net/iucv: fix use after free in iucv_sock_close()
In the Linux kernel, the following vulnerability has been resolved: net/iucv: fix use after free in iucv_sock_close() iucv_sever_path() is called from process context and from bh context. iucv->path is used as indicator whether somebody else is taking care of severing the path (or it is already removed / never existed). This needs to be done with atomic compare and swap, otherwise there is a small window where iucv_sock_close() will try to work with a path that has already been severed and freed by iucv_callback_connrej() called by iucv_tasklet_fn(). Example: [452744.123844] Call Trace: [452744.123845] ([<0000001e87f03880>] 0x1e87f03880) [452744.123966] [<00000000d593001e>] iucv_path_sever+0x96/0x138 [452744.124330] [<000003ff801ddbca>] iucv_sever_path+0xc2/0xd0 [af_iucv] [452744.124336] [<000003ff801e01b6>] iucv_sock_close+0xa6/0x310 [af_iucv] [452744.124341] [<000003ff801e08cc>] iucv_sock_release+0x3c/0xd0 [af_iucv] [452744.124345] [<00000000d574794e>] __sock_release+0x5e/0xe8 [452744.124815] [<00000000d5747a0c>] sock_close+0x34/0x48 [452744.124820] [<00000000d5421642>] __fput+0xba/0x268 [452744.124826] [<00000000d51b382c>] task_work_run+0xbc/0xf0 [452744.124832] [<00000000d5145710>] do_notify_resume+0x88/0x90 [452744.124841] [<00000000d5978096>] system_call+0xe2/0x2c8 [452744.125319] Last Breaking-Event-Address: [452744.125321] [<00000000d5930018>] iucv_path_sever+0x90/0x138 [452744.125324] [452744.125325] Kernel panic - not syncing: Fatal exception in interrupt Note that bh_lock_sock() is not serializing the tasklet context against process context, because the check for sock_owned_by_user() and corresponding handling is missing. Ideas for a future clean-up patch: A) Correct usage of bh_lock_sock() in tasklet context, as described in Re-enqueue, if needed. This may require adding return values to the tasklet functions and thus changes to all users of iucv. B) Change iucv tasklet into worker and use only lock_sock() in af_iucv.
- Published
- Aug 17, 2024
- Updated
- Aug 5, 2026
- EPSS
- 0.2% · 13th percentile
- CWE
- CWE-416
Sign in to follow · You’ll be notified if a followed record enters KEV, gets an exploit or is updated.
Report tools
Action score
31
Monitor
Low priority for now.
- CVSS
- 31 / 40 · 7.8 / 10
- CISA KEV
- 0 / 30 · Not listed
- EPSS
- 0 / 30 · 0.2%
CISA SSVC decision
- Exploitation
- none
- Automatable
- no
- Technical impact
- partial
Vulnrichment: CISA's decision-tree inputs.
CNA vs NVD score
- NVD
- 7.8
- CNA · Linux
- 7.8
- agree
The score given by the assigning authority versus NVD’s independent score. A gap means the severity is contested.
Affected systems
| Vendor | Product | CPE |
|---|---|---|
| linux | linux kernel | cpe:2.3:o:linux:linux_kernel |
Affected versions
NVD version ranges (for catalog products). Add the product to your stack with a version and matching uses these.
