.0:kernel-macros SUSE CaaS Platform 4.0:kernel-source SUSE CaaS Platform 4.0:reiserfs-kmp-default SUSE Enterprise Storage 7.1:kernel-default SUSE Enterprise Storage 7.1:kernel-default-devel SUSE Enterprise Storage 7.1:kernel-devel SUSE Enterprise Storage 7.1:kernel-macros SUSE Enterprise Storage 7.1:kernel-source SUSE Enterprise Storage 7.1:reiserfs-kmp-default SUSE Linux Enterprise High Performance Computing 12 SP5:kernel-default SUSE Linux Enterprise High Performance Computing 12 SP5:kernel-source SUSE Linux Enterprise High Performance Computing 12 SP5:kernel-source-azure SUSE Linux Enterprise High Performance Computing 15 SP1-LTSS:kernel-default SUSE Linux Enterprise High Performance Computing 15 SP1-LTSS:kernel-default-base SUSE Linux Enterprise High Performance Computing 15 SP1-LTSS:kernel-default-devel SUSE Linux Enterprise High Performance Computing 15 SP1-LTSS:kernel-devel SUSE Linux Enterprise High Performance Computing 15 SP1-LTSS:kernel-macros SUSE Linux Enterprise High Performance Computing 15 SP1-LTSS:kernel-source SUSE Linux Enterprise High Performance Computing 15 SP2-LTSS:kernel-default SUSE Linux Enterprise High Performance Computing 15 SP2-LTSS:kernel-default-devel SUSE Linux Enterprise High Performance Computing 15 SP2-LTSS:kernel-devel SUSE Linux Enterprise High Performance Computing 15 SP2-LTSS:kernel-macros SUSE Linux Enterprise High Performance Computing 15 SP2-LTSS:kernel-source SUSE Linux Enterprise High Performance Computing 15 SP3-LTSS:kernel-default SUSE Linux Enterprise High Performance Computing 15 SP3-LTSS:kernel-default-devel SUSE Linux Enterprise High Performance Computing 15 SP3-LTSS:kernel-devel SUSE Linux Enterprise High Performance Computing 15 SP3-LTSS:kernel-macros SUSE Linux Enterprise High Performance Computing 15 SP3-LTSS:kernel-source SUSE Linux Enterprise High Performance Computing 15 SP3-LTSS:reiserfs-kmp-default SUSE Linux Enterprise High Performance Computing 15 SP4-ESPOS:kernel-default SUSE Linux Enterprise High Performance Computing 15 SP4-ESPOS:kernel-default-devel SUSE Linux Enterprise High Performance Computing 15 SP4-ESPOS:kernel-devel SUSE Linux Enterprise High Performance Computing 15 SP4-ESPOS:kernel-macros SUSE Linux Enterprise High Performance Computing 15 SP4-ESPOS:kernel-source SUSE Linux Enterprise High Performance Computing 15 SP4-ESPOS:reiserfs-kmp-default SUSE Linux Enterprise High Performance Computing 15 SP4-LTSS:kernel-default SUSE Linux Enterprise High Performance Computing 15 SP4-LTSS:kernel-default-devel SUSE Linux Enterprise High Performance Computing 15 SP4-LTSS:kernel-devel SUSE Linux Enterprise High Performance Computing 15 SP4-LTSS:kernel-macros SUSE Linux Enterprise High Performance Computing 15 SP4-LTSS:kernel-source SUSE Linux Enterprise High Performance Computing 15 SP4-LTSS:reiserfs-kmp-default SUSE Linux Enterprise Micro 5.0:kernel-default SUSE Linux Enterprise Micro 5.1:kernel-default SUSE Linux Enterprise Micro 5.2:kernel-default SUSE Linux Enterprise Micro 5.3:kernel-default SUSE Linux Enterprise Micro 5.4:kernel-default SUSE Linux Enterprise Module for Basesystem 15 SP5:kernel-default SUSE Linux Enterprise Module for Basesystem 15 SP5:kernel-default-devel SUSE Linux Enterprise Module for Basesystem 15 SP5:kernel-devel SUSE Linux Enterprise Module for Basesystem 15 SP5:kernel-macros SUSE Linux Enterprise Module for Basesystem 15 SP5:kernel-source SUSE Linux