From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Google-Smtp-Source: AIpwx4/DHXSCAtys1can8gnBmVBDCCTRHW9BEtuxl1t5OFUXAGuhitML13Z7pYSiSSwZMF3HgPum ARC-Seal: i=1; a=rsa-sha256; t=1524653041; cv=none; d=google.com; s=arc-20160816; b=sjyZcvaetdKf5WD4ckGhVifTN7cz91FIF75270XOqUqF3u1RPrgFNFf7PGZO9r3wcu gV4dEE9HqtxkbSckVtvrx4EBGROUZ9YDZHfWsGJyHlKmf6zLxj3QFbnrfpi0iWG2gR8M 8Vhln6hK36tKfMa40QqXCYNnqVumIl+qoePf9bv0pQOTQJ5i8SS5zxeuwsTgGDSYqMkS NBCSU+NRnrh631Ru1s/XnjKKtA7m1aTb+bI4835gi0+nsTZOZuLsNO/DLz/45u0LTWuF MiTB21WVtescOCJB+r3ZG5cLY1RRi77L4tGZwngw3yt8JM7XppITnNrGbWbQViDSLLyn Ui0w== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=mime-version:user-agent:references:in-reply-to:message-id:date :subject:cc:to:from:arc-authentication-results; bh=aE3Ds4fkmW5dYH4oQL8TNFjRhqJZCXdfEO33/o+GFPU=; b=eqDbr8+EW2AIblTFd8/FoKIZsNYc6xCrqg9z2W5EUcpBWnP79YOQdNMlwW3llBua4w Dmofvxw+P3I/H7/sgNhSa6tadvlgMmIdBb3Dqno14mSBCoMW+blHho0/nfGN/s04WEiT 150hS/MZvVoAwW7YDQFT1mBLVzrIAVK4kz42ne2s+TJlpsleKkz9oKqaPSRiLl7im8Pl m1E0LJuLASkrbaH8PyourhDwi4iKEYg45UYqgqSj00/whS4ixLaxsLxyDYZrq223LTUr 70zjlfMZrAKnT1XhyMZsIfKOgu2eJ1tokIxgVU/xWpjfkDANsfZc7B8dLij6UXQKFXd8 E3jQ== ARC-Authentication-Results: i=1; mx.google.com; spf=softfail (google.com: domain of transitioning gregkh@linuxfoundation.org does not designate 90.92.61.202 as permitted sender) smtp.mailfrom=gregkh@linuxfoundation.org Authentication-Results: mx.google.com; spf=softfail (google.com: domain of transitioning gregkh@linuxfoundation.org does not designate 90.92.61.202 as permitted sender) smtp.mailfrom=gregkh@linuxfoundation.org From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Jia Zhang , Jiri Olsa , Al Viro , Linus Torvalds , Peter Zijlstra , Thomas Gleixner , jolsa@redhat.com, Ingo Molnar , Sasha Levin Subject: [PATCH 4.14 163/183] vfs/proc/kcore, x86/mm/kcore: Fix SMAP fault when dumping vsyscall user page Date: Wed, 25 Apr 2018 12:36:23 +0200 Message-Id: <20180425103249.076681278@linuxfoundation.org> X-Mailer: git-send-email 2.17.0 In-Reply-To: <20180425103242.532713678@linuxfoundation.org> References: <20180425103242.532713678@linuxfoundation.org> User-Agent: quilt/0.65 X-stable: review MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 X-getmail-retrieved-from-mailbox: INBOX X-GMAIL-LABELS: =?utf-8?b?IlxcU2VudCI=?= X-GMAIL-THRID: =?utf-8?q?1598714587379024076?= X-GMAIL-MSGID: =?utf-8?q?1598714587379024076?= X-Mailing-List: linux-kernel@vger.kernel.org List-ID: 4.14-stable review patch. If anyone has any objections, please let me know. ------------------ From: Jia Zhang [ Upstream commit 595dd46ebfc10be041a365d0a3fa99df50b6ba73 ] Commit: df04abfd181a ("fs/proc/kcore.c: Add bounce buffer for ktext data") ... introduced a bounce buffer to work around CONFIG_HARDENED_USERCOPY=y. However, accessing the vsyscall user page will cause an SMAP fault. Replace memcpy() with copy_from_user() to fix this bug works, but adding a common way to handle this sort of user page may be useful for future. Currently, only vsyscall page requires KCORE_USER. Signed-off-by: Jia Zhang Reviewed-by: Jiri Olsa Cc: Al Viro Cc: Linus Torvalds Cc: Peter Zijlstra Cc: Thomas Gleixner Cc: jolsa@redhat.com Link: http://lkml.kernel.org/r/1518446694-21124-2-git-send-email-zhang.jia@linux.alibaba.com Signed-off-by: Ingo Molnar Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman --- arch/x86/mm/init_64.c | 3 +-- fs/proc/kcore.c | 4 ++++ include/linux/kcore.h | 1 + 3 files changed, 6 insertions(+), 2 deletions(-) --- a/arch/x86/mm/init_64.c +++ b/arch/x86/mm/init_64.c @@ -1180,8 +1180,7 @@ void __init mem_init(void) after_bootmem = 1; /* Register memory areas for /proc/kcore */ - kclist_add(&kcore_vsyscall, (void *)VSYSCALL_ADDR, - PAGE_SIZE, KCORE_OTHER); + kclist_add(&kcore_vsyscall, (void *)VSYSCALL_ADDR, PAGE_SIZE, KCORE_USER); mem_init_print_info(NULL); } --- a/fs/proc/kcore.c +++ b/fs/proc/kcore.c @@ -510,6 +510,10 @@ read_kcore(struct file *file, char __use /* we have to zero-fill user buffer even if no read */ if (copy_to_user(buffer, buf, tsz)) return -EFAULT; + } else if (m->type == KCORE_USER) { + /* User page is handled prior to normal kernel page: */ + if (copy_to_user(buffer, (char *)start, tsz)) + return -EFAULT; } else { if (kern_addr_valid(start)) { /* --- a/include/linux/kcore.h +++ b/include/linux/kcore.h @@ -10,6 +10,7 @@ enum kcore_type { KCORE_VMALLOC, KCORE_RAM, KCORE_VMEMMAP, + KCORE_USER, KCORE_OTHER, };