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authorPaul Burton <paul.burton@imgtec.com>2016-02-04 13:05:02 +0000
committerRalf Baechle <ralf@linux-mips.org>2016-04-03 12:32:10 +0200
commit04211a574641e29b529dcc84e75c03d7e9e368cf (patch)
tree8acdcb1e2379f5707734460608a72b0d214ae831 /arch/mips/kernel/module.c
parentf7f797cfc6c80a3505d1a316ee9aa3ec329289e9 (diff)
downloadlinux-04211a574641e29b529dcc84e75c03d7e9e368cf.tar.bz2
MIPS: Bail on unsupported module relocs
When an unsupported reloc is encountered in a module, we currently blindly branch to whatever would be at its entry in the reloc handler function pointer arrays. This may be NULL, or if the unsupported reloc has a type greater than that of the supported reloc with the highest type then we'll dereference some value after the function pointer array & branch to that. The result is at best a kernel oops. Fix this by checking that the reloc type has an entry in the function pointer array (ie. is less than the number of items in the array) and that the handler is non-NULL, returning an error code to fail the module load if no handler is found. Signed-off-by: Paul Burton <paul.burton@imgtec.com> Cc: James Hogan <james.hogan@imgtec.com> Cc: Steven J. Hill <Steven.Hill@imgtec.com> Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: linux-mips@linux-mips.org Cc: linux-kernel@vger.kernel.org Patchwork: https://patchwork.linux-mips.org/patch/12432/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Diffstat (limited to 'arch/mips/kernel/module.c')
-rw-r--r--arch/mips/kernel/module.c19
1 files changed, 16 insertions, 3 deletions
diff --git a/arch/mips/kernel/module.c b/arch/mips/kernel/module.c
index 1833f5171ccd..f9b2936d598d 100644
--- a/arch/mips/kernel/module.c
+++ b/arch/mips/kernel/module.c
@@ -197,9 +197,10 @@ int apply_relocate(Elf_Shdr *sechdrs, const char *strtab,
struct module *me)
{
Elf_Mips_Rel *rel = (void *) sechdrs[relsec].sh_addr;
+ int (*handler)(struct module *me, u32 *location, Elf_Addr v);
Elf_Sym *sym;
u32 *location;
- unsigned int i;
+ unsigned int i, type;
Elf_Addr v;
int res;
@@ -223,9 +224,21 @@ int apply_relocate(Elf_Shdr *sechdrs, const char *strtab,
return -ENOENT;
}
- v = sym->st_value;
+ type = ELF_MIPS_R_TYPE(rel[i]);
+
+ if (type < ARRAY_SIZE(reloc_handlers_rel))
+ handler = reloc_handlers_rel[type];
+ else
+ handler = NULL;
- res = reloc_handlers_rel[ELF_MIPS_R_TYPE(rel[i])](me, location, v);
+ if (!handler) {
+ pr_err("%s: Unknown relocation type %u\n",
+ me->name, type);
+ return -EINVAL;
+ }
+
+ v = sym->st_value;
+ res = handler(me, location, v);
if (res)
return res;
}