Goal Reached Thanks to every supporter — we hit 100%!

Goal: 1000 CNY · Raised: 1359 CNY

100%
Buy Us a Coffee

CVE-2026-93168— dmaengine: xilinx_dma: Fix CPU stall in xilinx_dma_poll_timeout

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： dmaengine: xilinx_dma: 修复 xilinx_dma_poll_timeout 中的 CPU 停顿 问题描述： 当前在调用 时，若设置 且条件永远无法满足，CPU 会进行长时间的忙等待（busy-wait）。由于 对实际经过时间（wall clock time）存在巨大低估，导致超时触发时产生显著的延迟，从而引起 CPU 停顿。 根本原因： 提交 （"iopoll: Do not use timekeeping in read_poll_timeout_

AI Predicted 5.3 Difficulty: Moderate EPSS 0.15% · P4

Possible ATT&CK Techniques 1 AI

T1490 · Inhibit System Recovery

Affected Version Matrix 6

VendorProduct Version RangeStatus
Linux Linux 9495f2648287029fb5545c34a0fa318426ebe84c< 8b5654d317277e6e505c23f8fa7e415237fefc7f affected
9495f2648287029fb5545c34a0fa318426ebe84c< aa99c4d1d63bbc26a5fc4c667d89b2595743c19d affected
4.6 affected
< 4.6 unaffected
7.2.6≤ 7.2.* unaffected
7.3-rc1≤ * unaffected
Get alerts for future matching vulnerabilities Log in to subscribe

I. Basic Information for CVE-2026-93168

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Although we use advanced large model technology, its output may still contain inaccurate or outdated information.Shenlong tries to ensure data accuracy, but please verify and judge based on the actual situation.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
dmaengine: xilinx_dma: Fix CPU stall in xilinx_dma_poll_timeout
Source: CVE Program / CVE List V5
Vulnerability Description
In the Linux kernel, the following vulnerability has been resolved: dmaengine: xilinx_dma: Fix CPU stall in xilinx_dma_poll_timeout Currently when calling xilinx_dma_poll_timeout with delay_us=0 and a condition that is never fulfilled, the CPU busy-waits for prolonged time and the timeout triggers only with a massive delay causing a CPU stall. This happens due to a huge underestimation of wall clock time in poll_timeout_us_atomic. Commit 7349a69cf312 ("iopoll: Do not use timekeeping in read_poll_timeout_atomic()") changed the behavior to no longer use ktime_get at the expense of underestimation of wall clock time which appears to be very large for delay_us=0. Instead of timing out after approximately XILINX_DMA_LOOP_COUNT microseconds, the timeout takes XILINX_DMA_LOOP_COUNT * 1000 * (time that the overhead of the for loop in poll_timeout_us_atomic takes) which is in the range of several minutes for XILINX_DMA_LOOP_COUNT=1000000. Fix this by using a non-zero value for delay_us. Use delay_us=10 to keep the delay in the hot path of starting DMA transfers minimal but still avoid CPU stalls in case of unexpected hardware failures. One-off measurement with delay_us=0 causes the cpu to busy wait around 7 minutes in the timeout case. After applying this patch with delay_us=10 the measured timeout was 1053428 microseconds which is roughly equivalent to the expected 1000000 microseconds specified in XILINX_DMA_LOOP_COUNT. Add a constant XILINX_DMA_POLL_DELAY_US for delay_us value.
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

Vendor Product Affected Versions CPE Subscribe
Linux Linux 9495f2648287029fb5545c34a0fa318426ebe84c ~ 8b5654d317277e6e505c23f8fa7e415237fefc7f -
Linux Linux 4.6 -

II. Public POCs for CVE-2026-93168

# POC Description Source Link Shenlong Link
AI-Generated POC Premium

No public POC found.

Login to generate AI POC

III. Intelligence Information for CVE-2026-93168

请登录查看更多情报信息。

Patches & Fixes for CVE-2026-93168 (2)

Same Patch Batch · Linux · 2026-09-17 · 600 CVEs total

CVE-2026-92489 9.8 CRITICAL xfrm: Fix skb double-free in xfrm_dev_direct_output()
CVE-2026-90151 9.8 CRITICAL NFSv4: remove callback IDR entry on client allocation failure
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-2026-90173 9.8 CRITICAL smb: smbdirect: free completion queues with ib_free_cq()
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-2026-90413 9.1 CRITICAL IB/isert: reject login PDUs declaring more data than was received
CVE-2026-90414 9.1 CRITICAL IB/isert: reject PDUs declaring more data than was received
CVE-2026-90425 8.8 HIGH iommu/tegra241-cmdqv: Require exactly one Stream ID for a vSID
CVE-2026-93042 8.8 HIGH dmaengine: dw-edma: Terminate all descriptors without callbacks
CVE-2026-93189 8.8 HIGH HID: core: quiesce input in hid_hw_stop() to prevent use-after-free
CVE-2026-90329 8.8 HIGH HID: synchronize input before cleaning up a failed probe
CVE-2026-90357 8.8 HIGH wifi: mt76: mt7915: unlink TWT flow if the MCU rejects the agreement
CVE-2026-90256 8.8 HIGH Bluetooth: L2CAP: use proto_lock for l2cap_data to fix l2cap_disconn_ind
CVE-2026-90367 8.8 HIGH wifi: mt76: mt7996: hold dev->mt76.mutex while disabling tx worker in SER
CVE-2026-90381 8.8 HIGH wifi: mt76: fix handling channel context with different bands in mt76_switch_vif_chanctx()
CVE-2026-90379 8.8 HIGH wifi: mt76: mt7921: Add PCIe AER handler support to prevent system crash
CVE-2026-90380 8.8 HIGH wifi: mt76: mt792x: fix use-after-free in mt76_rx_poll_complete
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 &rarr; →

IV. Related Vulnerabilities

Same product: Linux
Same vendor: Linux

V. Comments for CVE-2026-93168

No comments yet

Leave a comment