From: Nick Alcock <nick.alcock@oracle.com>
Date: Mon, 31 Oct 2016 13:12:56 +0000 (+0000)
Subject: dtrace: check for errors when getting a new fd
X-Git-Tag: v4.1.12-92~25^2~6
X-Git-Url: https://www.infradead.org/git/?a=commitdiff_plain;h=9fe9473d0a8d810063bdfcc891edaef964827645;p=users%2Fjedix%2Flinux-maple.git

dtrace: check for errors when getting a new fd

get_unused_fd_flags() can legitimately fail, e.g. when the fd table is
full.  We need to diagnose that rather than trying to fd_install() the
resulting negative number.

Signed-off-by: Nick Alcock <nick.alcock@oracle.com>
Acked-by: Kris Van Hees <kris.van.hees@oracle.com>
Reviewed-by: Shannon Nelson <shannon.nelson@oracle.com>
Orabug: 24977175
---

diff --git a/kernel/ptrace.c b/kernel/ptrace.c
index 10467305c8eb..39d9be896e02 100644
--- a/kernel/ptrace.c
+++ b/kernel/ptrace.c
@@ -834,6 +834,11 @@ static int ptrace_getmapfd(struct task_struct *child, unsigned long addr,
 	}
 
 	new_fd = get_unused_fd_flags(O_CLOEXEC);
+	if (new_fd < 0) {
+		ret = new_fd;
+		goto err;
+	}
+
 	ret = __put_user(new_fd, datalp);
 	get_file(vma->vm_file);
 	fd_install(new_fd, vma->vm_file);