In the Linux kernel, the following vulnerability has been resolved: f2fs: fix to avoid racing on fsync_entry_slab by multi filesystem instances As syzbot reported, there is an use-after-free issue during f2fs recovery: Use-after-free write at 0xffff88823bc16040 (in kfence-#10): kmem_cache_destroy+0x1f/0x120 mm/slab_common.c:486 f2fs_recover_fsync_data+0x75b0/0x8380 fs/f2fs/recovery.c:869 f2fs_fill_super+0x9393/0xa420 fs/f2fs/super.c:3945 mount_bdev+0x26c/0x3a0 fs/super.c:1367 legacy_get_tree+0xea/0x180 fs/fs_context.c:592 vfs_get_tree+0x86/0x270 fs/super.c:1497 do_new_mount fs/namespace.c:2905 [inline] path_mount+0x196f/0x2be0 fs/namespace.c:3235 do_mount fs/namespace.c:3248 [inline] __do_sys_mount fs/namespace.c:3456 [inline] __se_sys_mount+0x2f9/0x3b0 fs/namespace.c:3433 do_syscall_64+0x3f/0xb0 arch/x86/entry/common.c:47 entry_SYSCALL_64_after_hwframe+0x44/0xae The root cause is multi f2fs filesystem instances can race on accessing global fsync_entry_slab pointer, result in use-after-free issue of slab cache, fixes to init/destroy this slab cache only once during module init/destroy procedure to avoid this issue.

The Unity Linux 20 host has a package installed that is affected by a vulnerability as referenced in the UTSA-2025-988846 advisory.

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

    f2fs: fix to avoid racing on fsync_entry_slab by multi filesystem instances

    As syzbot reported, there is an use-after-free issue during f2fs recovery:

    Use-after-free write at 0xffff88823bc16040 (in kfence-#10):
     kmem_cache_destroy+0x1f/0x120 mm/slab_common.c:486      f2fs_recover_fsync_data+0x75b0/0x8380 fs/f2fs/recovery.c:869      f2fs_fill_super+0x9393/0xa420 fs/f2fs/super.c:3945      mount_bdev+0x26c/0x3a0 fs/super.c:1367      legacy_get_tree+0xea/0x180 fs/fs_context.c:592      vfs_get_tree+0x86/0x270 fs/super.c:1497      do_new_mount fs/namespace.c:2905 [inline]      path_mount+0x196f/0x2be0 fs/namespace.c:3235      do_mount fs/namespace.c:3248 [inline]
     __do_sys_mount fs/namespace.c:3456 [inline]
     __se_sys_mount+0x2f9/0x3b0 fs/namespace.c:3433      do_syscall_64+0x3f/0xb0 arch/x86/entry/common.c:47      entry_SYSCALL_64_after_hwframe+0x44/0xae

    The root cause is multi f2fs filesystem instances can race on accessing     global fsync_entry_slab pointer, result in use-after-free issue of slab     cache, fixes to init/destroy this slab cache only once during module     init/destroy procedure to avoid this issue.

Tenable has extracted the preceding description block directly from the Unity Linux security advisory.

Note that Nessus has not tested for this issue but has instead relied only on the application's self-reported version number.

The Unity Linux 20 host has a package installed that is affected by a vulnerability as referenced in the UTSA-2025-986984 advisory.

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

    f2fs: fix to avoid racing on fsync_entry_slab by multi filesystem instances

    As syzbot reported, there is an use-after-free issue during f2fs recovery:

    Use-after-free write at 0xffff88823bc16040 (in kfence-#10):
     kmem_cache_destroy+0x1f/0x120 mm/slab_common.c:486      f2fs_recover_fsync_data+0x75b0/0x8380 fs/f2fs/recovery.c:869      f2fs_fill_super+0x9393/0xa420 fs/f2fs/super.c:3945      mount_bdev+0x26c/0x3a0 fs/super.c:1367      legacy_get_tree+0xea/0x180 fs/fs_context.c:592      vfs_get_tree+0x86/0x270 fs/super.c:1497      do_new_mount fs/namespace.c:2905 [inline]      path_mount+0x196f/0x2be0 fs/namespace.c:3235      do_mount fs/namespace.c:3248 [inline]
     __do_sys_mount fs/namespace.c:3456 [inline]
     __se_sys_mount+0x2f9/0x3b0 fs/namespace.c:3433      do_syscall_64+0x3f/0xb0 arch/x86/entry/common.c:47      entry_SYSCALL_64_after_hwframe+0x44/0xae

    The root cause is multi f2fs filesystem instances can race on accessing     global fsync_entry_slab pointer, result in use-after-free issue of slab     cache, fixes to init/destroy this slab cache only once during module     init/destroy procedure to avoid this issue.

Tenable has extracted the preceding description block directly from the Unity Linux security advisory.

Note that Nessus has not tested for this issue but has instead relied only on the application's self-reported version number.

The Linux/Unix host has one or more packages installed that are impacted by a vulnerability without a vendor supplied patch available.

  - f2fs: fix to avoid racing on fsync_entry_slab by multi filesystem instances As syzbot reported, there is     an use-after-free issue during f2fs recovery: Use-after-free write at 0xffff88823bc16040 (in kfence-#10):
    kmem_cache_destroy+0x1f/0x120 mm/slab_common.c:486 f2fs_recover_fsync_data+0x75b0/0x8380     fs/f2fs/recovery.c:869 f2fs_fill_super+0x9393/0xa420 fs/f2fs/super.c:3945 mount_bdev+0x26c/0x3a0     fs/super.c:1367 legacy_get_tree+0xea/0x180 fs/fs_context.c:592 vfs_get_tree+0x86/0x270 fs/super.c:1497     do_new_mount fs/namespace.c:2905 [inline] path_mount+0x196f/0x2be0 fs/namespace.c:3235 do_mount     fs/namespace.c:3248 [inline] __do_sys_mount fs/namespace.c:3456 [inline] __se_sys_mount+0x2f9/0x3b0     fs/namespace.c:3433 do_syscall_64+0x3f/0xb0 arch/x86/entry/common.c:47     entry_SYSCALL_64_after_hwframe+0x44/0xae The root cause is multi f2fs filesystem instances can race on     accessing global fsync_entry_slab pointer, result in use-after-free issue of slab cache, fixes to     init/destroy this slab cache only once during module init/destroy procedure to avoid this issue.
    (CVE-2021-47335)

Note that Nessus relies on the presence of the package as reported by the vendor.

ID	Name	Product	Family	Severity
273298	Unity Linux 20.1070a Security Update: kernel (UTSA-2025-988846)	Nessus	Unity Linux Local Security Checks	medium
268111	Unity Linux 20.1070e Security Update: kernel (UTSA-2025-986984)	Nessus	Unity Linux Local Security Checks	medium
239342	TencentOS Server 4: kernel (TSSA-2024:0981)	Nessus	Tencent Local Security Checks	high
238832	TencentOS Server 3: kernel (TSSA-2024:0719)	Nessus	Tencent Local Security Checks	high
238604	TencentOS Server 2: kernel (TSSA-2024:0720)	Nessus	Tencent Local Security Checks	high
224407	Linux Distros Unpatched Vulnerability : CVE-2021-47335	Nessus	Misc.	medium

Detections

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CVE-2021-47335

medium

Tenable Plugins

medium

medium

high

high

high

medium