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 5CE6A1CDFB8; Tue, 8 Oct 2024 12:15:55 +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=1728389755; cv=none; b=pIA4p4cR9X4wpl6Atev82YXW51z4BLvM44fP3gMNd6tnJAHkVF/8Tv/4EaCeT2rkl0oIm5m/4zFQbPSLhEWqUgUMU0NY65Tu3U6aAXVM7IWGzx9nRaGb4VNORFsAkPAKTkn/sgJQ6RYGdRAnSqfLxNbiIUMDo9OSciGL88YNinE= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1728389755; c=relaxed/simple; bh=ImdEs8DuuUpG5baIGGVvrXaSjQrdK22V1+UM00Em5j4=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=lnq+bJT4o3tpLu64MsRwEI99uvGTFNuBhbJDBGy6xS2Hv6wD6psZWLDRcuVb2U1cv53pQx6Pwb/B4Dsi6+QbjIicoSEvLty4Gber+oz+1Z+ToVxKyjIyH2KHbEvuBUMQJ3Wj0JjZCJid/x+dr4naFHf8Kps0FclhEaAoMM01GR4= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=cIIG8chG; 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="cIIG8chG" Received: by smtp.kernel.org (Postfix) with ESMTPSA id C0024C4CEC7; Tue, 8 Oct 2024 12:15:54 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1728389755; bh=ImdEs8DuuUpG5baIGGVvrXaSjQrdK22V1+UM00Em5j4=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=cIIG8chGgEBjRISiOWDGVu9NraNbva2HUZuNP97zEs6EzKzDdyG/NXSBZITAbGNcy DPsSUzVXKhQmKxxbRUZIsxn65a3kfNRmcYkQQRogWTUxh9up9wkIUrJM13SyprdwnO 5/e9IA36aB8TbdKcwmx0fKwROXlGCC0PMfXzLNI4= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Seiji Nishikawa , "Rafael J. Wysocki" , Sasha Levin Subject: [PATCH 6.10 085/482] ACPI: PAD: fix crash in exit_round_robin() Date: Tue, 8 Oct 2024 14:02:28 +0200 Message-ID: <20241008115651.651902510@linuxfoundation.org> X-Mailer: git-send-email 2.46.2 In-Reply-To: <20241008115648.280954295@linuxfoundation.org> References: <20241008115648.280954295@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: Seiji Nishikawa [ Upstream commit 0a2ed70a549e61c5181bad5db418d223b68ae932 ] The kernel occasionally crashes in cpumask_clear_cpu(), which is called within exit_round_robin(), because when executing clear_bit(nr, addr) with nr set to 0xffffffff, the address calculation may cause misalignment within the memory, leading to access to an invalid memory address. ---------- BUG: unable to handle kernel paging request at ffffffffe0740618 ... CPU: 3 PID: 2919323 Comm: acpi_pad/14 Kdump: loaded Tainted: G OE X --------- - - 4.18.0-425.19.2.el8_7.x86_64 #1 ... RIP: 0010:power_saving_thread+0x313/0x411 [acpi_pad] Code: 89 cd 48 89 d3 eb d1 48 c7 c7 55 70 72 c0 e8 64 86 b0 e4 c6 05 0d a1 02 00 01 e9 bc fd ff ff 45 89 e4 42 8b 04 a5 20 82 72 c0 48 0f b3 05 f4 9c 01 00 42 c7 04 a5 20 82 72 c0 ff ff ff ff 31 RSP: 0018:ff72a5d51fa77ec8 EFLAGS: 00010202 RAX: 00000000ffffffff RBX: ff462981e5d8cb80 RCX: 0000000000000000 RDX: 0000000000000000 RSI: 0000000000000246 RDI: 0000000000000246 RBP: ff46297556959d80 R08: 0000000000000382 R09: ff46297c8d0f38d8 R10: 0000000000000000 R11: 0000000000000001 R12: 000000000000000e R13: 0000000000000000 R14: ffffffffffffffff R15: 000000000000000e FS: 0000000000000000(0000) GS:ff46297a800c0000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: ffffffffe0740618 CR3: 0000007e20410004 CR4: 0000000000771ee0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 PKRU: 55555554 Call Trace: ? acpi_pad_add+0x120/0x120 [acpi_pad] kthread+0x10b/0x130 ? set_kthread_struct+0x50/0x50 ret_from_fork+0x1f/0x40 ... CR2: ffffffffe0740618 crash> dis -lr ffffffffc0726923 ... /usr/src/debug/kernel-4.18.0-425.19.2.el8_7/linux-4.18.0-425.19.2.el8_7.x86_64/./include/linux/cpumask.h: 114 0xffffffffc0726918 : mov %r12d,%r12d /usr/src/debug/kernel-4.18.0-425.19.2.el8_7/linux-4.18.0-425.19.2.el8_7.x86_64/./include/linux/cpumask.h: 325 0xffffffffc072691b : mov -0x3f8d7de0(,%r12,4),%eax /usr/src/debug/kernel-4.18.0-425.19.2.el8_7/linux-4.18.0-425.19.2.el8_7.x86_64/./arch/x86/include/asm/bitops.h: 80 0xffffffffc0726923 : lock btr %rax,0x19cf4(%rip) # 0xffffffffc0740620 crash> px tsk_in_cpu[14] $66 = 0xffffffff crash> px 0xffffffffc072692c+0x19cf4 $99 = 0xffffffffc0740620 crash> sym 0xffffffffc0740620 ffffffffc0740620 (b) pad_busy_cpus_bits [acpi_pad] crash> px pad_busy_cpus_bits[0] $42 = 0xfffc0 ---------- To fix this, ensure that tsk_in_cpu[tsk_index] != -1 before calling cpumask_clear_cpu() in exit_round_robin(), just as it is done in round_robin_cpu(). Signed-off-by: Seiji Nishikawa Link: https://patch.msgid.link/20240825141352.25280-1-snishika@redhat.com [ rjw: Subject edit, avoid updates to the same value ] Signed-off-by: Rafael J. Wysocki Signed-off-by: Sasha Levin --- drivers/acpi/acpi_pad.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) diff --git a/drivers/acpi/acpi_pad.c b/drivers/acpi/acpi_pad.c index bd1ad07f02907..e84509b19f94d 100644 --- a/drivers/acpi/acpi_pad.c +++ b/drivers/acpi/acpi_pad.c @@ -132,8 +132,10 @@ static void exit_round_robin(unsigned int tsk_index) { struct cpumask *pad_busy_cpus = to_cpumask(pad_busy_cpus_bits); - cpumask_clear_cpu(tsk_in_cpu[tsk_index], pad_busy_cpus); - tsk_in_cpu[tsk_index] = -1; + if (tsk_in_cpu[tsk_index] != -1) { + cpumask_clear_cpu(tsk_in_cpu[tsk_index], pad_busy_cpus); + tsk_in_cpu[tsk_index] = -1; + } } static unsigned int idle_pct = 5; /* percentage */ -- 2.43.0