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From: Michal Hocko <mhocko@kernel.org>
To: Andrew Morton <akpm@linux-foundation.org>
Cc: Christoph Hellwig <hch@lst.de>,
	Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>,
	Al Viro <viro@zeniv.linux.org.uk>, <linux-mm@kvack.org>,
	<linux-fsdevel@vger.kernel.org>,
	LKML <linux-kernel@vger.kernel.org>,
	Michal Hocko <mhocko@suse.com>
Subject: [PATCH 2/3] mm, fs: check for fatal signals in do_generic_file_read
Date: Wed,  1 Feb 2017 10:27:05 +0100	[thread overview]
Message-ID: <20170201092706.9966-3-mhocko@kernel.org> (raw)
In-Reply-To: <20170201092706.9966-1-mhocko@kernel.org>

From: Michal Hocko <mhocko@suse.com>

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.

Cc: stable
Signed-off-by: Michal Hocko <mhocko@suse.com>
---
 mm/filemap.c | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/mm/filemap.c b/mm/filemap.c
index 14bddd0d7fa4..2ba46f410c7c 100644
--- a/mm/filemap.c
+++ b/mm/filemap.c
@@ -1797,6 +1797,11 @@ static ssize_t do_generic_file_read(struct file *filp, loff_t *ppos,
 
 		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,
-- 
2.11.0

WARNING: multiple messages have this Message-ID (diff)
From: Michal Hocko <mhocko@kernel.org>
To: Andrew Morton <akpm@linux-foundation.org>
Cc: Christoph Hellwig <hch@lst.de>,
	Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>,
	Al Viro <viro@zeniv.linux.org.uk>, <linux-mm@kvack.org>,
	<linux-fsdevel@vger.kernel.org>,
	LKML <linux-kernel@vger.kernel.org>,
	Michal Hocko <mhocko@suse.com>
Subject: [PATCH 2/3] mm, fs: check for fatal signals in do_generic_file_read
Date: Wed,  1 Feb 2017 10:27:05 +0100	[thread overview]
Message-ID: <20170201092706.9966-3-mhocko@kernel.org> (raw)
In-Reply-To: <20170201092706.9966-1-mhocko@kernel.org>

From: Michal Hocko <mhocko@suse.com>

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.

Cc: stable
Signed-off-by: Michal Hocko <mhocko@suse.com>
---
 mm/filemap.c | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/mm/filemap.c b/mm/filemap.c
index 14bddd0d7fa4..2ba46f410c7c 100644
--- a/mm/filemap.c
+++ b/mm/filemap.c
@@ -1797,6 +1797,11 @@ static ssize_t do_generic_file_read(struct file *filp, loff_t *ppos,
 
 		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,
-- 
2.11.0

--
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WARNING: multiple messages have this Message-ID (diff)
From: Michal Hocko <mhocko@kernel.org>
To: Andrew Morton <akpm@linux-foundation.org>
Cc: Christoph Hellwig <hch@lst.de>,
	Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>,
	Al Viro <viro@zeniv.linux.org.uk>,
	linux-mm@kvack.org, linux-fsdevel@vger.kernel.org,
	LKML <linux-kernel@vger.kernel.org>,
	Michal Hocko <mhocko@suse.com>
Subject: [PATCH 2/3] mm, fs: check for fatal signals in do_generic_file_read
Date: Wed,  1 Feb 2017 10:27:05 +0100	[thread overview]
Message-ID: <20170201092706.9966-3-mhocko@kernel.org> (raw)
In-Reply-To: <20170201092706.9966-1-mhocko@kernel.org>

From: Michal Hocko <mhocko@suse.com>

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.

Cc: stable
Signed-off-by: Michal Hocko <mhocko@suse.com>
---
 mm/filemap.c | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/mm/filemap.c b/mm/filemap.c
index 14bddd0d7fa4..2ba46f410c7c 100644
--- a/mm/filemap.c
+++ b/mm/filemap.c
@@ -1797,6 +1797,11 @@ static ssize_t do_generic_file_read(struct file *filp, loff_t *ppos,
 
 		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,
-- 
2.11.0

--
To unsubscribe, send a message with 'unsubscribe linux-mm' in
the body to majordomo@kvack.org.  For more info on Linux MM,
see: http://www.linux-mm.org/ .
Don't email: <a href=mailto:"dont@kvack.org"> email@kvack.org </a>

  parent reply	other threads:[~2017-02-01  9:27 UTC|newest]

Thread overview: 20+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2017-02-01  9:27 [PATCH 0/3] fix few OOM victim allocation runaways Michal Hocko
2017-02-01  9:27 ` Michal Hocko
2017-02-01  9:27 ` Michal Hocko
2017-02-01  9:27 ` [PATCH 1/3] fs: break out of iomap_file_buffered_write on fatal signals Michal Hocko
2017-02-01  9:27   ` Michal Hocko
2017-02-01  9:27   ` Michal Hocko
2017-02-01  9:28   ` Christoph Hellwig
2017-02-01  9:28     ` Christoph Hellwig
2017-02-01  9:27 ` Michal Hocko [this message]
2017-02-01  9:27   ` [PATCH 2/3] mm, fs: check for fatal signals in do_generic_file_read Michal Hocko
2017-02-01  9:27   ` Michal Hocko
2017-02-01  9:28   ` Christoph Hellwig
2017-02-01  9:28     ` Christoph Hellwig
2017-02-01  9:27 ` [PATCH 3/3] vmalloc: back of when the current is killed Michal Hocko
2017-02-01  9:27   ` Michal Hocko
2017-02-01  9:27   ` Michal Hocko
2017-02-01  9:28   ` Christoph Hellwig
2017-02-01  9:28     ` Christoph Hellwig
2017-02-01 11:49 ` [PATCH 0/3] fix few OOM victim allocation runaways Tetsuo Handa
2017-02-01 11:49   ` Tetsuo Handa

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