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Commit 33933af4 authored by Eric W. Biederman's avatar Eric W. Biederman Committed by Greg Kroah-Hartman
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binfmt: Move install_exec_creds after setup_new_exec to match binfmt_elf 



[ Upstream commit e7f7785449a1f459a4a3ca92f82f56fb054dd2b9 ]

In 2016 Linus moved install_exec_creds immediately after
setup_new_exec, in binfmt_elf as a cleanup and as part of closing a
potential information leak.

Perform the same cleanup for the other binary formats.

Different binary formats doing the same things the same way makes exec
easier to reason about and easier to maintain.

Greg Ungerer reports:
> I tested the the whole series on non-MMU m68k and non-MMU arm
> (exercising binfmt_flat) and it all tested out with no problems,
> so for the binfmt_flat changes:
Tested-by: default avatarGreg Ungerer <gerg@linux-m68k.org>

Ref: 9f834ec1 ("binfmt_elf: switch to new creds when switching to new mm")
Reviewed-by: default avatarKees Cook <keescook@chromium.org>
Reviewed-by: default avatarGreg Ungerer <gerg@linux-m68k.org>
Signed-off-by: default avatar"Eric W. Biederman" <ebiederm@xmission.com>
Stable-dep-of: e7f703ff2507 ("binfmt: Fix error return code in load_elf_fdpic_binary()")
Signed-off-by: default avatarSasha Levin <sashal@kernel.org>
parent 3cdd91a9

arch/x86/ia32/ia32_aout.c

+1 −2
Original line number Diff line number Diff line
@@ -140,6 +140,7 @@ static int load_aout_binary(struct linux_binprm *bprm) 
	set_personality_ia32(false);



	setup_new_exec(bprm);

	install_exec_creds(bprm);



	regs->cs = __USER32_CS;

	regs->r8 = regs->r9 = regs->r10 = regs->r11 = regs->r12 =
@@ -156,8 +157,6 @@ static int load_aout_binary(struct linux_binprm *bprm) 
	if (retval < 0)

		return retval;



	install_exec_creds(bprm);



	if (N_MAGIC(ex) == OMAGIC) {

		unsigned long text_addr, map_size;

fs/binfmt_aout.c

+1 −1
Original line number Diff line number Diff line
@@ -162,6 +162,7 @@ static int load_aout_binary(struct linux_binprm * bprm) 
	set_personality(PER_LINUX);

#endif

	setup_new_exec(bprm);

	install_exec_creds(bprm);



	current->mm->end_code = ex.a_text +

		(current->mm->start_code = N_TXTADDR(ex));
@@ -174,7 +175,6 @@ static int load_aout_binary(struct linux_binprm * bprm) 
	if (retval < 0)

		return retval;



	install_exec_creds(bprm);



	if (N_MAGIC(ex) == OMAGIC) {

		unsigned long text_addr, map_size;

fs/binfmt_elf_fdpic.c

+1 −1
Original line number Diff line number Diff line
@@ -353,6 +353,7 @@ static int load_elf_fdpic_binary(struct linux_binprm *bprm) 
		current->personality |= READ_IMPLIES_EXEC;



	setup_new_exec(bprm);

	install_exec_creds(bprm);



	set_binfmt(&elf_fdpic_format);
@@ -434,7 +435,6 @@ static int load_elf_fdpic_binary(struct linux_binprm *bprm) 
	current->mm->start_stack = current->mm->start_brk + stack_size;

#endif



	install_exec_creds(bprm);

	if (create_elf_fdpic_tables(bprm, current->mm,

				    &exec_params, &interp_params) < 0)

		goto error;

fs/binfmt_flat.c

+1 −2
Original line number Diff line number Diff line
@@ -565,6 +565,7 @@ static int load_flat_file(struct linux_binprm *bprm, 
		/* OK, This is the point of no return */

		set_personality(PER_LINUX_32BIT);

		setup_new_exec(bprm);

		install_exec_creds(bprm);

	}



	/*
@@ -992,8 +993,6 @@ static int load_flat_binary(struct linux_binprm *bprm) 
		}

	}



	install_exec_creds(bprm);



	set_binfmt(&flat_format);



#ifdef CONFIG_MMU