{"cve":"CVE-2021-46951","nvd":{"published":"2024-02-27T19:04:06.470","modified":"2026-06-17T04:15:57.507","status":"Modified","description":"In the Linux kernel, the following vulnerability has been resolved:\n\ntpm: efi: Use local variable for calculating final log size\n\nWhen tpm_read_log_efi is called multiple times, which happens when\none loads and unloads a TPM2 driver multiple times, then the global\nvariable efi_tpm_final_log_size will at some point become a negative\nnumber due to the subtraction of final_events_preboot_size occurring\neach time. Use a local variable to avoid this integer underflow.\n\nThe following issue is now resolved:\n\nMar  8 15:35:12 hibinst kernel: Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 0.0.0 02/06/2015\nMar  8 15:35:12 hibinst kernel: Workqueue: tpm-vtpm vtpm_proxy_work [tpm_vtpm_proxy]\nMar  8 15:35:12 hibinst kernel: RIP: 0010:__memcpy+0x12/0x20\nMar  8 15:35:12 hibinst kernel: Code: 00 b8 01 00 00 00 85 d2 74 0a c7 05 44 7b ef 00 0f 00 00 00 c3 cc cc cc 66 66 90 66 90 48 89 f8 48 89 d1 48 c1 e9 03 83 e2 07 <f3> 48 a5 89 d1 f3 a4 c3 66 0f 1f 44 00 00 48 89 f8 48 89 d1 f3 a4\nMar  8 15:35:12 hibinst kernel: RSP: 0018:ffff9ac4c0fcfde0 EFLAGS: 00010206\nMar  8 15:35:12 hibinst kernel: RAX: ffff88f878cefed5 RBX: ffff88f878ce9000 RCX: 1ffffffffffffe0f\nMar  8 15:35:12 hibinst kernel: RDX: 0000000000000003 RSI: ffff9ac4c003bff9 RDI: ffff88f878cf0e4d\nMar  8 15:35:12 hibinst kernel: RBP: ffff9ac4c003b000 R08: 0000000000001000 R09: 000000007e9d6073\nMar  8 15:35:12 hibinst kernel: R10: ffff9ac4c003b000 R11: ffff88f879ad3500 R12: 0000000000000ed5\nMar  8 15:35:12 hibinst kernel: R13: ffff88f878ce9760 R14: 0000000000000002 R15: ffff88f77de7f018\nMar  8 15:35:12 hibinst kernel: FS:  0000000000000000(0000) GS:ffff88f87bd00000(0000) knlGS:0000000000000000\nMar  8 15:35:12 hibinst kernel: CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033\nMar  8 15:35:12 hibinst kernel: CR2: ffff9ac4c003c000 CR3: 00000001785a6004 CR4: 0000000000060ee0\nMar  8 15:35:12 hibinst kernel: Call Trace:\nMar  8 15:35:12 hibinst kernel: tpm_read_log_efi+0x152/0x1a7\nMar  8 15:35:12 hibinst kernel: tpm_bios_log_setup+0xc8/0x1c0\nMar  8 15:35:12 hibinst kernel: tpm_chip_register+0x8f/0x260\nMar  8 15:35:12 hibinst kernel: vtpm_proxy_work+0x16/0x60 [tpm_vtpm_proxy]\nMar  8 15:35:12 hibinst kernel: process_one_work+0x1b4/0x370\nMar  8 15:35:12 hibinst kernel: worker_thread+0x53/0x3e0\nMar  8 15:35:12 hibinst kernel: ? process_one_work+0x370/0x370","cvss_v4":null,"cvss_v3":{"version":"3.1","vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H","score":5.5},"cwes":["CWE-191"],"references":["https://git.kernel.org/stable/c/2f12258b5224cfaa808c54fd29345f3c1cbfca76","https://git.kernel.org/stable/c/3818b753277f5ca0c170bf5b98e0a5a225542fcb","https://git.kernel.org/stable/c/48cff270b037022e37835d93361646205ca25101","https://git.kernel.org/stable/c/60a01ecc9f68067e4314a0b55148e39e5d58a51b","https://git.kernel.org/stable/c/ac07c557ca12ec9276c0375517bac7ae5be4e50c"],"products":["linux:linux_kernel"],"source":"nvd","synced_at":"2026-10-19T21:45:59.823092188+00:00"},"epss":{"cve":"CVE-2021-46951","score":0.00235,"percentile":0.1455,"date":"2026-11-01"},"kev":null,"osv":[],"attribution":["This product uses the NVD API but is not endorsed or certified by the NVD.","EPSS scores: FIRST Exploit Prediction Scoring System, https://www.first.org/epss","Known exploited vulnerabilities: CISA Known Exploited Vulnerabilities Catalog, https://www.cisa.gov/known-exploited-vulnerabilities-catalog","Package advisories: OSV (https://osv.dev), from the GitHub Advisory Database, PyPA, Go, RustSec and other ecosystem databases, under CC-BY 4.0 or CC0","CVE records: the CVE Program's CVE List (https://www.cve.org), under its terms of use (https://www.cve.org/Legal/TermsOfUse). CVE is a registered trademark of The MITRE Corporation; this product is not affiliated with the CVE Program."]}