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authorLakshmi Ramasubramanian <nramas@linux.microsoft.com>2021-02-04 09:49:51 -0800
committerMimi Zohar <zohar@linux.ibm.com>2021-02-10 15:49:38 -0500
commitf31e3386a4e92ba6eda7328cb508462956c94c64 (patch)
treed98da3e377fd2f3cfd48683f66c7e57246f70700
parent6d14c6517885fa68524238787420511b87d671df (diff)
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 <nramas@linux.microsoft.com> Suggested-by: Tyler Hicks <tyhicks@linux.microsoft.com> Reviewed-by: Thiago Jung Bauermann <bauerman@linux.ibm.com> Reviewed-by: Tyler Hicks <tyhicks@linux.microsoft.com> Fixes: 7b8589cc29e7 ("ima: on soft reboot, save the measurement list") Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
-rw-r--r--include/linux/kexec.h5
-rw-r--r--kernel/kexec_file.c5
-rw-r--r--security/integrity/ima/ima_kexec.c2
3 files changed, 12 insertions, 0 deletions
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);
}