Patch "mm, fs: check for fatal signals in do_generic_file_read()" has been added to the 4.4-stable tree

Patch "mm, fs: check for fatal signals in do_generic_file_read()" has been added to the 4.4-stable tree

[gregkh]

This is a note to let you know that I've just added the patch titled

    mm, fs: check for fatal signals in do_generic_file_read()

to the 4.4-stable tree which can be found at:
    http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
     mm-fs-check-for-fatal-signals-in-do_generic_file_read.patch
and it can be found in the queue-4.4 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@vger.kernel.org> know about it.


>From 5abf186a30a89d5b9c18a6bf93a2c192c9fd52f6 Mon Sep 17 00:00:00 2001
From: Michal Hocko <mhocko@suse.com>
Date: Fri, 3 Feb 2017 13:13:29 -0800
Subject: mm, fs: check for fatal signals in do_generic_file_read()

From: Michal Hocko <mhocko@suse.com>

commit 5abf186a30a89d5b9c18a6bf93a2c192c9fd52f6 upstream.

do_generic_file_read() can be told to perform a large request from
userspace.  If the system is under OOM and the reading task is the OOM
victim then it has an access to memory reserves and finishing the full
request can lead to the full memory depletion which is dangerous.  Make
sure we rather go with a short read and allow the killed task to
terminate.

Link: http://lkml.kernel.org/r/20170201092706.9966-3-mhocko@kernel.org
Signed-off-by: Michal Hocko <mhocko@suse.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Cc: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
 mm/filemap.c |    5 +++++
 1 file changed, 5 insertions(+)

--- a/mm/filemap.c
+++ b/mm/filemap.c
@@ -1559,6 +1559,11 @@ static ssize_t do_generic_file_read(stru
 
 		cond_resched();
 find_page:
+		if (fatal_signal_pending(current)) {
+			error = -EINTR;
+			goto out;
+		}
+
 		page = find_get_page(mapping, index);
 		if (!page) {
 			page_cache_sync_readahead(mapping,


Patches currently in stable-queue which might be from mhocko@suse.com are

queue-4.4/mm-fs-check-for-fatal-signals-in-do_generic_file_read.patch