From 1dbf74e00a5f882b04b398399b6def65cd51ef21 Mon Sep 17 00:00:00 2001 From: Jonathan McDowell Date: Fri, 7 Mar 2025 12:25:23 +0000 Subject: [PATCH] tpm: End any active auth session before shutdown MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit Lazy flushing of TPM auth sessions can interact badly with IMA + kexec, resulting in loaded session handles being leaked across the kexec and not cleaned up. Fix by ensuring any active auth session is ended before the TPM is told about the shutdown, matching what is done when suspending. Before: root@debian-qemu-efi:~# tpm2_getcap handles-loaded-session root@debian-qemu-efi:~# tpm2_getcap handles-saved-session root@debian-qemu-efi:~# kexec --load --kexec-file-syscall … root@debian-qemu-efi:~# systemctl kexec … root@debian-qemu-efi:~# tpm2_getcap handles-loaded-session - 0x2000000 root@debian-qemu-efi:~# tpm2_getcap handles-saved-session root@debian-qemu-efi:~# (repeat kexec steps) root@debian-qemu-efi:~# tpm2_getcap handles-loaded-session - 0x2000000 - 0x2000001 root@debian-qemu-efi:~# tpm2_getcap handles-saved-session root@debian-qemu-efi:~# After: root@debian-qemu-efi:~# tpm2_getcap handles-loaded-session root@debian-qemu-efi:~# tpm2_getcap handles-saved-session root@debian-qemu-efi:~# kexec --load --kexec-file-syscall … root@debian-qemu-efi:~# systemctl kexec … root@debian-qemu-efi:~# tpm2_getcap handles-loaded-session root@debian-qemu-efi:~# tpm2_getcap handles-saved-session root@debian-qemu-efi:~# Signed-off-by: Jonathan McDowell Signed-off-by: Jarkko Sakkinen --- drivers/char/tpm/tpm-chip.c | 1 + 1 file changed, 1 insertion(+) diff --git a/drivers/char/tpm/tpm-chip.c b/drivers/char/tpm/tpm-chip.c index 6db864696a58..e25daf2396d3 100644 --- a/drivers/char/tpm/tpm-chip.c +++ b/drivers/char/tpm/tpm-chip.c @@ -305,6 +305,7 @@ int tpm_class_shutdown(struct device *dev) down_write(&chip->ops_sem); if (chip->flags & TPM_CHIP_FLAG_TPM2) { if (!tpm_chip_start(chip)) { + tpm2_end_auth_session(chip); tpm2_shutdown(chip, TPM2_SU_CLEAR); tpm_chip_stop(chip); } -- 2.50.1