CVE-2026-93794— smb/client: flush dirty data before punching a hole
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，已修复以下漏洞： smb/client：在打洞（punch a hole）之前刷新脏数据 在大规模缓冲区写入之后执行“打洞”操作，可能导致该范围被错误地报告为包含数据。可使用以下命令复现该问题： 在偏移量 1 MiB 处打孔 1 MiB 后，预期文件布局应为： 但实际中，整个文件都被报告为包含数据。 返回 EOF，而 返回 1M。 发生此问题的原因是：在打洞操作之后，跨越被打洞范围的脏页（folio）可能被写回，从而重新填充该空洞。 修复方法是：在失效页面缓存并发送 之前，先刷新并等待完成对
Possible ATT&CK Techniques 1 AI
T1070.002Affected Version Matrix 10
| Vendor | Product | Version Range | Status |
|---|---|---|---|
| Linux | Linux | 31742c5a331766bc7df6b0d525df00c6cd20d5a6< 216e469586057c29409e4ef8311d282388c6e251 |
affected |
31742c5a331766bc7df6b0d525df00c6cd20d5a6< 6c265aca08155e519a8f6f6071c59dff4f535f70 |
affected | ||
31742c5a331766bc7df6b0d525df00c6cd20d5a6< 39562a56cdb515f6635c3e7bfe6629439b18a169 |
affected | ||
31742c5a331766bc7df6b0d525df00c6cd20d5a6< d7d2adcd022baade5cab65ca492ce63421ce3a6e |
affected | ||
3.17 |
affected | ||
< 3.17 |
unaffected | ||
6.6.158≤ 6.6.* |
unaffected | ||
6.12.111≤ 6.12.* |
unaffected | ||
| … +2 more rows | |||
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I. Basic Information for CVE-2026-93794
Vulnerability Information
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Vulnerability Title
smb/client: flush dirty data before punching a hole
Source: CVE Program / CVE List V5
Vulnerability Description
In the Linux kernel, the following vulnerability has been resolved:
smb/client: flush dirty data before punching a hole
Punching a hole after a large buffered write may leave the range
reported as data. Reproduce it with:
xfs_io -f \
-c "pwrite -b 3m -S 0x61 0 3m" \
-c "fpunch 1m 1m" \
-c "seek -h 0" \
-c "seek -d 1m" \
/mnt/test/repro
Punching 1 MiB at offset 1 MiB should produce:
0 1 MiB 2 MiB 3 MiB
| DATA | HOLE | DATA | EOF
Instead, the entire file is reported as data. SEEK_HOLE(0) returns EOF,
and SEEK_DATA(1M) returns 1M.
This happens because a dirty folio spanning the punched range can be
written back after the punch and refill the hole.
Fix this by flushing and waiting for dirty data in the punched range
before invalidating the page cache and issuing FSCTL_SET_ZERO_DATA.
The xfstests generic/539 pass against Samba/ksmbd with this change.
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-2026-93794
| # | POC Description | Source Link | Shenlong Link |
|---|
AI-Generated POC
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No public POC found.
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Patches & Fixes for CVE-2026-93794 (4)
Same Patch Batch · Linux · 2026-09-24 · 234 CVEs total
| CVE-2026-93207 | 9.8 CRITICAL | SUNRPC: Zero rpc_gss_wire_cred at svcauth_gss_decode_credbody() entry |
| CVE-2026-97413 | 9.8 CRITICAL | RDMA/rtrs-srv: Fix integer underflow in process_read and process_write |
| CVE-2026-93228 | 9.1 CRITICAL | svcrdma: Reject Write/Reply chunks with segcount 0 |
| CVE-2026-93793 | 8.8 HIGH | wifi: iwlwifi: mvm: validate TX_CMD response layout |
| CVE-2026-93799 | 8.8 HIGH | wifi: iwlwifi: mvm: validate sta_id in BA window status notif |
| CVE-2026-93790 | 8.8 HIGH | wifi: iwlwifi: mvm: fix out-of-bounds tid_data access in BA notif |
| CVE-2026-97442 | 8.8 HIGH | wifi: ath11k: fix invalid data access in ath11k_dp_rx_h_undecap_nwifi |
| CVE-2026-93806 | 8.8 HIGH | wifi: cfg80211: validate assoc response length before status and IE access |
| CVE-2026-97509 | 8.8 HIGH | thunderbolt: Keep XDomain reference during the lifetime of a service |
| CVE-2026-97409 | 8.8 HIGH | nvme-fc: Do not cancel requests in io target before it is initialized |
| CVE-2026-93280 | 8.8 HIGH | greybus: audio: bound the topology section sizes against the fetched size |
| CVE-2026-93284 | 8.8 HIGH | drm/pagemap: dma-unmap pages before handling migration errors |
| CVE-2026-97451 | 8.4 HIGH | ACPICA: Fix integer overflow in acpi_ex_opcode_3A_1T_1R() (mid_op) |
| CVE-2026-97452 | 8.4 HIGH | ACPICA: Prevent adding invalid references |
| CVE-2026-97455 | 8.4 HIGH | ACPICA: Fix use-after-free in acpi_ds_terminate_control_method() |
| CVE-2026-97450 | 8.4 HIGH | ACPICA: validate handler object type in two places |
| CVE-2026-93827 | 8.4 HIGH | virtio-fs: avoid double-free on failed queue setup |
| CVE-2026-97433 | 8.2 HIGH | nvme: validate FDP configuration descriptor sizes |
| CVE-2026-93224 | 8.1 HIGH | svcrdma: Fix unmatched rn_unregister on failed accept |
| CVE-2026-93787 | 8.1 HIGH | smb: client: bound dirent name against end of SMB response in cifs_filldir |
Showing top 20 of 234 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-2026-93794
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