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 122DB222D54; Thu, 12 Dec 2024 15:53:43 +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=1734018823; cv=none; b=uv7bn+EWDdUbfvoVxYeAoLJmsCvu8QM3krCIWqU8HEpsx/Xgcut2xwueYoAFFdtkV51piANYA0Mq6sf0cdh/gnFc/F7btgZODk2F4wLPfPU300OCqK7ZBgmK/JBsBCuicptAcWHpXHeF9FJX4wI2qpmt5WQzf5Pne4SIKsHpH6I= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1734018823; c=relaxed/simple; bh=IN4YstUWjP/asVNcZ8ItDWvUJexJjnUqTT/PaTZ0yP0=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=Kxmo+tx4OiACFyZXGk8C85eum6xE7qH6fX1Z2UX4ZwZPmIezKJJIKm5YOwoakx+HV/QAD+vEODLsTWmnzrLuzl5StKRdUxjBU+/6k/ZfvXsel1pt1gezIGezuP3AoKX9TF3GsbYyVTP7S27pcaYAhY6dpmb6sePSigDrmvpvx3E= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=Fw9wf1j0; 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="Fw9wf1j0" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 6FE3EC4CECE; Thu, 12 Dec 2024 15:53:42 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1734018822; bh=IN4YstUWjP/asVNcZ8ItDWvUJexJjnUqTT/PaTZ0yP0=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=Fw9wf1j0PcDGHOA9031uX6ZJDQAibnClb8yERUUvwplB/Rm2c35cwJ7AsUK8Zoevr 1Vs7tK7FP1F9aDazyQHAW5t6UqkDg6vaDczPcnZhw1W34K2vmpxv+RMIOFssqhPuHJ O+1TQVGYMLmuqXm8qG5DnbIg07H/CVetoSXGJhV4= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Li Zhijian , Jan Kara , Christian Brauner , Sasha Levin , Xiangyu Chen Subject: [PATCH 6.1 044/772] fs/inode: Prevent dump_mapping() accessing invalid dentry.d_name.name Date: Thu, 12 Dec 2024 15:49:49 +0100 Message-ID: <20241212144351.756738891@linuxfoundation.org> X-Mailer: git-send-email 2.47.1 In-Reply-To: <20241212144349.797589255@linuxfoundation.org> References: <20241212144349.797589255@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 6.1-stable review patch. If anyone has any objections, please let me know. ------------------ From: Li Zhijian [ Upstream commit 7f7b850689ac06a62befe26e1fd1806799e7f152 ] It's observed that a crash occurs during hot-remove a memory device, in which user is accessing the hugetlb. See calltrace as following: ------------[ cut here ]------------ WARNING: CPU: 1 PID: 14045 at arch/x86/mm/fault.c:1278 do_user_addr_fault+0x2a0/0x790 Modules linked in: kmem device_dax cxl_mem cxl_pmem cxl_port cxl_pci dax_hmem dax_pmem nd_pmem cxl_acpi nd_btt cxl_core crc32c_intel nvme virtiofs fuse nvme_core nfit libnvdimm dm_multipath scsi_dh_rdac scsi_dh_emc s mirror dm_region_hash dm_log dm_mod CPU: 1 PID: 14045 Comm: daxctl Not tainted 6.10.0-rc2-lizhijian+ #492 Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS rel-1.16.3-0-ga6ed6b701f0a-prebuilt.qemu.org 04/01/2014 RIP: 0010:do_user_addr_fault+0x2a0/0x790 Code: 48 8b 00 a8 04 0f 84 b5 fe ff ff e9 1c ff ff ff 4c 89 e9 4c 89 e2 be 01 00 00 00 bf 02 00 00 00 e8 b5 ef 24 00 e9 42 fe ff ff <0f> 0b 48 83 c4 08 4c 89 ea 48 89 ee 4c 89 e7 5b 5d 41 5c 41 5d 41 RSP: 0000:ffffc90000a575f0 EFLAGS: 00010046 RAX: ffff88800c303600 RBX: 0000000000000000 RCX: 0000000000000000 RDX: 0000000000001000 RSI: ffffffff82504162 RDI: ffffffff824b2c36 RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000000 R12: ffffc90000a57658 R13: 0000000000001000 R14: ffff88800bc2e040 R15: 0000000000000000 FS: 00007f51cb57d880(0000) GS:ffff88807fd00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000000001000 CR3: 00000000072e2004 CR4: 00000000001706f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: ? __warn+0x8d/0x190 ? do_user_addr_fault+0x2a0/0x790 ? report_bug+0x1c3/0x1d0 ? handle_bug+0x3c/0x70 ? exc_invalid_op+0x14/0x70 ? asm_exc_invalid_op+0x16/0x20 ? do_user_addr_fault+0x2a0/0x790 ? exc_page_fault+0x31/0x200 exc_page_fault+0x68/0x200 <...snip...