{"api_version":"1","generated_at":"2026-08-15T08:44:18+00:00","cve":"CVE-2026-74348","urls":{"html":"https://cve.report/CVE-2026-74348","api":"https://cve.report/api/cve/CVE-2026-74348.json","docs":"https://cve.report/api","cve_org":"https://www.cve.org/CVERecord?id=CVE-2026-74348","nvd":"https://nvd.nist.gov/vuln/detail/CVE-2026-74348"},"summary":{"title":"ocfs2/dlm: require a ref for locking_state debugfs open","description":"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->i_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->i_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->dl_ctxt and           dlm_free_ctxt_mem() and frees it.\n   returns success.\n4. debug_lockres_release() later\n   calls dlm_put(dl->dl_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 (?:?)","state":"PUBLISHED","assigner":"Linux","published_at":"2026-08-15 06:22:35","updated_at":"2026-08-15 06:22:35"},"problem_types":[],"metrics":[],"references":[{"url":"https://git.kernel.org/stable/c/a087b2d3411e7f9df71ba3293596923ee2c70d65","name":"https://git.kernel.org/stable/c/a087b2d3411e7f9df71ba3293596923ee2c70d65","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/6cc93dea4078cbcddee63fa2234e382a76600464","name":"https://git.kernel.org/stable/c/6cc93dea4078cbcddee63fa2234e382a76600464","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/aa7883b6a3c76301a3299deb34de948e73bb6a08","name":"https://git.kernel.org/stable/c/aa7883b6a3c76301a3299deb34de948e73bb6a08","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/03ad858ce8064861ea580021976dc19b7aabb549","name":"https://git.kernel.org/stable/c/03ad858ce8064861ea580021976dc19b7aabb549","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/a09831214912a1f270663d935613910fafd8d883","name":"https://git.kernel.org/stable/c/a09831214912a1f270663d935613910fafd8d883","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/90a6512425414098a63fc97b77bed089c75d106b","name":"https://git.kernel.org/stable/c/90a6512425414098a63fc97b77bed089c75d106b","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/5bee5d5f67aedd26d2b72e00e49dd93331fbcc30","name":"https://git.kernel.org/stable/c/5bee5d5f67aedd26d2b72e00e49dd93331fbcc30","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/9c81c1a61a52b6ecf0d14f1dbd95f154a7a9e92a","name":"https://git.kernel.org/stable/c/9c81c1a61a52b6ecf0d14f1dbd95f154a7a9e92a","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://www.cve.org/CVERecord?id=CVE-2026-74348","name":"CVE Program record","refsource":"CVE.ORG","tags":["canonical"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-74348","name":"NVD vulnerability detail","refsource":"NVD","tags":["canonical","analysis"]}],"affected":[{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 4e3d24ed1a1285fe3289653aacc965642706bacb 6cc93dea4078cbcddee63fa2234e382a76600464 git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 4e3d24ed1a1285fe3289653aacc965642706bacb 90a6512425414098a63fc97b77bed089c75d106b git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 4e3d24ed1a1285fe3289653aacc965642706bacb 5bee5d5f67aedd26d2b72e00e49dd93331fbcc30 git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 4e3d24ed1a1285fe3289653aacc965642706bacb aa7883b6a3c76301a3299deb34de948e73bb6a08 git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 4e3d24ed1a1285fe3289653aacc965642706bacb 9c81c1a61a52b6ecf0d14f1dbd95f154a7a9e92a git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 4e3d24ed1a1285fe3289653aacc965642706bacb a087b2d3411e7f9df71ba3293596923ee2c70d65 git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 4e3d24ed1a1285fe3289653aacc965642706bacb a09831214912a1f270663d935613910fafd8d883 git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 4e3d24ed1a1285fe3289653aacc965642706bacb 03ad858ce8064861ea580021976dc19b7aabb549 git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 2.6.26","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 2.6.26 semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 5.10.261 5.10.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 5.15.212 5.15.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 6.1.178 6.1.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 6.6.145 6.6.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 6.12.97 6.12.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 6.18.40 6.18.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 7.1.5 7.1.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 7.2-rc1 * original_commit_for_fix","platforms":[]}],"timeline":[],"solutions":[],"workarounds":[],"exploits":[],"credits":[],"nvd_cpes":[],"vendor_comments":[],"enrichments":{"kev":null,"epss":null,"legacy_qids":[]},"source_records":{"cve_program":{"containers":{"cna":{"affected":[{"defaultStatus":"unaffected","product":"Linux","programFiles":["fs/ocfs2/dlm/dlmdebug.c"],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","vendor":"Linux","versions":[{"lessThan":"6cc93dea4078cbcddee63fa2234e382a76600464","status":"affected","version":"4e3d24ed1a1285fe3289653aacc965642706bacb","versionType":"git"},{"lessThan":"90a6512425414098a63fc97b77bed089c75d106b","status":"affected","version":"4e3d24ed1a1285fe3289653aacc965642706bacb","versionType":"git"},{"lessThan":"5bee5d5f67aedd26d2b72e00e49dd93331fbcc30","