{"id":"AZL-73458","summary":"CVE-2025-38488 affecting package kernel for versions less than 5.15.200.1-1","details":"In the Linux kernel, the following vulnerability has been resolved:\n\nsmb: client: fix use-after-free in crypt_message when using async crypto\n\nThe CVE-2024-50047 fix removed asynchronous crypto handling from\ncrypt_message(), assuming all crypto operations are synchronous.\nHowever, when hardware crypto accelerators are used, this can cause\nuse-after-free crashes:\n\n  crypt_message()\n    // Allocate the creq buffer containing the req\n    creq = smb2_get_aead_req(..., &req);\n\n    // Async encryption returns -EINPROGRESS immediately\n    rc = enc ? crypto_aead_encrypt(req) : crypto_aead_decrypt(req);\n\n    // Free creq while async operation is still in progress\n    kvfree_sensitive(creq, ...);\n\nHardware crypto modules often implement async AEAD operations for\nperformance. When crypto_aead_encrypt/decrypt() returns -EINPROGRESS,\nthe operation completes asynchronously. Without crypto_wait_req(),\nthe function immediately frees the request buffer, leading to crashes\nwhen the driver later accesses the freed memory.\n\nThis results in a use-after-free condition when the hardware crypto\ndriver later accesses the freed request structure, leading to kernel\ncrashes with NULL pointer dereferences.\n\nThe issue occurs because crypto_alloc_aead() with mask=0 doesn't\nguarantee synchronous operation. Even without CRYPTO_ALG_ASYNC in\nthe mask, async implementations can be selected.\n\nFix by restoring the async crypto handling:\n- DECLARE_CRYPTO_WAIT(wait) for completion tracking\n- aead_request_set_callback() for async completion notification\n- crypto_wait_req() to wait for operation completion\n\nThis ensures the request buffer isn't freed until the crypto operation\ncompletes, whether synchronous or asynchronous, while preserving the\nCVE-2024-50047 fix.","modified":"2026-04-01T05:22:17.200170Z","published":"2025-07-28T12:15:30Z","upstream":["CVE-2025-38488"],"references":[{"type":"WEB","url":"https://nvd.nist.gov/vuln/detail/CVE-2025-38488"}],"affected":[{"package":{"name":"kernel","ecosystem":"Azure Linux:2","purl":"pkg:rpm/azure-linux/kernel"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"5.15.200.1-1"}]}],"database_specific":{"source":"https://github.com/microsoft/AzureLinuxVulnerabilityData/blob/main/osv/AZL-73458.json"}}],"schema_version":"1.7.5"}