{"schema":"threatline.record/2","record":{"id":"CVE-2026-99204","aliases":[],"summary":"ocfs2/dlm: Protect the recovery list during debugfs reads","details":"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.]","categories":["Operating systems"],"product":"Linux","vendor":"Linux","ecosystem":null,"affected_ranges":[{"source":"CVE List","source_url":"https://www.cve.org/CVERecord?id=CVE-2026-99204","source_modified_at":"2026-10-28T10:35:58.336Z","fetched_at":"2026-10-28T15:55:58.673066Z","product":"Linux","vendor":"Linux","versions":[{"version":"007dce53a29ccffc000ab5373d188f73881390fd","lessThan":"04d4571c00db61a9664f387752fa05cb3c08a537","status":"affected","versionType":"git"},{"version":"007dce53a29ccffc000ab5373d188f73881390fd","lessThan":"2bc426a32bfb78868c7f76d9547132837b6b5284","status":"affected","versionType":"git"},{"version":"007dce53a29ccffc000ab5373d188f73881390fd","lessThan":"4c435828932bf46f29860e4a0375bcae101b778a","status":"affected","versionType":"git"}],"defaultStatus":"unaffected"},{"source":"CVE List","source_url":"https://www.cve.org/CVERecord?id=CVE-2026-99204","source_modified_at":"2026-10-28T10:35:58.336Z","fetched_at":"2026-10-28T15:55:58.673066Z","product":"Linux","vendor":"Linux","versions":[{"version":"2.6.26","status":"affected"},{"version":"0","lessThan":"2.6.26","status":"unaffected","versionType":"semver"},{"version":"6.18.59","lessThanOrEqual":"6.18.*","status":"unaffected","versionType":"semver"},{"version":"7.2.13","lessThanOrEqual":"7.2.*","status":"unaffected","versionType":"semver"},{"version":"7.3","lessThanOrEqual":"*","status":"unaffected","versionType":"original_commit_for_fix"}],"defaultStatus":"affected"}],"fixed_versions":[{"source":"CVE List","source_url":"https://www.cve.org/CVERecord?id=CVE-2026-99204","source_modified_at":"2026-10-28T10:35:58.336Z","fetched_at":"2026-10-28T15:55:58.673066Z","package":{"name":"Linux","ecosystem":null},"version":"04d4571c00db61a9664f387752fa05cb3c08a537","basis":"first unaffected version stated in the CVE record"},{"source":"CVE List","source_url":"https://www.cve.org/CVERecord?id=CVE-2026-99204","source_modified_at":"2026-10-28T10:35:58.336Z","fetched_at":"2026-10-28T15:55:58.673066Z","package":{"name":"Linux","ecosystem":null},"version":"2bc426a32bfb78868c7f76d9547132837b6b5284","basis":"first unaffected version stated in the CVE record"},{"source":"CVE List","source_url":"https://www.cve.org/CVERecord?id=CVE-2026-99204","source_modified_at":"2026-10-28T10:35:58.336Z","fetched_at":"2026-10-28T15:55:58.673066Z","package":{"name":"Linux","ecosystem":null},"version":"4c435828932bf46f29860e4a0375bcae101b778a","basis":"first unaffected version stated in the CVE record"}],"cvss":null,"severity":null,"kev":{"listed":false},"epss":{"probability":null,"percentile":null,"score_date":null},"published_at":"2026-10-28T10:35:58.336Z","modified_at":"2026-10-28T10:35:58.336Z","provenance":[{"source":"CVE List","url":"https://www.cve.org/CVERecord?id=CVE-2026-99204","fetched_at":"2026-10-28T15:55:58.673066Z","source_modified_at":"2026-10-28T10:35:58.336Z"}],"sources":["CVE List"],"references":[{"source":"CVE List","url":"https://git.kernel.org/stable/c/04d4571c00db61a9664f387752fa05cb3c08a537"},{"source":"CVE List","url":"https://git.kernel.org/stable/c/2bc426a32bfb78868c7f76d9547132837b6b5284"},{"source":"CVE List","url":"https://git.kernel.org/stable/c/4c435828932bf46f29860e4a0375bcae101b778a"}],"locations":[],"motoko_assessment":{"status":"requires_architecture_review","automatic_remediation":false},"cve_state":"PUBLISHED","classification":{"method":"product-first software-layer rules","rules_version":"2.1","matched_on":"product","confidence":"heuristic","reviewed":false},"change_timestamp":"2026-10-28T10:35:58.336Z","content_hash":"7965cb6bcbcf35a9c0d9aed88d315aec7f5e3c10d03aaa2a452ea5d4e98ba799"}}