{"api_version":"1","generated_at":"2026-10-30T03:50:18+00:00","cve":"CVE-2026-99204","urls":{"html":"https://cve.report/CVE-2026-99204","api":"https://cve.report/api/cve/CVE-2026-99204.json","docs":"https://cve.report/api","cve_org":"https://www.cve.org/CVERecord?id=CVE-2026-99204","nvd":"https://nvd.nist.gov/vuln/detail/CVE-2026-99204"},"summary":{"title":"ocfs2/dlm: Protect the recovery list during debugfs reads","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nocfs2/dlm: Protect the recovery list during debugfs reads\n\nRecovery participant records must remain alive while debug_state_print()\nwalks reco.node_data and formats their fields. The formatter holds\ndlm->spinlock, but the recovery participant list is protected by\ndlm_reco_state_lock. In particular, dlm_destroy_recovery_area() detaches\nthe list under dlm_reco_state_lock and frees the detached records after\nreleasing it. A concurrent debugfs open can therefore read freed memory.\n\nProtect the participant traversal and field reads in debug_state_print()\nwith dlm_reco_state_lock, matching the existing list writers. This also\nserializes the traversal against list_add_tail() during recovery-area\ninitialization. Make the existing lock available to the debug code\nthrough dlmcommon.h; the lock remains internal to the OCFS2 DLM module.\n\nRelease dlm->spinlock after formatting the other domain state and before\nacquiring dlm_reco_state_lock, so the debug reader does not nest the two\nlocks. Leave recovery list insertion, detachment and freeing unchanged.\n\nKASAN report as below:\n\n    BUG: KASAN: slab-use-after-free in debug_state_open+0x1169/0x12d0\n    Read of size 4 at addr ffff88810662ef80 by task dlm-state-stres/896\n\n    CPU: 1 UID: 0 PID: 896 Comm: dlm-state-stres Not tainted 7.3.0-rc4-next-20260921-pmb-ocfs2-functional-v1+ #1 PREEMPT(lazy)\n    Hardware name: QEMU Ubuntu 24.04 PC v2 (i440FX + PIIX, arch_caps fix, 1996), BIOS 1.16.3-debian-1.16.3-2 04/01/2014\n    Call Trace:\n     <TASK>\n     dump_stack_lvl+0x93/0xd0\n     print_report+0xce/0x630\n     ? debug_state_open+0x1169/0x12d0\n     ? srso_alias_return_thunk+0x5/0xfbef5\n     ? __virt_addr_valid+0x20e/0x420\n     ? debug_state_open+0x1169/0x12d0\n     kasan_report+0xe0/0x110\n     ? debug_state_open+0x1169/0x12d0\n     debug_state_open+0x1169/0x12d0\n     ? __pfx_debug_state_open+0x10/0x10\n     full_proxy_open_regular+0x193/0x310\n     do_dentry_open+0x595/0x12d0\n     ? __pfx_full_proxy_open_regular+0x10/0x10\n     vfs_open_consume+0xd1/0x400\n     ? srso_alias_return_thunk+0x5/0xfbef5\n     path_openat+0x18d0/0x2020\n     ? __pfx_path_openat+0x10/0x10\n     do_file_open+0x21e/0x470\n     ? __pfx_do_file_open+0x10/0x10\n     ? _raw_spin_unlock+0x23/0x40\n     ? srso_alias_return_thunk+0x5/0xfbef5\n     ? alloc_fd+0x3a6/0x6b0\n     do_sys_openat2+0xf4/0x1b0\n     ? __pfx_do_sys_openat2+0x10/0x10\n     ? srso_alias_return_thunk+0x5/0xfbef5\n     ? __fput+0x5b5/0xa60\n     __x64_sys_openat+0x136/0x1e0\n     ? __pfx___x64_sys_openat+0x10/0x10\n     do_syscall_64+0x114/0x620\n     entry_SYSCALL_64_after_hwframe+0x77/0x7f\n    [Register dump omitted.]