From: ebiederm@xmission.com (Eric W. Biederman)
To: <linux-kernel@vger.kernel.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>,
Oleg Nesterov <oleg@redhat.com>, Jann Horn <jannh@google.com>,
Kees Cook <keescook@chromium.org>,
Greg Ungerer <gerg@linux-m68k.org>, Rob Landley <rob@landley.net>,
Bernd Edlinger <bernd.edlinger@hotmail.de>,
<linux-fsdevel@vger.kernel.org>,
Al Viro <viro@ZenIV.linux.org.uk>,
Alexey Dobriyan <adobriyan@gmail.com>,
Andrew Morton <akpm@linux-foundation.org>
Subject: [PATCH 6/7] exec: Move most of setup_new_exec into flush_old_exec
Date: Tue, 05 May 2020 14:45:33 -0500 [thread overview]
Message-ID: <87ftcei2si.fsf@x220.int.ebiederm.org> (raw)
In-Reply-To: <87h7wujhmz.fsf@x220.int.ebiederm.org> (Eric W. Biederman's message of "Tue, 05 May 2020 14:39:32 -0500")
The current idiom for the callers is:
flush_old_exec(bprm);
set_personality(...);
setup_new_exec(bprm);
In 2010 Linus split flush_old_exec into flush_old_exec and
setup_new_exec. With the intention that setup_new_exec be what is
called after the processes new personality is set.
Move the code that doesn't depend upon the personality from
setup_new_exec into flush_old_exec. This is to facilitate future
changes by having as much code together in one function as possible.
Ref: 221af7f87b97 ("Split 'flush_old_exec' into two functions")
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
---
fs/exec.c | 85 ++++++++++++++++++++++++++++---------------------------
1 file changed, 44 insertions(+), 41 deletions(-)
diff --git a/fs/exec.c b/fs/exec.c
index 8c3abafb9bb1..0eff20558735 100644
--- a/fs/exec.c
+++ b/fs/exec.c
@@ -1359,39 +1359,7 @@ int flush_old_exec(struct linux_binprm * bprm)
* undergoing exec(2).
*/
do_close_on_exec(me->files);
- return 0;
-
-out_unlock:
- mutex_unlock(&me->signal->exec_update_mutex);
-out:
- return retval;
-}
-EXPORT_SYMBOL(flush_old_exec);
-
-void would_dump(struct linux_binprm *bprm, struct file *file)
-{
- struct inode *inode = file_inode(file);
- if (inode_permission(inode, MAY_READ) < 0) {
- struct user_namespace *old, *user_ns;
- bprm->interp_flags |= BINPRM_FLAGS_ENFORCE_NONDUMP;
-
- /* Ensure mm->user_ns contains the executable */
- user_ns = old = bprm->mm->user_ns;
- while ((user_ns != &init_user_ns) &&
- !privileged_wrt_inode_uidgid(user_ns, inode))
- user_ns = user_ns->parent;
- if (old != user_ns) {
- bprm->mm->user_ns = get_user_ns(user_ns);
- put_user_ns(old);
- }
- }
-}
-EXPORT_SYMBOL(would_dump);
-
-void setup_new_exec(struct linux_binprm * bprm)
-{
- struct task_struct *me = current;
/*
* Once here, prepare_binrpm() will not be called any more, so
* the final state of setuid/setgid/fscaps can be merged into the
@@ -1414,8 +1382,6 @@ void setup_new_exec(struct linux_binprm * bprm)
bprm->rlim_stack.rlim_cur = _STK_LIM;
}
- arch_pick_mmap_layout(me->mm, &bprm->rlim_stack);
-
me->sas_ss_sp = me->sas_ss_size = 0;
/*
@@ -1430,16 +1396,9 @@ void setup_new_exec(struct linux_binprm * bprm)
else
set_dumpable(current->mm, SUID_DUMP_USER);
- arch_setup_new_exec();
perf_event_exec();
__set_task_comm(me, kbasename(bprm->filename), true);
- /* Set the new mm task size. We have to do that late because it may
- * depend on TIF_32BIT which is only updated in flush_thread() on
- * some architectures like powerpc
- */
- me->mm->task_size = TASK_SIZE;
-
/* An exec changes our domain. We are no longer part of the thread
group */
WRITE_ONCE(me->self_exec_id, me->self_exec_id + 1);
@@ -1467,6 +1426,50 @@ void setup_new_exec(struct linux_binprm * bprm)
* credentials; any time after this it may be unlocked.
