{ "affected": [ { "ranges": [ { "events": [ { "introduced": "4e3d24ed1a1285fe3289653aacc965642706bacb" }, { "fixed": "6cc93dea4078cbcddee63fa2234e382a76600464" }, { "fixed": "90a6512425414098a63fc97b77bed089c75d106b" }, { "fixed": "5bee5d5f67aedd26d2b72e00e49dd93331fbcc30" }, { "fixed": "aa7883b6a3c76301a3299deb34de948e73bb6a08" }, { "fixed": "9c81c1a61a52b6ecf0d14f1dbd95f154a7a9e92a" }, { "fixed": "a087b2d3411e7f9df71ba3293596923ee2c70d65" }, { "fixed": "a09831214912a1f270663d935613910fafd8d883" }, { "fixed": "03ad858ce8064861ea580021976dc19b7aabb549" } ], "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "type": "GIT" } ] }, { "package": { "ecosystem": "Linux", "name": "Kernel" }, "ranges": [ { "events": [ { "introduced": "2.6.26" }, { "fixed": "5.10.261" } ], "type": "ECOSYSTEM" }, { "events": [ { "introduced": "5.11.0" }, { "fixed": "5.15.212" } ], "type": "ECOSYSTEM" }, { "events": [ { "introduced": "5.16.0" }, { "fixed": "6.1.178" } ], "type": "ECOSYSTEM" }, { "events": [ { "introduced": "6.2.0" }, { "fixed": "6.6.145" } ], "type": "ECOSYSTEM" }, { "events": [ { "introduced": "6.7.0" }, { "fixed": "6.12.97" } ], "type": "ECOSYSTEM" }, { "events": [ { "introduced": "6.13.0" }, { "fixed": "6.18.40" } ], "type": "ECOSYSTEM" }, { "events": [ { "introduced": "6.19.0" }, { "fixed": "7.1.5" } ], "type": "ECOSYSTEM" } ] } ], "database_specific": { "cna_assigner": "Linux", "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/74xxx/CVE-2026-74348.json" }, "details": "In the Linux kernel, the following vulnerability has been resolved:\n\nocfs2/dlm: require a ref for locking_state debugfs open\n\ndebug_lockres_open() copies inode-\u003ei_private into struct debug_lockres and\ndebug_lockres_release() later drops that pointer with dlm_put(). That\nonly works if open successfully pins the struct dlm_ctxt.\n\nToday open calls dlm_grab(dlm) but ignores its return value. Once the\nlast domain unregister has removed the context from dlm_domains,\ndlm_grab() returns NULL, yet open still stores the raw pointer and returns\nsuccess. The later release path is outside the debugfs removal barrier,\nso it can call dlm_put() after dlm_free_ctxt_mem() has freed the context. \nKASAN reports this as a slab-use-after-free in dlm_put() called from\ndebug_lockres_release().\n\nFail the open when dlm_grab() cannot acquire the reference and unwind the\nseq_file private state before returning. That keeps locking_state from\nhanding out a file descriptor whose release path does not own the\ndlm_ctxt.\n\nThe buggy scenario involves two paths, with each column showing the order\nwithin that path:\n\nlocking_state debugfs open: last domain unregister:\n1. debug_lockres_open() reads 1. dlm_unregister_domain() calls\n inode-\u003ei_private. dlm_complete_dlm_shutdown().\n2. debug_lockres_open() calls 2. shutdown removes the dlm_ctxt from\n dlm_grab(dlm) and gets NULL. dlm_domains.\n3. open still stores the raw dlm 3. final teardown reaches\n pointer in dl-\u003edl_ctxt and dlm_free_ctxt_mem() and frees it.\n returns success.\n4. debug_lockres_release() later\n calls dlm_put(dl-\u003edl_ctxt).