\n     </TASK>\n\n    Allocated by task 880:\n     kasan_save_stack+0x33/0x60\n     kasan_save_track+0x14/0x30\n     __kasan_kmalloc+0xaa/0xb0\n     __kmalloc_cache_noprof+0x28d/0x610\n     dlm_remaster_locks+0x147/0x1d90\n     dlm_do_recovery+0xde1/0x1580\n     dlm_recovery_thread+0x109/0x300\n     kthread+0x351/0x460\n     ret_from_fork+0x659/0x940\n     ret_from_fork_asm+0x1a/0x30\n\n    Freed by task 880:\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+0x308/0x580\n     dlm_destroy_recovery_area+0x285/0x460\n     dlm_remaster_locks+0x17c4/0x1d90\n     dlm_do_recovery+0xde1/0x1580\n     dlm_recovery_thread+0x109/0x300\n     kthread+0x351/0x460\n     ret_from_fork+0x659/0x940\n     ret_from_fork_asm+0x1a/0x30\n\n    The buggy address belongs to the object at ffff88810662ef80\n     which belongs to the cache kmalloc-32 of size 32\n    The buggy address is located 0 bytes inside of\n     freed 32-byte region [ffff88810662ef80, ffff88810662efa0)\n\n    [Page and memory-state dumps omitted.]","state":"PUBLISHED","assigner":"Linux","published_at":"2026-10-28 11:17:41","updated_at":"2026-10-28 11:17:41"},"problem_types":[],"metrics":[],"references":[{"url":"https://git.kernel.org/stable/c/2bc426a32bfb78868c7f76d9547132837b6b5284","name":"https://git.kernel.org/stable/c/2bc426a32bfb78868c7f76d9547132837b6b5284","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/4c435828932bf46f29860e4a0375bcae101b778a","name":"https://git.kernel.org/stable/c/4c435828932bf46f29860e4a0375bcae101b778a","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/04d4571c00db61a9664f387752fa05cb3c08a537","name":"https://git.kernel.org/stable/c/04d4571c00db61a9664f387752fa05cb3c08a537","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://www.cve.org/CVERecord?id=CVE-2026-99204","name":"CVE Program record","refsource":"CVE.ORG","tags":["canonical"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-99204","name":"NVD vulnerability detail","refsource":"NVD","tags":["canonical","analysis"]}],"affected":[{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 007dce53a29ccffc000ab5373d188f73881390fd 04d4571c00db61a9664f387752fa05cb3c08a537 git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 007dce53a29ccffc000ab5373d188f73881390fd 2bc426a32bfb78868c7f76d9547132837b6b5284 git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 007dce53a29ccffc000ab5373d188f73881390fd 4c435828932bf46f29860e4a0375bcae101b778a 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 6.18.59 6.18.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 7.2.13 7.2.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 7.3 * 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/dlmcommon.h","fs/ocfs2/dlm/dlmdebug.c","fs/ocfs2/dlm/dlmrecovery.c"],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","vendor":"Linux","versions":[{"lessThan":"04d4571c00db61a9664f387752fa05cb3c08a537","status":"affected","version":"007dce53a29ccffc000ab5373d188f73881390fd","versionType":"git"},{"lessThan":"2bc426a32bfb78868c7f76d9547132837b6b5284","status":"affected","version":"007dce53a29ccffc000ab5373d188f73881390fd","versionType":"git"},{"lessThan":"4c435828932bf46f29860e4a0375bcae101b778a","status":"affected","version":"007dce53a29ccffc000ab5373d188f73881390fd","versionType":"git"}]},{"defaultStatus":"affected","product":"Linux","programFiles":["fs/ocfs2/dlm/dlmcommon.h","fs/ocfs2/dlm/dlmdebug.c","fs/ocfs2/dlm/dlmrecovery.