Commit 762cd3a5 authored by Michal Hocko's avatar Michal Hocko Committed by Sasha Levin

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

[ Upstream commit 5abf186a ]

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 avatarSasha Levin <alexander.levin@verizon.com>
parent 0445c144
...@@ -1485,6 +1485,11 @@ static ssize_t do_generic_file_read(struct file *filp, loff_t *ppos, ...@@ -1485,6 +1485,11 @@ static ssize_t do_generic_file_read(struct file *filp, loff_t *ppos,
cond_resched(); cond_resched();
find_page: find_page:
if (fatal_signal_pending(current)) {
error = -EINTR;
goto out;
}
page = find_get_page(mapping, index); page = find_get_page(mapping, index);
if (!page) { if (!page) {
page_cache_sync_readahead(mapping, page_cache_sync_readahead(mapping,
......
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