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 B9C8F1C4ED4; Tue, 27 Aug 2024 15:12:47 +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=1724771567; cv=none; b=TzB377mGzyF1hyRVFUKDQJogkpqdgUUnEvrG3LPSmliy41x1ucgF6acZRIXOGaCQlHojgM2lKgP8WJqKlDFptFS9LNJgJ0/p78KR5SN6N1jJxkpwUmdHd12NmQDASUS5wKoVQlj04p8reFcxkXvMpYPVSCm9axnjmZTXkD6Ce9M= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1724771567; c=relaxed/simple; bh=OShEwELeqrRA+/vjLcKebScmKCAoVgH5vnkt0B3y6/M=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=Eo3QpkoAZ+PTrrZNaPMRbtho2sLwKfB0tIt2CB3l/krT6+PpeMTGcWJ5sEF+IEDDGin7fgZf5d6MdEatCfICXg++2zpPZsVXnppddNWP8KXuFRB75N0PcYUXNP0K9FtZQFC7yF6sI3zc66tIAbkca730pIiFpvoxBIBb9XsBc6Q= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=Tf9vt+aU; 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="Tf9vt+aU" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 24732C6104A; Tue, 27 Aug 2024 15:12:46 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1724771567; bh=OShEwELeqrRA+/vjLcKebScmKCAoVgH5vnkt0B3y6/M=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=Tf9vt+aULZerJlqIBM2gVjTOyUvKwTUlXtn52GO4ce5jL6Ozj/il/5VGfpaoI0v/P XM4r4oCMA/JjIOKskOy3BISWNq67M49GGGxdK3LQAoEAu2lYaN8pgGrny9DASVKiPn Rxg3dxyyOjDve/jgbQSRURRVXzg3HsjRPnKqMziw= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Tejun Heo , Lai Jiangshan , Will Deacon , Sasha Levin Subject: [PATCH 6.10 200/273] workqueue: Fix UBSAN subtraction overflow error in shift_and_mask() Date: Tue, 27 Aug 2024 16:38:44 +0200 Message-ID: <20240827143841.021166201@linuxfoundation.org> X-Mailer: git-send-email 2.46.0 In-Reply-To: <20240827143833.371588371@linuxfoundation.org> References: <20240827143833.371588371@linuxfoundation.org> User-Agent: quilt/0.67 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 6.10-stable review patch. If anyone has any objections, please let me know. ------------------ From: Will Deacon [ Upstream commit 38f7e14519d39cf524ddc02d4caee9b337dad703 ] UBSAN reports the following 'subtraction overflow' error when booting in a virtual machine on Android: | Internal error: UBSAN: integer subtraction overflow: 00000000f2005515 [#1] PREEMPT SMP | Modules linked in: | CPU: 0 PID: 1 Comm: swapper/0 Not tainted 6.10.0-00006-g3cbe9e5abd46-dirty #4 | Hardware name: linux,dummy-virt (DT) | pstate: 600000c5 (nZCv daIF -PAN -UAO -TCO -DIT -SSBS BTYPE=--) | pc : cancel_delayed_work+0x34/0x44 | lr : cancel_delayed_work+0x2c/0x44 | sp : ffff80008002ba60 | x29: ffff80008002ba60 x28: 0000000000000000 x27: 0000000000000000 | x26: 0000000000000000 x25: 0000000000000000 x24: 0000000000000000 | x23: 0000000000000000 x22: 0000000000000000 x21: ffff1f65014cd3c0 | x20: ffffc0e84c9d0da0 x19: ffffc0e84cab3558 x18: ffff800080009058 | x17: 00000000247ee1f8 x16: 00000000247ee1f8 x15: 00000000bdcb279d | x14: 0000000000000001 x13: 0000000000000075 x12: 00000a0000000000 | x11: ffff1f6501499018 x10: 00984901651fffff x9 : ffff5e7cc35af000 | x8 : 0000000000000001 x7 : 3d4d455453595342 x6 : 000000004e514553 | x5 : ffff1f6501499265 x4 : ffff1f650ff60b10 x3 : 0000000000000620 | x2 : ffff80008002ba78 x1 : 0000000000000000 x0 : 0000000000000000 | Call trace: | cancel_delayed_work+0x34/0x44 | deferred_probe_extend_timeout+0x20/0x70 | driver_register+0xa8/0x110 | __platform_driver_register+0x28/0x3c | syscon_init+0x24/0x38 | do_one_initcall+0xe4/0x338 | do_initcall_level+0xac/0x178 | do_initcalls+0x5c/0xa0 | do_basic_setup+0x20/0x30 | kernel_init_freeable+0x8c/0xf8 | kernel_init+0x28/0x1b4 | ret_from_fork+0x10/0x20 | Code: f9000fbf 97fffa2f 39400268 37100048 (d42aa2a0) | ---[ end trace 0000000000000000 ]--- | Kernel panic - not syncing: UBSAN: integer subtraction overflow: Fatal exception This is due to shift_and_mask() using a signed immediate to construct the mask and being called with a shift of 31 (WORK_OFFQ_POOL_SHIFT) so that it ends up decrementing from INT_MIN. Use an unsigned constant '1U' to generate the mask in shift_and_mask(). Cc: Tejun Heo Cc: Lai Jiangshan Fixes: 1211f3b21c2a ("workqueue: Preserve OFFQ bits in cancel[_sync] paths") Signed-off-by: Will Deacon Signed-off-by: Tejun Heo Signed-off-by: Sasha Levin --- kernel/workqueue.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/kernel/workqueue.c b/kernel/workqueue.c index f98247ec99c20..c8687c0ab3645 100644 --- a/kernel/workqueue.c +++ b/kernel/workqueue.c @@ -896,7 +896,7 @@ static struct worker_pool *get_work_pool(struct work_struct *work) static unsigned long shift_and_mask(unsigned long v, u32 shift, u32 bits) { - return (v >> shift) & ((1 << bits) - 1); + return (v >> shift) & ((1U << bits) - 1); } static void work_offqd_unpack(struct work_offq_data *offqd, unsigned long data) -- 2.43.0