- linux linux kernel3.4 and later · before 4.19.320
- linux linux kernel4.20 and later · before 5.4.282
- linux linux kernel5.5 and later · before 5.10.224
- linux linux kernel5.11 and later · before 5.15.165
- linux linux kernel5.16 and later · before 6.1.104
- linux linux kernel6.2 and later · before 6.6.45
- linux linux kernel6.7 and later · before 6.10.4
- linux linux kernel6.11
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
- 3.4affected
- 7d316b9453523498246e9e19a659c423d4c5081e and later · before 84f40b46787ecb67c7ad08a5bb1376141fa10c01affected · git
- 7d316b9453523498246e9e19a659c423d4c5081e and later · before 37652fbef9809411cea55ea5fa1a170e299efcd0affected · git
- 7d316b9453523498246e9e19a659c423d4c5081e and later · before c65f72eec60a34ace031426e04e9aff8e5f04895affected · git
- 7d316b9453523498246e9e19a659c423d4c5081e and later · before ac758e1f663fe9bc64f6b47212a2aa18697524f5affected · git
- 7d316b9453523498246e9e19a659c423d4c5081e and later · before 8b424c9e44111c5a76f41c6b741f8d4c4179d876affected · git
- 7d316b9453523498246e9e19a659c423d4c5081e and later · before 01437282fd3904810603f3dc98d2cac6b8b6fc84affected · git
- 7d316b9453523498246e9e19a659c423d4c5081e and later · before 69620522c48ce8215e5eb55ffbab8cafee8f407daffected · git
- 7d316b9453523498246e9e19a659c423d4c5081e and later · before f558120cd709682b739207b48cf7479fd9568431affected · git
- before 3.4not affected · semver
Package-level exposure
OSV and GitHub Advisory data: ecosystem, package and range. SBOM matching uses this table.
| Ecosystem | Package | Affected range | Fix |
|---|---|---|---|
| Debian:12 | linux | before 6.1.106-1 | 6.1.106-1 |
| Debian:13 | linux | before 6.10.4-1 | 6.10.4-1 |
| Red Hat:rhel_eus:9.2::appstream | bpftool-debuginfo | before 0:7.0.0-284.92.1.el9_2 | 0:7.0.0-284.92.1.el9_2 |
| Red Hat:rhel_eus:9.2::appstream | kernel-64k-debug-debuginfo | before 0:5.14.0-284.92.1.el9_2 | 0:5.14.0-284.92.1.el9_2 |
| Red Hat:rhel_eus:9.2::appstream | kernel-64k-debug-devel | before 0:5.14.0-284.92.1.el9_2 | 0:5.14.0-284.92.1.el9_2 |
| Red Hat:rhel_eus:9.2::appstream | kernel-64k-debug-devel-matched | before 0:5.14.0-284.92.1.el9_2 | 0:5.14.0-284.92.1.el9_2 |
| Red Hat:rhel_eus:9.2::appstream | kernel-64k-debuginfo | before 0:5.14.0-284.92.1.el9_2 | 0:5.14.0-284.92.1.el9_2 |
| Red Hat:rhel_eus:9.2::appstream | kernel-64k-devel | before 0:5.14.0-284.92.1.el9_2 | 0:5.14.0-284.92.1.el9_2 |
| Red Hat:rhel_eus:9.2::appstream | kernel-64k-devel-matched | before 0:5.14.0-284.92.1.el9_2 | 0:5.14.0-284.92.1.el9_2 |
| Red Hat:rhel_eus:9.2::appstream | kernel-debug-debuginfo | before 0:5.14.0-284.92.1.el9_2 | 0:5.14.0-284.92.1.el9_2 |
| Red Hat:rhel_eus:9.2::appstream | kernel-debug-devel | before 0:5.14.0-284.92.1.el9_2 | 0:5.14.0-284.92.1.el9_2 |
| Red Hat:rhel_eus:9.2::appstream | kernel-debug-devel-matched | before 0:5.14.0-284.92.1.el9_2 | 0:5.14.0-284.92.1.el9_2 |
| Red Hat:rhel_eus:9.2::appstream | kernel-debuginfo | before 0:5.14.0-284.92.1.el9_2 | 0:5.14.0-284.92.1.el9_2 |
| Red Hat:rhel_eus:9.2::appstream | kernel-debuginfo-common-aarch64 | before 0:5.14.0-284.92.1.el9_2 | 0:5.14.0-284.92.1.el9_2 |