*/
security_bprm_committed_creds(bprm);
+ return 0;
+
+out_unlock:
+ mutex_unlock(&me->signal->exec_update_mutex);
+out:
+ return retval;
+}
+EXPORT_SYMBOL(flush_old_exec);
+
+void would_dump(struct linux_binprm *bprm, struct file *file)
+{
+ struct inode *inode = file_inode(file);
+ if (inode_permission(inode, MAY_READ) < 0) {
+ struct user_namespace *old, *user_ns;
+ bprm->interp_flags |= BINPRM_FLAGS_ENFORCE_NONDUMP;
+
+ /* Ensure mm->user_ns contains the executable */
+ user_ns = old = bprm->mm->user_ns;
+ while ((user_ns != &init_user_ns) &&
+ !privileged_wrt_inode_uidgid(user_ns, inode))
+ user_ns = user_ns->parent;
+
+ if (old != user_ns) {
+ bprm->mm->user_ns = get_user_ns(user_ns);
+ put_user_ns(old);
+ }
+ }
+}
+EXPORT_SYMBOL(would_dump);
+
+void setup_new_exec(struct linux_binprm * bprm)
+{
+ /* Setup things that can depend upon the personality */
+ struct task_struct *me = current;
+
+ arch_pick_mmap_layout(me->mm, &bprm->rlim_stack);
+
+ arch_setup_new_exec();
+
+ /* Set the new mm task size. We have to do that late because it may
+ * depend on TIF_32BIT which is only updated in flush_thread() on
+ * some architectures like powerpc
+ */
+ me->mm->task_size = TASK_SIZE;
mutex_unlock(&me->signal->exec_update_mutex);
mutex_unlock(&me->signal->cred_guard_mutex);
}
--
2.20.1
next prev parent reply other threads:[~2020-05-05 19:49 UTC|newest]
Thread overview: 149+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-05-05 19:39 exec: Promised cleanups after introducing exec_update_mutex Eric W. Biederman
2020-05-05 19:41 ` [PATCH 1/7] binfmt: Move install_exec_creds after setup_new_exec to match binfmt_elf Eric W. Biederman
2020-05-05 20:45 ` Kees Cook
2020-05-06 12:42 ` Greg Ungerer
2020-05-06 12:56 ` Eric W. Biederman
2020-05-05 19:41 ` [PATCH 2/7] exec: Make unlocking exec_update_mutex explict Eric W. Biederman
2020-05-05 20:46 ` Kees Cook
2020-05-05 19:42 ` [PATCH 3/7] exec: Rename the flag called_exec_mmap point_of_no_return Eric W. Biederman
2020-05-05 20:49 ` Kees Cook
2020-05-05 19:43 ` [PATCH 4/7] exec: Merge install_exec_creds into setup_new_exec Eric W. Biederman
2020-05-05 20:50 ` Kees Cook
2020-05-05 19:44 ` [PATCH 5/7] exec: In setup_new_exec cache current in the local variable me Eric W. Biederman
2020-05-05 20:51 ` Kees Cook
2020-05-05 19:45 ` Eric W. Biederman [this message]
2020-05-05 21:29 ` [PATCH 6/7] exec: Move most of setup_new_exec into flush_old_exec Kees Cook
2020-05-06 14:57 ` Eric W. Biederman
2020-05-06 15:30 ` Kees Cook
2020-05-07 19:51 ` Eric W. Biederman
2020-05-07 21:51 ` Eric W. Biederman
2020-05-08 5:50 ` Kees Cook
2020-05-05 19:46 ` [PATCH 7/7] exec: Rename flush_old_exec begin_new_exec Eric W. Biederman
2020-05-05 21:30 ` Kees Cook
2020-05-06 12:41 ` exec: Promised cleanups after introducing exec_update_mutex Greg Ungerer
2020-05-08 18:43 ` [PATCH 0/6] exec: Trivial cleanups for exec Eric W. Biederman
2020-05-08 18:44 ` [PATCH 1/6] exec: Move the comment from above de_thread to above unshare_sighand Eric W. Biederman
2020-05-09 5:02 ` Kees Cook
2020-05-08 18:44 ` [PATCH 2/6] exec: Fix spelling of search_binary_handler in a comment Eric W. Biederman
2020-05-09 5:03 ` Kees Cook
2020-05-08 18:45 ` [PATCH 3/6] exec: Stop open coding mutex_lock_killable of cred_guard_mutex Eric W. Biederman
