From 0be70cf211a7c060c1eefa1c9190296652e48419 Mon Sep 17 00:00:00 2001 From: "Eric W. Biederman" Date: Thu, 12 Mar 2020 10:17:17 -0500 Subject: [PATCH] binfmt: Move install_exec_creds after setup_new_exec to match binfmt_elf [ Upstream commit a6ed697e132e94715ac57e427bf97a73109c776a ] 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: Greg Ungerer Ref: 7ef7b9e2eed4 ("binfmt_elf: switch to new creds when switching to new mm") Reviewed-by: Kees Cook Reviewed-by: Greg Ungerer Signed-off-by: "Eric W. Biederman" Stable-dep-of: e7f703ff2507 ("binfmt: Fix error return code in load_elf_fdpic_binary()") Signed-off-by: Sasha Levin --- arch/x86/ia32/ia32_aout.c | 3 +-- fs/binfmt_aout.c | 2 +- fs/binfmt_elf_fdpic.c | 2 +- fs/binfmt_flat.c | 3 +-- 4 files changed, 4 insertions(+), 6 deletions(-) diff --git a/arch/x86/ia32/ia32_aout.c b/arch/x86/ia32/ia32_aout.c index 9bb71abd66bd3..37b36a8ce5fa7 100644 --- a/arch/x86/ia32/ia32_aout.c +++ b/arch/x86/ia32/ia32_aout.c @@ -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; diff --git a/fs/binfmt_aout.c b/fs/binfmt_aout.c index 8e8346a81723c..ace587b66904c 100644 --- a/fs/binfmt_aout.c +++ b/fs/binfmt_aout.c @@ -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; diff --git a/fs/binfmt_elf_fdpic.c b/fs/binfmt_elf_fdpic.c index d86ebd0dcc3d3..9f785627009ca 100644 --- a/fs/binfmt_elf_fdpic.c +++ b/fs/binfmt_elf_fdpic.c @@ -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; diff --git a/fs/binfmt_flat.c b/fs/binfmt_flat.c index c999bc0c0691f..22a7d7547a91b 100644 --- a/fs/binfmt_flat.c +++ b/fs/binfmt_flat.c @@ -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 -- 2.39.5