Commit 32686879 authored by Michal Hocko's avatar Michal Hocko Committed by Jiri Slaby

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

commit 5abf186a 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.orgSigned-off-by: default avatarMichal Hocko <mhocko@suse.com>
Reviewed-by: default avatarChristoph 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: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: default avatarJiri Slaby <jslaby@suse.cz>
parent 2a30945e
......@@ -1338,6 +1338,11 @@ 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,
......
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