From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 2B5212E093A; Mon, 20 Apr 2026 15:54:49 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1776700489; cv=none; b=EmOUOrT2RVeom4otTKnZzI5CK5L0uynX19g5v5YK28+LsfSXGS8HAVJ8isLggpBoUQaI1pNMPssdKLmqQ/BkqgD0DDMY00KvMAR3zw9mKpQ5TEPoxx1zWEqKgAk4VmGehe3iFyEnoU6T3kqYn0Wfi/ZPuLiz4c6iKtBsOh9Mh0g= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1776700489; c=relaxed/simple; bh=4eiApwrGy2kebTZLivE8/XCMGj36g/ItG8DXkJIiqvQ=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=qbu3JgKo1jNoe2A2JVPRoO6T+H8koTkaW/rxzt2HTHEAi1bOGdDuR79GbF6Ko/kDK3jEnCVq5d+aLdXjR7JFo5jvKEqyA5u0W+NavavsAU6CH9cknNyCWrVDdEr9W9SunuPGI+vBWpUEo5JpwT3Vb7BL1jesCb92iygQ7WcLFLI= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=gcaFd6uO; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="gcaFd6uO" Received: by smtp.kernel.org (Postfix) with ESMTPSA id B616CC19425; Mon, 20 Apr 2026 15:54:48 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1776700489; bh=4eiApwrGy2kebTZLivE8/XCMGj36g/ItG8DXkJIiqvQ=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=gcaFd6uOfJd6gNTvLYqmmyS0Ywpkck6+BtIvcLjrY/R9/4XOe4hbD6NHZAHJ/Vx+N oBMbILIBthBLoYWypa73PDRAvmgYDJH2no6jXC8WVWm/2wCUu1MmcaqPrzNpADMFqO VjwprrVvAO0R4hNoN5dgKvHV9m01J/wDLXsE8pgQ= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, "Matthew Wilcox (Oracle)" , Google Big Sleep , Jens Axboe , Jan Kara , Andrew Morton Subject: [PATCH 6.19 193/220] mm: call ->free_folio() directly in folio_unmap_invalidate() Date: Mon, 20 Apr 2026 17:42:14 +0200 Message-ID: <20260420153940.974540985@linuxfoundation.org> X-Mailer: git-send-email 2.53.0 In-Reply-To: <20260420153934.013228280@linuxfoundation.org> References: <20260420153934.013228280@linuxfoundation.org> User-Agent: quilt/0.69 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 6.19-stable review patch. If anyone has any objections, please let me know. ------------------ From: Matthew Wilcox (Oracle) commit 615d9bb2ccad42f9e21d837431e401db2e471195 upstream. We can only call filemap_free_folio() if we have a reference to (or hold a lock on) the mapping. Otherwise, we've already removed the folio from the mapping so it no longer pins the mapping and the mapping can be removed, causing a use-after-free when accessing mapping->a_ops. Follow the same pattern as __remove_mapping() and load the free_folio function pointer before dropping the lock on the mapping. That lets us make filemap_free_folio() static as this was the only caller outside filemap.c. Link: https://lore.kernel.org/20260413184314.3419945-1-willy@infradead.org Fixes: fb7d3bc41493 ("mm/filemap: drop streaming/uncached pages when writeback completes") Signed-off-by: Matthew Wilcox (Oracle) Reported-by: Google Big Sleep Cc: Jens Axboe Cc: Jan Kara Cc: Signed-off-by: Andrew Morton Signed-off-by: Greg Kroah-Hartman --- mm/filemap.c | 3 ++- mm/internal.h | 1 - mm/truncate.c | 6 +++++- 3 files changed, 7 insertions(+), 3 deletions(-) --- a/mm/filemap.c +++ b/mm/filemap.c @@ -228,7 +228,8 @@ void __filemap_remove_folio(struct folio page_cache_delete(mapping, folio, shadow); } -void filemap_free_folio(struct address_space *mapping, struct folio *folio) +static void filemap_free_folio(const struct address_space *mapping, + struct folio *folio) { void (*free_folio)(struct folio *); --- a/mm/internal.h +++ b/mm/internal.h @@ -471,7 +471,6 @@ unsigned find_lock_entries(struct addres pgoff_t end, struct folio_batch *fbatch, pgoff_t *indices); unsigned find_get_entries(struct address_space *mapping, pgoff_t *start, pgoff_t end, struct folio_batch *fbatch, pgoff_t *indices); -void filemap_free_folio(struct address_space *mapping, struct folio *folio); int truncate_inode_folio(struct address_space *mapping, struct folio *folio); bool truncate_inode_partial_folio(struct folio *folio, loff_t start, loff_t end); --- a/mm/truncate.c +++ b/mm/truncate.c @@ -622,6 +622,7 @@ static int folio_launder(struct address_ int folio_unmap_invalidate(struct address_space *mapping, struct folio *folio, gfp_t gfp) { + void (*free_folio)(struct folio *); int ret; VM_BUG_ON_FOLIO(!folio_test_locked(folio), folio); @@ -648,9 +649,12 @@ int folio_unmap_invalidate(struct addres xa_unlock_irq(&mapping->i_pages); if (mapping_shrinkable(mapping)) inode_lru_list_add(mapping->host); + free_folio = mapping->a_ops->free_folio; spin_unlock(&mapping->host->i_lock); - filemap_free_folio(mapping, folio); + if (free_folio) + free_folio(folio); + folio_put_refs(folio, folio_nr_pages(folio)); return 1; failed: xa_unlock_irq(&mapping->i_pages);