net: bridge: mcast: wait for previous gc cycles when removing port
In the Linux kernel, the following vulnerability has been resolved: net: bridge: mcast: wait for previous gc cycles when removing port syzbot hit a use-after-free[1] which is caused because the bridge doesn't make sure that all previous garbage has been collected when removing a port. What happens is: CPU 1 CPU 2 start gc cycle remove port acquire gc lock first wait for lock call br_multicasg_gc() directly acquire lock now but free port the port can be freed while grp timers still running Make sure all previous gc cycles have finished by using flush_work before freeing the port. [1] BUG: KASAN: slab-use-after-free in br_multicast_port_group_expired+0x4c0/0x550 net/bridge/br_multicast.c:861 Read of size 8 at addr ffff888071d6d000 by task syz.5.1232/9699 CPU: 1 PID: 9699 Comm: syz.5.1232 Not tainted 6.10.0-rc5-syzkaller-00021-g24ca36a562d6 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/07/2024 Call Trace: <IRQ> __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0x116/0x1f0 lib/dump_stack.c:114 print_address_description mm/kasan/report.c:377 [inline] print_report+0xc3/0x620 mm/kasan/report.c:488 kasan_report+0xd9/0x110 mm/kasan/report.c:601 br_multicast_port_group_expired+0x4c0/0x550 net/bridge/br_multicast.c:861 call_timer_fn+0x1a3/0x610 kernel/time/timer.c:1792 expire_timers kernel/time/timer.c:1843 [inline] __run_timers+0x74b/0xaf0 kernel/time/timer.c:2417 __run_timer_base kernel/time/timer.c:2428 [inline] __run_timer_base kernel/time/timer.c:2421 [inline] run_timer_base+0x111/0x190 kernel/time/timer.c:2437
- Published
- Aug 26, 2024
- Updated
- Aug 5, 2026
- EPSS
- 0.2% · 11th percentile
- CWE
- CWE-416
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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 kernel5.10 and later · before 5.15.165
- linux linux kernel5.16 and later · before 6.1.105
- linux linux kernel6.2 and later · before 6.6.46
- linux linux kernel6.7 and later · before 6.10.5
- 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
- 5.10affected
- e12cec65b5546f19217e26aafb8add6e2fadca18 and later · before 1e16828020c674b3be85f52685e8b80f9008f50faffected · git
- e12cec65b5546f19217e26aafb8add6e2fadca18 and later · before 0d8b26e10e680c01522d7cc14abe04c3265a928faffected · git
- e12cec65b5546f19217e26aafb8add6e2fadca18 and later · before e3145ca904fa8dbfd1a5bf0187905bc117b0efceaffected · git
- e12cec65b5546f19217e26aafb8add6e2fadca18 and later · before b2f794b168cf560682ff976b255aa6d29d14a658affected · git
- e12cec65b5546f19217e26aafb8add6e2fadca18 and later · before 92c4ee25208d0f35dafc3213cdf355fbe449e078affected · git
- before 5.10not affected · semver
- 5.15.165 and later · up to and including 5.15.*not affected · semver
- 6.1.105 and later · up to and including 6.1.*not affected · semver
- 6.6.46 and later · up to and including 6.6.*not 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 6.10.6-1 | 6.10.6-1 |
| openSUSE:Leap 15.6 | dtb-aarch64 | before 6.4.0-150600.23.33.1 | 6.4.0-150600.23.33.1 |
| openSUSE:Leap 15.6 | kernel-debug | before 6.4.0-150600.23.33.1 | 6.4.0-150600.23.33.1 |
| openSUSE:Leap 15.6 | kernel-kvmsmall | before 6.4.0-150600.23.33.1 | 6.4.0-150600.23.33.1 |
| openSUSE:Leap 15.6 | kernel-obs-qa | before 6.4.0-150600.23.33.1 | 6.4.0-150600.23.33.1 |
| SUSE:Linux Enterprise High Performance Computing 15 SP5-ESPOS | kernel-64kb | before 5.14.21-150500.55.91.1 | 5.14.21-150500.55.91.1 |
| SUSE:Linux Enterprise High Performance Computing 15 SP5-ESPOS | kernel-docs | before 5.14.21-150500.55.91.1 | 5.14.21-150500.55.91.1 |
| SUSE:Linux Enterprise High Performance Computing 15 SP5-ESPOS | kernel-obs-build | before 5.14.21-150500.55.91.1 | 5.14.21-150500.55.91.1 |
| SUSE:Linux Enterprise High Performance Computing 15 SP5-ESPOS | kernel-source | before 5.14.21-150500.55.91.1 | 5.14.21-150500.55.91.1 |
| SUSE:Linux Enterprise High Performance Computing 15 SP5-ESPOS | kernel-syms | before 5.14.21-150500.55.91.1 | 5.14.21-150500.55.91.1 |
