nbd: fix uaf in nbd_genl_connect() error path

MITRE NVD CVE.ORG JSON API

Summary

CVECVE-2025-38443
StatePUBLISHED
AssignerLinux
Source PriorityCVE Program / NVD first with legacy fallback
Published2025-07-25 16:15:29 UTC
Updated2026-11-05 21:18:31 UTC
DescriptionIn the Linux kernel, the following vulnerability has been resolved: nbd: fix uaf in nbd_genl_connect() error path There is a use-after-free issue in nbd: block nbd6: Receive control failed (result -104) block nbd6: shutting down sockets ================================================================== BUG: KASAN: slab-use-after-free in recv_work+0x694/0xa80 drivers/block/nbd.c:1022 Write of size 4 at addr ffff8880295de478 by task kworker/u33:0/67 CPU: 2 UID: 0 PID: 67 Comm: kworker/u33:0 Not tainted 6.15.0-rc5-syzkaller-00123-g2c89c1b655c0 #0 PREEMPT(full) Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2~bpo12+1 04/01/2014 Workqueue: nbd6-recv recv_work Call Trace: <TASK> __dump_stack lib/dump_stack.c:94 [inline] dump_stack_lvl+0x116/0x1f0 lib/dump_stack.c:120 print_address_description mm/kasan/report.c:408 [inline] print_report+0xc3/0x670 mm/kasan/report.c:521 kasan_report+0xe0/0x110 mm/kasan/report.c:634 check_region_inline mm/kasan/generic.c:183 [inline] kasan_check_range+0xef/0x1a0 mm/kasan/generic.c:189 instrument_atomic_read_write include/linux/instrumented.h:96 [inline] atomic_dec include/linux/atomic/atomic-instrumented.h:592 [inline] recv_work+0x694/0xa80 drivers/block/nbd.c:1022 process_one_work+0x9cc/0x1b70 kernel/workqueue.c:3238 process_scheduled_works kernel/workqueue.c:3319 [inline] worker_thread+0x6c8/0xf10 kernel/workqueue.c:3400 kthread+0x3c2/0x780 kernel/kthread.c:464 ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:153 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 </TASK> nbd_genl_connect() does not properly stop the device on certain error paths after nbd_start_device() has been called. This causes the error path to put nbd->config while recv_work continue to use the config after putting it, leading to use-after-free in recv_work. This patch moves nbd_start_device() after the backend file creation.

Risk And Classification

Primary CVSS: v3.1 7.8 HIGH from [email protected]

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

Problem Types: CWE-416

CVSS v3.1 Breakdown

Attack Vector
Local
Attack Complexity
Low
Privileges Required
Low
User Interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
High
Availability
High

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

NVD Known Affected Configurations (CPE 2.3)

TypeVendorProductVersionUpdateEditionLanguage
Operating System Linux Linux Kernel All All All All

Vendor Declared Affected Products

SourceVendorProductVersionPlatforms
CNA Linux Linux affected 6497ef8df568afbf5f3e38825a4590ff41611a54 cb121c47f364b51776c4db904a6a5a90ab0a7ec5 git Not specified
CNA Linux Linux affected 6497ef8df568afbf5f3e38825a4590ff41611a54 91fa560c73a8126868848ed6cd70607cbf8d87e2 git Not specified
CNA Linux Linux affected 6497ef8df568afbf5f3e38825a4590ff41611a54 d46186eb7bbd9a11c145120f2d77effa8d4d44c2 git Not specified
CNA Linux Linux affected 6497ef8df568afbf5f3e38825a4590ff41611a54 8586552df591e0a367eff44af0c586213eeecc3f git Not specified
CNA Linux Linux affected 6497ef8df568afbf5f3e38825a4590ff41611a54 002aca89753f666d878ca0eb8584c372684ac4ba git Not specified
CNA Linux Linux affected 6497ef8df568afbf5f3e38825a4590ff41611a54 aa9552438ebf015fc5f9f890dbfe39f0c53cf37e git Not specified
CNA Linux Linux affected 5.14 Not specified
CNA Linux Linux unaffected 5.14 semver Not specified
CNA Linux Linux unaffected 5.15.189 5.15.* semver Not specified
CNA Linux Linux unaffected 6.1.146 6.1.* semver Not specified
CNA Linux Linux unaffected 6.6.99 6.6.* semver Not specified
CNA Linux Linux unaffected 6.12.39 6.12.* semver Not specified
CNA Linux Linux unaffected 6.15.7 6.15.* semver Not specified
CNA Linux Linux unaffected 6.16 * original_commit_for_fix Not specified

References

ReferenceSourceLinkTags
lists.debian.org/debian-lts-announce/2025/10/msg00008.html af854a3a-2127-422b-91ae-364da2661108 lists.debian.org Third Party Advisory
git.kernel.org/stable/c/8586552df591e0a367eff44af0c586213eeecc3f 416baaa9-dc9f-4396-8d5f-8c081fb06d67 git.kernel.org Patch
git.kernel.org/stable/c/d46186eb7bbd9a11c145120f2d77effa8d4d44c2 416baaa9-dc9f-4396-8d5f-8c081fb06d67 git.kernel.org Patch
git.kernel.org/stable/c/aa9552438ebf015fc5f9f890dbfe39f0c53cf37e 416baaa9-dc9f-4396-8d5f-8c081fb06d67 git.kernel.org Patch
git.kernel.org/stable/c/002aca89753f666d878ca0eb8584c372684ac4ba 416baaa9-dc9f-4396-8d5f-8c081fb06d67 git.kernel.org Patch
git.kernel.org/stable/c/cb121c47f364b51776c4db904a6a5a90ab0a7ec5 416baaa9-dc9f-4396-8d5f-8c081fb06d67 git.kernel.org Patch
git.kernel.org/stable/c/91fa560c73a8126868848ed6cd70607cbf8d87e2 416baaa9-dc9f-4396-8d5f-8c081fb06d67 git.kernel.org Patch
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