{"id":"CVE-2023-53401","summary":"mm: kmem: fix a NULL pointer dereference in obj_stock_flush_required()","details":"In the Linux kernel, the following vulnerability has been resolved:\n\nmm: kmem: fix a NULL pointer dereference in obj_stock_flush_required()\n\nKCSAN found an issue in obj_stock_flush_required():\nstock-\u003ecached_objcg can be reset between the check and dereference:\n\n==================================================================\nBUG: KCSAN: data-race in drain_all_stock / drain_obj_stock\n\nwrite to 0xffff888237c2a2f8 of 8 bytes by task 19625 on cpu 0:\n drain_obj_stock+0x408/0x4e0 mm/memcontrol.c:3306\n refill_obj_stock+0x9c/0x1e0 mm/memcontrol.c:3340\n obj_cgroup_uncharge+0xe/0x10 mm/memcontrol.c:3408\n memcg_slab_free_hook mm/slab.h:587 [inline]\n __cache_free mm/slab.c:3373 [inline]\n __do_kmem_cache_free mm/slab.c:3577 [inline]\n kmem_cache_free+0x105/0x280 mm/slab.c:3602\n __d_free fs/dcache.c:298 [inline]\n dentry_free fs/dcache.c:375 [inline]\n __dentry_kill+0x422/0x4a0 fs/dcache.c:621\n dentry_kill+0x8d/0x1e0\n dput+0x118/0x1f0 fs/dcache.c:913\n __fput+0x3bf/0x570 fs/file_table.c:329\n ____fput+0x15/0x20 fs/file_table.c:349\n task_work_run+0x123/0x160 kernel/task_work.c:179\n resume_user_mode_work include/linux/resume_user_mode.h:49 [inline]\n exit_to_user_mode_loop+0xcf/0xe0 kernel/entry/common.c:171\n exit_to_user_mode_prepare+0x6a/0xa0 kernel/entry/common.c:203\n __syscall_exit_to_user_mode_work kernel/entry/common.c:285 [inline]\n syscall_exit_to_user_mode+0x26/0x140 kernel/entry/common.c:296\n do_syscall_64+0x4d/0xc0 arch/x86/entry/common.c:86\n entry_SYSCALL_64_after_hwframe+0x63/0xcd\n\nread to 0xffff888237c2a2f8 of 8 bytes by task 19632 on cpu 1:\n obj_stock_flush_required mm/memcontrol.c:3319 [inline]\n drain_all_stock+0x174/0x2a0 mm/memcontrol.c:2361\n try_charge_memcg+0x6d0/0xd10 mm/memcontrol.c:2703\n try_charge mm/memcontrol.c:2837 [inline]\n mem_cgroup_charge_skmem+0x51/0x140 mm/memcontrol.c:7290\n sock_reserve_memory+0xb1/0x390 net/core/sock.c:1025\n sk_setsockopt+0x800/0x1e70 net/core/sock.c:1525\n udp_lib_setsockopt+0x99/0x6c0 net/ipv4/udp.c:2692\n udp_setsockopt+0x73/0xa0 net/ipv4/udp.c:2817\n sock_common_setsockopt+0x61/0x70 net/core/sock.c:3668\n __sys_setsockopt+0x1c3/0x230 net/socket.c:2271\n __do_sys_setsockopt net/socket.c:2282 [inline]\n __se_sys_setsockopt net/socket.c:2279 [inline]\n __x64_sys_setsockopt+0x66/0x80 net/socket.c:2279\n do_syscall_x64 arch/x86/entry/common.c:50 [inline]\n do_syscall_64+0x41/0xc0 arch/x86/entry/common.c:80\n entry_SYSCALL_64_after_hwframe+0x63/0xcd\n\nvalue changed: 0xffff8881382d52c0 -\u003e 0xffff888138893740\n\nReported by Kernel Concurrency Sanitizer on:\nCPU: 1 PID: 19632 Comm: syz-executor.0 Not tainted 6.3.0-rc2-syzkaller-00387-g534293368afa #0\nHardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/02/2023\n\nFix it by using READ_ONCE()/WRITE_ONCE() for all accesses to\nstock-\u003ecached_objcg.","modified":"2026-03-20T12:33:08.310279Z","published":"2025-09-18T13:33:41.076Z","related":["ALSA-2025:22800","ALSA-2025:22801","SUSE-SU-2025:03600-1","SUSE-SU-2025:03634-1","SUSE-SU-2025:20851-1","SUSE-SU-2025:20861-1","SUSE-SU-2025:20870-1","SUSE-SU-2025:20898-1","SUSE-SU-2025:3751-1","SUSE-SU-2025:4057-1","SUSE-SU-2025:4132-1","SUSE-SU-2025:4141-1"],"database_specific":{"osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2023/53xxx/CVE-2023-53401.json","cna_assigner":"Linux"},"references":[{"type":"WEB","url":"https://git.kernel.org/stable/c/33391c7e1a2ad612bf3922cc168cb09a46bbe236"},{"type":"WEB","url":"https://git.kernel.org/stable/c/33d9490b27e5d8da4444aefd714a4f50189db978"},{"type":"WEB","url":"https://git.kernel.org/stable/c/3b8abb3239530c423c0b97e42af7f7e856e1ee96"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2023/53xxx/CVE-2023-53401.json"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2023-53401"},{"type":"PACKAGE","url":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git"}],"affected":[{"ranges":[{"type":"GIT","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","events":[{"introduced":"bf4f059954dcb221384b2f784677e19a13cd4bdb"},{"fixed":"33d9490b27e5d8da4444aefd714a4f50189db978"},{"fixed":"33391c7e1a2ad612bf3922cc168cb09a46bbe236"},{"fixed":"3b8abb3239530c423c0b97e42af7f7e856e1ee96"}]}],"database_specific":{"source":"https://storage.googleapis.com/osv-test-cve-osv-conversion/osv-output/CVE-2023-53401.json"}}],"schema_version":"1.7.5","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:H"}]}