2020-05-09 5:08 ` Kees Cook
2020-05-09 19:18 ` Linus Torvalds
2020-05-09 19:57 ` Eric W. Biederman
2020-05-10 20:33 ` Kees Cook
2020-05-08 18:45 ` [PATCH 4/6] exec: Run sync_mm_rss before taking exec_update_mutex Eric W. Biederman
2020-05-09 5:15 ` Kees Cook
2020-05-09 14:17 ` Eric W. Biederman
2020-05-08 18:47 ` [PATCH 5/6] exec: Move handling of the point of no return to the top level Eric W. Biederman
2020-05-09 5:31 ` Kees Cook
2020-05-09 13:39 ` Eric W. Biederman
2020-05-08 18:48 ` [PATCH 6/6] exec: Set the point of no return sooner Eric W. Biederman
2020-05-09 5:33 ` Kees Cook
2020-05-09 19:40 ` [PATCH 0/5] exec: Control flow simplifications Eric W. Biederman
2020-05-09 19:40 ` [PATCH 1/5] exec: Call cap_bprm_set_creds directly from prepare_binprm Eric W. Biederman
2020-05-09 20:04 ` Linus Torvalds
2020-05-09 19:41 ` [PATCH 2/5] exec: Directly call security_bprm_set_creds from __do_execve_file Eric W. Biederman
2020-05-09 20:07 ` Linus Torvalds
2020-05-09 20:12 ` Eric W. Biederman
2020-05-09 20:19 ` Linus Torvalds
2020-05-11 3:15 ` Kees Cook
2020-05-11 16:52 ` Eric W. Biederman
2020-05-11 21:18 ` Kees Cook
2020-05-09 19:41 ` [PATCH 3/5] exec: Remove recursion from search_binary_handler Eric W. Biederman
2020-05-09 20:16 ` Linus Torvalds
2020-05-10 4:22 ` Tetsuo Handa
2020-05-10 19:38 ` Linus Torvalds
2020-05-11 14:33 ` Eric W. Biederman
2020-05-11 19:10 ` Rob Landley
2020-05-13 21:59 ` Eric W. Biederman
2020-05-14 18:46 ` Rob Landley
2020-05-11 21:55 ` Kees Cook
2020-05-12 18:42 ` Eric W. Biederman
2020-05-12 19:25 ` Kees Cook
2020-05-12 20:31 ` Eric W. Biederman
2020-05-12 23:08 ` Kees Cook
2020-05-12 23:47 ` Kees Cook
2020-05-12 23:51 ` Kees Cook
2020-05-14 14:56 ` Eric W. Biederman
2020-05-14 16:56 ` Casey Schaufler
2020-05-14 17:02 ` Eric W. Biederman
2020-05-13 0:20 ` Linus Torvalds
2020-05-13 2:39 ` Rob Landley
2020-05-13 19:51 ` Linus Torvalds
2020-05-14 16:49 ` Eric W. Biederman
2020-05-09 19:42 ` [PATCH 4/5] exec: Allow load_misc_binary to call prepare_binfmt unconditionally Eric W. Biederman
2020-05-11 22:09 ` Kees Cook
2020-05-09 19:42 ` [PATCH 5/5] exec: Move the call of prepare_binprm into search_binary_handler Eric W. Biederman
2020-05-11 22:24 ` Kees Cook
2020-05-19 0:29 ` [PATCH v2 0/8] exec: Control flow simplifications Eric W. Biederman
2020-05-19 0:29 ` [PATCH v2 1/8] exec: Teach prepare_exec_creds how exec treats uids & gids Eric W. Biederman
2020-05-19 18:03 ` Kees Cook
2020-05-19 18:28 ` Linus Torvalds
2020-05-19 18:57 ` Eric W. Biederman
2020-05-19 0:30 ` [PATCH v2 2/8] exec: Factor security_bprm_creds_for_exec out of security_bprm_set_creds Eric W. Biederman
2020-05-19 15:34 ` Casey Schaufler
2020-05-19 18:10 ` Kees Cook
2020-05-19 21:28 ` James Morris
2020-05-19 0:31 ` [PATCH v2 3/8] exec: Convert security_bprm_set_creds into security_bprm_repopulate_creds Eric W. Biederman
2020-05-19 18:21 ` Kees Cook
2020-05-19 19:03 ` Eric W. Biederman
2020-05-19 19:14 ` Kees Cook
2020-05-20 20:22 ` Eric W. Biederman
2020-05-20 20:53 ` Kees Cook
2020-05-19 21:52 ` James Morris
2020-05-20 12:40 ` Eric W. Biederman
2020-05-19 0:31 ` [PATCH v2 4/8] exec: Allow load_misc_binary to call prepare_binfmt unconditionally Eric W. Biederman
2020-05-19 18:27 ` Kees Cook
