iio: event: Fix event FIFO reset race
In the Linux kernel, the following vulnerability has been resolved: iio: event: Fix event FIFO reset race `iio_event_getfd()` creates the event file descriptor with `anon_inode_getfd()`, which allocates a new fd, creates the anonymous file and installs it in the process fd table before returning to the caller. The IIO code resets the event FIFO after `anon_inode_getfd()` has returned, but before `IIO_GET_EVENT_FD_IOCTL` has copied the fd number to userspace. But since fd tables are shared between threads, another thread can guess the newly allocated fd number and issue a `read()` on it as soon as the fd has been installed. This means the `kfifo_to_user()` in `iio_event_chrdev_read()` can run in parallel with the `kfifo_reset_out()` in `iio_event_getfd()`. The kfifo documentation says that `kfifo_reset_out()` is only safe when it is called from the reader thread and there is only one concurrent reader. Otherwise it is dangerous and must be handled in the same way as `kfifo_reset()`. If that happens, `kfifo_to_user()` can advance the FIFO `out` index based on state from before the reset, after the reset has already moved the `out` index to the current `in` index. That can leave the FIFO with an `out` index past the `in` index. A later `read()` can then see an underflowed FIFO length and copy more data than the event FIFO buffer contains. This can result in an out-of-bounds read and leak adjacent kernel memory to userspace. Move the FIFO reset before `anon_inode_getfd()`. At that point the event fd is marked busy, but the new fd has not been installed yet, so userspace cannot access it while the FIFO is reset.
- Published
- Jul 25, 2026
- Updated
- Aug 17, 2026
- EPSS
- 0.2% · 5th percentile
- CWE
- —
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Report tools
Action score
28
Monitor
Low priority for now.
- CVSS
- 28 / 40 · 7.1 / 10
- CISA KEV
- 0 / 30 · Not listed
- EPSS
- 0 / 30 · 0.2%
CNA vs NVD score
- NVD
- —
- CNA · Linux
- 7.1
- NVD has not scored this yet; the score shown is the CNA’s.
The score given by the assigning authority versus NVD’s independent score. A gap means the severity is contested.
Noroxi analysis
No Noroxi analysis for this record yet
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We use this product, ask for helpAffected systems
—
Versions reported by the vendor
Affected version ranges reported by the assigning authority (Linux). Independent of NVD's CPE analysis and usually ahead of it.
Linux Linux
- 3.15affected
- b91accafbb1031b80d22ad83576877ff2f8b4774 and later · before 9dc84ba4be5bbeb29ee49efe6cea2cb32c461424affected · git
- b91accafbb1031b80d22ad83576877ff2f8b4774 and later · before d16a702ca7d29c0b7a9b509339d1b044a1cadb32affected · git
- b91accafbb1031b80d22ad83576877ff2f8b4774 and later · before a13ef1adbc62085b21b546b07b0be7e2fbf52150affected · git
- b91accafbb1031b80d22ad83576877ff2f8b4774 and later · before 0d4a646d7f87ea3625fafe387043fddc6a2f5e7faffected · git
- b91accafbb1031b80d22ad83576877ff2f8b4774 and later · before 72c6aa8e0d74eab91b8694cde97dec088c248feeaffected · git
- b91accafbb1031b80d22ad83576877ff2f8b4774 and later · before 9edefd4c56bee3fe331e0355d1f10a533134999daffected · git
- b91accafbb1031b80d22ad83576877ff2f8b4774 and later · before f187dc5a4c4846ffa07d9bda6e760837ed005574affected · git
- b91accafbb1031b80d22ad83576877ff2f8b4774 and later · before af791d295737ea6b6ff2c8d8488462a49c14af01affected · git
- before 3.15not affected · semver
Package-level exposure
OSV and GitHub Advisory data: ecosystem, package and range. SBOM matching uses this table.
