From f31e3386a4e92ba6eda7328cb508462956c94c64 Mon Sep 17 00:00:00 2001 From: Lakshmi Ramasubramanian Date: Thu, 4 Feb 2021 09:49:51 -0800 Subject: [PATCH] ima: Free IMA measurement buffer after kexec syscall 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 Suggested-by: Tyler Hicks Reviewed-by: Thiago Jung Bauermann Reviewed-by: Tyler Hicks Fixes: 7b8589cc29e7 ("ima: on soft reboot, save the measurement list") Signed-off-by: Mimi Zohar --- include/linux/kexec.h | 5 +++++ kernel/kexec_file.c | 5 +++++ security/integrity/ima/ima_kexec.c | 2 ++ 3 files changed, 12 insertions(+) diff --git a/include/linux/kexec.h b/include/linux/kexec.h index 9e93bef..5f61389 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 b02086d..5c3447c 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 206ddca..e29bea3 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); } -- 2.7.4