CVE-2026-99204
2026-10-28
11h17 +00:00
11h17 +00:00
Thông báo cho một CVE
Luôn được thông báo về mọi thay đổi đối với một CVE cụ thể.
Mô tả CVE
In the Linux kernel, the following vulnerability has been resolved:
ocfs2/dlm: Protect the recovery list during debugfs reads
Recovery participant records must remain alive while debug_state_print()
walks reco.node_data and formats their fields. The formatter holds
dlm->spinlock, but the recovery participant list is protected by
dlm_reco_state_lock. In particular, dlm_destroy_recovery_area() detaches
the list under dlm_reco_state_lock and frees the detached records after
releasing it. A concurrent debugfs open can therefore read freed memory.
Protect the participant traversal and field reads in debug_state_print()
with dlm_reco_state_lock, matching the existing list writers. This also
serializes the traversal against list_add_tail() during recovery-area
initialization. Make the existing lock available to the debug code
through dlmcommon.h; the lock remains internal to the OCFS2 DLM module.
Release dlm->spinlock after formatting the other domain state and before
acquiring dlm_reco_state_lock, so the debug reader does not nest the two
locks. Leave recovery list insertion, detachment and freeing unchanged.
KASAN report as below:
BUG: KASAN: slab-use-after-free in debug_state_open+0x1169/0x12d0
Read of size 4 at addr ffff88810662ef80 by task dlm-state-stres/896
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)
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
Call Trace:
dump_stack_lvl+0x93/0xd0
print_report+0xce/0x630
? debug_state_open+0x1169/0x12d0
? srso_alias_return_thunk+0x5/0xfbef5
? __virt_addr_valid+0x20e/0x420
? debug_state_open+0x1169/0x12d0
kasan_report+0xe0/0x110
? debug_state_open+0x1169/0x12d0
debug_state_open+0x1169/0x12d0
? __pfx_debug_state_open+0x10/0x10
full_proxy_open_regular+0x193/0x310
do_dentry_open+0x595/0x12d0
? __pfx_full_proxy_open_regular+0x10/0x10
vfs_open_consume+0xd1/0x400
? srso_alias_return_thunk+0x5/0xfbef5
path_openat+0x18d0/0x2020
? __pfx_path_openat+0x10/0x10
do_file_open+0x21e/0x470
? __pfx_do_file_open+0x10/0x10
? _raw_spin_unlock+0x23/0x40
? srso_alias_return_thunk+0x5/0xfbef5
? alloc_fd+0x3a6/0x6b0
do_sys_openat2+0xf4/0x1b0
? __pfx_do_sys_openat2+0x10/0x10
? srso_alias_return_thunk+0x5/0xfbef5
? __fput+0x5b5/0xa60
__x64_sys_openat+0x136/0x1e0
? __pfx___x64_sys_openat+0x10/0x10
do_syscall_64+0x114/0x620
entry_SYSCALL_64_after_hwframe+0x77/0x7f
[Register dump omitted.]
Allocated by task 880:
kasan_save_stack+0x33/0x60
kasan_save_track+0x14/0x30
__kasan_kmalloc+0xaa/0xb0
__kmalloc_cache_noprof+0x28d/0x610
dlm_remaster_locks+0x147/0x1d90
dlm_do_recovery+0xde1/0x1580
dlm_recovery_thread+0x109/0x300
kthread+0x351/0x460
ret_from_fork+0x659/0x940
ret_from_fork_asm+0x1a/0x30
Freed by task 880:
kasan_save_stack+0x33/0x60
kasan_save_track+0x14/0x30
kasan_save_free_info+0x3b/0x60
__kasan_slab_free+0x5f/0x80
kfree+0x308/0x580
dlm_destroy_recovery_area+0x285/0x460
dlm_remaster_locks+0x17c4/0x1d90
dlm_do_recovery+0xde1/0x1580
dlm_recovery_thread+0x109/0x300
kthread+0x351/0x460
ret_from_fork+0x659/0x940
ret_from_fork_asm+0x1a/0x30
The buggy address belongs to the object at ffff88810662ef80
which belongs to the cache kmalloc-32 of size 32
The buggy address is located 0 bytes inside of
freed 32-byte region [ffff88810662ef80, ffff88810662efa0)
[Page and memory-state dumps omitted.]
