[PATCH] fs/binfmt_elf: Fix memleak in load_elf_binary

From: Dinghao Liu
Date: Thu Aug 27 2020 - 08:09:21 EST


When arch_setup_additional_pages() fails, interp_elf_ex may
not have been freed, which leads to memleak. It's the same
when create_elf_tables() fails.

Signed-off-by: Dinghao Liu <dinghao.liu@xxxxxxxxxx>
---
fs/binfmt_elf.c | 9 +++++++--
1 file changed, 7 insertions(+), 2 deletions(-)

diff --git a/fs/binfmt_elf.c b/fs/binfmt_elf.c
index 13d053982dd7..984c30684e49 100644
--- a/fs/binfmt_elf.c
+++ b/fs/binfmt_elf.c
@@ -1204,6 +1204,7 @@ static int load_elf_binary(struct linux_binprm *bprm)
fput(interpreter);

kfree(interp_elf_ex);
+ interp_elf_ex = NULL;
kfree(interp_elf_phdata);
} else {
elf_entry = e_entry;
@@ -1219,14 +1220,18 @@ static int load_elf_binary(struct linux_binprm *bprm)

#ifdef ARCH_HAS_SETUP_ADDITIONAL_PAGES
retval = arch_setup_additional_pages(bprm, !!interpreter);
- if (retval < 0)
+ if (retval < 0) {
+ kfree(interp_elf_ex);
goto out;
+ }
#endif /* ARCH_HAS_SETUP_ADDITIONAL_PAGES */

retval = create_elf_tables(bprm, elf_ex,
load_addr, interp_load_addr, e_entry);
- if (retval < 0)
+ if (retval < 0) {
+ kfree(interp_elf_ex);
goto out;
+ }

mm = current->mm;
mm->end_code = end_code;
--
2.17.1