[PATCH 3.16 250/366] mm, elf: handle vm_brk error

Ben Hutchings
2018-11-12T05:48:12Z

From: Michal Hocko <mhocko@suse.com>

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@decadent.org.uk>
---
fs/binfmt_elf.c | 7 +++++--
1 file changed, 5 insertions(+), 2 deletions(-)

--- a/fs/binfmt_elf.c
+++ b/fs/binfmt_elf.c
@@ -1084,8 +1084,11 @@ static int load_elf_library(struct 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;