| Ecosystem | Package | Affected range | Fix |
|---|---|---|---|
| AlmaLinux:8 | bpftool | before 4.18.0-553.154.1.el8_10 | 4.18.0-553.154.1.el8_10 |
| AlmaLinux:8 | kernel | before 4.18.0-553.154.1.el8_10 | 4.18.0-553.154.1.el8_10 |
| AlmaLinux:8 | kernel-abi-stablelists | before 4.18.0-553.154.1.el8_10 | 4.18.0-553.154.1.el8_10 |
| AlmaLinux:8 | kernel-core | before 4.18.0-553.154.1.el8_10 | 4.18.0-553.154.1.el8_10 |
| AlmaLinux:8 | kernel-cross-headers | before 4.18.0-553.154.1.el8_10 | 4.18.0-553.154.1.el8_10 |
| AlmaLinux:8 | kernel-debug | before 4.18.0-553.154.1.el8_10 | 4.18.0-553.154.1.el8_10 |
| AlmaLinux:8 | kernel-debug-core | before 4.18.0-553.154.1.el8_10 | 4.18.0-553.154.1.el8_10 |
| AlmaLinux:8 | kernel-debug-devel | before 4.18.0-553.154.1.el8_10 | 4.18.0-553.154.1.el8_10 |
| AlmaLinux:8 | kernel-debug-modules | before 4.18.0-553.154.1.el8_10 | 4.18.0-553.154.1.el8_10 |
| AlmaLinux:8 | kernel-debug-modules-extra | before 4.18.0-553.154.1.el8_10 | 4.18.0-553.154.1.el8_10 |
| AlmaLinux:8 | kernel-devel | before 4.18.0-553.154.1.el8_10 | 4.18.0-553.154.1.el8_10 |
| AlmaLinux:8 | kernel-doc | before 4.18.0-553.154.1.el8_10 | 4.18.0-553.154.1.el8_10 |
| AlmaLinux:8 | kernel-headers | before 4.18.0-553.154.1.el8_10 | 4.18.0-553.154.1.el8_10 |
| AlmaLinux:8 | kernel-modules | before 4.18.0-553.154.1.el8_10 | 4.18.0-553.154.1.el8_10 |
| AlmaLinux:8 | kernel-modules-extra | before 4.18.0-553.154.1.el8_10 | 4.18.0-553.154.1.el8_10 |
| AlmaLinux:8 | kernel-rt | before 4.18.0-553.154.1.rt7.495.el8_10 | 4.18.0-553.154.1.rt7.495.el8_10 |
| AlmaLinux:8 | kernel-rt-core | before 4.18.0-553.154.1.rt7.495.el8_10 | 4.18.0-553.154.1.rt7.495.el8_10 |
| AlmaLinux:8 | kernel-rt-debug | before 4.18.0-553.154.1.rt7.495.el8_10 | 4.18.0-553.154.1.rt7.495.el8_10 |
| AlmaLinux:8 | kernel-rt-debug-core | before 4.18.0-553.154.1.rt7.495.el8_10 | 4.18.0-553.154.1.rt7.495.el8_10 |
| AlmaLinux:8 | kernel-rt-debug-devel | before 4.18.0-553.154.1.rt7.495.el8_10 | 4.18.0-553.154.1.rt7.495.el8_10 |
| AlmaLinux:8 | kernel-rt-debug-modules | before 4.18.0-553.154.1.rt7.495.el8_10 | 4.18.0-553.154.1.rt7.495.el8_10 |
| AlmaLinux:8 | kernel-rt-debug-modules-extra | before 4.18.0-553.154.1.rt7.495.el8_10 | 4.18.0-553.154.1.rt7.495.el8_10 |
| AlmaLinux:8 | kernel-rt-devel | before 4.18.0-553.154.1.rt7.495.el8_10 | 4.18.0-553.154.1.rt7.495.el8_10 |
| AlmaLinux:8 | kernel-rt-modules | before 4.18.0-553.154.1.rt7.495.el8_10 | 4.18.0-553.154.1.rt7.495.el8_10 |
+66
Same product
linux: all recordsOther highest-scoring records for the same primary product.
- CVE-2026-74705udp: fix potential use-after-free in tunnel segmentation40Plan
- CVE-2026-74612veth: fix skb length accounting after XDP frag adjustment40Plan
- CVE-2026-74475vxlan: use neigh_ha_snapshot() in route_shortcircuit()40Plan
- CVE-2026-74309vdpa/octeon_ep: fix IRQ-to-ring mapping in interrupt handler40Plan
- CVE-2026-74280crypto: marvell/octeontx - fix DMA cleanup using wrong loop index40Plan
- CVE-2026-74279crypto: cavium/cpt - fix DMA cleanup using wrong loop index40Plan
Remediation
Which version to upgrade to
Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.
| Product / package | Fixed version | Source |
|---|---|---|
| Linux Linux | 0d4a646d7f87ea3625fafe387043fddc6a2f5e7f | Vendor (CNA) |
| Linux Linux | 72c6aa8e0d74eab91b8694cde97dec088c248fee | Vendor (CNA) |
| Linux Linux | 9dc84ba4be5bbeb29ee49efe6cea2cb32c461424 | Vendor (CNA) |
| Linux Linux | 9edefd4c56bee3fe331e0355d1f10a533134999d | Vendor (CNA) |
| Linux Linux | a13ef1adbc62085b21b546b07b0be7e2fbf52150 | Vendor (CNA) |
| Linux Linux | af791d295737ea6b6ff2c8d8488462a49c14af01 | Vendor (CNA) |
| Linux Linux | d16a702ca7d29c0b7a9b509339d1b044a1cadb32 | Vendor (CNA) |
| Linux Linux | f187dc5a4c4846ffa07d9bda6e760837ed005574 | Vendor (CNA) |
| azl3 kernel 6.6.144.1-1 on Azure Linux 3.0 | 6.6.145.2-1 · CBL-Mariner Releases | Microsoft (MSRC) |
| almalinux:bpftool | 4.18.0-553.154.1.el8_10 · AlmaLinux:8 | Package registry (OSV) |
| almalinux:kernel | 4.18.0-553.154.1.el8_10 · AlmaLinux:8 | Package registry (OSV) |
| almalinux:kernel-rt | 4.18.0-553.154.1.rt7.495.el8_10 · AlmaLinux:8 | Package registry (OSV) |
| almalinux:kernel-rt-core | 4.18.0-553.154.1.rt7.495.el8_10 · AlmaLinux:8 | Package registry (OSV) |
| almalinux:kernel-rt-debug | 4.18.0-553.154.1.rt7.495.el8_10 · AlmaLinux:8 | Package registry (OSV) |
| almalinux:kernel-rt-debug-core | 4.18.0-553.154.1.rt7.495.el8_10 · AlmaLinux:8 | Package registry (OSV) |
| almalinux:kernel-rt-debug-devel | 4.18.0-553.154.1.rt7.495.el8_10 · AlmaLinux:8 | Package registry (OSV) |
| almalinux:kernel-rt-debug-modules | 4.18.0-553.154.1.rt7.495.el8_10 · AlmaLinux:8 | Package registry (OSV) |
| almalinux:kernel-rt-debug-modules-extra | 4.18.0-553.154.1.rt7.495.el8_10 · AlmaLinux:8 | Package registry (OSV) |
| almalinux:kernel-rt-devel | 4.18.0-553.154.1.rt7.495.el8_10 · AlmaLinux:8 | Package registry (OSV) |
| almalinux:kernel-rt-modules | 4.18.0-553.154.1.rt7.495.el8_10 · AlmaLinux:8 | Package registry (OSV) |
| almalinux:kernel-rt-modules-extra | 4.18.0-553.154.1.rt7.495.el8_10 · AlmaLinux:8 | Package registry (OSV) |
| debian:linux | 6.1.180-1 · Debian:12 | Package registry (OSV) |
| debian:linux-6.12 | 6.12.100-1~deb12u1 · Debian:12 | Package registry (OSV) |
| red hat:kernel-rt | 0:4.18.0-553.154.1.rt7.495.el8_10 · Red Hat:enterprise_linux:8::nfv | Package registry (OSV) |
| red hat:kernel-rt-core | 0:4.18.0-553.154.1.rt7.495.el8_10 · Red Hat:enterprise_linux:8::nfv | Package registry (OSV) |
| red hat:kernel-rt-debug | 0:4.18.0-553.154.1.rt7.495.el8_10 · Red Hat:enterprise_linux:8::nfv | Package registry (OSV) |
| red hat:kernel-rt-debug-core | 0:4.18.0-553.154.1.rt7.495.el8_10 · Red Hat:enterprise_linux:8::nfv | Package registry (OSV) |
| red hat:kernel-rt-debug-debuginfo | 0:4.18.0-553.154.1.rt7.495.el8_10 · Red Hat:enterprise_linux:8::nfv | Package registry (OSV) |
| red hat:kernel-rt-debug-devel | 0:4.18.0-553.154.1.rt7.495.el8_10 · Red Hat:enterprise_linux:8::nfv | Package registry (OSV) |
| red hat:kernel-rt-debug-kvm | 0:4.18.0-553.154.1.rt7.495.el8_10 · Red Hat:enterprise_linux:8::nfv | Package registry (OSV) |
+7
Exploit status
No known public exploit
No public exploit has been observed yet. That doesn't mean you're safe, only that the bar is a little higher.
