CVE-2025-21731
CVE.org · Published
- Record status
- Published
- Identifier year (not publication year)
- 2025
- Source publication
- Source updated
- Imported by cveboard
- Source snapshot
- cve_2026-10-24_midnight_baseline ·
CNA source text (English)
nbd: don't allow reconnect after disconnect
In the Linux kernel, the following vulnerability has been resolved: nbd: don't allow reconnect after disconnect Following process can cause nbd_config UAF: 1) grab nbd_config temporarily; 2) nbd_genl_disconnect() flush all recv_work() and release the initial reference: nbd_genl_disconnect nbd_disconnect_and_put nbd_disconnect flush_workqueue(nbd->recv_workq) if (test_and_clear_bit(NBD_RT_HAS_CONFIG_REF, ...)) nbd_config_put -> due to step 1), reference is still not zero 3) nbd_genl_reconfigure() queue recv_work() again; nbd_genl_reconfigure config = nbd_get_config_unlocked(nbd) if (!config) -> succeed if (!test_bit(NBD_RT_BOUND, ...)) -> succeed nbd_reconnect_socket queue_work(nbd->recv_workq, &args->work) 4) step 1) release the reference; 5) Finially, recv_work() will trigger UAF: recv_work nbd_config_put(nbd) -> nbd_config is freed atomic_dec(&config->recv_threads) -> UAF Fix the problem by clearing NBD_RT_BOUND in nbd_genl_disconnect(), so that nbd_genl_reconfigure() will fail.
Scoped product and version facts
Fix information unknown; no fixed version is derived here. Missing information does not prove that no fix exists.
Exploitation unknown; this catalogue does not assess exploitation.
Linux
- Vendor
- Linux
- Product
- Linux
- Platforms
- Unknown
- Default status
unaffected
| Version (version) | Status (status) | Version scheme (versionType) | Exclusive end (lessThan) | Inclusive end (lessThanOrEqual) | Status changes (at → status) |
|---|---|---|---|---|---|
| b7aa3d39385dc2d95899f9e379623fef446a2acd | affected | git | e70a578487a47d7cf058904141e586684d1c3381 | Unavailable | None listed |
| b7aa3d39385dc2d95899f9e379623fef446a2acd | affected | git | 6bef6222a3f6c7adb6396f77f25a3579d821b09a | Unavailable | None listed |
| b7aa3d39385dc2d95899f9e379623fef446a2acd | affected | git | e3be8862d73cac833e0fb7602636c19c6cb94b11 | Unavailable | None listed |
| b7aa3d39385dc2d95899f9e379623fef446a2acd | affected | git | e7343fa33751cb07c1c56b666bf37cfca357130e | Unavailable | None listed |
| b7aa3d39385dc2d95899f9e379623fef446a2acd | affected | git | d208d2c52b652913b5eefc8ca434b0d6b757f68f | Unavailable | None listed |
| b7aa3d39385dc2d95899f9e379623fef446a2acd | affected | git | a8ee6ecde2b7bfb58c8a3afe8a9d2b848f580739 | Unavailable | None listed |
| b7aa3d39385dc2d95899f9e379623fef446a2acd | affected | git | 9793bd5ae4bdbdb2dde401a3cab94a6bfd05e302 | Unavailable | None listed |
| b7aa3d39385dc2d95899f9e379623fef446a2acd | affected | git | 844b8cdc681612ff24df62cdefddeab5772fadf1 | Unavailable | None listed |
Linux
- Vendor
- Linux
- Product
- Linux
- Platforms
- Unknown
- Default status
affected
| Version (version) | Status (status) | Version scheme (versionType) | Exclusive end (lessThan) | Inclusive end (lessThanOrEqual) | Status changes (at → status) |
|---|---|---|---|---|---|
| 4.12 | affected | Unavailable | Unavailable | Unavailable | None listed |
| 0 | unaffected | semver | 4.12 | Unavailable | None listed |
| 5.4.291 | unaffected | semver | Unavailable | 5.4.* | None listed |
| 5.10.235 | unaffected | semver | Unavailable | 5.10.* | None listed |
| 5.15.179 | unaffected | semver | Unavailable | 5.15.* | None listed |
| 6.1.129 | unaffected | semver | Unavailable | 6.1.* | None listed |
| 6.6.76 | unaffected | semver | Unavailable | 6.6.* | None listed |
| 6.12.13 | unaffected | semver | Unavailable | 6.12.* | None listed |
| 6.13.2 | unaffected | semver | Unavailable | 6.13.* | None listed |
| 6.14 | unaffected | original_commit_for_fix | Unavailable | * | None listed |