status":"affected","version":"4e3d24ed1a1285fe3289653aacc965642706bacb","versionType":"git"},{"lessThan":"aa7883b6a3c76301a3299deb34de948e73bb6a08","status":"affected","version":"4e3d24ed1a1285fe3289653aacc965642706bacb","versionType":"git"},{"lessThan":"9c81c1a61a52b6ecf0d14f1dbd95f154a7a9e92a","status":"affected","version":"4e3d24ed1a1285fe3289653aacc965642706bacb","versionType":"git"},{"lessThan":"a087b2d3411e7f9df71ba3293596923ee2c70d65","status":"affected","version":"4e3d24ed1a1285fe3289653aacc965642706bacb","versionType":"git"},{"lessThan":"a09831214912a1f270663d935613910fafd8d883","status":"affected","version":"4e3d24ed1a1285fe3289653aacc965642706bacb","versionType":"git"},{"lessThan":"03ad858ce8064861ea580021976dc19b7aabb549","status":"affected","version":"4e3d24ed1a1285fe3289653aacc965642706bacb","versionType":"git"}]},{"defaultStatus":"affected","product":"Linux","programFiles":["fs/ocfs2/dlm/dlmdebug.c"],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","vendor":"Linux","versions":[{"status":"affected","version":"2.6.26"},{"lessThan":"2.6.26","status":"unaffected","version":"0","versionType":"semver"},{"lessThanOrEqual":"5.10.*","status":"unaffected","version":"5.10.261","versionType":"semver"},{"lessThanOrEqual":"5.15.*","status":"unaffected","version":"5.15.212","versionType":"semver"},{"lessThanOrEqual":"6.1.*","status":"unaffected","version":"6.1.178","versionType":"semver"},{"lessThanOrEqual":"6.6.*","status":"unaffected","version":"6.6.145","versionType":"semver"},{"lessThanOrEqual":"6.12.*","status":"unaffected","version":"6.12.97","versionType":"semver"},{"lessThanOrEqual":"6.18.*","status":"unaffected","version":"6.18.40","versionType":"semver"},{"lessThanOrEqual":"7.1.*","status":"unaffected","version":"7.1.5","versionType":"semver"},{"lessThanOrEqual":"*","status":"unaffected","version":"7.2-rc1","versionType":"original_commit_for_fix"}]}],"cpeApplicability":[{"nodes":[{"cpeMatch":[{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"5.10.261","versionStartIncluding":"2.6.26","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"5.15.212","versionStartIncluding":"2.6.26","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"6.1.178","versionStartIncluding":"2.6.26","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"6.6.145","versionStartIncluding":"2.6.26","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"6.12.97","versionStartIncluding":"2.6.26","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"6.18.40","versionStartIncluding":"2.6.26","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"7.1.5","versionStartIncluding":"2.6.26","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"7.2-rc1","versionStartIncluding":"2.6.26","vulnerable":true}],"negate":false,"operator":"OR"}]}],"descriptions":[{"lang":"en","value":"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->i_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->i_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->dl_ctxt and           dlm_free_ctxt_mem() and frees it.\n   returns success.\n4. debug_lockres_release() later\n   calls dlm_put(dl->dl_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 (?:?)"}],"providerMetadata":{"dateUpdated":"2026-08-15T05:58:35.977Z","orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","shortName":"Linux"},"references":[{"url":"https://git.kernel.org/stable/c/6cc93dea4078cbcddee63fa2234e382a76600464"},{"url":"https://git.kernel.org/stable/c/90a6512425414098a63fc97b77bed089c75d106b"},{"url":"https://git.kernel.org/stable/c/5bee5d5f67aedd26d2b72e00e49dd93331fbcc30"},{"url":"https://git.kernel.org/stable/c/aa7883b6a3c76301a3299deb34de948e73bb6a08"},{"url":"https://git.kernel.org/stable/c/9c81c1a61a52b6ecf0d14f1dbd95f154a7a9e92a"},{"url":"https://git.kernel.org/stable/c/a087b2d3411e7f9df71ba3293596923ee2c70d65"},{"url":"https://git.kernel.org/stable/c/a09831214912a1f270663d935613910fafd8d883"},{"url":"https://git.kernel.org/stable/c/03ad858ce8064861ea580021976dc19b7aabb549"}],"title":"ocfs2/dlm: require a ref for locking_state debugfs open","x_generator":{"engine":"bippy-1.2.0"}}},"cveMetadata":{"assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","assignerShortName":"Linux","cveId":"CVE-2026-74348","datePublished":"2026-08-15T05:58:35.977Z","dateReserved":"2026-08-15T05:44:03.886Z","dateUpdated":"2026-08-15T05:58:35.977Z","state":"PUBLISHED"},"dataType":"CVE_RECORD","dataVersion":"5.2"},"nvd":{"publishedDate":"2026-08-15 06:22:35","lastModifiedDate":"2026-08-15 06:22:35","problem_types":[],"metrics":[],"configurations":[]},"legacy_mitre":{"record":{"CveYear":"2026","CveId":"74348","Ordinal":"1","Title":"ocfs2/dlm: require a ref for locking_state debugfs open","CVE":"CVE-2026-74348","Year":"2026"},"notes":[{"CveYear":"2026","CveId":"74348","Ordinal":"1","NoteData":"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->i_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->i_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->dl_ctxt and           dlm_free_ctxt_mem() and frees it.\n   returns success.\n4. debug_lockres_release() later\n   calls dlm_put(dl->dl_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 (?:?)","Type":"Description","Title":"ocfs2/dlm: require a ref for locking_state debugfs open"}]}}}