From: Oleg Nesterov <oleg@redhat.com>
To: Andrew Morton <akpm@linux-foundation.org>
Cc: linux-kernel@vger.kernel.org, andi@firstfloor.org,
David Howells <dhowells@redhat.com>,
Neil Horman <nhorman@tuxdriver.com>,
Roland McGrath <roland@redhat.com>
Subject: [PATCH 1/4] coredump: factor out the not-ispipe file checks
Date: Tue, 16 Mar 2010 20:38:31 +0100 [thread overview]
Message-ID: <20100316193831.GB31632@redhat.com> (raw)
In-Reply-To: <20100316193750.GA31632@redhat.com>
do_coredump() does a lot of file checks after it opens the file or
calls usermode helper. But all of these checks are only needed in
!ispipe case.
Move this code into the "else" branch and kill the ugly repetitive
ispipe checks.
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
---
fs/exec.c | 61 ++++++++++++++++++++++++++++++-------------------------------
1 file changed, 30 insertions(+), 31 deletions(-)
--- 34-rc1/fs/exec.c~1_ISREG 2010-03-15 20:00:42.000000000 +0100
+++ 34-rc1/fs/exec.c 2010-03-16 18:06:12.000000000 +0100
@@ -1834,7 +1834,6 @@ void do_coredump(long signr, int exit_co
char corename[CORENAME_MAX_SIZE + 1];
struct mm_struct *mm = current->mm;
struct linux_binfmt * binfmt;
- struct inode * inode;
const struct cred *old_cred;
struct cred *cred;
int retval = 0;
@@ -1911,9 +1910,6 @@ void do_coredump(long signr, int exit_co
ispipe = format_corename(corename, signr);
unlock_kernel();
- if ((!ispipe) && (cprm.limit < binfmt->min_coredump))
- goto fail_unlock;
-
if (ispipe) {
if (cprm.limit == 1) {
/*
@@ -1966,39 +1962,42 @@ void do_coredump(long signr, int exit_co
corename);
goto fail_dropcount;
}
- } else
+ } else {
+ struct inode *inode;
+
+ if (cprm.limit < binfmt->min_coredump)
+ goto fail_unlock;
+
cprm.file = filp_open(corename,
O_CREAT | 2 | O_NOFOLLOW | O_LARGEFILE | flag,
0600);
- if (IS_ERR(cprm.file))
- goto fail_dropcount;
- inode = cprm.file->f_path.dentry->d_inode;
- if (inode->i_nlink > 1)
- goto close_fail; /* multiple links - don't dump */
- if (!ispipe && d_unhashed(cprm.file->f_path.dentry))
- goto close_fail;
+ if (IS_ERR(cprm.file))
+ goto fail_unlock;
- /* AK: actually i see no reason to not allow this for named pipes etc.,
- but keep the previous behaviour for now. */
- if (!ispipe && !S_ISREG(inode->i_mode))
- goto close_fail;
- /*
- * Dont allow local users get cute and trick others to coredump
- * into their pre-created files:
- * Note, this is not relevant for pipes
- */
- if (!ispipe && (inode->i_uid != current_fsuid()))
- goto close_fail;
- if (!cprm.file->f_op)
- goto close_fail;
- if (!cprm.file->f_op->write)
- goto close_fail;
- if (!ispipe &&
- do_truncate(cprm.file->f_path.dentry, 0, 0, cprm.file) != 0)
- goto close_fail;
+ inode = cprm.file->f_path.dentry->d_inode;
+ if (inode->i_nlink > 1)
+ goto close_fail;
+ if (d_unhashed(cprm.file->f_path.dentry))
+ goto close_fail;
+ /*
+ * AK: actually i see no reason to not allow this for named
+ * pipes etc, but keep the previous behaviour for now.
+ */
+ if (!S_ISREG(inode->i_mode))
+ goto close_fail;
+ /*
+ * Dont allow local users get cute and trick others to coredump
+ * into their pre-created files.
+ */
+ if (inode->i_uid != current_fsuid())
+ goto close_fail;
+ if (!cprm.file->f_op || !cprm.file->f_op->write)
+ goto close_fail;
+ if (do_truncate(cprm.file->f_path.dentry, 0, 0, cprm.file))
+ goto close_fail;
+ }
retval = binfmt->core_dump(&cprm);
-
if (retval)
current->signal->group_exit_code |= 0x80;
close_fail:
next prev parent reply other threads:[~2010-03-16 19:40 UTC|newest]
Thread overview: 18+ messages / expand[flat|nested] mbox.gz Atom feed top
2010-03-15 12:29 [PATCH 0/2] exec: refactor how call_usermodehelper works, and update the sense of the core_pipe recursion check (v4 rediff) Neil Horman
2010-03-15 12:33 ` [PATCH 1/2] kmod: add init function to usermodehelper Neil Horman
2010-03-15 17:34 ` Oleg Nesterov
2010-03-15 17:56 ` Neil Horman
2010-03-15 12:36 ` [PATCH 2/2] exec: replace call_usermodehelper_pipe with use of umh init function and resolve limit Neil Horman
2010-03-15 17:39 ` Oleg Nesterov
2010-03-15 19:46 ` [PATCH 0/6] umh: keys, signals, misc Oleg Nesterov
2010-03-15 19:46 ` [PATCH 1/6] umh: creds: convert call_usermodehelper_keys() to use subprocess_info->init() Oleg Nesterov
2010-03-15 19:47 ` [PATCH 2/6] umh: creds: kill subprocess_info->cred logic Oleg Nesterov
2010-03-15 19:47 ` [PATCH 3/6] call_usermodehelper: no need to unblock signals Oleg Nesterov
2010-03-15 19:48 ` [PATCH 4/6] wait_for_helper: SIGCHLD from user-space can lead to use-after-free Oleg Nesterov
2010-03-15 19:48 ` [PATCH 5/6] call_usermodehelper: simplify/fix UMH_NO_WAIT case Oleg Nesterov
2010-03-15 19:49 ` [PATCH 6/6] call_usermodehelper: UMH_WAIT_EXEC ignores kernel_thread() failure Oleg Nesterov
2010-03-16 19:37 ` [PATCH 0/4] do_coredump: cleanups Oleg Nesterov
2010-03-16 19:38 ` Oleg Nesterov [this message]
2010-03-16 19:38 ` [PATCH 2/4] coredump: cleanup "ispipe" code Oleg Nesterov
2010-03-16 19:39 ` [PATCH 3/4] coredump: factor out put_cred() calls Oleg Nesterov
2010-03-16 19:39 ` [PATCH 4/4] coredump: shift down_write(mmap_sem) into coredump_wait() Oleg Nesterov
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20100316193831.GB31632@redhat.com \
--to=oleg@redhat.com \
--cc=akpm@linux-foundation.org \
--cc=andi@firstfloor.org \
--cc=dhowells@redhat.com \
--cc=linux-kernel@vger.kernel.org \
--cc=nhorman@tuxdriver.com \
--cc=roland@redhat.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox