From 762cd3a51cfcf231b7ff559af547c9dd82e8648e Mon Sep 17 00:00:00 2001 From: Michal Hocko Date: Fri, 3 Feb 2017 13:13:29 -0800 Subject: mm, fs: check for fatal signals in do_generic_file_read() [ Upstream commit 5abf186a30a89d5b9c18a6bf93a2c192c9fd52f6 ] 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 Reviewed-by: Christoph Hellwig Cc: Tetsuo Handa Cc: Al Viro Cc: Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds Signed-off-by: Sasha Levin --- mm/filemap.c | 5 +++++ 1 file changed, 5 insertions(+) (limited to 'mm/filemap.c') diff --git a/mm/filemap.c b/mm/filemap.c index 1ffef05f1c1f..fc5165c744a8 100644 --- a/mm/filemap.c +++ b/mm/filemap.c @@ -1485,6 +1485,11 @@ 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, -- cgit v1.2.3