From: Christoph Hellwig <hch@lst.de>
To: Vasily Gorbik <gor@linux.ibm.com>
Cc: Jens Axboe <axboe@kernel.dk>, Christoph Hellwig <hch@lst.de>,
Chaitanya Kulkarni <kch@nvidia.com>,
"Martin K. Petersen" <martin.petersen@oracle.com>,
linux-block@vger.kernel.org, linux-kernel@vger.kernel.org,
syzkaller-bugs@googlegroups.com,
syzbot <syzbot+09ddb593eea76a158f42@syzkaller.appspotmail.com>
Subject: Re: [PATCH] block: fix bio_alloc_bioset slowpath GFP handling
Date: Mon, 23 Mar 2026 07:44:17 +0100 [thread overview]
Message-ID: <20260323064417.GA24833@lst.de> (raw)
In-Reply-To: <p01.gc6e9ad5845ad.ttca29g@ub.hpns>
On Sun, Mar 22, 2026 at 03:35:10AM +0100, Vasily Gorbik wrote:
> bio_alloc_bioset() first strips __GFP_DIRECT_RECLAIM from the optimistic
> fast allocation attempt with try_alloc_gfp(). If that fast path fails,
> the slowpath checks saved_gfp to decide whether blocking allocation is
> allowed, but then still calls mempool_alloc() with the stripped gfp mask.
> That can lead to a NULL bio pointer being passed into bio_init().
>
> Fix the slowpath by using saved_gfp for the bio and bvec mempool
> allocations.
Looks good, thanks:
Reviewed-by: Christoph Hellwig <hch@lst.de>
next prev parent reply other threads:[~2026-03-23 6:44 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-03-20 22:44 [syzbot] [block?] general protection fault in bio_alloc_bioset syzbot
2026-03-21 8:36 ` [PATCH next] block: mempool alloc fail due to insufficient memory Edward Adam Davis
2026-03-21 14:17 ` Jens Axboe
2026-03-21 22:52 ` [syzbot] [block?] general protection fault in bio_alloc_bioset Vasily Gorbik
2026-03-22 0:18 ` syzbot
2026-03-22 2:23 ` Vasily Gorbik
2026-03-22 2:35 ` [PATCH] block: fix bio_alloc_bioset slowpath GFP handling Vasily Gorbik
2026-03-23 6:44 ` Christoph Hellwig [this message]
2026-03-23 13:58 ` Jens Axboe
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