Research context
For pentesters and researchers: attack profile, score disagreement, timeline, patch commits, credits, variant and chain candidates, bug bounty scope. All derived from existing data; no exploit code.
Timeline
From publication to today: proof of concept, Metasploit module, CISA KEV and fix record. Dates are as reported by the sources.
No dated events beyond publication.
FIRST EPSS daily score; only changes of 0.01 or more are recorded (step chart).
Patch and commit links
Commit, PR and diff links among the references. A starting point for patch-diffing and variant hunting; fixes, not exploits.
No commit or PR link among the references.
Credits
All researchersFinders, reporters and analysts named in the CNA record. Click a name for that researcher’s other records.
No credits in the CNA record.
Variant candidates
Same product, same weakness class, within 18 months. If the patch missed the root cause, the sibling bug is here.
No nightly-computed relations.
Chain candidates
An authentication bypass and a privilege-requiring bug in the same product, published close together: combined they may become an unauthenticated path.
—
Bug bounty scope
No known public program.
Source: bounty-targets-data (public HackerOne, Bugcrowd, Intigriti, YesWeHack listings).
Technical details
Attack conditions
- Someone with local access to the system can trigger it.
- A low-privileged account is enough.
- No user action is required.
- No special conditions are required; it is repeatable.
If successful
- Confidentiality
- high · data can be read
- Integrity
- none
- Availability
- high · the service can be disrupted
- Attack vector
- Local
- Attack complexity
- Low
- Privileges required
- Low
- User interaction
- None
- Scope
- Unchanged
- Confidentiality impact
- High
- Integrity impact
- None
- Availability impact
- High
Weakness class (CWE)
—
CVSS vector
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:H
nvd-secondary
Attack context
MITRE CAPEC attack patterns and ATT&CK techniques for this weakness class (CWE). A starting point for detection rules and threat hunting.
MITRE has no CAPEC/ATT&CK mapping for this CWE.
Change log
- Fix✗ → ✓
For records you follow, these changes also arrive as notifications. →
References
- git.kernel.org/stable/c/0d4a646d7f87ea3625fafe387043fddc6a2f5e7f
- git.kernel.org/stable/c/72c6aa8e0d74eab91b8694cde97dec088c248fee
- git.kernel.org/stable/c/9dc84ba4be5bbeb29ee49efe6cea2cb32c461424
- git.kernel.org/stable/c/9edefd4c56bee3fe331e0355d1f10a533134999d
- git.kernel.org/stable/c/a13ef1adbc62085b21b546b07b0be7e2fbf52150
- git.kernel.org/stable/c/af791d295737ea6b6ff2c8d8488462a49c14af01
- git.kernel.org/stable/c/d16a702ca7d29c0b7a9b509339d1b044a1cadb32
- git.kernel.org/stable/c/f187dc5a4c4846ffa07d9bda6e760837ed005574
Vendor advisories and official records. Exploit/PoC links are deliberately left out.