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CVE-2026-98253— RDMA/ucma: Serialize join and leave on copy_to_user failure

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，已解决以下漏洞： RDMA/ucma：在 copy_to_user 失败时序列化加入（join）和离开（leave）操作 会调度 RoCE 工作项，该工作项稍后通过 读取 ，然后通过 将该 CMA 多播条目添加到 的头部。而 仅根据 进行匹配，并销毁第一个匹配到的条目。 此前， 在加入成功后会释放 ，仅在 失败时才重新获取该互斥锁。因此，针对同一地址的两个并发 调用可能在第一个线程执行离开操作之前插入第二个 CMA 条目。随后的离开操作会取消较新的工作项，但较旧的 Worker 仍会解引用已

CVSS 7.8 · High EPSS 0.14% · P3

Possible ATT&CK Techniques 1 AI

T1190 · Exploit Public-Facing Application

Affected Version Matrix 21

VendorProduct Version RangeStatus
Linux Linux 60d613b39e8d0c9f3b526e9c96445422b4562d76< 29b9ed83d8bfab5c6e11fcbf1aa836aa4ae26cb9 affected
fe454dc31e84f8c14cb8942fcb61666c9f40745b< 52172e11bd074ccaded21740ffeb67123f01dd00 affected
fe454dc31e84f8c14cb8942fcb61666c9f40745b< 01e29d0d78a8f66f221625720a04939eef5ec1f6 affected
fe454dc31e84f8c14cb8942fcb61666c9f40745b< ae805d204cf1f15b87d1bf3529b4c649f3519420 affected
fe454dc31e84f8c14cb8942fcb61666c9f40745b< 43c4e24bd10370fc976f6220518049ce71419399 affected
fe454dc31e84f8c14cb8942fcb61666c9f40745b< 01cbdb724c584d7772fd25af2e4dfdf8527ce0d5 affected
fe454dc31e84f8c14cb8942fcb61666c9f40745b< 83610ee5e498fa5bfcb80031d2b959baea276bf6 affected
fe454dc31e84f8c14cb8942fcb61666c9f40745b< 662ade4de9ff5eceb0820a9f8e9fac70ba6a815b affected
… +13 more rows
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I. Basic Information for CVE-2026-98253

Vulnerability Information
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Vulnerability Title
RDMA/ucma: Serialize join and leave on copy_to_user failure
Source: CVE Program / CVE List V5
Vulnerability Description
In the Linux kernel, the following vulnerability has been resolved: RDMA/ucma: Serialize join and leave on copy_to_user failure rdma_join_multicast() queues RoCE work that later reads the ucma_multicast through event->param.ud.private_data, then list_add()s the CMA multicast at the head of id_priv->mc_list. rdma_leave_multicast() matches only by sockaddr and destroys the first hit. ucma_process_join() used to drop ctx->mutex after a successful join and retake it only if copy_to_user() failed. Two concurrent JOIN_MCAST calls with the same address can therefore insert a second CMA entry before the first thread's leave. leave then cancels the newer work and the older worker still dereferences the ucma_multicast that the first thread frees. Keep ctx->mutex held from rdma_join_multicast() through copy_to_user() and, on -EFAULT, through rdma_leave_multicast() so leave cannot miss this join. Do not leave if join itself failed: that path never published this address on mc_list, and a leave-by-addr would destroy an earlier successful join.
Source: CVE Program / CVE List V5
CVSS Information
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Source: CVE Program / CVE List V5
Vulnerability Type
N/A
Source: CVE Program / CVE List V5

Affected Products

Vendor Product Affected Versions CPE Subscribe
Linux Linux 60d613b39e8d0c9f3b526e9c96445422b4562d76 ~ 29b9ed83d8bfab5c6e11fcbf1aa836aa4ae26cb9 -
Linux Linux 5.12 -

II. Public POCs for CVE-2026-98253

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III. Intelligence Information for CVE-2026-98253

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Patches & Fixes for CVE-2026-98253 (8)

Same Patch Batch · Linux · 2026-10-06 · 208 CVEs total

CVE-2026-98323 9.8 CRITICAL RDMA/siw: Bound fragmented header copies by the remaining length
CVE-2026-98365 9.8 CRITICAL RDMA/rxe: Fix integer overflow in mr_check_range() leading to OOB access
CVE-2026-98282 8.8 HIGH powerpc/iommu: Fix the overflow validation in iommu_tce_check_ioba
CVE-2026-98283 8.8 HIGH KVM: PPC: Book3S HV: fix use-after-free in kvmhv_emulate_tlbie_all_lpid()
CVE-2026-98339 8.8 HIGH wifi: cfg80211: don't filter by BSS type when removing stale entries
CVE-2026-98171 8.8 HIGH smb: client: fix next_buffer UAF and NextCommand bounds in compound PDUs
CVE-2026-98261 8.1 HIGH cifs: Fix server use-after-free in cifs_chan_skip_or_disable()
CVE-2026-98357 8.1 HIGH IB/isert: wait for deferred control PDU completions before releasing the connection
CVE-2026-98239 8.1 HIGH net: lan743x: fix RX checksum use-after-free
CVE-2026-98341 7.8 HIGH wifi: cfg80211: don't free driver-owned scan requests
CVE-2026-98324 7.8 HIGH dmaengine: pxa: fix double counting of the hw descriptors
CVE-2026-98320 7.8 HIGH netfilter: flowtable: hold reference on ct until flow is released
CVE-2026-98228 7.8 HIGH mips: select CONFIG_WEAK_REORDERING_BEYOND_LLSC from CONFIG_EYEQ
CVE-2026-98229 7.8 HIGH xfrm: save input state data before secpath resets
CVE-2026-98318 7.8 HIGH smb: client: validate absolute native symlink targets before NT fixups
CVE-2026-98315 7.8 HIGH ntfs: protect runlist updates with the runlist lock
CVE-2026-98276 7.8 HIGH net: lock the socket in sock_gettstamp()
CVE-2026-98258 7.8 HIGH posix-cpu-timers: Prevent freeing a timer which is queued on the expiry list
CVE-2026-98260 7.8 HIGH exec: Cleanup POSIX timers right after de_thread()
CVE-2026-98256 7.8 HIGH signal: Prevent exec() race

Showing top 20 of 208 CVEs. View all on vendor page &rarr; →

IV. Related Vulnerabilities

Same product: Linux
Same vendor: Linux

V. Comments for CVE-2026-98253

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