From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from galois.linutronix.de (Galois.linutronix.de [193.142.43.55]) (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 32E5A53BE for ; Tue, 4 Jun 2024 16:10:05 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=193.142.43.55 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1717517407; cv=none; b=ExEUuxEepCdAxrnoWa37LkwpxhIjD/gYgg/hjzKoPz0/nFbvu3Mibdd8eoLIs+sYY34V7KxsB2L/V014xCtiZRDIrTcv8HXojGttHGt6LjA/Uu59eajxtxGQBHysxKBf0PXaoZw1JS1zJuWVDqv8oGWRhZ4T+WPnQtuA4n8kozo= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1717517407; c=relaxed/simple; bh=k/qLKUrFXNR9X5ncu7ZzLByVbnqxCevGaXRBjnYGXgI=; h=From:To:Cc:Subject:In-Reply-To:References:Date:Message-ID: MIME-Version:Content-Type; b=FjVKsDLhrsvIuydOfWQW3HbcSC9bOs8v6vFwLGepfpQHMj9oTgW1KcxZyi/sfY7rISEn6Q3g5QtQs12EbW+bhWhh2b6UDAoa4oDv4PyclmEeGsk2lyAy9zS8agz4PEOMFGHHTFT+WL3zbAN03uTxWKvf86tiNJbBX4zOWPg9MTk= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linutronix.de; spf=pass smtp.mailfrom=linutronix.de; dkim=pass (2048-bit key) header.d=linutronix.de header.i=@linutronix.de header.b=BIvwWegi; dkim=permerror (0-bit key) header.d=linutronix.de header.i=@linutronix.de header.b=NFaNIAN2; arc=none smtp.client-ip=193.142.43.55 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linutronix.de Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=linutronix.de Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=linutronix.de header.i=@linutronix.de header.b="BIvwWegi"; dkim=permerror (0-bit key) header.d=linutronix.de header.i=@linutronix.de header.b="NFaNIAN2" From: Thomas Gleixner DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020; t=1717517404; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=zDitCF42fLHdt1Ig5HhwFq8CPx2Qx1QENuZVXfNm13Y=; b=BIvwWegi7CD+kZNJ9sTl+y7f/7MCPyDa1WKqUw4DEWQAnTfDKVmIohW0jHcIj4Y2I93xY9 OBpBAVel/k624TguD5vxr97nwwdjJox9iaqeXx6+4HmI5wmaqLMNv6lpI1Yo/Hj0whSy/M bnUotbQp+hL/IPt7k95ePa0JBJ9HSLR0KNnbGqkPDHm9+vPdFFGre0URtFbFSb94AUAVX5 fqgIaw74DO5DxHJJ5Js8uBTScRxdzD6sWiIOzJavlOPr5KSyjN6qjhaCNHkIwPQUYPoeWg 4KG38oBtnqMJmukuHtR3gH4sYCYQ/SY6kAmiSi0Wpn9FTmeejMSSR2jo5YELPQ== DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020e; t=1717517404; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=zDitCF42fLHdt1Ig5HhwFq8CPx2Qx1QENuZVXfNm13Y=; b=NFaNIAN2rWRNzsnQdgBI6XcMfwPbZMpA3kZxiUPFFCL/ZBtQMWHNOuKWU5sCs4S0hx1ndW th+uAWi3nkL1RrAA== To: Will Deacon Cc: syzbot , anna-maria@linutronix.de, frederic@kernel.org, linux-kernel@vger.kernel.org, syzkaller-bugs@googlegroups.com, Catalin Marinas Subject: Re: [syzbot] [kernel?] BUG: unable to handle kernel NULL pointer dereference in __hrtimer_run_queues In-Reply-To: <20240604133448.GB20384@willie-the-truck> References: <000000000000deb5250619f9b5f4@google.com> <87tti86gca.ffs@tglx> <20240604133448.GB20384@willie-the-truck> Date: Tue, 04 Jun 2024 18:10:04 +0200 Message-ID: <87mso0665f.ffs@tglx> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain Will! On Tue, Jun 04 2024 at 14:34, Will Deacon wrote: > On Tue, Jun 04, 2024 at 02:29:57PM +0200, Thomas Gleixner wrote: >> On Mon, Jun 03 2024 at 03:22, syzbot wrote: >> > * 10: f9400821 ldr x1, [x1, #16] <-- trapping instruction >> while (node->rb_left) >> >> > x2 : ff7000007f8cf8e8 x1 : 0000000000000080 x0 : 0000000000000080 >> >> which obviously crashes. Now the question is how does the original node >> end up with node::rb_right == 0x80? >> >> I doubt that this is a hrtimer or rbtree problem. It smells like random >> data corruption caused by whatever. It might not even be an ARM64 >> specific issue though the C repro does not trigger on x86... >> >> Handing it over to Catalin and Will. > > I suspect this is a duplicate of: > > https://lore.kernel.org/lkml/20240604110119.GA20284@willie-the-truck/ > > and there's a fix queued in the -mm tree. That looks very much so. Thanks, tglx