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 F11E51BCA07 for ; Sun, 14 Sep 2025 13:12:04 +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=1757855525; cv=none; b=McIQsPovmFSbv8mU4kQKHTHd9x/VBkuQd0A5zlF0vQzcXX1feVm8jTUbGbs3twrzXj19sIf/7mOPXoAjy6T3DAigHgDSiW3QoO3ZTn+zYaxHS6QkM8BkEhFifbNEwuKxvoLgJKU6Hdjxi8Oxrs3n+rC8GMBHhQMwfmXkElactbo= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1757855525; c=relaxed/simple; bh=kFgOSHGireA8JhmM/ZnQKoEe0hmCQSB030ukNcLlnTs=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=MlCzNRbIY12+q2TyBz1fXcVCmi/oIJTQ20aCnvkuSLzhCPGL6gbSl3jTzyrEoKu1qvur1HYo62yW4R1l8s0IDjS9O6iZDSRmhZG6obmQYSQNoEZJ1+PYjb6551D9pnazdVkY6I/4YWBMzKac1VFw+4XP+/xiK/3IvR1zWUwr+Hw= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=alq4qa7R; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="alq4qa7R" Received: by smtp.kernel.org (Postfix) with ESMTPSA id A1F11C4CEF0; Sun, 14 Sep 2025 13:12:03 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1757855524; bh=kFgOSHGireA8JhmM/ZnQKoEe0hmCQSB030ukNcLlnTs=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=alq4qa7RP0NAitQmQocj8+LIg7LaBrXXVihMDOYtMSMKrzO+1pbX6gNNjLc/PEN1v aH1gz4qVmNamjq1ynC4V59dUjIjrg/Zs261R7XaTYW7z32SHuG+SNIcByt0hyqKyc5 x8dWQhFFHSZFxaa5XZ5tdRfLBd2tOG8DzemWsP+DeHyjPlMtl0qEeDuc/2/781N/lD V7CGCcRutbN+RQKWdDgkKALd8B/dyrlfanmVTbyl91LrxDZ7nh9USQgBsVU4p1W9km UIg55r8dMpaBodiuwlaw/YMR8P6BSGYBoZ7h9d7Pi0z/F79Q2yVXVsa7IuTQvh/i5W 32eDa/FmQB/oA== From: Sasha Levin To: stable@vger.kernel.org Cc: Miaohe Lin , David Hildenbrand , Naoya Horiguchi , Andrew Morton , Sasha Levin Subject: [PATCH 5.15.y] mm/memory-failure: fix VM_BUG_ON_PAGE(PagePoisoned(page)) when unpoison memory Date: Sun, 14 Sep 2025 09:12:01 -0400 Message-ID: <20250914131201.67627-1-sashal@kernel.org> X-Mailer: git-send-email 2.51.0 In-Reply-To: <2025091331-revocable-fountain-3136@gregkh> References: <2025091331-revocable-fountain-3136@gregkh> Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit From: Miaohe Lin [ Upstream commit d613f53c83ec47089c4e25859d5e8e0359f6f8da ] When I did memory failure tests, below panic occurs: page dumped because: VM_BUG_ON_PAGE(PagePoisoned(page)) kernel BUG at include/linux/page-flags.h:616! Oops: invalid opcode: 0000 [#1] PREEMPT SMP NOPTI CPU: 3 PID: 720 Comm: bash Not tainted 6.10.0-rc1-00195-g148743902568 #40 RIP: 0010:unpoison_memory+0x2f3/0x590 RSP: 0018:ffffa57fc8787d60 EFLAGS: 00000246 RAX: 0000000000000037 RBX: 0000000000000009 RCX: ffff9be25fcdc9c8 RDX: 0000000000000000 RSI: 0000000000000027 RDI: ffff9be25fcdc9c0 RBP: 0000000000300000 R08: ffffffffb4956f88 R09: 0000000000009ffb R10: 0000000000000284 R11: ffffffffb4926fa0 R12: ffffe6b00c000000 R13: ffff9bdb453dfd00 R14: 0000000000000000 R15: fffffffffffffffe FS: 00007f08f04e4740(0000) GS:ffff9be25fcc0000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000564787a30410 CR3: 000000010d4e2000 CR4: 00000000000006f0 Call Trace: unpoison_memory+0x2f3/0x590 simple_attr_write_xsigned.constprop.0.isra.0+0xb3/0x110 