| Red Hat:rhel_eus:9.2::appstream | kernel-debuginfo-common-ppc64le | before 0:5.14.0-284.92.1.el9_2 | 0:5.14.0-284.92.1.el9_2 |
| Red Hat:rhel_eus:9.2::appstream | kernel-debuginfo-common-s390x | before 0:5.14.0-284.92.1.el9_2 | 0:5.14.0-284.92.1.el9_2 |
| Red Hat:rhel_eus:9.2::appstream | kernel-debuginfo-common-x86_64 | before 0:5.14.0-284.92.1.el9_2 | 0:5.14.0-284.92.1.el9_2 |
| Red Hat:rhel_eus:9.2::appstream | kernel-devel | before 0:5.14.0-284.92.1.el9_2 | 0:5.14.0-284.92.1.el9_2 |
| Red Hat:rhel_eus:9.2::appstream | kernel-devel-matched | before 0:5.14.0-284.92.1.el9_2 | 0:5.14.0-284.92.1.el9_2 |
| Red Hat:rhel_eus:9.2::appstream | kernel-tools-debuginfo | before 0:5.14.0-284.92.1.el9_2 | 0:5.14.0-284.92.1.el9_2 |
| Red Hat:rhel_eus:9.2::appstream | kernel-zfcpdump-debuginfo | before 0:5.14.0-284.92.1.el9_2 | 0:5.14.0-284.92.1.el9_2 |
| Red Hat:rhel_eus:9.2::appstream | kernel-zfcpdump-devel | before 0:5.14.0-284.92.1.el9_2 | 0:5.14.0-284.92.1.el9_2 |
| Red Hat:rhel_eus:9.2::appstream | kernel-zfcpdump-devel-matched | before 0:5.14.0-284.92.1.el9_2 | 0:5.14.0-284.92.1.el9_2 |
| Red Hat:rhel_eus:9.2::appstream | perf | before 0:5.14.0-284.92.1.el9_2 | 0:5.14.0-284.92.1.el9_2 |
+53
Same product
linux: all recordsOther highest-scoring records for the same primary product.
- CVE-2022-0847A flaw was found in the way the "flags" member of the new pipe buffer structure was lacking proper initialization in copy_page_to_iter_pipe KEV89Now
- CVE-2021-22555Heap Out-Of-Bounds Write in Netfilter IP6T_SO_SET_REPLACEKEV85Now
- CVE-2016-5195Race condition in mm/gup.c in the Linux kernel 2.x through 4.x before 4.8.3 allows local users to gain privileges by leveraging incorrect haKEV83Now
- CVE-2019-13272In the Linux kernel before 5.1.17, ptrace_link in kernel/ptrace.c mishandles the recording of the credentials of a process that wants to creKEV77This week
- CVE-2013-6282The (1) get_user and (2) put_user API functions in the Linux kernel before 3.5.5 on the v6k and v7 ARM platforms do not validate certain addKEV77This week
- CVE-2013-2094The perf_swevent_init function in kernel/events/core.c in the Linux kernel before 3.8.9 uses an incorrect integer data type, which allows loKEV77This week
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 | 01437282fd3904810603f3dc98d2cac6b8b6fc84 | Vendor (CNA) |
| Linux Linux | 37652fbef9809411cea55ea5fa1a170e299efcd0 | Vendor (CNA) |
| Linux Linux | 69620522c48ce8215e5eb55ffbab8cafee8f407d | Vendor (CNA) |
| Linux Linux | 84f40b46787ecb67c7ad08a5bb1376141fa10c01 | Vendor (CNA) |
| Linux Linux | 8b424c9e44111c5a76f41c6b741f8d4c4179d876 | Vendor (CNA) |
| Linux Linux | ac758e1f663fe9bc64f6b47212a2aa18697524f5 | Vendor (CNA) |
| Linux Linux | c65f72eec60a34ace031426e04e9aff8e5f04895 | Vendor (CNA) |
| Linux Linux | f558120cd709682b739207b48cf7479fd9568431 | Vendor (CNA) |
| debian:linux | 6.1.106-1 · Debian:12 | Package registry (OSV) |
| red hat:bpftool-debuginfo | 0:7.0.0-284.92.1.el9_2 · Red Hat:rhel_eus:9.2::appstream | Package registry (OSV) |
| red hat:kernel-64k-debug-debuginfo | 0:5.14.0-284.92.1.el9_2 · Red Hat:rhel_eus:9.2::appstream | Package registry (OSV) |
