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-rw-r--r--fs/binfmt_elf.c12
-rw-r--r--include/linux/auxvec.h6
2 files changed, 15 insertions, 3 deletions
diff --git a/fs/binfmt_elf.c b/fs/binfmt_elf.c
index c41fa2af767..e3ff2b9e602 100644
--- a/fs/binfmt_elf.c
+++ b/fs/binfmt_elf.c
@@ -152,8 +152,10 @@ create_elf_tables(struct linux_binprm *bprm, struct elfhdr *exec,
elf_addr_t __user *sp;
elf_addr_t __user *u_platform;
elf_addr_t __user *u_base_platform;
+ elf_addr_t __user *u_rand_bytes;
const char *k_platform = ELF_PLATFORM;
const char *k_base_platform = ELF_BASE_PLATFORM;
+ unsigned char k_rand_bytes[16];
int items;
elf_addr_t *elf_info;
int ei_index = 0;
@@ -196,6 +198,15 @@ create_elf_tables(struct linux_binprm *bprm, struct elfhdr *exec,
return -EFAULT;
}
+ /*
+ * Generate 16 random bytes for userspace PRNG seeding.
+ */
+ get_random_bytes(k_rand_bytes, sizeof(k_rand_bytes));
+ u_rand_bytes = (elf_addr_t __user *)
+ STACK_ALLOC(p, sizeof(k_rand_bytes));
+ if (__copy_to_user(u_rand_bytes, k_rand_bytes, sizeof(k_rand_bytes)))
+ return -EFAULT;
+
/* Create the ELF interpreter info */
elf_info = (elf_addr_t *)current->mm->saved_auxv;
/* update AT_VECTOR_SIZE_BASE if the number of NEW_AUX_ENT() changes */
@@ -228,6 +239,7 @@ create_elf_tables(struct linux_binprm *bprm, struct elfhdr *exec,
NEW_AUX_ENT(AT_GID, cred->gid);
NEW_AUX_ENT(AT_EGID, cred->egid);
NEW_AUX_ENT(AT_SECURE, security_bprm_secureexec(bprm));
+ NEW_AUX_ENT(AT_RANDOM, (elf_addr_t)(unsigned long)u_rand_bytes);
NEW_AUX_ENT(AT_EXECFN, bprm->exec);
if (k_platform) {
NEW_AUX_ENT(AT_PLATFORM,
diff --git a/include/linux/auxvec.h b/include/linux/auxvec.h
index d7afa9dd663..f3b5d4e3a2a 100644
--- a/include/linux/auxvec.h
+++ b/include/linux/auxvec.h
@@ -23,16 +23,16 @@
#define AT_PLATFORM 15 /* string identifying CPU for optimizations */
#define AT_HWCAP 16 /* arch dependent hints at CPU capabilities */
#define AT_CLKTCK 17 /* frequency at which times() increments */
-
+/* AT_* values 18 through 22 are reserved */
#define AT_SECURE 23 /* secure mode boolean */
-
#define AT_BASE_PLATFORM 24 /* string identifying real platform, may
* differ from AT_PLATFORM. */
+#define AT_RANDOM 25 /* address of 16 random bytes */
#define AT_EXECFN 31 /* filename of program */
#ifdef __KERNEL__
-#define AT_VECTOR_SIZE_BASE 18 /* NEW_AUX_ENT entries in auxiliary table */
+#define AT_VECTOR_SIZE_BASE 19 /* NEW_AUX_ENT entries in auxiliary table */
/* number of "#define AT_.*" above, minus {AT_NULL, AT_IGNORE, AT_NOTELF} */
#endif