1 files changed, 34 insertions, 9 deletions

diff --git a/arch/mips/kernel/module.c b/arch/mips/kernel/module.c
index a5066b1c3de3..4f8c3cba8c0c 100644
--- a/arch/mips/kernel/module.c
+++ b/arch/mips/kernel/module.c
@@ -39,8 +39,6 @@ struct mips_hi16 {
 	Elf_Addr value;
 };
 
-static struct mips_hi16 *mips_hi16_list;
-
 static LIST_HEAD(dbe_list);
 static DEFINE_SPINLOCK(dbe_lock);
 
@@ -128,8 +126,8 @@ static int apply_r_mips_hi16_rel(struct module *me, u32 *location, Elf_Addr v)
 
 	n->addr = (Elf_Addr *)location;
 	n->value = v;
-	n->next = mips_hi16_list;
-	mips_hi16_list = n;
+	n->next = me->arch.r_mips_hi16_list;
+	me->arch.r_mips_hi16_list = n;
 
 	return 0;
 }
@@ -142,18 +140,28 @@ static int apply_r_mips_hi16_rela(struct module *me, u32 *location, Elf_Addr v)
 	return 0;
 }
 
+static void free_relocation_chain(struct mips_hi16 *l)
+{
+	struct mips_hi16 *next;
+
+	while (l) {
+		next = l->next;
+		kfree(l);
+		l = next;
+	}
+}
+
 static int apply_r_mips_lo16_rel(struct module *me, u32 *location, Elf_Addr v)
 {
 	unsigned long insnlo = *location;
+	struct mips_hi16 *l;
 	Elf_Addr val, vallo;
 
 	/* Sign extend the addend we extract from the lo insn.  */
 	vallo = ((insnlo & 0xffff) ^ 0x8000) - 0x8000;
 
-	if (mips_hi16_list != NULL) {
-		struct mips_hi16 *l;
-
-		l = mips_hi16_list;
+	if (me->arch.r_mips_hi16_list != NULL) {
+		l = me->arch.r_mips_hi16_list;
 		while (l != NULL) {
 			struct mips_hi16 *next;
 			unsigned long insn;
@@ -188,7 +196,7 @@ static int apply_r_mips_lo16_rel(struct module *me, u32 *location, Elf_Addr v)
 			l = next;
 		}
 
-		mips_hi16_list = NULL;
+		me->arch.r_mips_hi16_list = NULL;
 	}
 
 	/*
@@ -201,6 +209,9 @@ static int apply_r_mips_lo16_rel(struct module *me, u32 *location, Elf_Addr v)
 	return 0;
 
 out_danger:
+	free_relocation_chain(l);
+	me->arch.r_mips_hi16_list = NULL;
+
 	pr_err("module %s: dangerous R_MIPS_LO16 REL relocation\n", me->name);
 
 	return -ENOEXEC;
@@ -273,6 +284,7 @@ int apply_relocate(Elf_Shdr *sechdrs, const char *strtab,
 	pr_debug("Applying relocate section %u to %u\n", relsec,
 	       sechdrs[relsec].sh_info);
 
+	me->arch.r_mips_hi16_list = NULL;
 	for (i = 0; i < sechdrs[relsec].sh_size / sizeof(*rel); i++) {
 		/* This is where to make the change */
 		location = (void *)sechdrs[sechdrs[relsec].sh_info].sh_addr
@@ -296,6 +308,19 @@ int apply_relocate(Elf_Shdr *sechdrs, const char *strtab,
 			return res;
 	}
 
+	/*
+	 * Normally the hi16 list should be deallocated at this point.  A
+	 * malformed binary however could contain a series of R_MIPS_HI16
+	 * relocations not followed by a R_MIPS_LO16 relocation.  In that
+	 * case, free up the list and return an error.
+	 */
+	if (me->arch.r_mips_hi16_list) {
+		free_relocation_chain(me->arch.r_mips_hi16_list);
+		me->arch.r_mips_hi16_list = NULL;
+
+		return -ENOEXEC;
+	}
+
 	return 0;
 }