From e48604e79a9d49f573d84f32b52004dd3a9f7bff Mon Sep 17 00:00:00 2001 From: Michal Hocko Date: Fri, 3 Feb 2017 13:13:29 -0800 Subject: [PATCH] mm, fs: check for fatal signals in do_generic_file_read() 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 Reviewed-by: Christoph Hellwig Cc: Tetsuo Handa Cc: Al Viro Cc: Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds Signed-off-by: Willy Tarreau --- mm/filemap.c | 5 +++++ 1 file changed, 5 insertions(+) diff --git a/mm/filemap.c b/mm/filemap.c index 0c5f1295a60e..c905efb20352 100644 --- a/mm/filemap.c +++ b/mm/filemap.c @@ -1175,6 +1175,11 @@ static void 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,