From 63e46b95e9eae1161832bf45cb40bbad37bfb182 Mon Sep 17 00:00:00 2001
From: Oleg Nesterov <oleg@redhat.com>
Date: Thu, 23 Jan 2014 15:55:51 -0800
Subject: [PATCH] exec: move the final allow_write_access/fput into free_bprm()
Both success/failure paths cleanup bprm->file, we can move this
code into free_bprm() to simlify and cleanup this logic.
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Acked-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Acked-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
---
fs/exec.c | 20 +++++---------------
1 file changed, 5 insertions(+), 15 deletions(-)
diff --git a/fs/exec.c b/fs/exec.c
index 389fe7b0ba148..f860866e04ba1 100644
--- a/fs/exec.c
+++ b/fs/exec.c
@@ -1138,9 +1138,7 @@ void setup_new_exec(struct linux_binprm * bprm)
/* An exec changes our domain. We are no longer part of the thread
group */
-
current->self_exec_id++;
-
flush_signal_handlers(current, 0);
do_close_on_exec(current->files);
}
@@ -1172,6 +1170,10 @@ void free_bprm(struct linux_binprm *bprm)
mutex_unlock(¤t->signal->cred_guard_mutex);
abort_creds(bprm->cred);
}
+ if (bprm->file) {
+ allow_write_access(bprm->file);
+ fput(bprm->file);
+ }
/* If a binfmt changed the interp, free it. */
if (bprm->interp != bprm->filename)
kfree(bprm->interp);
@@ -1424,12 +1426,6 @@ static int exec_binprm(struct linux_binprm *bprm)
ptrace_event(PTRACE_EVENT_EXEC, old_vpid);
current->did_exec = 1;
proc_exec_connector(current);
-
- if (bprm->file) {
- allow_write_access(bprm->file);
- fput(bprm->file);
- bprm->file = NULL; /* to catch use-after-free */
- }
}
return ret;
@@ -1492,7 +1488,7 @@ static int do_execve_common(const char *filename,
retval = bprm_mm_init(bprm);
if (retval)
- goto out_file;
+ goto out_unmark;
bprm->argc = count(argv, MAX_ARG_STRINGS);
if ((retval = bprm->argc) < 0)
@@ -1539,12 +1535,6 @@ static int do_execve_common(const char *filename,
mmput(bprm->mm);
}
-out_file:
- if (bprm->file) {
- allow_write_access(bprm->file);
- fput(bprm->file);
- }
-
out_unmark:
current->fs->in_exec = 0;
current->in_execve = 0;
--
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