CVE-2026-97902— fs: don't return -EINVAL for successful nested thaw
Quick assessment
Affected
Linux Linux
Exploitation
No confirmed in-the-wild exploitation; assess based on exposure
Recommended action
Check the vendor advisory and references for a fixed version. If immediate upgrade is impossible, restrict exposure and increase monitoring.
在 Linux 内核中，以下漏洞已得到修复： fs: 不要在成功的嵌套解冻时返回 -EINVAL 提交 （"fs: handle freezing from multiple devices"）用每个持有者的计数器替换了 位图，以支持嵌套冻结。在位图版本中，当释放共享持有者且仍有其他持有者存在时，解冻操作返回 0。在重构之后， 通过 减少了冻结引用计数，但由于仍有其他冻结者存在，它却返回 ，这误导了调用方：解冻实际上已成功，超级块仅因剩余持有者而保持冻结状态。 此问题破坏了由块设备（bdev）发起的冻结流程。当文件
Possible ATT&CK Techniques 1 AI
T1562.008Affected Version Matrix 10
| Vendor | Product | Version Range | Status |
|---|---|---|---|
| Linux | Linux | 7366f8b6fc6aa21c4199cb5d337b023df69745b0< 111339816138f042a59778322f941edc26903484 |
affected |
7366f8b6fc6aa21c4199cb5d337b023df69745b0< 76e478499913dc1f368aebe85b28b7d1265985ff |
affected | ||
7366f8b6fc6aa21c4199cb5d337b023df69745b0< ff2a694f6613d54ebd77ba72583d4d94446f55bd |
affected | ||
7366f8b6fc6aa21c4199cb5d337b023df69745b0< fe967191e5851ea79818c5fe4e781c3882139218 |
affected | ||
6.8 |
affected | ||
< 6.8 |
unaffected | ||
6.12.111≤ 6.12.* |
unaffected | ||
6.18.53≤ 6.18.* |
unaffected | ||
| … +2 more rows | |||
Get alerts for future matching vulnerabilities
Log in to subscribe
I. Basic Information for CVE-2026-97902
Vulnerability Information
Have questions about the vulnerability? See if Shenlong's analysis helps!
View Shenlong Deep Dive ↗
Although we use advanced large model technology, its output may still contain inaccurate or outdated information.Shenlong tries to ensure data accuracy, but please verify and judge based on the actual situation.
Vulnerability Title
fs: don't return -EINVAL for successful nested thaw
Source: CVE Program / CVE List V5
Vulnerability Description
In the Linux kernel, the following vulnerability has been resolved:
fs: don't return -EINVAL for successful nested thaw
Commit 7366f8b6fc6a ("fs: handle freezing from multiple devices")
replaced the freeze_holders bitmask with per-holder counters to allow
nested freezes. In the bitmask version, a thaw that released a shared
hold while another holder remained returned 0. Since the rework,
thaw_super_locked() drops the freeze reference via freeze_dec() but
then returns -EINVAL when other freezers remain, misinforming the
caller: the thaw did succeed, the superblock just stays frozen for the
remaining holders.
This breaks bdev-initiated freezing. When a filesystem is frozen with
FIFREEZE and additionally frozen via bdev_freeze() -- which nests by
design, see fs_bdev_freeze() -- the subsequent bdev_thaw() receives
-EINVAL from the holder op although its freeze reference was dropped,
and therefore keeps bd_fsfreeze_count elevated. Then device-mapper's
unlock_fs() ignores bdev_thaw()'s return value, so nothing rebalances
the count. After the user's FITHAW and umount, the block device can
never be mounted again:
dm-1: Can't mount, blockdev is frozen
There is no way for userspace to drop the leaked count; only
destroying the block device (or a reboot) recovers the device.
Reproducer (any kernel since v6.8):
dmsetup create dut --table "0 $(blockdev --getsz "$DEV") linear $DEV 0"
mkfs.ext4 /dev/mapper/dut
mount /dev/mapper/dut /mnt
fsfreeze --freeze /mnt # freeze_ucount == 1
dmsetup suspend dut # bd_fsfreeze_count == 1, ucount == 2
dmsetup resume dut # ucount 2 -> 1, but thaw_super()
# returns -EINVAL, so bdev_thaw()
# keeps bd_fsfreeze_count at 1
fsfreeze --unfreeze /mnt # filesystem thaws fine
umount /mnt
mount /dev/mapper/dut /mnt # EBUSY, forever
The same happens with fsfreeze held across an LVM snapshot of the
origin volume.
fs_bdev_thaw()'s documentation already describes the intended
semantics: "If this function returns zero it doesn't mean that the
filesystem is unfrozen as it may have been frozen multiple times".