| red hat:kernel-64k-debug-devel | 0:5.14.0-284.92.1.el9_2 · Red Hat:rhel_eus:9.2::appstream | Package registry (OSV) |
| red hat:kernel-64k-debug-devel-matched | 0:5.14.0-284.92.1.el9_2 · Red Hat:rhel_eus:9.2::appstream | Package registry (OSV) |
| red hat:kernel-64k-debuginfo | 0:5.14.0-284.92.1.el9_2 · Red Hat:rhel_eus:9.2::appstream | Package registry (OSV) |
| red hat:kernel-64k-devel | 0:5.14.0-284.92.1.el9_2 · Red Hat:rhel_eus:9.2::appstream | Package registry (OSV) |
| red hat:kernel-64k-devel-matched | 0:5.14.0-284.92.1.el9_2 · Red Hat:rhel_eus:9.2::appstream | Package registry (OSV) |
| red hat:kernel-debug-debuginfo | 0:5.14.0-284.92.1.el9_2 · Red Hat:rhel_eus:9.2::appstream | Package registry (OSV) |
| red hat:kernel-debug-devel | 0:5.14.0-284.92.1.el9_2 · Red Hat:rhel_eus:9.2::appstream | Package registry (OSV) |
| red hat:kernel-debug-devel-matched | 0:5.14.0-284.92.1.el9_2 · Red Hat:rhel_eus:9.2::appstream | Package registry (OSV) |
| red hat:kernel-debuginfo | 0:5.14.0-284.92.1.el9_2 · Red Hat:rhel_eus:9.2::appstream | Package registry (OSV) |
| red hat:kernel-debuginfo-common-aarch64 | 0:5.14.0-284.92.1.el9_2 · Red Hat:rhel_eus:9.2::appstream | Package registry (OSV) |
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
- high · data or configuration can be modified
- 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
- High
- Availability impact
- High
Weakness class (CWE)
CWE-416 · Use After FreeCVSS vector
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
nvd-primary
Root cause
After a memory region is freed, another reference pointing to it is still used. By then, the same region may have been allocated for different data.
The bug in code
The whole CWE-416 classA representative example of this vulnerability class. Not the vendor's source code; it shows the faulty pattern and its fix.
Vulnerable
free(dev->buf);/* ... another thread is still running ... */process(dev->buf);Fixed
lock(&dev->lock);free(dev->buf);dev->buf = NULL;unlock(&dev->lock);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.
Noroxi analysis
No Noroxi analysis for this record yet
We don't hand-write analysis for all 385,000+ vulnerabilities; that wouldn't be honest. For notable, high-impact vulnerabilities our team writes the mechanism, detection and remediation steps.
We use this product, ask for helpChange log
- Fix✗ → ✓
For records you follow, these changes also arrive as notifications. →
References
- git.kernel.org/stable/c/01437282fd3904810603f3dc98d2cac6b8b6fc84
- git.kernel.org/stable/c/37652fbef9809411cea55ea5fa1a170e299efcd0
- git.kernel.org/stable/c/69620522c48ce8215e5eb55ffbab8cafee8f407d
- git.kernel.org/stable/c/84f40b46787ecb67c7ad08a5bb1376141fa10c01
- git.kernel.org/stable/c/8b424c9e44111c5a76f41c6b741f8d4c4179d876
- git.kernel.org/stable/c/ac758e1f663fe9bc64f6b47212a2aa18697524f5
- git.kernel.org/stable/c/c65f72eec60a34ace031426e04e9aff8e5f04895
- git.kernel.org/stable/c/f558120cd709682b739207b48cf7479fd9568431
- lists.debian.org/debian-lts-announce/2025/01/msg00001.html
Vendor advisories and official records. Exploit/PoC links are deliberately left out.