4.9-stable review patch. If anyone has any objections, please let me know.
------------------ From: Michal Hocko <[email protected]> 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/[email protected] Signed-off-by: Michal Hocko <[email protected]> Reviewed-by: Christoph Hellwig <[email protected]> Cc: Tetsuo Handa <[email protected]> Cc: Al Viro <[email protected]> Cc: <[email protected]> Signed-off-by: Andrew Morton <[email protected]> Signed-off-by: Linus Torvalds <[email protected]> Signed-off-by: Greg Kroah-Hartman <[email protected]> --- mm/filemap.c | 5 +++++ 1 file changed, 5 insertions(+) --- a/mm/filemap.c +++ b/mm/filemap.c @@ -1703,6 +1703,11 @@ static ssize_t do_generic_file_read(stru 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,
