From 6d14c6517885fa68524238787420511b87d671df Mon Sep 17 00:00:00 2001 From: Lakshmi Ramasubramanian Date: Thu, 4 Feb 2021 09:49:50 -0800 Subject: ima: Free IMA measurement buffer on error 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. In error code paths this memory is not freed resulting in memory leak. Free the memory allocated for the IMA measurement list in the error code paths in ima_add_kexec_buffer() function. Signed-off-by: Lakshmi Ramasubramanian Suggested-by: Tyler Hicks Fixes: 7b8589cc29e7 ("ima: on soft reboot, save the measurement list") Signed-off-by: Mimi Zohar --- security/integrity/ima/ima_kexec.c | 1 + 1 file changed, 1 insertion(+) diff --git a/security/integrity/ima/ima_kexec.c b/security/integrity/ima/ima_kexec.c index 121de3e04af2..206ddcaa5c67 100644 --- a/security/integrity/ima/ima_kexec.c +++ b/security/integrity/ima/ima_kexec.c @@ -119,6 +119,7 @@ void ima_add_kexec_buffer(struct kimage *image) ret = kexec_add_buffer(&kbuf); if (ret) { pr_err("Error passing over kexec measurement buffer.\n"); + vfree(kexec_buffer); return; } -- cgit v1.2.3 From f31e3386a4e92ba6eda7328cb508462956c94c64 Mon Sep 17 00:00:00 2001 From: Lakshmi Ramasubramanian Date: Thu, 4 Feb 2021 09:49:51 -0800 Subject: 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 9e93bef52968..5f61389f5f36 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 b02086d70492..5c3447cf7ad5 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 206ddcaa5c67..e29bea3dd4cc 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); } -- cgit v1.2.3