mm, elf: handle vm_brk error

commit ecc2bc8ac03884266cf73f8a2a42b911465b2fbc upstream.

load_elf_library doesn't handle vm_brk failure although nothing really
indicates it cannot do that because the function is allowed to fail due
to vm_mmap failures already.  This might be not a problem now but later
patch will make vm_brk killable (resp.  mmap_sem for write waiting will
become killable) and so the failure will be more probable.

Signed-off-by: Michal Hocko <mhocko@suse.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Ben Hutchings <ben.hutchings@codethink.co.uk>
Signed-off-by: Sasha Levin <sashal@kernel.org>

diff --git a/fs/binfmt_elf.c b/fs/binfmt_elf.c
index 62bc720..70ea4b9 100644 (file)
--- a/fs/binfmt_elf.c
+++ b/fs/binfmt_elf.c
@@ -1215,8 +1215,11 @@ static int load_elf_library(struct file *file)
        len = ELF_PAGESTART(eppnt->p_filesz + eppnt->p_vaddr +
                            ELF_MIN_ALIGN - 1);
        bss = eppnt->p_memsz + eppnt->p_vaddr;
-       if (bss > len)
-               vm_brk(len, bss - len);
+       if (bss > len) {
+               error = vm_brk(len, bss - len);
+               if (BAD_ADDR(error))
+                       goto out_free_ph;
+       }
        error = 0;
 
 out_free_ph: