Bugzilla – Bug 1223708
VUL-0: CVE-2024-27058: kernel: tmpfs: fix race on handling dquot rbtree
Last modified: 2024-05-23 15:58:09 UTC
In the Linux kernel, the following vulnerability has been resolved: tmpfs: fix race on handling dquot rbtree A syzkaller reproducer found a race while attempting to remove dquot information from the rb tree. Fetching the rb_tree root node must also be protected by the dqopt->dqio_sem, otherwise, giving the right timing, shmem_release_dquot() will trigger a warning because it couldn't find a node in the tree, when the real reason was the root node changing before the search starts: Thread 1 Thread 2 - shmem_release_dquot() - shmem_{acquire,release}_dquot() - fetch ROOT - Fetch ROOT - acquire dqio_sem - wait dqio_sem - do something, triger a tree rebalance - release dqio_sem - acquire dqio_sem - start searching for the node, but from the wrong location, missing the node, and triggering a warning. References: http://web.nvd.nist.gov/view/vuln/detail?vulnId=CVE-2024-27058 https://www.cve.org/CVERecord?id=CVE-2024-27058 https://git.kernel.org/stable/c/0a69b6b3a026543bc215ccc866d0aea5579e6ce2 https://git.kernel.org/stable/c/617d55b90e73c7b4aa2733ca6cc3f9b72d1124bb https://git.kernel.org/stable/c/c7077f43f30d817d10a9f8245e51576ac114b2f0 https://git.kernel.org/stable/c/f82f184874d2761ebaa60dccf577921a0dbb3810 https://git.kernel.org/pub/scm/linux/security/vulns.git/plain/cve/published/2024/CVE-2024-27058.mbox https://bugzilla.redhat.com/show_bug.cgi?id=2278404
All done, closing.