[PATCH] coredump: run the coredump helper using the same namespace as the dead process

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



/proc/sys/kernel/core_pattern can be used to specify a userspace helper
to handle core files and it currently runs in the root namespace.
This patch allows the helper to run in the same namespace in a step
towards letting containers setting their own helpers.

Cc: "Serge E. Hallyn" <serge@xxxxxxxxxx>
Cc: "Eric W. Biederman" <ebiederm@xxxxxxxxxxxx>
Cc: Al Viro <viro@xxxxxxxxxxxxxxxxxx>
Signed-off-by: Aristeu Rozanski <aris@xxxxxxxxxx>

diff --git a/fs/coredump.c b/fs/coredump.c
index ce47379..fa14ea1 100644
--- a/fs/coredump.c
+++ b/fs/coredump.c
@@ -455,6 +455,19 @@ static int umh_pipe_setup(struct subprocess_info *info, struct cred *new)
 	/* and disallow core files too */
 	current->signal->rlim[RLIMIT_CORE] = (struct rlimit){1, 1};
 
+	/*
+	 * We want to run the helper within the same namespace. Since we
+	 * already forked, current here is using init_nsproxy and the usage
+	 * was already accounted. switch_task_namespace() will revert that
+	 * but we need to bump the dead process' nsproxy before calling the
+	 * the helper. Once it exits, the dead process' nsproxy usage will be
+	 * decremented as part of normal process exit.
+	 */
+	if (current->nsproxy != cp->nsproxy) {
+		get_nsproxy(cp->nsproxy);
+		switch_task_namespaces(current, cp->nsproxy);
+	}
+
 	return err;
 }
 
@@ -482,6 +495,8 @@ void do_coredump(siginfo_t *siginfo, struct pt_regs *regs)
 		 * by any locks.
 		 */
 		.mm_flags = mm->flags,
+		/* we run the helper in the same namespace */
+		.nsproxy = current->nsproxy,
 	};
 
 	audit_core_dumps(siginfo->si_signo);
diff --git a/include/linux/binfmts.h b/include/linux/binfmts.h
index cfcc6bf..45113e6 100644
--- a/include/linux/binfmts.h
+++ b/include/linux/binfmts.h
@@ -63,6 +63,7 @@ struct coredump_params {
 	struct file *file;
 	unsigned long limit;
 	unsigned long mm_flags;
+	struct nsproxy *nsproxy;
 };
 
 /*
--
To unsubscribe from this list: send the line "unsubscribe linux-fsdevel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html


[Index of Archives]     [Linux Ext4 Filesystem]     [Union Filesystem]     [Filesystem Testing]     [Ceph Users]     [Ecryptfs]     [AutoFS]     [Kernel Newbies]     [Share Photos]     [Security]     [Netfilter]     [Bugtraq]     [Yosemite News]     [MIPS Linux]     [ARM Linux]     [Linux Security]     [Linux Cachefs]     [Reiser Filesystem]     [Linux RAID]     [Samba]     [Device Mapper]     [CEPH Development]
  Powered by Linux