CVE-2025-39885

/// Technical description

In the Linux kernel, the following vulnerability has been resolved:

ocfs2: fix recursive semaphore deadlock in fiemap call

syzbot detected a OCFS2 hang due to a recursive semaphore on a

FS_IOC_FIEMAP of the extent list on a specially crafted mmap file.

context_switch kernel/sched/core.c:5357 [inline]

__schedule+0x1798/0x4cc0 kernel/sched/core.c:6961

__schedule_loop kernel/sched/core.c:7043 [inline]

schedule+0x165/0x360 kernel/sched/core.c:7058

schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7115

rwsem_down_write_slowpath+0x872/0xfe0 kernel/locking/rwsem.c:1185

__down_write_common kernel/locking/rwsem.c:1317 [inline]

__down_write kernel/locking/rwsem.c:1326 [inline]

down_write+0x1ab/0x1f0 kernel/locking/rwsem.c:1591

ocfs2_page_mkwrite+0x2ff/0xc40 fs/ocfs2/mmap.c:142

do_page_mkwrite+0x14d/0x310 mm/memory.c:3361

wp_page_shared mm/memory.c:3762 [inline]

do_wp_page+0x268d/0x5800 mm/memory.c:3981

handle_pte_fault mm/memory.c:6068 [inline]

/// Remediation

Check the references section for vendor advisories, patches, and mitigation guidance. If immediate patching is not possible, review the CVSS vector to understand the attack surface and apply compensating controls such as network segmentation or access restrictions.

/// References