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":"6.18.*","status":"unaffected","version":"6.18.59","versionType":"semver"},{"lessThanOrEqual":"7.2.*","status":"unaffected","version":"7.2.13","versionType":"semver"},{"lessThanOrEqual":"*","status":"unaffected","version":"7.3","versionType":"original_commit_for_fix"}]}],"cpeApplicability":[{"nodes":[{"cpeMatch":[{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"6.18.59","versionStartIncluding":"2.6.26","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"7.2.13","versionStartIncluding":"2.6.26","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"7.3","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: Protect the recovery list during debugfs reads\n\nRecovery participant records must remain alive while debug_state_print()\nwalks reco.node_data and formats their fields. The formatter holds\ndlm->spinlock, but the recovery participant list is protected by\ndlm_reco_state_lock. In particular, dlm_destroy_recovery_area() detaches\nthe list under dlm_reco_state_lock and frees the detached records after\nreleasing it. A concurrent debugfs open can therefore read freed memory.\n\nProtect the participant traversal and field reads in debug_state_print()\nwith dlm_reco_state_lock, matching the existing list writers. This also\nserializes the traversal against list_add_tail() during recovery-area\ninitialization. Make the existing lock available to the debug code\nthrough dlmcommon.h; the lock remains internal to the OCFS2 DLM module.\n\nRelease dlm->spinlock after formatting the other domain state and before\nacquiring dlm_reco_state_lock, so the debug reader does not nest the two\nlocks. Leave recovery list insertion, detachment and freeing unchanged.\n\nKASAN report as below:\n\n    BUG: KASAN: slab-use-after-free in debug_state_open+0x1169/0x12d0\n    Read of size 4 at addr ffff88810662ef80 by task dlm-state-stres/896\n\n    CPU: 1 UID: 0 PID: 896 Comm: dlm-state-stres Not tainted 7.3.0-rc4-next-20260921-pmb-ocfs2-functional-v1+ #1 PREEMPT(lazy)\n    Hardware name: QEMU Ubuntu 24.04 PC v2 (i440FX + PIIX, arch_caps fix, 1996), BIOS 1.16.3-debian-1.16.3-2 04/01/2014\n    Call Trace:\n     <TASK>\n     dump_stack_lvl+0x93/0xd0\n     print_report+0xce/0x630\n     ? debug_state_open+0x1169/0x12d0\n     ? srso_alias_return_thunk+0x5/0xfbef5\n     ? __virt_addr_valid+0x20e/0x420\n     ? debug_state_open+0x1169/0x12d0\n     kasan_report+0xe0/0x110\n     ? debug_state_open+0x1169/0x12d0\n     debug_state_open+0x1169/0x12d0\n     ? __pfx_debug_state_open+0x10/0x10\n     full_proxy_open_regular+0x193/0x310\n     do_dentry_open+0x595/0x12d0\n     ? __pfx_full_proxy_open_regular+0x10/0x10\n     vfs_open_consume+0xd1/0x400\n     ? srso_alias_return_thunk+0x5/0xfbef5\n     path_openat+0x18d0/0x2020\n     ? __pfx_path_openat+0x10/0x10\n     do_file_open+0x21e/0x470\n     ? __pfx_do_file_open+0x10/0x10\n     ? _raw_spin_unlock+0x23/0x40\n     ? srso_alias_return_thunk+0x5/0xfbef5\n     ? alloc_fd+0x3a6/0x6b0\n     do_sys_openat2+0xf4/0x1b0\n     ? __pfx_do_sys_openat2+0x10/0x10\n     ? srso_alias_return_thunk+0x5/0xfbef5\n     ? __fput+0x5b5/0xa60\n     __x64_sys_openat+0x136/0x1e0\n     ? __pfx___x64_sys_openat+0x10/0x10\n     do_syscall_64+0x114/0x620\n     entry_SYSCALL_64_after_hwframe+0x77/0x7f\n    [Register dump omitted.]