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 A62862E7BC7; Tue, 15 Jul 2025 13:27:53 +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=1752586073; cv=none; b=jvlRfRGLz7myyNOG2Szk94/D268ABjEXZcxiv095cfdC58lhUXAt4bIe8csEkz/s9E7INhcASJjRTdj3xtAEqSWXDyfVcMPfbwFN3nUy8DBM/skFuK2ubxSLxkTPJtoUPZ1rlB1yT1B9HGVn0IPSF5gzjH1PiE+8GvYqmKdSlvo= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1752586073; c=relaxed/simple; bh=jXhHlPEiYb9IClA6cWVvt4BNBXcbs4tqndbGr8qtk+o=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=F8vmIU5wXPfyzI5zbEcinQggL5Xcs9LNpW6y7JEeQjBRAbJk9+9Rzlb1sN/Tn2YjE0pARFrgx0CmDNHFSnT9xmIG/IcRhpOlWNlU7/q5zXw1sn+lYRtUjrt1cM3GwHaZ39kX1gDweHv7VvH0bwBIjrfszOH50sNb5pyyB/azaLc= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=tc6nUs9o; 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="tc6nUs9o" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 0C958C4CEE3; Tue, 15 Jul 2025 13:27:53 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1752586073; bh=jXhHlPEiYb9IClA6cWVvt4BNBXcbs4tqndbGr8qtk+o=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=tc6nUs9oTWCTbrikHI/fGMunNMWDjwRLg9K/3LBjUsnnWXfL/izLFJWd+zhG1TXaH 2IypoitR72sQgZF/qLWujx3pC3uKmZlY1/njuXicUW7/p9w3W2ZiZ14eC6YIp4HITf KPuXY+EXW/ZezsTOE1gh+I8axSlZLahqYn2RYa3M= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Yeoreum Yun , Yunseong Kim , Andrey Ryabinin , Alexander Potapenko , Andrey Konovalov , Byungchul Park , Dmitriy Vyukov , Sebastian Andrzej Siewior , Steven Rostedt , Vincenzo Frascino , Andrew Morton Subject: [PATCH 6.6 108/109] kasan: remove kasan_find_vm_area() to prevent possible deadlock Date: Tue, 15 Jul 2025 15:14:04 +0200 Message-ID: <20250715130803.200687993@linuxfoundation.org> X-Mailer: git-send-email 2.50.1 In-Reply-To: <20250715130758.864940641@linuxfoundation.org> References: <20250715130758.864940641@linuxfoundation.org> User-Agent: quilt/0.68 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 6.6-stable review patch. If anyone has any objections, please let me know. ------------------ From: Yeoreum Yun commit 6ee9b3d84775944fb8c8a447961cd01274ac671c upstream. find_vm_area() couldn't be called in atomic_context. If find_vm_area() is called to reports vm area information, kasan can trigger deadlock like: CPU0 CPU1 vmalloc(); alloc_vmap_area(); spin_lock(&vn->busy.lock) spin_lock_bh(&some_lock); spin_lock(&some_lock); kasan_report(); print_report(); print_address_description(); kasan_find_vm_area(); find_vm_area(); spin_lock(&vn->busy.lock) // deadlock! To prevent possible deadlock while kasan reports, remove kasan_find_vm_area(). Link: https://lkml.kernel.org/r/20250703181018.580833-1-yeoreum.yun@arm.com Fixes: c056a364e954 ("kasan: print virtual mapping info in reports") Signed-off-by: Yeoreum Yun Reported-by: Yunseong Kim Reviewed-by: Andrey Ryabinin Cc: Alexander Potapenko Cc: Andrey Konovalov Cc: Byungchul Park Cc: Dmitriy Vyukov Cc: Sebastian Andrzej Siewior Cc: Steven Rostedt Cc: Vincenzo Frascino Cc: Signed-off-by: Andrew Morton Signed-off-by: Greg Kroah-Hartman --- mm/kasan/report.c | 13 ++----------- 1 file changed, 2 insertions(+), 11 deletions(-) --- a/mm/kasan/report.c +++ b/mm/kasan/report.c @@ -385,17 +385,8 @@ static void print_address_description(vo } if (is_vmalloc_addr(addr)) { - struct vm_struct *va = find_vm_area(addr); - - if (va) { - pr_err("The buggy address belongs to the virtual mapping at\n" - " [%px, %px) created by:\n" - " %pS\n", - va->addr, va->addr + va->size, va->caller); - pr_err("\n"); - - page = vmalloc_to_page(addr); - } + pr_err("The buggy address %px belongs to a vmalloc virtual mapping\n", addr); + page = vmalloc_to_page(addr); } if (page) {