\n\nValidation reproduced this kernel report:\nKASAN slab-use-after-free in dlm_put+0x82/0x200\nRIP: 0033:0x7f4d349bc9e0\nThe buggy address belongs to the object at ffff888103a3c000 which belongs\nto the cache kmalloc-2k of size 2048\nThe buggy address is located 816 bytes inside of freed 2048-byte region\n[ffff888103a3c000, ffff888103a3c800)\nWrite of size 4\nCall trace:\n dump_stack_lvl+0x66/0xa0 (?:?)\n print_report+0xd0/0x630 (?:?)\n dlm_put+0x82/0x200 (?:?)\n srso_alias_return_thunk+0x5/0xfbef5 (?:?)\n __virt_addr_valid+0x188/0x2f0 (?:?)\n kasan_report+0xe4/0x120 (?:?)\n kasan_check_range+0x105/0x1b0 (?:?)\n debug_lockres_release+0x53/0x80 (fs/ocfs2/dlm/dlmdebug.c:587)\n dlm_put+0x9/0x200 (?:?)\n debug_lockres_release+0x5c/0x80 (fs/ocfs2/dlm/dlmdebug.c:587)\n full_proxy_release+0x67/0x90 (?:?)\n __fput+0x1df/0x4b0 (?:?)\n do_raw_spin_lock+0x10f/0x1b0 (?:?)\n fput_close_sync+0xd2/0x170 (?:?)\n __x64_sys_close+0x55/0x90 (?:?)\n do_syscall_64+0x10c/0x640 (arch/x86/entry/syscall_64.c:87)\n irqentry_exit+0xac/0x6e0 (?:?)\n entry_SYSCALL_64_after_hwframe+0x77/0x7f (?:?)\nFreed by task stack:\n kasan_save_stack+0x33/0x60 (?:?)\n kasan_save_track+0x14/0x30 (?:?)\n kasan_save_free_info+0x3b/0x60 (?:?)\n __kasan_slab_free+0x5f/0x80 (?:?)\n kfree+0x30f/0x580 (?:?)\n dlm_put+0x1ce/0x200 (?:?)\n dlm_unregister_domain+0xf6/0xb30 (?:?)\n o2cb_cluster_disconnect+0x6b/0x90 (?:?)\n ocfs2_cluster_disconnect+0x41/0x70 (?:?)\n ocfs2_dlm_shutdown+0x1c4/0x220 (?:?)\n ocfs2_dismount_volume+0x38a/0x550 (?:?)\n generic_shutdown_super+0xc3/0x220 (?:?)\n kill_block_super+0x29/0x60 (?:?)\n deactivate_locked_super+0x66/0xe0 (?:?)\n cleanup_mnt+0x13d/0x210 (?:?)\n task_work_run+0xfa/0x170 (?:?)\n exit_to_user_mode_loop+0xd6/0x430 (?:?)\n do_syscall_64+0x3cb/0x640 (arch/x86/entry/syscall_64.c:87)\n entry_SYSCALL_64_after_hwframe+0x77/0x7f (?:?)", "id": "CVE-2026-74348", "modified": "2026-08-16T03:31:15.599869980Z", "published": "2026-08-15T05:58:35.977Z", "references": [ { "type": "WEB", "url": "https://git.kernel.org/stable/c/03ad858ce8064861ea580021976dc19b7aabb549" }, { "type": "WEB", "url": "https://git.kernel.org/stable/c/5bee5d5f67aedd26d2b72e00e49dd93331fbcc30" }, { "type": "WEB", "url": "https://git.kernel.org/stable/c/6cc93dea4078cbcddee63fa2234e382a76600464" }, { "type": "WEB", "url": "https://git.kernel.org/stable/c/90a6512425414098a63fc97b77bed089c75d106b" }, { "type": "WEB", "url": "https://git.kernel.org/stable/c/9c81c1a61a52b6ecf0d14f1dbd95f154a7a9e92a" }, { "type": "WEB", "url": "https://git.kernel.org/stable/c/a087b2d3411e7f9df71ba3293596923ee2c70d65" }, { "type": "WEB", "url": "https://git.kernel.org/stable/c/a09831214912a1f270663d935613910fafd8d883" }, { "type": "WEB", "url": "https://git.kernel.org/stable/c/aa7883b6a3c76301a3299deb34de948e73bb6a08" }, { "type": "ADVISORY", "url": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/74xxx/CVE-2026-74348.json" }, { "type": "ADVISORY", "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-74348" }, { "type": "PACKAGE", "url": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git" } ], "schema_version": "1.9.0", "summary": "ocfs2/dlm: require a ref for locking_state debugfs open" }