brain-hackers_pepepper-mirror
/
linux-brain
mirror of https://github.com/brain-hackers/linux-brain.git
1
0
Fork 0
Code Issues Projects Releases Wiki Activity

binfmt_elf: Do not move brk for INTERP-less ET_EXEC 

commit 7be3cb019d upstream.

When brk was moved for binaries without an interpreter, it should have
been limited to ET_DYN only. In other words, the special case was an
ET_DYN that lacks an INTERP, not just an executable that lacks INTERP.
The bug manifested for giant static executables, where the brk would end
up in the middle of the text area on 32-bit architectures.

Reported-and-tested-by: Richard Kojedzinszky <richard@kojedz.in>
Fixes: bbdc6076d2 ("binfmt_elf: move brk out of mmap when doing direct loader exec")
Cc: stable@vger.kernel.org
Signed-off-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Kees Cook 2019-09-26 10:15:25 -07:00 committed by Greg Kroah-Hartman
parent 02ef5c299d
commit 29ecf8cae5
1 changed files with 2 additions and 1 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

3
fs/binfmt_elf.c
View File

@ -1144,7 +1144,8 @@ static int load_elf_binary(struct linux_binprm *bprm)
* (since it grows up, and may collide early with the stack
* growing down), and into the unused ELF_ET_DYN_BASE region.
*/
if (IS_ENABLED(CONFIG_ARCH_HAS_ELF_RANDOMIZE) && !interpreter)
if (IS_ENABLED(CONFIG_ARCH_HAS_ELF_RANDOMIZE) &&
loc->elf_ex.e_type == ET_DYN && !interpreter)
current->mm->brk = current->mm->start_brk =
ELF_ET_DYN_BASE;