Enterprise Module for Development Tools 15 SP5:kernel-default SUSE Linux Enterprise Module for Development Tools 15 SP5:kernel-source SUSE Linux Enterprise Module for Public Cloud 15 SP2:kernel-source-azure SUSE Linux Enterprise Module for Public Cloud 15 SP3:kernel-source-azure SUSE Linux Enterprise Module for Public Cloud 15 SP4:kernel-source-azure SUSE Linux Enterprise Module for Public Cloud 15 SP5:kernel-devel-azure SUSE Linux Enterprise Module for Public Cloud 15 SP5:kernel-source-azure SUSE Linux Enterprise Real Time 12 SP5:kernel-devel-rt SUSE Linux Enterprise Real Time 12 SP5:kernel-source-rt SUSE Linux Enterprise Server 11 SP4 LTSS EXTREME CORE:kernel-default SUSE Linux Enterprise Server 11 SP4 LTSS EXTREME CORE:kernel-default-base SUSE Linux Enterprise Server 11 SP4 LTSS EXTREME CORE:kernel-default-devel SUSE Linux Enterprise Server 11 SP4 LTSS EXTREME CORE:kernel-source SUSE Linux Enterprise Server 11 SP4 LTSS:kernel-default SUSE Linux Enterprise Server 11 SP4 LTSS:kernel-source SUSE Linux Enterprise Server 12 SP2-LTSS:kernel-default SUSE Linux Enterprise Server 12 SP2-LTSS:kernel-default-base SUSE Linux Enterprise Server 12 SP2-LTSS:kernel-default-devel SUSE Linux Enterprise Server 12 SP2-LTSS:kernel-default-man SUSE Linux Enterprise Server 12 SP2-LTSS:kernel-devel SUSE Linux Enterprise Server 12 SP2-LTSS:kernel-macros SUSE Linux Enterprise Server 12 SP2-LTSS:kernel-source SUSE Linux Enterprise Server 12 SP4-LTSS:kernel-default SUSE Linux Enterprise Server 12 SP4-LTSS:kernel-default-base SUSE Linux Enterprise Server 12 SP4-LTSS:kernel-default-devel SUSE Linux Enterprise Server 12 SP4-LTSS:kernel-default-man SUSE Linux Enterprise Server 12 SP4-LTSS:kernel-devel SUSE Linux Enterprise Server 12 SP4-LTSS:kernel-macros SUSE Linux Enterprise Server 12 SP4-LTSS:kernel-source SUSE Linux Enterprise Server 12 SP5:kernel-default SUSE Linux Enterprise Server 12 SP5:kernel-default-base SUSE Linux Enterprise Server 12 SP5:kernel-default-devel SUSE Linux Enterprise Server 12 SP5:kernel-default-man SUSE Linux Enterprise Server 12 SP5:kernel-devel SUSE Linux Enterprise Server 12 SP5:kernel-devel-azure SUSE Linux Enterprise Server 12 SP5:kernel-macros SUSE Linux Enterprise Server 12 SP5:kernel-source SUSE Linux Enterprise Server 12 SP5:kernel-source-azure SUSE Linux Enterprise Server 15 SP1-LTSS:kernel-default SUSE Linux Enterprise Server 15 SP1-LTSS:kernel-default-base SUSE Linux Enterprise Server 15 SP1-LTSS:kernel-default-devel SUSE Linux Enterprise Server 15 SP1-LTSS:kernel-default-man SUSE Linux Enterprise Server 15 SP1-LTSS:kernel-devel SUSE Linux Enterprise Server 15 SP1-LTSS:kernel-macros SUSE Linux Enterprise Server 15 SP1-LTSS:kernel-source SUSE Linux Enterprise Server 15 SP1-LTSS:reiserfs-kmp-default SUSE Linux Enterprise Server 15 SP2-LTSS:kernel-default SUSE Linux Enterprise Server 15 SP2-LTSS:kernel-default-devel SUSE Linux Enterprise Server 15 SP2-LTSS:kernel-devel SUSE Linux Enterprise Server 15 SP2-LTSS:kernel-macros SUSE Linux Enterprise Server 15 SP2-LTSS:kernel-source SUSE Linux Enterprise Server 15 SP2-LTSS:reiserfs-kmp-default SUSE Linux Enterprise Server 15 SP3-LTSS:kernel-default SUSE Linux Enterprise Server 15 SP3-LTSS:kernel-default-devel SUSE Linux Enterprise Server 15 SP3-LTSS:kernel-devel SUSE Linux Enterprise Server 15 SP3-LTSS:kernel-macros SUSE Linux Enterprise Server 15 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