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From: Andrew Morton <akpm@linux-foundation.org>
To: Sunny Patel <nueralspacetech@gmail.com>
Cc: David Hildenbrand <david@kernel.org>, Zi Yan <ziy@nvidia.com>,
	Matthew Brost <matthew.brost@intel.com>,
	Joshua Hahn <joshua.hahnjy@gmail.com>,
	Rakie Kim <rakie.kim@sk.com>, Byungchul Park <byungchul@sk.com>,
	Gregory Price <gourry@gourry.net>,
	Ying Huang <ying.huang@linux.alibaba.com>,
	Alistair Popple <apopple@nvidia.com>,
	linux-mm@kvack.org, linux-kernel@vger.kernel.org,
	Balbir Singh <balbirs@nvidia.com>
Subject: Re: [PATCH] mm/migrate_device: fix spinlock leak in migrate_vma_insert_huge_pmd_page
Date: Sat, 25 Apr 2026 06:54:11 -0700	[thread overview]
Message-ID: <20260425065411.39842a941750fadab250cd79@linux-foundation.org> (raw)
In-Reply-To: <20260425133537.17463-1-nueralspacetech@gmail.com>

On Sat, 25 Apr 2026 19:05:27 +0530 Sunny Patel <nueralspacetech@gmail.com> wrote:

> When check_stable_address_space() fails after the PMD spinlock has
> been acquired via pmd_lock(), the code jumps directly to the abort
> label, bypassing the spin_unlock() call in unlock_abort. This causes
> the PMD spinlock to be permanently held, leading to a deadlock.
> 
> Change the goto target from abort to unlock_abort to ensure the
> spinlock is always released on this error path.
> 
> ...
>
> --- a/mm/migrate_device.c
> +++ b/mm/migrate_device.c
> @@ -850,7 +850,7 @@ static int migrate_vma_insert_huge_pmd_page(struct migrate_vma *migrate,
>  	ptl = pmd_lock(vma->vm_mm, pmdp);
>  	csa_ret = check_stable_address_space(vma->vm_mm);
>  	if (csa_ret)
> -		goto abort;
> +		goto unlock_abort;
>  
>  	/*
>  	 * Check for userfaultfd but do not deliver the fault. Instead,

whoops.

Fixes: a30b48bf1b24 ("mm/migrate_device: implement THP migration of zone device pages")
Cc: <stable@vger.kernel.org>


  reply	other threads:[~2026-04-25 13:54 UTC|newest]

Thread overview: 5+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2026-04-25 13:35 [PATCH] mm/migrate_device: fix spinlock leak in migrate_vma_insert_huge_pmd_page Sunny Patel
2026-04-25 13:54 ` Andrew Morton [this message]
2026-04-26  0:50   ` Balbir Singh
2026-04-25 14:21 ` Zi Yan
2026-04-27 10:18 ` David Hildenbrand (Arm)

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