Bluetooth: hci_sync: fix double free in 'hci_discovery_filter_clear()'
In the Linux kernel, the following vulnerability has been resolved: Bluetooth: hci_sync: fix double free in 'hci_discovery_filter_clear()' Function 'hci_discovery_filter_clear()' frees 'uuids' array and then sets it to NULL. There is a tiny chance of the following race: 'hci_cmd_sync_work()' 'update_passive_scan_sync()' 'hci_update_passive_scan_sync()' 'hci_discovery_filter_clear()' kfree(uuids); <-------------------------preempted--------------------------------> 'start_service_discovery()' 'hci_discovery_filter_clear()' kfree(uuids); // DOUBLE FREE <-------------------------preempted--------------------------------> uuids = NULL; To fix it let's add locking around 'kfree()' call and NULL pointer assignment. Otherwise the following backtrace fires: [ ] ------------[ cut here ]------------ [ ] kernel BUG at mm/slub.c:547! [ ] Internal error: Oops - BUG: 00000000f2000800 [#1] PREEMPT SMP [ ] CPU: 3 UID: 0 PID: 246 Comm: bluetoothd Tainted: G O 6.12.19-kernel #1 [ ] Tainted: [O]=OOT_MODULE [ ] pstate: 60400005 (nZCv daif +PAN -UAO -TCO -DIT -SSBS BTYPE=--) [ ] pc : __slab_free+0xf8/0x348 [ ] lr : __slab_free+0x48/0x348 ... [ ] Call trace: [ ] __slab_free+0xf8/0x348 [ ] kfree+0x164/0x27c [ ] start_service_discovery+0x1d0/0x2c0 [ ] hci_sock_sendmsg+0x518/0x924 [ ] __sock_sendmsg+0x54/0x60 [ ] sock_write_iter+0x98/0xf8 [ ] do_iter_readv_writev+0xe4/0x1c8 [ ] vfs_writev+0x128/0x2b0 [ ] do_writev+0xfc/0x118 [ ] __arm64_sys_writev+0x20/0x2c [ ] invoke_syscall+0x68/0xf0 [ ] el0_svc_common.constprop.0+0x40/0xe0 [ ] do_el0_svc+0x1c/0x28 [ ] el0_svc+0x30/0xd0 [ ] el0t_64_sync_handler+0x100/0x12c [ ] el0t_64_sync+0x194/0x198 [ ] Code: 8b0002e6 eb17031f 54fffbe1 d503201f (d4210000) [ ] ---[ end trace 0000000000000000 ]---
Noroxi analysis
No Noroxi analysis for this record yet
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We use this product, ask for help- Published
- Aug 19, 2025
- Updated
- Aug 5, 2026
- EPSS
- 0.2% · 6th percentile
- CWE
- CWE-415
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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%
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 kernel5.17 and later · before 6.6.117
- linux linux kernel6.7 and later · before 6.12.42
- linux linux kernel6.13 and later · before 6.15.10
- linux linux kernel6.16 and later · before 6.16.1
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
- 5.17affected
- ad383c2c65a5baf16e334cd40a013cc302176891 and later · before 86f3dcd1f331cfd4fd7ec88906955134ec51afbeaffected · git
- ad383c2c65a5baf16e334cd40a013cc302176891 and later · before 7ce9bb0b95fc280e9212b8922590c492ca1d9c39affected · git
- ad383c2c65a5baf16e334cd40a013cc302176891 and later · before 16852eccbdfaf41a666705e3f8be55cf2864c5caaffected · git
- ad383c2c65a5baf16e334cd40a013cc302176891 and later · before a351ff6b8ecca4229afaa0d98042bead8de64799affected · git
- ad383c2c65a5baf16e334cd40a013cc302176891 and later · before f8069f34c4c976786ded97498012225af87435d7affected · git
- ad383c2c65a5baf16e334cd40a013cc302176891 and later · before 2935e556850e9c94d7a00adf14d3cd7fe406ac03affected · git
- before 5.17not affected · semver
- 6.1.159 and later · up to and including 6.1.*not affected · semver
- 6.6.117 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:11 | linux-6.1 | before 6.1.159-1~deb11u1 | 6.1.159-1~deb11u1 |
| Debian:12 | linux | before 6.1.159-1 | 6.1.159-1 |
| Debian:13 | linux | before 6.12.43-1 | 6.12.43-1 |
| Debian:14 | linux | before 6.16.3-1 | 6.16.3-1 |
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 | 16852eccbdfaf41a666705e3f8be55cf2864c5ca | Vendor (CNA) |
| Linux Linux | 2935e556850e9c94d7a00adf14d3cd7fe406ac03 | Vendor (CNA) |
| Linux Linux | 7ce9bb0b95fc280e9212b8922590c492ca1d9c39 | Vendor (CNA) |
| Linux Linux | 86f3dcd1f331cfd4fd7ec88906955134ec51afbe | Vendor (CNA) |
| Linux Linux | a351ff6b8ecca4229afaa0d98042bead8de64799 | Vendor (CNA) |
| Linux Linux | f8069f34c4c976786ded97498012225af87435d7 | Vendor (CNA) |
| debian:linux | 6.1.159-1 · Debian:12 | Package registry (OSV) |
| debian:linux-6.1 | 6.1.159-1~deb11u1 · Debian:11 | 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.
- CVE-2026-31608248 days apartsmb: server: avoid double-free in smb_direct_free_sendmsg after smb_direct_flush_send_list()39Monitor
- CVE-2026-31609248 days apartsmb: client: avoid double-free in smbd_free_send_io() after smbd_send_batch_flush()39Monitor
- CVE-2026-43011255 days apartnet/x25: Fix potential double free of skb39Monitor
- CVE-2026-43414262 days apartscsi: qla2xxx: Completely fix fcport double free39Monitor
- CVE-2026-52993309 days aparttipc: fix double-free in tipc_buf_append()39Monitor
- CVE-2026-64383340 days apartsmb: client: fix double-free in SMB2_flush() replay39Monitor
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-415 · Double FreeCVSS vector
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
nvd-primary
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/16852eccbdfaf41a666705e3f8be55cf2864c5ca
- git.kernel.org/stable/c/2935e556850e9c94d7a00adf14d3cd7fe406ac03
- git.kernel.org/stable/c/7ce9bb0b95fc280e9212b8922590c492ca1d9c39
- git.kernel.org/stable/c/86f3dcd1f331cfd4fd7ec88906955134ec51afbe
- git.kernel.org/stable/c/a351ff6b8ecca4229afaa0d98042bead8de64799
- git.kernel.org/stable/c/f8069f34c4c976786ded97498012225af87435d7
Vendor advisories and official records. Exploit/PoC links are deliberately left out.