CVE-2026-90125— smb: client: fix request buffer leak in smb2_new_read_req()
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： smb: 客户端：修复 smb2_new_read_req() 中的请求缓冲区泄漏 使用 分配请求缓冲区，但直到函数末尾才通过 将其发布给调用者。而在两者之间存在两个错误返回路径： 在这两种情况下，缓冲区既未被释放，也未被交还给调用者，因此发生了泄漏。调用者无法在之后进行清理：当返回非零值时， 会执行 ，从而跳过了 标签处的 调用；而且在该时刻， 尚未被赋值，因此无论如何都无法释放。 写路径从未出现过此问题。 是内联注册内存区域，并在失败时跳转到其释放标签，而不是直接返
Possible ATT&CK Techniques 1 AI
T1581Affected Version Matrix 12
| Vendor | Product | Version Range | Status |
|---|---|---|---|
| Linux | Linux | bd3dcc6a22a9186ed78da51ce09e889803552189< 58066940076b90c16e821fd6f9767cd979cbdb5e |
affected |
bd3dcc6a22a9186ed78da51ce09e889803552189< 12092ed28434bf41e08d41e3c5269eb6b337fc02 |
affected | ||
bd3dcc6a22a9186ed78da51ce09e889803552189< 442c5f1358ced0d4e716778ac06f1e323a7e4f21 |
affected | ||
bd3dcc6a22a9186ed78da51ce09e889803552189< 73f6bdb0380486ab37fe12cd74de20abfaf5d3ae |
affected | ||
bd3dcc6a22a9186ed78da51ce09e889803552189< deb6468f4164640e4dc875f008aa449cf55987a5 |
affected | ||
4.16 |
affected | ||
< 4.16 |
unaffected | ||
6.6.157≤ 6.6.* |
unaffected | ||
| … +4 more rows | |||
Get alerts for future matching vulnerabilities
Log in to subscribe
I. Basic Information for CVE-2026-90125
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Although we use advanced large model technology, its output may still contain inaccurate or outdated information.Shenlong tries to ensure data accuracy, but please verify and judge based on the actual situation.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
smb: client: fix request buffer leak in smb2_new_read_req()
Source: CVE Program / CVE List V5
Vulnerability Description
In the Linux kernel, the following vulnerability has been resolved:
smb: client: fix request buffer leak in smb2_new_read_req()
smb2_new_read_req() allocates the request buffer with
smb2_plain_req_init() but only publishes it to the caller with
*buf = req at the very end of the function. Two error returns sit in
between:
rc = smb2_plain_req_init(SMB2_READ, io_parms->tcon, server,
(void **) &req, total_len);
if (rc)
return rc;
if (server == NULL)
return -ECONNABORTED;
[...]
rdata->mr = smbd_register_mr(server->smbd_conn,
&rdata->subreq.io_iter,
true, need_invalidate);
if (!rdata->mr)
return -EAGAIN;
On either of them the buffer is neither released nor handed back, so
it is leaked. The caller cannot clean up after it: smb2_async_readv()
does 'goto out' on a non-zero return, which skips the
cifs_small_buf_release(buf) at async_readv_out, and buf has not been
assigned at that point in any case.
The write path has never had this problem. smb2_async_writev()
registers the memory region inline and jumps to its release label
instead of returning:
wdata->mr = smbd_register_mr(...);
if (!wdata->mr) {
rc = -EAGAIN;
goto async_writev_out;
}
Commit b7972092199f ("cifs: smbd: Retry on memory registration
failure") changed both sides from -ENOBUFS to -EAGAIN in a single
patch, which puts the two shapes next to each other.
Only the -EAGAIN return is reachable in practice, because
smb2_plain_req_init() calls smb2_reconnect() first and that already
fails with -EIO when server is NULL, before anything is allocated.
Both returns are given the same treatment here rather than leaving
one of them correct only by accident.