\n     </TASK>\n\n    Allocated by task 880:\n     kasan_save_stack+0x33/0x60\n     kasan_save_track+0x14/0x30\n     __kasan_kmalloc+0xaa/0xb0\n     __kmalloc_cache_noprof+0x28d/0x610\n     dlm_remaster_locks+0x147/0x1d90\n     dlm_do_recovery+0xde1/0x1580\n     dlm_recovery_thread+0x109/0x300\n     kthread+0x351/0x460\n     ret_from_fork+0x659/0x940\n     ret_from_fork_asm+0x1a/0x30\n\n    Freed by task 880:\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+0x308/0x580\n     dlm_destroy_recovery_area+0x285/0x460\n     dlm_remaster_locks+0x17c4/0x1d90\n     dlm_do_recovery+0xde1/0x1580\n     dlm_recovery_thread+0x109/0x300\n     kthread+0x351/0x460\n     ret_from_fork+0x659/0x940\n     ret_from_fork_asm+0x1a/0x30\n\n    The buggy address belongs to the object at ffff88810662ef80\n     which belongs to the cache kmalloc-32 of size 32\n    The buggy address is located 0 bytes inside of\n     freed 32-byte region [ffff88810662ef80, ffff88810662efa0)\n\n    [Page and memory-state dumps omitted.]"}],"providerMetadata":{"dateUpdated":"2026-10-28T10:35:58.336Z","orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","shortName":"Linux"},"references":[{"url":"https://git.kernel.org/stable/c/04d4571c00db61a9664f387752fa05cb3c08a537"},{"url":"https://git.kernel.org/stable/c/2bc426a32bfb78868c7f76d9547132837b6b5284"},{"url":"https://git.kernel.org/stable/c/4c435828932bf46f29860e4a0375bcae101b778a"}],"title":"ocfs2/dlm: Protect the recovery list during debugfs reads","x_generator":{"engine":"bippy-1.2.0"}}},"cveMetadata":{"assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","assignerShortName":"Linux","cveId":"CVE-2026-99204","datePublished":"2026-10-28T10:35:58.336Z","dateReserved":"2026-09-25T10:25:14.400Z","dateUpdated":"2026-10-28T10:35:58.336Z","state":"PUBLISHED"},"dataType":"CVE_RECORD","dataVersion":"5.2"},"nvd":{"publishedDate":"2026-10-28 11:17:41","lastModifiedDate":"2026-10-28 11:17:41","problem_types":[],"metrics":[],"configurations":[]},"legacy_mitre":{"record":{"CveYear":"2026","CveId":"99204","Ordinal":"1","Title":"ocfs2/dlm: Protect the recovery list during debugfs reads","CVE":"CVE-2026-99204","Year":"2026"},"notes":[{"CveYear":"2026","CveId":"99204","Ordinal":"1","NoteData":"In the Linux kernel, the following vulnerability has been resolved:\n\nocfs2/dlm: Protect the recovery list during debugfs reads\n\nRecovery participant records must remain alive while debug_state_print()\nwalks reco.node_data and formats their fields. The formatter holds\ndlm->spinlock, but the recovery participant list is protected by\ndlm_reco_state_lock. In particular, dlm_destroy_recovery_area() detaches\nthe list under dlm_reco_state_lock and frees the detached records after\nreleasing it. A concurrent debugfs open can therefore read freed memory.