This is a note to let you know that I've just added the patch titled ima: Free IMA measurement buffer after kexec syscall to the 5.10-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: ima-free-ima-measurement-buffer-after-kexec-syscall.patch and it can be found in the queue-5.10 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. commit 6697f438241d5db81f9f6236c69c08f59a37bdae Author: Lakshmi Ramasubramanian <nramas@xxxxxxxxxxxxxxxxxxx> Date: Thu Feb 4 09:49:51 2021 -0800 ima: Free IMA measurement buffer after kexec syscall [ Upstream commit f31e3386a4e92ba6eda7328cb508462956c94c64 ] IMA allocates kernel virtual memory to carry forward the measurement list, from the current kernel to the next kernel on kexec system call, in ima_add_kexec_buffer() function. This buffer is not freed before completing the kexec system call resulting in memory leak. Add ima_buffer field in "struct kimage" to store the virtual address of the buffer allocated for the IMA measurement list. Free the memory allocated for the IMA measurement list in kimage_file_post_load_cleanup() function. Signed-off-by: Lakshmi Ramasubramanian <nramas@xxxxxxxxxxxxxxxxxxx> Suggested-by: Tyler Hicks <tyhicks@xxxxxxxxxxxxxxxxxxx> Reviewed-by: Thiago Jung Bauermann <bauerman@xxxxxxxxxxxxx> Reviewed-by: Tyler Hicks <tyhicks@xxxxxxxxxxxxxxxxxxx> Fixes: 7b8589cc29e7 ("ima: on soft reboot, save the measurement list") Signed-off-by: Mimi Zohar <zohar@xxxxxxxxxxxxx> Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> diff --git a/include/linux/kexec.h b/include/linux/kexec.h index 9e93bef529680..5f61389f5f361 100644 --- a/include/linux/kexec.h +++ b/include/linux/kexec.h @@ -300,6 +300,11 @@ struct kimage { /* Information for loading purgatory */ struct purgatory_info purgatory_info; #endif + +#ifdef CONFIG_IMA_KEXEC + /* Virtual address of IMA measurement buffer for kexec syscall */ + void *ima_buffer; +#endif }; /* kexec interface functions */ diff --git a/kernel/kexec_file.c b/kernel/kexec_file.c index e21f6b9234f7a..7825adcc5efc3 100644 --- a/kernel/kexec_file.c +++ b/kernel/kexec_file.c @@ -166,6 +166,11 @@ void kimage_file_post_load_cleanup(struct kimage *image) vfree(pi->sechdrs); pi->sechdrs = NULL; +#ifdef CONFIG_IMA_KEXEC + vfree(image->ima_buffer); + image->ima_buffer = NULL; +#endif /* CONFIG_IMA_KEXEC */ + /* See if architecture has anything to cleanup post load */ arch_kimage_file_post_load_cleanup(image); diff --git a/security/integrity/ima/ima_kexec.c b/security/integrity/ima/ima_kexec.c index 206ddcaa5c67a..e29bea3dd4ccd 100644 --- a/security/integrity/ima/ima_kexec.c +++ b/security/integrity/ima/ima_kexec.c @@ -129,6 +129,8 @@ void ima_add_kexec_buffer(struct kimage *image) return; } + image->ima_buffer = kexec_buffer; + pr_debug("kexec measurement buffer for the loaded kernel at 0x%lx.\n", kbuf.mem); }