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CVE PROGRAM SOURCE RECORD7.8 High

CVE-2025-21731

nbd: don't allow reconnect after disconnect

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Status
Published
Published
Updated
Assigning organization
Linux

Description

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.

Affected products

Version statuses are supplied by the assigning organization. Consult the original record for detailed ranges and platform conditions.

Linux Linux

Default version status: unaffected

  • b7aa3d39385dc2d95899f9e379623fef446a2acd to < e70a578487a47d7cf058904141e586684d1c3381affected
  • b7aa3d39385dc2d95899f9e379623fef446a2acd to < 6bef6222a3f6c7adb6396f77f25a3579d821b09aaffected
  • b7aa3d39385dc2d95899f9e379623fef446a2acd to < e3be8862d73cac833e0fb7602636c19c6cb94b11affected
  • b7aa3d39385dc2d95899f9e379623fef446a2acd to < e7343fa33751cb07c1c56b666bf37cfca357130eaffected
  • b7aa3d39385dc2d95899f9e379623fef446a2acd to < d208d2c52b652913b5eefc8ca434b0d6b757f68faffected
  • b7aa3d39385dc2d95899f9e379623fef446a2acd to < a8ee6ecde2b7bfb58c8a3afe8a9d2b848f580739affected
  • b7aa3d39385dc2d95899f9e379623fef446a2acd to < 9793bd5ae4bdbdb2dde401a3cab94a6bfd05e302affected
  • b7aa3d39385dc2d95899f9e379623fef446a2acd to < 844b8cdc681612ff24df62cdefddeab5772fadf1affected

Linux Linux

Default version status: affected

  • 4.12affected
  • 0 to < 4.12unaffected
  • 5.4.291 to ≤ 5.4.*unaffected
  • 5.10.235 to ≤ 5.10.*unaffected
  • 5.15.179 to ≤ 5.15.*unaffected
  • 6.1.129 to ≤ 6.1.*unaffected
  • 6.6.76 to ≤ 6.6.*unaffected
  • 6.12.13 to ≤ 6.12.*unaffected
  • 6.13.2 to ≤ 6.13.*unaffected
  • 6.14 to ≤ *unaffected

References