From mboxrd@z Thu Jan 1 00:00:00 1970 From: Theodore Ts'o Subject: [PATCH] ext4: add check to io_submit_init_bio Date: Thu, 6 Jun 2013 10:19:41 -0400 Message-ID: <20130606141941.GA5382@thunk.org> References: <20130606115653.a21b0c6a7bdbbbac23164b85@canb.auug.org.au> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: Andreas Dilger , linux-ext4@vger.kernel.org, LKML To: Stephen Rothwell Return-path: Content-Disposition: inline In-Reply-To: <20130606115653.a21b0c6a7bdbbbac23164b85@canb.auug.org.au> Sender: linux-kernel-owner@vger.kernel.org List-Id: linux-ext4.vger.kernel.org On Thu, Jun 06, 2013 at 11:56:53AM +1000, Stephen Rothwell wrote: > > In tracking this down, I followed the call chains and discovered that > io_submit_init_bio() only ever returned 0. Switching that to return > void and following back up the chain lead to the following patch. Actually, that's a bug. We're missing an check in that function. Thanks for looking at this code. (I'll fix the uninitialized err warning another way.) - Ted commit 7745883f99c0e81e6bc71527d23ca363eb125a3f Author: Theodore Ts'o Date: Thu Jun 6 10:18:22 2013 -0400 ext4: add check to io_submit_init_bio The bio_alloc() function can return NULL if the memory allocation fails. So we need to check for this. Signed-off-by: "Theodore Ts'o" diff --git a/fs/ext4/page-io.c b/fs/ext4/page-io.c index ce8c15a..48786cd 100644 --- a/fs/ext4/page-io.c +++ b/fs/ext4/page-io.c @@ -372,6 +372,8 @@ static int io_submit_init_bio(struct ext4_io_submit *io, struct bio *bio; bio = bio_alloc(GFP_NOIO, min(nvecs, BIO_MAX_PAGES)); + if (!bio) + return -ENOMEM; bio->bi_sector = bh->b_blocknr * (bh->b_size >> 9); bio->bi_bdev = bh->b_bdev; bio->bi_end_io = ext4_end_bio;