| SUSE:Linux Enterprise Live Patching 15 SP5 | kernel-livepatch-SLE15-SP5_Update_22 | before 1-150500.11.3.1 | 1-150500.11.3.1 |
| SUSE:Linux Enterprise Live Patching 15 SP6 | kernel-livepatch-SLE15-SP6_Update_7 | before 1-150600.13.3.1 | 1-150600.13.3.1 |
| SUSE:Linux Enterprise Live Patching 15 SP6 | kernel-livepatch-SLE15-SP6_Update_7 | before 1-150600.13.3.1 | 1-150600.13.3.1 |
| SUSE:Linux Enterprise Live Patching 15 SP6 | kernel-livepatch-SLE15-SP6-RT_Update_7 | before 1-150600.1.3.1 | 1-150600.1.3.1 |
| SUSE:Linux Enterprise Live Patching 15 SP6 | kernel-livepatch-SLE15-SP6-RT_Update_7 | before 1-150600.1.3.1 | 1-150600.1.3.1 |
| SUSE:Linux Enterprise Micro 5.5 | kernel-default | before 5.14.21-150500.55.91.1 | 5.14.21-150500.55.91.1 |
| SUSE:Linux Enterprise Micro 5.5 | kernel-default-base | before 5.14.21-150500.55.91.1.150500.6.41.1 | 5.14.21-150500.55.91.1.150500.6.41.1 |
| SUSE:Linux Enterprise Micro 5.5 | kernel-rt | before 5.14.21-150500.13.82.1 | 5.14.21-150500.13.82.1 |
| SUSE:Linux Enterprise Micro 5.5 | kernel-source-rt | before 5.14.21-150500.13.82.1 | 5.14.21-150500.13.82.1 |
| SUSE:Linux Enterprise Module for Basesystem 15 SP6 | kernel-64kb | before 6.4.0-150600.23.33.1 | 6.4.0-150600.23.33.1 |
| SUSE:Linux Enterprise Module for Basesystem 15 SP6 | kernel-64kb | before 6.4.0-150600.23.33.1 | 6.4.0-150600.23.33.1 |
| SUSE:Linux Enterprise Module for Basesystem 15 SP6 | kernel-default | before 6.4.0-150600.23.33.1 | 6.4.0-150600.23.33.1 |
| SUSE:Linux Enterprise Module for Basesystem 15 SP6 | kernel-default | before 6.4.0-150600.23.33.1 | 6.4.0-150600.23.33.1 |
+36
Same product
linux: all recordsOther highest-scoring records for the same primary product.
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- 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 | 0d8b26e10e680c01522d7cc14abe04c3265a928f | Vendor (CNA) |
| Linux Linux | 1e16828020c674b3be85f52685e8b80f9008f50f | Vendor (CNA) |
| Linux Linux | 92c4ee25208d0f35dafc3213cdf355fbe449e078 | Vendor (CNA) |
| Linux Linux | b2f794b168cf560682ff976b255aa6d29d14a658 | Vendor (CNA) |
| Linux Linux | e3145ca904fa8dbfd1a5bf0187905bc117b0efce | Vendor (CNA) |
| debian:linux | 6.1.106-1 · Debian:12 | Package registry (OSV) |
| opensuse:kernel-azure | 6.4.0-150600.8.23.1 · openSUSE:Leap 15.6 | Package registry (OSV) |
| opensuse:kernel-rt | 6.4.0-150600.10.23.1 · openSUSE:Leap 15.6 | Package registry (OSV) |
| opensuse:kernel-source-azure | 6.4.0-150600.8.23.1 · openSUSE:Leap 15.6 | Package registry (OSV) |
| opensuse:kernel-syms-azure | 6.4.0-150600.8.23.1 · openSUSE:Leap 15.6 | Package registry (OSV) |
| suse:kernel-azure | 6.4.0-150600.8.23.1 · SUSE:Linux Enterprise Module for Public Cloud 15 SP6 | Package registry (OSV) |
| suse:kernel-livepatch-SLE15-SP6-RT_Update_7 | 1-150600.1.3.1 · SUSE:Linux Enterprise Live Patching 15 SP6 | Package registry (OSV) |
| suse:kernel-rt | 6.4.0-150600.10.23.1 · SUSE:Real Time Module 15 SP6 | Package registry (OSV) |
| suse:kernel-rt_debug | 6.4.0-150600.10.23.1 · SUSE:Real Time Module 15 SP6 | Package registry (OSV) |
| suse:kernel-source-azure | 6.4.0-150600.8.23.1 · SUSE:Linux Enterprise Module for Public Cloud 15 SP6 | Package registry (OSV) |
| suse:kernel-source-rt | 6.4.0-150600.10.23.1 · SUSE:Real Time Module 15 SP6 | Package registry (OSV) |
| suse:kernel-syms-azure | 6.4.0-150600.8.23.1 · SUSE:Linux Enterprise Module for Public Cloud 15 SP6 | Package registry (OSV) |
| suse:kernel-syms-rt | 6.4.0-150600.10.23.1 · SUSE:Real Time Module 15 SP6 | 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/0d8b26e10e680c01522d7cc14abe04c3265a928f
- git.kernel.org/stable/c/1e16828020c674b3be85f52685e8b80f9008f50f
- git.kernel.org/stable/c/92c4ee25208d0f35dafc3213cdf355fbe449e078
- git.kernel.org/stable/c/b2f794b168cf560682ff976b255aa6d29d14a658
- git.kernel.org/stable/c/e3145ca904fa8dbfd1a5bf0187905bc117b0efce
- lists.debian.org/debian-lts-announce/2025/01/msg00001.html
Vendor advisories and official records. Exploit/PoC links are deliberately left out.