debugfs_attr_write+0x42/0x60 full_proxy_write+0x5b/0x80 vfs_write+0xd5/0x540 ksys_write+0x64/0xe0 do_syscall_64+0xb9/0x1d0 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f08f0314887 RSP: 002b:00007ffece710078 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 0000000000000009 RCX: 00007f08f0314887 RDX: 0000000000000009 RSI: 0000564787a30410 RDI: 0000000000000001 RBP: 0000564787a30410 R08: 000000000000fefe R09: 000000007fffffff R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000009 R13: 00007f08f041b780 R14: 00007f08f0417600 R15: 00007f08f0416a00 Modules linked in: hwpoison_inject ---[ end trace 0000000000000000 ]--- RIP: 0010:unpoison_memory+0x2f3/0x590 RSP: 0018:ffffa57fc8787d60 EFLAGS: 00000246 RAX: 0000000000000037 RBX: 0000000000000009 RCX: ffff9be25fcdc9c8 RDX: 0000000000000000 RSI: 0000000000000027 RDI: ffff9be25fcdc9c0 RBP: 0000000000300000 R08: ffffffffb4956f88 R09: 0000000000009ffb R10: 0000000000000284 R11: ffffffffb4926fa0 R12: ffffe6b00c000000 R13: ffff9bdb453dfd00 R14: 0000000000000000 R15: fffffffffffffffe FS: 00007f08f04e4740(0000) GS:ffff9be25fcc0000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000564787a30410 CR3: 000000010d4e2000 CR4: 00000000000006f0 Kernel panic - not syncing: Fatal exception Kernel Offset: 0x31c00000 from 0xffffffff81000000 (relocation range: 0xffffffff80000000-0xffffffffbfffffff) ---[ end Kernel panic - not syncing: Fatal exception ]--- The root cause is that unpoison_memory() tries to check the PG_HWPoison flags of an uninitialized page. So VM_BUG_ON_PAGE(PagePoisoned(page)) is triggered. This can be reproduced by below steps: 1.Offline memory block: echo offline > /sys/devices/system/memory/memory12/state 2.Get offlined memory pfn: page-types -b n -rlN 3.Write pfn to unpoison-pfn echo > /sys/kernel/debug/hwpoison/unpoison-pfn This scenario can be identified by pfn_to_online_page() returning NULL. And ZONE_DEVICE pages are never expected, so we can simply fail if pfn_to_online_page() == NULL to fix the bug. Link: https://lkml.kernel.org/r/20250828024618.1744895-1-linmiaohe@huawei.com Fixes: f1dd2cd13c4b ("mm, memory_hotplug: do not associate hotadded memory to zones until online") Signed-off-by: Miaohe Lin Suggested-by: David Hildenbrand Acked-by: David Hildenbrand Cc: Naoya Horiguchi Cc: Signed-off-by: Andrew Morton [ Adjust context ] Signed-off-by: Sasha Levin --- mm/memory-failure.c | 7 +++---- 1 file changed, 3 insertions(+), 4 deletions(-) diff --git a/mm/memory-failure.c b/mm/memory-failure.c index e2b1591a85963..66390688a62c0 100644 --- a/mm/memory-failure.c +++ b/mm/memory-failure.c @@ -2056,10 +2056,9 @@ int unpoison_memory(unsigned long pfn) static DEFINE_RATELIMIT_STATE(unpoison_rs, DEFAULT_RATELIMIT_INTERVAL, DEFAULT_RATELIMIT_BURST); - if (!pfn_valid(pfn)) - return -ENXIO; - - p = pfn_to_page(pfn); + p = pfn_to_online_page(pfn); + if (!p) + return -EIO; page = compound_head(p); mutex_lock(&mf_mutex); -- 2.51.0