2020-05-19 19:08 ` Eric W. Biederman
2020-05-19 19:17 ` Kees Cook
2020-05-19 0:32 ` [PATCH v2 5/8] exec: Move the call of prepare_binprm into search_binary_handler Eric W. Biederman
2020-05-19 18:27 ` Kees Cook
2020-05-19 21:30 ` James Morris
2020-05-19 0:33 ` [PATCH v2 6/8] exec/binfmt_script: Don't modify bprm->buf and then return -ENOEXEC Eric W. Biederman
2020-05-19 19:08 ` Kees Cook
2020-05-19 19:19 ` Eric W. Biederman
2020-05-19 0:33 ` [PATCH v2 7/8] exec: Generic execfd support Eric W. Biederman
2020-05-19 19:46 ` Kees Cook
2020-05-19 19:54 ` Linus Torvalds
2020-05-19 20:20 ` Eric W. Biederman
2020-05-19 21:59 ` Rob Landley
2020-05-20 16:05 ` Eric W. Biederman
2020-05-21 22:50 ` Rob Landley
2020-05-22 3:28 ` Eric W. Biederman
2020-05-22 4:51 ` Rob Landley
2020-05-22 13:35 ` Eric W. Biederman
2020-05-19 0:34 ` [PATCH v2 8/8] exec: Remove recursion from search_binary_handler Eric W. Biederman
2020-05-19 20:37 ` Kees Cook
2020-05-19 1:25 ` [PATCH v2 0/8] exec: Control flow simplifications Linus Torvalds
2020-05-19 21:55 ` Kees Cook
2020-05-20 13:02 ` Eric W. Biederman
2020-05-20 22:12 ` Eric W. Biederman
2020-05-20 23:43 ` Kees Cook
2020-05-21 11:53 ` Eric W. Biederman
2020-05-28 15:38 ` [PATCH 0/11] exec: cred calculation simplifications Eric W. Biederman
2020-05-28 15:41 ` [PATCH 01/11] exec: Reduce bprm->per_clear to a single bit Eric W. Biederman
2020-05-28 19:04 ` Linus Torvalds
2020-05-28 19:17 ` Eric W. Biederman
2020-05-28 15:42 ` [PATCH 02/11] exec: Introduce active_per_clear the per file version of per_clear Eric W. Biederman
2020-05-28 19:05 ` Linus Torvalds
2020-05-28 15:42 ` [PATCH 03/11] exec: Compute file based creds only once Eric W. Biederman
2020-05-28 15:43 ` [PATCH 04/11] exec: Move uid/gid handling from creds_from_file into bprm_fill_uid Eric W. Biederman
2020-05-28 15:44 ` Eric W. Biederman
2020-05-28 15:44 ` [PATCH 05/11] exec: In bprm_fill_uid use CAP_SETGID to see if a gid change is safe Eric W. Biederman
2020-05-28 15:48 ` [PATCH 06/11] exec: Don't set secureexec when the uid or gid changes are abandoned Eric W. Biederman
2020-05-28 15:48 ` [PATCH 07/11] exec: Set saved, fs, and effective ids together in bprm_fill_uid Eric W. Biederman
2020-05-28 15:49 ` [PATCH 08/11] exec: In bprm_fill_uid remove unnecessary no new privs check Eric W. Biederman
2020-05-28 15:49 ` [PATCH 09/11] exec: In bprm_fill_uid only set per_clear when honoring suid or sgid Eric W. Biederman
2020-05-28 19:08 ` Linus Torvalds
2020-05-28 19:21 ` Eric W. Biederman
2020-05-28 15:50 ` [PATCH 10/11] exec: In bprm_fill_uid set secureexec at same time as per_clear Eric W. Biederman
2020-05-28 15:50 ` [PATCH 11/11] exec: Remove the label after_setid from bprm_fill_uid Eric W. Biederman
2020-05-29 16:45 ` [PATCH 0/2] exec: Remove the computation of bprm->cred Eric W. Biederman
2020-05-29 16:46 ` [PATCH 1/2] exec: Add a per bprm->file version of per_clear Eric W. Biederman
2020-05-29 21:06 ` Kees Cook
2020-05-30 3:23 ` Eric W. Biederman
2020-05-30 5:14 ` Kees Cook
2020-05-29 16:47 ` [PATCH 2/2] exec: Compute file based creds only once Eric W. Biederman
2020-05-29 21:24 ` Kees Cook
2020-05-30 3:28 ` Eric W. Biederman
2020-05-30 5:18 ` Kees Cook
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