CVE-2025-22126
md: fix mddev uaf while iterating all_mddevs list
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md: fix mddev uaf while iterating all_mddevs list
In the Linux kernel, the following vulnerability has been resolved: md: fix mddev uaf while iterating all_mddevs list While iterating all_mddevs list from md_notify_reboot() and md_exit(), list_for_each_entry_safe is used, and this can race with deletint the next mddev, causing UAF: t1: spin_lock //list_for_each_entry_safe(mddev, n, ...) mddev_get(mddev1) // assume mddev2 is the next entry spin_unlock t2: //remove mddev2 ... mddev_free spin_lock list_del spin_unlock kfree(mddev2) mddev_put(mddev1) spin_lock //continue dereference mddev2->all_mddevs The old helper for_each_mddev() actually grab the reference of mddev2 while holding the lock, to prevent from being freed. This problem can be fixed the same way, however, the code will be complex. Hence switch to use list_for_each_entry, in this case mddev_put() can free the mddev1 and it's not safe as well. Refer to md_seq_show(), also factor out a helper mddev_put_locked() to fix this problem.
Reserved 2024-12-29 | Published 2025-04-16 | Updated 2025-05-26 | Assigner Linuxgit.kernel.org/...c/ca9f84de76723b358dfc0606668efdca54afc2e5
git.kernel.org/...c/d69a23d8e925f8052d657652a6875ec2712c7e33
git.kernel.org/...c/e2a9f73ee408a460f4c9dfe03b4741d6b11652b8
git.kernel.org/...c/5462544ccbad3fc938a71b01fa5bd3a0dc2b750a
git.kernel.org/...c/8542870237c3a48ff049b6c5df5f50c8728284fa
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