> BUG: unable to handle page fault for address: 0000000000001000 #PF: supervisor read access in kernel mode #PF: error_code(0x0000) - not-present page PGD 800000000ad92067 P4D 800000000ad92067 PUD 7677067 PMD 0 Oops: Oops: 0000 [#1] PREEMPT SMP PTI ---[ end trace 0000000000000000 ]--- BUG: unable to handle page fault for address: 0000000000001000 #PF: supervisor read access in kernel mode #PF: error_code(0x0000) - not-present page PGD 800000000ad92067 P4D 800000000ad92067 PUD 7677067 PMD 0 Oops: Oops: 0000 [#1] PREEMPT SMP PTI CPU: 1 PID: 14045 Comm: daxctl Kdump: loaded Tainted: G W 6.10.0-rc2-lizhijian+ #492 Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS rel-1.16.3-0-ga6ed6b701f0a-prebuilt.qemu.org 04/01/2014 RIP: 0010:dentry_name+0x1f4/0x440 <...snip...> ? dentry_name+0x2fa/0x440 vsnprintf+0x1f3/0x4f0 vprintk_store+0x23a/0x540 vprintk_emit+0x6d/0x330 _printk+0x58/0x80 dump_mapping+0x10b/0x1a0 ? __pfx_free_object_rcu+0x10/0x10 __dump_page+0x26b/0x3e0 ? vprintk_emit+0xe0/0x330 ? _printk+0x58/0x80 ? dump_page+0x17/0x50 dump_page+0x17/0x50 do_migrate_range+0x2f7/0x7f0 ? do_migrate_range+0x42/0x7f0 ? offline_pages+0x2f4/0x8c0 offline_pages+0x60a/0x8c0 memory_subsys_offline+0x9f/0x1c0 ? lockdep_hardirqs_on+0x77/0x100 ? _raw_spin_unlock_irqrestore+0x38/0x60 device_offline+0xe3/0x110 state_store+0x6e/0xc0 kernfs_fop_write_iter+0x143/0x200 vfs_write+0x39f/0x560 ksys_write+0x65/0xf0 do_syscall_64+0x62/0x130 Previously, some sanity check have been done in dump_mapping() before the print facility parsing '%pd' though, it's still possible to run into an invalid dentry.d_name.name. Since dump_mapping() only needs to dump the filename only, retrieve it by itself in a safer way to prevent an unnecessary crash. Note that either retrieving the filename with '%pd' or strncpy_from_kernel_nofault(), the filename could be unreliable. Signed-off-by: Li Zhijian Link: https://lore.kernel.org/r/20240826055503.1522320-1-lizhijian@fujitsu.com Reviewed-by: Jan Kara Signed-off-by: Christian Brauner Signed-off-by: Sasha Levin [Xiangyu: Bp to fix CVE: CVE-2024-49934, modified strscpy step due to 6.1/6.6 need pass the max len to strscpy] Signed-off-by: Xiangyu Chen Signed-off-by: Sasha Levin --- fs/inode.c | 10 +++++++--- 1 file changed, 7 insertions(+), 3 deletions(-) diff --git a/fs/inode.c b/fs/inode.c index 5dd0f81e9721e..0036d5c68fd41 100644 --- a/fs/inode.c +++ b/fs/inode.c @@ -593,6 +593,7 @@ void dump_mapping(const struct address_space *mapping) struct hlist_node *dentry_first; struct dentry *dentry_ptr; struct dentry dentry; + char fname[64] = {}; unsigned long ino; /* @@ -628,11 +629,14 @@ void dump_mapping(const struct address_space *mapping) return; } + if (strncpy_from_kernel_nofault(fname, dentry.d_name.name, 63) < 0) + strscpy(fname, "", 63); /* - * if dentry is corrupted, the %pd handler may still crash, - * but it's unlikely that we reach here with a corrupt mapping + * Even if strncpy_from_kernel_nofault() succeeded, + * the fname could be unreliable */ - pr_warn("aops:%ps ino:%lx dentry name:\"%pd\"\n", a_ops, ino, &dentry); + pr_warn("aops:%ps ino:%lx dentry name(?):\"%s\"\n", + a_ops, ino, fname); } void clear_inode(struct inode *inode) -- 2.43.0