Restore them by returning 0 when a nested thaw drops its hold while
other freezers remain. Thawing without holding a freeze still fails
with -EINVAL as may_unfreeze() rejects that case before the reference
count is touched.
Source: CVE Program / CVE List V5
CVSS Information
N/A
Source: CVE Program / CVE List V5
Vulnerability Type
N/A
Source: CVE Program / CVE List V5
Affected Products
II. Public POCs for CVE-2026-97902
| # | POC Description | Source Link | Shenlong Link |
|---|
AI-Generated POC
Premium
No public POC found.
Login to generate AI POCIII. Intelligence Information for CVE-2026-97902
请登录查看更多情报信息。
Patches & Fixes for CVE-2026-97902 (4)
Same Patch Batch · Linux · 2026-09-25 · 372 CVEs total
| CVE-2026-100075 | 9.8 CRITICAL | RDMA/srpt: Fix srpt_alloc_rw_ctxs() unwind counters |
| CVE-2026-97555 | 8.8 HIGH | smb: client: fix heap overflow in DACL owner/group rewrite |
| CVE-2026-97957 | 8.8 HIGH | net: hinic: fix mailbox segment buffer overflow |
| CVE-2026-97527 | 8.8 HIGH | scsi: qla2xxx: Serialize NVMe unsol ctx list with a per-fcport lock |
| CVE-2026-97528 | 8.8 HIGH | scsi: qla2xxx: Unlink NVMe unsol ctx before freeing on LS reject error |
| CVE-2026-98115 | 8.8 HIGH | ksmbd: safely drain sessions during logoff |
| CVE-2026-97525 | 8.2 HIGH | x86/mm/pat: Allocate split page tables as kernel page tables |
| CVE-2026-98069 | 8.1 HIGH | net/rds: acquire the fastpath locks in rds_conn_shutdown() |
| CVE-2026-97573 | 8.1 HIGH | bnxt_en: Handle buffer allocation failure in bnxt_rx_ring_reset() |
| CVE-2026-97570 | 8.1 HIGH | bnxt_en: Bound SW TPA IDs to prevent crashes |
| CVE-2026-98130 | 8.1 HIGH | sctp: fix a TOCTOU race in SCTP_CMD_TIMER_START |
| CVE-2026-98070 | 8.1 HIGH | net/rds: acquire RDS_IN_XMIT in rds_tcp_reset_callbacks() |
| CVE-2026-98122 | 7.8 HIGH | vxlan: mdb: Fix use-after-free in vxlan_mdb_remote_src_del() |
| CVE-2026-97575 | 7.8 HIGH | media: v4l2-ctrls: validate AV1 tile counts |
| CVE-2026-97576 | 7.8 HIGH | media: v4l2-ctrls: validate HEVC tile counts |
| CVE-2026-98112 | 7.8 HIGH | ksmbd: fix listener task lifetime on netdev events |
| CVE-2026-98002 | 7.8 HIGH | iommu/amd: Fix ineffective error check in nested domain allocation |
| CVE-2026-98116 | 7.8 HIGH | ALSA: pcm: Serialize PCM mmap with buffer reallocation to fix page UAF |
| CVE-2026-97580 | 7.8 HIGH | media: rkvdec: bound HEVC tile loops and PPS id to the array capacity |
| CVE-2026-97940 | 7.8 HIGH | ipv6: fix fib6 walker UAF on seq stop |
Showing top 20 of 372 CVEs. View all on vendor page → →
IV. Related Vulnerabilities
Same product: Linux
-
CVE-2026-98384
bpf: Fix out-of-bounds read of sk_protocol in bpf_sock_destr -
CVE-2026-98383
bpf: Disallow bpf_skb_pull_data() for LWT_SEG6LOCAL -
CVE-2026-98382
bpf: Reject dev-bound-only programs on other devices -
CVE-2026-98381
veth: manage XDP program pointers during channel resize -
CVE-2026-98380
net/sched: reject IDR error pointers when deleting actions
Same vendor: Linux
-
CVE-2026-98384
bpf: Fix out-of-bounds read of sk_protocol in bpf_sock_destr -
CVE-2026-98383
bpf: Disallow bpf_skb_pull_data() for LWT_SEG6LOCAL -
CVE-2026-98382
bpf: Reject dev-bound-only programs on other devices -
CVE-2026-98381
veth: manage XDP program pointers during channel resize -
CVE-2026-98380
net/sched: reject IDR error pointers when deleting actions
V. Comments for CVE-2026-97902
No comments yet