{"id":"AZL-54895","summary":"CVE-2024-56755 affecting package kernel for versions less than 6.6.64.2-1","details":"In the Linux kernel, the following vulnerability has been resolved:\n\nnetfs/fscache: Add a memory barrier for FSCACHE_VOLUME_CREATING\n\nIn fscache_create_volume(), there is a missing memory barrier between the\nbit-clearing operation and the wake-up operation. This may cause a\nsituation where, after a wake-up, the bit-clearing operation hasn't been\ndetected yet, leading to an indefinite wait. The triggering process is as\nfollows:\n\n  [cookie1]                [cookie2]                  [volume_work]\nfscache_perform_lookup\n  fscache_create_volume\n                        fscache_perform_lookup\n                          fscache_create_volume\n\t\t\t                        fscache_create_volume_work\n                                                  cachefiles_acquire_volume\n                                                  clear_and_wake_up_bit\n    test_and_set_bit\n                            test_and_set_bit\n                              goto maybe_wait\n      goto no_wait\n\nIn the above process, cookie1 and cookie2 has the same volume. When cookie1\nenters the -no_wait- process, it will clear the bit and wake up the waiting\nprocess. If a barrier is missing, it may cause cookie2 to remain in the\n-wait- process indefinitely.\n\nIn commit 3288666c7256 (\"fscache: Use clear_and_wake_up_bit() in\nfscache_create_volume_work()\"), barriers were added to similar operations\nin fscache_create_volume_work(), but fscache_create_volume() was missed.\n\nBy combining the clear and wake operations into clear_and_wake_up_bit() to\nfix this issue.","modified":"2026-04-01T05:18:26.104893Z","published":"2024-12-29T12:15:09Z","upstream":["CVE-2024-56755"],"references":[{"type":"WEB","url":"https://nvd.nist.gov/vuln/detail/CVE-2024-56755"}],"affected":[{"package":{"name":"kernel","ecosystem":"Azure Linux:3","purl":"pkg:rpm/azure-linux/kernel"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"6.6.64.2-1"}]}],"database_specific":{"source":"https://github.com/microsoft/AzureLinuxVulnerabilityData/blob/main/osv/AZL-54895.json"}}],"schema_version":"1.7.5","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H"}]}