From mboxrd@z Thu Jan 1 00:00:00 1970 Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.remote-ip=100.103.45.18 ARC-Seal: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; cv=none; t=1794247218; b=PVsm88czc2xROs401hzcBZlxKscngT2O5XTcpv7Whdr1bbov0sW7PwaeI6BpIrx997fz TaGI1fYxUHua4UrlXl140czdllUr3aRyHztEfwTHxwAYaOBoK7w7CBBNlMnzgDIeKAR0Q ue8dkvoDjJfgvRRQUPzphBpe6FVPAC/umD5edfqJmpvrzWqhKuX0mm4IMQAQ9K3ix4ZUP LduE23Q8eDwE7zM0NAQu64STeTJerTXMWD8qoR7pyKXHd5CQdb4JP2T54MDKaglOW34tL v/BHCqQb4i16eeoX2XEAatP7tYzVRC/f8GkWgMfsVFSlQw87Pe0WbyFqNZvS8+zhUHg== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1794247218; h=Received:DKIM-Signature:From:Date:Subject:MIME-Version:Content-Type: Content-Transfer-Encoding:Message-Id:X-B4-Tracking:X-Change-ID:To:Cc: X-Mailer:X-Developer-Signature:X-Developer-Key; bh=3xK7L4/JaYx0EL19I/D7/R7R2oh/67eUA0pLpz/4Vyg=; b=M+7agcWX1SlR0XDCWq948Kq5Z2g9YvQZU8PA33GsB/vlcooG13QZD8WdzaKrYcrWXqcB PynamZj5zZPk27hdFORHkt7ozQWNvQbPGWktDNn27Ig1Xqq50TQwdes6EOOqBR3nxwTNH /6i8d3g6hLcwYSlKrIRT5tvv5MGhppuybEazHLG5s5T8g3bHZok85knfts5DbY997s8uN 5CU9TbVNFm7PGsnVGBpUoGvQfAKswK7TCj2pADBfiFug8zK8wHuRXEnslNtebvKT4v03F EnN5zdnvTSyxButHskmKTkDMthposwyxxBVKs5N5Qkcrk7H2w0mCUGlaNXpeTah3t2A== ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=k20260515 header.b=Hj+qJx5a; arc=none smtp.remote-ip=100.103.45.18 Received: from smtp.kernel.org (quasi.space.kernel.org [100.103.45.18]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (prime256v1)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 86922606A31C for ; Mon, 9 Nov 2026 18:00:18 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=k20260515 header.b=Hj+qJx5a Received: by smtp.kernel.org (Postfix) with ESMTPSA id 376BB1F0089F; Mon, 9 Nov 2026 18:00:16 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1794247218; bh=3xK7L4/JaYx0EL19I/D7/R7R2oh/67eUA0pLpz/4Vyg=; h=From:Date:Subject:To:Cc; b=Hj+qJx5aYVz8wK7JQmQamBE+WqPvz9takatG7seQvX/+mEnAjhg5HqjTgUO9AgK1p 7JQccuZtWODOtPoz0vz5gKnYz3cLFdcB6eWIIcHQmjWUFFxq0t1m90MpHowj4bdhAd ZYrqYFD70FTKY3KcwFLPH//jbT98bTNV+7hZD2jbtduxZcFpnLUKbtgKG+X2ot0LDw skhG2yTcYv5/2l22SKOPOUFyeWchNU4zu2SZJoGyPtTDjPBkBcgT3X01HPzT6uRdQH j9pZWXIJopS1wbHocqT4MJs1YLXq6zdZf9NEgRVUqytdkt0bi8CKVo5Jd2B4+4V70k 77LvMITkLKnSw== From: Nathan Chancellor Date: Mon, 09 Nov 2026 13:00:12 -0500 Subject: [PATCH] powerpc/smp: Handle of_property_count_u32_elems() error in parse_thread_groups() X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Post: List-Help: List-Subscribe: List-Unsubscribe: List-Owner: Precedence: list MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit Message-Id: <20261109-powerpc-smp-handle-count-err-v1-1-e777fde7f71a@kernel.org> X-B4-Tracking: v=1; b=H4sIAAAAAAAA/yXMQQrCMBBA0auUWTuQFCnGq4gLk0x0RJMw09ZC6 d0bdfng81dQEiaFc7eC0MzKJTfYQwfhcct3Qo7N0Jt+sNY4rOVDUgPqu2IL4oswlCmPSCLojyf vUooDOQNtUYUSL7/95fq3Tv5JYfw+Ydt2RwA6oYAAAAA= X-Change-ID: 