{"id":"CVE-2026-53038","summary":"ima_fs: Correctly create securityfs files for unsupported hash algos","details":"In the Linux kernel, the following vulnerability has been resolved:\n\nima_fs: Correctly create securityfs files for unsupported hash algos\n\nima_tpm_chip-\u003eallocated_banks[i].crypto_id is initialized to\nHASH_ALGO__LAST if the TPM algorithm is not supported. However there\nare places relying on the algorithm to be valid because it is accessed\nby hash_algo_name[].\n\nOn 6.12.40 I observe the following read out-of-bounds in hash_algo_name:\n  ==================================================================\n  BUG: KASAN: global-out-of-bounds in create_securityfs_measurement_lists+0x396/0x440\n  Read of size 8 at addr ffffffff83e18138 by task swapper/0/1\n\n  CPU: 4 UID: 0 PID: 1 Comm: swapper/0 Not tainted 6.12.40 #3\n  Call Trace:\n   \u003cTASK\u003e\n   dump_stack_lvl+0x61/0x90\n   print_report+0xc4/0x580\n   ? kasan_addr_to_slab+0x26/0x80\n   ? create_securityfs_measurement_lists+0x396/0x440\n   kasan_report+0xc2/0x100\n   ? create_securityfs_measurement_lists+0x396/0x440\n   create_securityfs_measurement_lists+0x396/0x440\n   ima_fs_init+0xa3/0x300\n   ima_init+0x7d/0xd0\n   init_ima+0x28/0x100\n   do_one_initcall+0xa6/0x3e0\n   kernel_init_freeable+0x455/0x740\n   kernel_init+0x24/0x1d0\n   ret_from_fork+0x38/0x80\n   ret_from_fork_asm+0x11/0x20\n   \u003c/TASK\u003e\n\n  The buggy address belongs to the variable:\n   hash_algo_name+0xb8/0x420\n\n  Memory state around the buggy address:\n   ffffffff83e18000: 00 01 f9 f9 f9 f9 f9 f9 00 01 f9 f9 f9 f9 f9 f9\n   ffffffff83e18080: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00\n  \u003effffffff83e18100: 00 00 00 00 00 00 00 f9 f9 f9 f9 f9 00 05 f9 f9\n                                          ^\n   ffffffff83e18180: f9 f9 f9 f9 00 00 00 00 00 00 00 04 f9 f9 f9 f9\n   ffffffff83e18200: 00 00 00 00 00 00 00 00 04 f9 f9 f9 f9 f9 f9 f9\n  ==================================================================\n\nSeems like the TPM chip supports sha3_256, which isn't yet in\ntpm_algorithms:\n  tpm tpm0: TPM with unsupported bank algorithm 0x0027\n\nThat's TPM_ALG_SHA3_256 == 0x0027 from \"Trusted Platform Module 2.0\nLibrary Part 2: Structures\", page 51 [1].\nSee also the related U-Boot algorithms update [2].\n\nThus solve the problem by creating a file name with \"_tpm_alg_\u003cID\u003e\"\npostfix if the crypto algorithm isn't initialized.\n\nThis is how it looks on the test machine (patch ported to v6.12 release):\n  # ls -1 /sys/kernel/security/ima/\n  ascii_runtime_measurements\n  ascii_runtime_measurements_tpm_alg_27\n  ascii_runtime_measurements_sha1\n  ascii_runtime_measurements_sha256\n  binary_runtime_measurements\n  binary_runtime_measurements_tpm_alg_27\n  binary_runtime_measurements_sha1\n  binary_runtime_measurements_sha256\n  policy\n  runtime_measurements_count\n  violations\n\n[1]: https://trustedcomputinggroup.org/wp-content/uploads/Trusted-Platform-Module-2.0-Library-Part-2-Version-184_pub.pdf\n[2]: https://lists.denx.de/pipermail/u-boot/2024-July/558835.html","modified":"2026-07-16T03:32:26.932904118Z","published":"2026-06-24T16:29:45.086Z","database_specific":{"cna_assigner":"Linux","osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/53xxx/CVE-2026-53038.json"},"references":[{"type":"WEB","url":"https://git.kernel.org/stable/c/081b557cb56e1cfa8d1619b2601b01c53e3f418c"},{"type":"WEB","url":"https://git.kernel.org/stable/c/88d4e89a39f0de07798ca3fd93bd1a9ea212a82e"},{"type":"WEB","url":"https://git.kernel.org/stable/c/b6766b171a5c4c33b26ff6fec530cb798db1f75e"},{"type":"WEB","url":"https://git.kernel.org/stable/c/d7bd8cf0b348d3edae7bee33e74a32b21668b181"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/53xxx/CVE-2026-53038.json"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-53038"},{"type":"PACKAGE","url":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git"}],"affected":[{"ranges":[{"type":"GIT","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","events":[{"introduced":"9fa8e76250082a45d0d3dad525419ab98bd01658"},{"fixed":"081b557cb56e1cfa8d1619b2601b01c53e3f418c"},{"fixed":"b6766b171a5c4c33b26ff6fec530cb798db1f75e"},{"fixed":"88d4e89a39f0de07798ca3fd93bd1a9ea212a82e"},{"fixed":"d7bd8cf0b348d3edae7bee33e74a32b21668b181"}]}],"database_specific":{"source":"https://storage.googleapis.com/osv-test-cve-osv-conversion/osv-output/CVE-2026-53038.json"}},{"package":{"name":"Kernel","ecosystem":"Linux"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"6.10.0"},{"fixed":"6.12.91"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.13.0"},{"fixed":"6.18.33"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.19.0"},{"fixed":"7.0.10"}]}],"database_specific":{"source":"https://storage.googleapis.com/osv-test-cve-osv-conversion/osv-output/CVE-2026-53038.json"}}],"schema_version":"1.7.5"}