\n\nProtect the participant traversal and field reads in debug_state_print()\nwith dlm_reco_state_lock, matching the existing list writers. This also\nserializes the traversal against list_add_tail() during recovery-area\ninitialization. Make the existing lock available to the debug code\nthrough dlmcommon.h; the lock remains internal to the OCFS2 DLM module.\n\nRelease dlm->spinlock after formatting the other domain state and before\nacquiring dlm_reco_state_lock, so the debug reader does not nest the two\nlocks. Leave recovery list insertion, detachment and freeing unchanged.\n\nKASAN report as below:\n\n    BUG: KASAN: slab-use-after-free in debug_state_open+0x1169/0x12d0\n    Read of size 4 at addr ffff88810662ef80 by task dlm-state-stres/896\n\n    CPU: 1 UID: 0 PID: 896 Comm: dlm-state-stres Not tainted 7.3.0-rc4-next-20260921-pmb-ocfs2-functional-v1+ #1 PREEMPT(lazy)\n    Hardware name: QEMU Ubuntu 24.04 PC v2 (i440FX + PIIX, arch_caps fix, 1996), BIOS 1.16.3-debian-1.16.3-2 04/01/2014\n    Call Trace:\n     <TASK>\n     dump_stack_lvl+0x93/0xd0\n     print_report+0xce/0x630\n     ? debug_state_open+0x1169/0x12d0\n     ? srso_alias_return_thunk+0x5/0xfbef5\n     ? __virt_addr_valid+0x20e/0x420\n     ? debug_state_open+0x1169/0x12d0\n     kasan_report+0xe0/0x110\n     ? debug_state_open+0x1169/0x12d0\n     debug_state_open+0x1169/0x12d0\n     ? __pfx_debug_state_open+0x10/0x10\n     full_proxy_open_regular+0x193/0x310\n     do_dentry_open+0x595/0x12d0\n     ? __pfx_full_proxy_open_regular+0x10/0x10\n     vfs_open_consume+0xd1/0x400\n     ? srso_alias_return_thunk+0x5/0xfbef5\n     path_openat+0x18d0/0x2020\n     ? __pfx_path_openat+0x10/0x10\n     do_file_open+0x21e/0x470\n     ? __pfx_do_file_open+0x10/0x10\n     ? _raw_spin_unlock+0x23/0x40\n     ? srso_alias_return_thunk+0x5/0xfbef5\n     ? alloc_fd+0x3a6/0x6b0\n     do_sys_openat2+0xf4/0x1b0\n     ? __pfx_do_sys_openat2+0x10/0x10\n     ? srso_alias_return_thunk+0x5/0xfbef5\n     ? __fput+0x5b5/0xa60\n     __x64_sys_openat+0x136/0x1e0\n     ? __pfx___x64_sys_openat+0x10/0x10\n     do_syscall_64+0x114/0x620\n     entry_SYSCALL_64_after_hwframe+0x77/0x7f\n    [Register dump omitted.]\n     </TASK>\n\n    Allocated by task 880:\n     kasan_save_stack+0x33/0x60\n     kasan_save_track+0x14/0x30\n     __kasan_kmalloc+0xaa/0xb0\n     __kmalloc_cache_noprof+0x28d/0x610\n     dlm_remaster_locks+0x147/0x1d90\n     dlm_do_recovery+0xde1/0x1580\n     dlm_recovery_thread+0x109/0x300\n     kthread+0x351/0x460\n     ret_from_fork+0x659/0x940\n     ret_from_fork_asm+0x1a/0x30\n\n    Freed by task 880:\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+0x308/0x580\n     dlm_destroy_recovery_area+0x285/0x460\n     dlm_remaster_locks+0x17c4/0x1d90\n     dlm_do_recovery+0xde1/0x1580\n     dlm_recovery_thread+0x109/0x300\n     kthread+0x351/0x460\n     ret_from_fork+0x659/0x940\n     ret_from_fork_asm+0x1a/0x30\n\n    The buggy address belongs to the object at ffff88810662ef80\n     which belongs to the cache kmalloc-32 of size 32\n    The buggy address is located 0 bytes inside of\n     freed 32-byte region [ffff88810662ef80, ffff88810662efa0)\n\n    [Page and memory-state dumps omitted.]","Type":"Description","Title":"ocfs2/dlm: Protect the recovery list during debugfs reads"}]}}}