{"id":"CVE-2026-99204","revision":"757c8d65fe1a41ffb66a53834bff0b43","records":[{"revision":"757c8d65fe1a41ffb66a53834bff0b43","observedAt":"2026-10-28T11:27:43.363+00:00","statement":{"source":"cve-program","id":"CVE-2026-99204","aliases":[],"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 \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 \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":0,"publishedAt":"2026-10-28T10:35:58.336+00:00","modifiedAt":"2026-10-28T10:35:58.336+00:00","affected":[{"ecosystem":"Vendor product","name":"Linux","ranges":[],"versions":[],"rawVersionEvidence":"{\n \"product\": \"Linux\",\n \"vendor\": \"Linux\",\n \"defaultStatus\": \"unaffected\",\n \"repo\": \"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git\",\n \"programFiles\": [\n \"fs/ocfs2/dlm/dlmcommon.h\",\n \"fs/ocfs2/dlm/dlmdebug.c\",\n \"fs/ocfs2/dlm/dlmrecovery.c\"\n ],\n \"versions\": [\n {\n \"version\": \"007dce53a29ccffc000ab5373d188f73881390fd\",\n \"lessThan\": \"04d4571c00db61a9664f387752fa05cb3c08a537\",\n \"status\": \"affected\",\n \"versionType\": \"git\"\n },\n {\n \"version\": \"007dce53a29ccffc000ab5373d188f73881390fd\",\n \"lessThan\": \"2bc426a32bfb78868c7f76d9547132837b6b5284\",\n \"status\": \"affected\",\n \"versionType\": \"git\"\n },\n {\n \"version\": \"007dce53a29ccffc000ab5373d188f73881390fd\",\n \"lessThan\": \"4c435828932bf46f29860e4a0375bcae101b778a\",\n \"status\": \"affected\",\n \"versionType\": \"git\"\n }\n ]\n }"},{"ecosystem":"Vendor product","name":"Linux","ranges":[],"versions":[],"rawVersionEvidence":"{\n \"product\": \"Linux\",\n \"vendor\": \"Linux\",\n \"defaultStatus\": \"affected\",\n \"repo\": \"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git\",\n \"programFiles\": [\n \"fs/ocfs2/dlm/dlmcommon.h\",\n \"fs/ocfs2/dlm/dlmdebug.c\",\n \"fs/ocfs2/dlm/dlmrecovery.c\"\n ],\n \"versions\": [\n {\n \"version\": \"2.6.26\",\n \"status\": \"affected\"\n },\n {\n \"version\": \"0\",\n \"lessThan\": \"2.6.26\",\n \"status\": \"unaffected\",\n \"versionType\": \"semver\"\n },\n {\n \"version\": \"6.18.59\",\n \"lessThanOrEqual\": \"6.18.*\",\n \"status\": \"unaffected\",\n \"versionType\": \"semver\"\n },\n {\n \"version\": \"7.2.13\",\n \"lessThanOrEqual\": \"7.2.*\",\n \"status\": \"unaffected\",\n \"versionType\": \"semver\"\n },\n {\n \"version\": \"7.3\",\n \"lessThanOrEqual\": \"*\",\n \"status\": \"unaffected\",\n \"versionType\": \"original_commit_for_fix\"\n }\n ]\n }"}],"metrics":[],"references":["https://git.kernel.org/stable/c/04d4571c00db61a9664f387752fa05cb3c08a537","https://git.kernel.org/stable/c/2bc426a32bfb78868c7f76d9547132837b6b5284","https://git.kernel.org/stable/c/4c435828932bf46f29860e4a0375bcae101b778a"],"sourceUrl":"https://www.cve.org/CVERecord?id=CVE-2026-99204","license":"CVE Program Terms of Use","key":"cve-program:CVE-2026-99204","identifiers":["CVE-2026-99204"]},"retained":false,"historicalAffected":[]}],"coverage":[]}