7.8

CVE-2025-40028: binder: fix double-free in dbitmap

Deferred
AliasesUBUNTU-CVE-2025-40028DEBIAN-CVE-2025-40028
Published 28-10-2025Last modified 05-08-2026

Vulnerability summary

CVE-2025-40028 is a high (CVSS 7.8) vulnerability in linux. EPSS estimates a 0.15% chance of exploitation in the next 30 days, higher than 4.5% of scored vulnerabilities.

Priority
Routine

Not severe (CVSS 7.8, local access); no exploitation reported by the 5 checked sources

Source freshness unavailable

How is this decided?
CVSS score
7.8/10
010
High · v3.1 (CVE.org)
EPSS score
0.15%
0%100%
Low · 0.00 pp in 30 days
KEVNot listedNot listed by any tracked catalog.
RansomwareNot flaggedNo ransomware use recorded.
Public exploits0No public exploits recorded

Advisory lineage

Upstream 0 · Downstream 5 · Related 5
OPENSUSE-SU-2025:15702-1OPENSUSE-SU-2026:10301-1USN-7906-1USN-7906-2USN-7906-3

Timeline

  1. 28-10-2025
    PublishedVulnerability first disclosed.
  2. 05-08-2026
    Last modifiedVulnerability information updated.

Description

In the Linux kernel, the following vulnerability has been resolved: binder: fix double-free in dbitmap A process might fail to allocate a new bitmap when trying to expand its proc->dmap. In that case, dbitmap_grow() fails and frees the old bitmap via dbitmap_free(). However, the driver calls dbitmap_free() again when the same process terminates, leading to a double-free error: ================================================================== BUG: KASAN: double-free in binder_proc_dec_tmpref+0x2e0/0x55c Free of addr ffff00000b7c1420 by task kworker/9:1/209 CPU: 9 UID: 0 PID: 209 Comm: kworker/9:1 Not tainted 6.17.0-rc6-dirty #5 PREEMPT Hardware name: linux,dummy-virt (DT) Workqueue: events binder_deferred_func Call trace: kfree+0x164/0x31c binder_proc_dec_tmpref+0x2e0/0x55c binder_deferred_func+0xc24/0x1120 process_one_work+0x520/0xba4 [...] Allocated by task 448: __kmalloc_noprof+0x178/0x3c0 bitmap_zalloc+0x24/0x30 binder_open+0x14c/0xc10 [...] Freed by task 449: kfree+0x184/0x31c binder_inc_ref_for_node+0xb44/0xe44 binder_transaction+0x29b4/0x7fbc binder_thread_write+0x1708/0x442c binder_ioctl+0x1b50/0x2900 [...] ================================================================== Fix this issue by marking proc->map NULL in dbitmap_free().

CVSS metrics

4 scores · 4 sources · 1 version

EPSS trend

Probability

0.15%

Chance of exploitation in the next 30 days

Percentile

5%

Versus all other CVEs

30-day change

No change 0.00 pp

From 0.15% on 04-10-2026

04-10-202603-11-2026

Known exploited

Compare KEV catalogs
CISA KEV

Not in the CISA KEV catalog.

ENISA CNW

Not in the ENISA CNW catalog.

CIRCL

Not in the CIRCL catalog.

Public exploits

0 found

No public exploits indexed.

Weaknesses

CWE · root cause

No weakness data has been published for this record.

Affected systems

Version check

Known conditions: local access, low-privilege account, no user interaction (CVSS vector). Other conditions: not stated in public data.

Ubuntu99 products
  • linux< 6.17.0-7.7
  • linux-allwinner-5.19All versions (No fix recorded)
  • linux-aws< 6.17.0-1004.4
  • linux-aws-5.0All versions (No fix recorded)
  • linux-aws-5.11All versions (No fix recorded)
Debian1 product
  • linux< 6.12.57-1 | < 6.17.6-1
Linux1 product
  • linux≥ 15d9da3f818cae676f822a04407d3c17b53357d2, < c301ec61ce6f16e21a36b99225ca8a20c1591e10 | ≥ 15d9da3f818cae676f822a04407d3c17b53357d2, < 0390633979969c54c0ce6a198d6f45cdbe2c84b1 | ≥ 15d9da3f818cae676f822a04407d3c17b53357d2, < b781e5635a3398e2b64440371233c2c5102cd6cb | ≥ 15d9da3f818cae676f822a04407d3c17b53357d2, < 3ebcd3460cad351f198c39c6edb4af519a0ed934 | 6.11

3 vendors · 101 products

References

10 links