20261109-powerpc-smp-handle-count-err-b48b9ffd6e90 To: Madhavan Srinivasan Cc: Michael Ellerman , Nicholas Piggin , "Christophe Leroy (CS GROUP)" , "Ritesh Harjani (IBM)" , Shrikanth Hegde , Kees Cook , linuxppc-dev@lists.ozlabs.org, linux-kernel@vger.kernel.org, Nathan Chancellor X-Mailer: b4 0.17-dev X-Developer-Signature: v=1; a=openpgp-sha256; l=2255; i=nathan@kernel.org; h=from:subject:message-id; bh=57alKDJGvf9NrPNQP0TZ4PGabY5w76Ut3KmDPbLom1M=; b=owGbwMvMwCUmm602sfCA1DTG02pJDFmfuHRzNF12rtI6FLD2qMrtB3cCrwkJL511bZZJz8qQt 3rTIjSKO0pZGMS4GGTFFFmqH6seNzScc5bxxqlJMHNYmUCGMHBxCsBE3oUx/E/TmHWsXZ5dp8Y6 ceG8v27fjN8+3RA1J8js9YYiw9MHt8xiZNh5WVpB4Kltw8T7ScptjjeqTp79siaO69qGabfb3r9 e1cEOAA== X-Developer-Key: i=nathan@kernel.org; a=openpgp; fpr=2437CB76E544CB6AB3D9DFD399739260CB6CB716 After commit 0af298e62e5c ("treewide: refresh kmalloc_obj() conversions"), there is a warning on boot for several PowerPC configurations in QEMU: WARNING: mm/slub.c:5459 at ___kmalloc_large_node+0x174/0x1b0, CPU#0: swapper/0/1 Modules linked in: CPU: 0 UID: 0 PID: 1 Comm: swapper/0 Not tainted 7.4.0-rc1-00262-g0af298e62e5c #1 PREEMPT(lazy) NIP [c0000000006074e4] ___kmalloc_large_node+0x174/0x1b0 LR [c00000000060782c] __kmalloc_large_node_noprof+0x3c/0x150 Call Trace: ... [c00000000369fb60] [c000000000614ff0] __kmalloc_noprof+0x490/0x690 [c00000000369fbe0] [c000000000051308] _kzalloc_noprof.constprop.0+0x1c/0x74 [c00000000369fc00] [c00000000200b450] init_thread_group_cache_map+0xc0/0x2c4 ... In this case, of_property_count_u32_elems() returns -EINVAL because there is no "ibm,thread-groups" property. When kcalloc() was used to allocate thread_group_array, the multiplication overflow check in _kmalloc_array_noprof() caught that a really large allocation was requested (as -EINVAL was converted to size_t) and returned NULL. kzalloc_objs() has no such check, so the large allocation check in __kmalloc_large_noprof() triggers the visible warning above. Check if of_property_count_u32_elems() has returned an error and bail out if so, clearing up the warning. Fixes: 790a1662d3a2 ("powerpc/smp: Parse ibm,thread-groups with multiple properties") Signed-off-by: Nathan Chancellor --- arch/powerpc/kernel/smp.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/arch/powerpc/kernel/smp.c b/arch/powerpc/kernel/smp.c index 7a25eaa59e62..58824f5f4c80 100644 --- a/arch/powerpc/kernel/smp.c +++ b/arch/powerpc/kernel/smp.c @@ -824,6 +824,8 @@ static int parse_thread_groups(struct device_node *dn, int i = 0; count = of_property_count_u32_elems(dn, "ibm,thread-groups"); + if (count < 0) + return count; thread_group_array = kzalloc_objs(u32, count); if (!thread_group_array) return -ENOMEM; --- base-commit: 7475ea8b58616b33c04afb976cf0fbaad9dd63fb base-tree: git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git master change-id: 20261109-powerpc-smp-handle-count-err-b48b9ffd6e90 Best regards, -- Cheers, Nathan