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

Goal: 1000 CNY · Raised: 1359 CNY

100%
Buy Us a Coffee

CVE-2026-23355— ata: libata: cancel pending work after clearing deferred_qc

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.

Linux kernel是美国Linux基金会的开源操作系统Linux所使用的内核。 Linux kernel存在安全漏洞，该漏洞源于清除deferred_qc后未取消待处理工作，可能导致警告触发。

AI Predicted 4.3 Difficulty: Theoretical EPSS 0.12% · P2

Affected Version Matrix 8

VendorProduct Version RangeStatus
Linux Linux ce22aaed011206fed9cbd8c9c2d44718607f31ee< 0d12453818c35e1ded84633152c6b05002ae48b9 affected
888cd7e40adb2ef4af1b4d3b6e2e83ad409ae8c2< 6c5e8f16b5e8e614e829aaf38619bdd79107bb0a affected
5d61a38a60e62750526d94663b69b7ac5c7f07a5< 58e658763ba2aa9168d8516b98a6314d7461a53e affected
0ea84089dbf62a92dc7889c79e6b18fc89260808< aac9b27f7c1f2b2cf7f50a9ca633ecbbcaf22af9 affected
33abac5b5a5303ba2c66d89e063a806033be07fc affected
21e0d7a15a789e99be89231dae25cb6ffc482a7c affected
6.18.14< 6.18.18 affected
6.19.4< 6.19.7 affected
Get alerts for future matching vulnerabilities Log in to subscribe

I. Basic Information for CVE-2026-23355

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Although we use advanced large model technology, its output may still contain inaccurate or outdated information.Shenlong tries to ensure data accuracy, but please verify and judge based on the actual situation.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
ata: libata: cancel pending work after clearing deferred_qc
Source: CVE Program / CVE List V5
Vulnerability Description
In the Linux kernel, the following vulnerability has been resolved: ata: libata: cancel pending work after clearing deferred_qc Syzbot reported a WARN_ON() in ata_scsi_deferred_qc_work(), caused by ap->ops->qc_defer() returning non-zero before issuing the deferred qc. ata_scsi_schedule_deferred_qc() is called during each command completion. This function will check if there is a deferred QC, and if ap->ops->qc_defer() returns zero, meaning that it is possible to queue the deferred qc at this time (without being deferred), then it will queue the work which will issue the deferred qc. Once the work get to run, which can potentially be a very long time after the work was scheduled, there is a WARN_ON() if ap->ops->qc_defer() returns non-zero. While we hold the ap->lock both when assigning and clearing deferred_qc, and the work itself holds the ap->lock, the code currently does not cancel the work after clearing the deferred qc. This means that the following scenario can happen: 1) One or several NCQ commands are queued. 2) A non-NCQ command is queued, gets stored in ap->deferred_qc. 3) Last NCQ command gets completed, work is queued to issue the deferred qc. 4) Timeout or error happens, ap->deferred_qc is cleared. The queued work is currently NOT canceled. 5) Port is reset. 6) One or several NCQ commands are queued. 7) A non-NCQ command is queued, gets stored in ap->deferred_qc. 8) Work is finally run. Yet at this time, there is still NCQ commands in flight. The work in 8) really belongs to the non-NCQ command in 2), not to the non-NCQ command in 7). The reason why the work is executed when it is not supposed to, is because it was never canceled when ap->deferred_qc was cleared in 4). Thus, ensure that we always cancel the work after clearing ap->deferred_qc. Another potential fix would have been to let ata_scsi_deferred_qc_work() do nothing if ap->ops->qc_defer() returns non-zero. However, canceling the work when clearing ap->deferred_qc seems slightly more logical, as we hold the ap->lock when clearing ap->deferred_qc, so we know that the work cannot be holding the lock. (The function could be waiting for the lock, but that is okay since it will do nothing if ap->deferred_qc is not set.)
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
Vulnerability Title
Linux kernel 安全漏洞
Source: CNNVD (China National Vulnerability Database)
Vulnerability Description
Linux kernel是美国Linux基金会的开源操作系统Linux所使用的内核。 Linux kernel存在安全漏洞，该漏洞源于清除deferred_qc后未取消待处理工作，可能导致警告触发。
Source: CNNVD (China National Vulnerability Database)
CVSS Information
N/A
Source: CNNVD (China National Vulnerability Database)
Vulnerability Type
N/A
Source: CNNVD (China National Vulnerability Database)

Affected Products

Vendor Product Affected Versions CPE Subscribe
Linux Linux ce22aaed011206fed9cbd8c9c2d44718607f31ee ~ 0d12453818c35e1ded84633152c6b05002ae48b9 -
Linux Linux 6.18.14 ~ 6.18.18 -

II. Public POCs for CVE-2026-23355

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

No public POC found.

Login to generate AI POC

III. Intelligence Information for CVE-2026-23355

请登录查看更多情报信息。

Patches & Fixes for CVE-2026-23355 (4)

Same Patch Batch · Linux · 2026-03-25 · 116 CVEs total

CVE-2026-23395 8.8 HIGH Bluetooth: L2CAP: Fix accepting multiple L2CAP_ECRED_CONN_REQ
CVE-2026-31788 8.2 HIGH xen/privcmd: restrict usage in unprivileged domU
CVE-2026-23340 7.8 HIGH net: sched: avoid qdisc_reset_all_tx_gt() vs dequeue race for lockless qdiscs
CVE-2026-23336 7.8 HIGH wifi: cfg80211: cancel rfkill_block work in wiphy_unregister()
CVE-2026-23350 7.8 HIGH drm/xe/queue: Call fini on exec queue creation fail
CVE-2026-23351 7.8 HIGH netfilter: nft_set_pipapo: split gc into unlink and reclaim phase
CVE-2026-23317 7.8 HIGH drm/vmwgfx: Return the correct value in vmw_translate_ptr functions
CVE-2026-23306 7.8 HIGH scsi: pm8001: Fix use-after-free in pm8001_queue_command()
CVE-2026-23372 7.8 HIGH nfc: rawsock: cancel tx_work before socket teardown
CVE-2026-23378 7.8 HIGH net/sched: act_ife: Fix metalist update behavior
CVE-2026-23383 7.8 HIGH bpf, arm64: Force 8-byte alignment for JIT buffer to prevent atomic tearing
CVE-2026-23391 7.8 HIGH netfilter: xt_CT: drop pending enqueued packets on template removal
CVE-2026-23392 7.8 HIGH netfilter: nf_tables: release flowtable after rcu grace period on error
CVE-2026-23393 7.8 HIGH bridge: cfm: Fix race condition in peer_mep deletion
CVE-2026-23280 7.8 HIGH accel/amdxdna: Prevent ubuf size overflow
CVE-2026-23288 7.8 HIGH accel/amdxdna: Fix out-of-bounds memset in command slot handling
CVE-2026-23364 7.4 HIGH ksmbd: Compare MACs in constant time
CVE-2026-23294 7.0 HIGH bpf: Fix race in devmap on PREEMPT_RT
CVE-2026-23354 x86/fred: Correct speculative safety in fred_extint()
CVE-2026-23356 drbd: fix "LOGIC BUG" in drbd_al_begin_io_nonblock()

Showing top 20 of 116 CVEs. View all on vendor page &rarr; →

IV. Related Vulnerabilities

Same product: Linux
Same vendor: Linux

V. Comments for CVE-2026-23355

No comments yet

Leave a comment