Because -EAGAIN is a replayable error, the failure also reaches the
retry block at the end of smb2_async_readv(), which marks the
subrequest NETFS_SREQ_NEED_RETRY, so a failing registration can be
retried rather than ending the I/O, and every attempt that reaches it
leaks another buffer. smb2_should_replay() short-circuits on
tcon->retry, so on a hard mount the attempt count is not bounded by
the retrans setting.
Only the asynchronous read path is affected. The synchronous
SMB2_read() caller passes rdata == NULL and the memory registration
block is guarded on rdata.
The memory registration failure path was pointed out by the Sashiko
AI reviewer while it was reviewing an unrelated patch to
smb2_async_readv().
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-2026-90125
| # | POC Description | Source Link | Shenlong Link |
|---|
AI-Generated POC
Premium
No public POC found.
Login to generate AI POCIII. Intelligence Information for CVE-2026-90125
请登录查看更多情报信息。
Patches & Fixes for CVE-2026-90125 (5)
Same Patch Batch · Linux · 2026-09-17 · 600 CVEs total
| CVE-2026-90235 | 9.8 CRITICAL | sunrpc: xprtsock: annotate shared socket callbacks with READ_ONCE/WRITE_ONCE |
| CVE-2026-90104 | 9.8 CRITICAL | NFSv4.1: zero referring call lists before decoding |
| CVE-2026-92489 | 9.8 CRITICAL | xfrm: Fix skb double-free in xfrm_dev_direct_output() |
| CVE-2026-90173 | 9.8 CRITICAL | smb: smbdirect: free completion queues with ib_free_cq() |
| CVE-2026-90151 | 9.8 CRITICAL | NFSv4: remove callback IDR entry on client allocation failure |
| CVE-2026-90110 | 9.4 CRITICAL | inetpeer: randomize RB-tree node comparison using SipHash |
| CVE-2026-90230 | 9.1 CRITICAL | nvmet: fix heap out-of-bounds read in nvmet_auth_negotiate() |
| CVE-2026-90414 | 9.1 CRITICAL | IB/isert: reject PDUs declaring more data than was received |
| CVE-2026-90413 | 9.1 CRITICAL | IB/isert: reject login PDUs declaring more data than was received |
| CVE-2026-93189 | 8.8 HIGH | HID: core: quiesce input in hid_hw_stop() to prevent use-after-free |
| CVE-2026-90256 | 8.8 HIGH | Bluetooth: L2CAP: use proto_lock for l2cap_data to fix l2cap_disconn_ind |
| CVE-2026-93042 | 8.8 HIGH | dmaengine: dw-edma: Terminate all descriptors without callbacks |
| CVE-2026-90286 | 8.8 HIGH | drm/amdgpu/gfx6: Use PFP on the compute queues too |
| CVE-2026-90255 | 8.8 HIGH | Bluetooth: hci_conn: fix the SCO setup context lifetime |
| CVE-2026-90425 | 8.8 HIGH | iommu/tegra241-cmdqv: Require exactly one Stream ID for a vSID |
| CVE-2026-90329 | 8.8 HIGH | HID: synchronize input before cleaning up a failed probe |
| CVE-2026-90162 | 8.8 HIGH | ksmbd: defer publishing granted locks to prevent UAF/double-free race |
| CVE-2026-90240 | 8.8 HIGH | iommu/vt-d: Flush context cache with correct SID when tearing down aliases |
| CVE-2026-90367 | 8.8 HIGH | wifi: mt76: mt7996: hold dev->mt76.mutex while disabling tx worker in SER |
| CVE-2026-90371 | 8.8 HIGH | wifi: mt76: fix RXDMAD_C buffer recycling race |
Showing top 20 of 600 CVEs. View all on vendor page → →
IV. Related Vulnerabilities
Same product: Linux
-
CVE-2026-98385
sched/cache: Decouple sched_cache_group from mm to fix UAF -
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
Same vendor: Linux
-
CVE-2026-98385
sched/cache: Decouple sched_cache_group from mm to fix UAF -
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
V. Comments for CVE-2026-90125
No comments yet