From: Tetsuo Handa <penguin-kernel@i-love.sakura.ne.jp> To: Alexei Starovoitov <alexei.starovoitov@gmail.com> Cc: "Eric W. Biederman" <ebiederm@xmission.com>, Linus Torvalds <torvalds@linux-foundation.org>, David Miller <davem@davemloft.net>, Greg Kroah-Hartman <greg@kroah.com>, Kees Cook <keescook@chromium.org>, Andrew Morton <akpm@linux-foundation.org>, Alexei Starovoitov <ast@kernel.org>, Al Viro <viro@zeniv.linux.org.uk>, bpf <bpf@vger.kernel.org>, linux-fsdevel <linux-fsdevel@vger.kernel.org>, Daniel Borkmann <daniel@iogearbox.net>, Jakub Kicinski <kuba@kernel.org>, Masahiro Yamada <yamada.masahiro@socionext.com>, Gary Lin <GLin@suse.com>, Bruno Meneguele <bmeneg@redhat.com>, LSM List <linux-security-module@vger.kernel.org>, Casey Schaufler <casey@schaufler-ca.com> Subject: Re: [PATCH 00/14] Make the user mode driver code a better citizen Date: Mon, 29 Jun 2020 11:20:14 +0900 Message-ID: <c99d0cfc-8526-0daf-90b5-33e560efdede@i-love.sakura.ne.jp> (raw) In-Reply-To: <20200628194440.puzh7nhdnk6i4rqj@ast-mbp.dhcp.thefacebook.com> On 2020/06/29 4:44, Alexei Starovoitov wrote: > But all the defensive programming kinda goes against general kernel style. > I wouldn't do it. Especially pr_info() ?! > Though I don't feel strongly about it. Honestly speaking, caller should check for errors and print appropriate messages. info->wd.mnt->mnt_root != info->wd.dentry indicates that something went wrong (maybe memory corruption). But other conditions are not fatal. That is, I consider even pr_info() here should be unnecessary. > > I would like to generalize elf_header_check() a bit and call it > before doing blob_to_mnt() to make sure that all blobs are elf files only. > Supporting '#!/bin/bash' or other things as blobs seems wrong to me. Why? There is no point with forbidding "#!", for users can use a wrapper ELF binary which contains instructions including glibc's execv()/system() functions even if "#!" cannot be used. What is more important is what protection/isolation properties processes started via fork_usermode_driver() should hold, for ELF binary can contain arbitrary instructions, these processes run as daemons (reading request from stdin and writing response to stdout) but hidden from "/usr/bin/pstree -p 1" (because they are forked from kthreadd kernel thread).
next prev parent reply index Thread overview: 136+ messages / expand[flat|nested] mbox.gz Atom feed top [not found] <87d066vd4y.fsf@x220.int.ebiederm.org> [not found] ` <20200611233134.5vofl53dj5wpwp5j@ast-mbp.dhcp.thefacebook.com> [not found] ` <87bllngirv.fsf@x220.int.ebiederm.org> [not found] ` <CAADnVQ+qNxFjTYBpYW9ZhStMh_oJBS5C_FsxSS=0Mzy=u54MSg@mail.gmail.com> [not found] ` <CAADnVQLuGYX=LamARhrZcze1ej4ELj-y99fLzOCgz60XLPw_cQ@mail.gmail.com> [not found] ` <87ftaxd7ky.fsf@x220.int.ebiederm.org> [not found] ` <20200616015552.isi6j5x732okiky4@ast-mbp.dhcp.thefacebook.com> [not found] ` <87h7v1pskt.fsf@x220.int.ebiederm.org> [not found] ` <20200623183520.5e7fmlt3omwa2lof@ast-mbp.dhcp.thefacebook.com> [not found] ` <87h7v1mx4z.fsf@x220.int.ebiederm.org> [not found] ` <20200623194023.lzl34qt2wndhcehk@ast-mbp.dhcp.thefacebook.com> [not found] ` <b4a805e7-e009-dfdf-d011-be636ce5c4f5@i-love.sakura.ne.jp> [not found] ` <20200624040054.x5xzkuhiw67cywzl@ast-mbp.dhcp.thefacebook.com> [not found] ` <5254444e-465e-6dee-287b-bef58526b724@i-love.sakura.ne.jp> [not found] ` <20200624063940.ctzhf4nnh3cjyxqi@ast-mbp.dhcp.thefacebook.com> 2020-06-24 7:05 ` [RFC][PATCH] net/bpfilter: Remove this broken and apparently unmantained Tetsuo Handa 2020-06-24 15:41 ` Casey Schaufler 2020-06-24 17:54 ` Alexei Starovoitov 2020-06-24 19:48 ` Casey Schaufler [not found] ` <878sgck6g0.fsf@x220.int.ebiederm.org> [not found] ` <CAADnVQL8WrfV74v1ChvCKE=pQ_zo+A5EtEBB3CbD=P5ote8_MA@mail.gmail.com> 2020-06-24 23:14 ` Tetsuo Handa 2020-06-25 1:35 ` Alexei Starovoitov 2020-06-25 6:38 ` Tetsuo Handa 2020-06-25 9:57 ` Greg KH 2020-06-25 11:03 ` Tetsuo Handa 2020-06-25 12:07 ` Greg KH 2020-06-25 14:21 ` Tetsuo Handa 2020-06-25 19:34 ` David Miller 2020-06-26 1:36 ` Linus Torvalds 2020-06-26 1:51 ` Alexei Starovoitov 2020-06-26 4:58 ` Tetsuo Handa 2020-06-26 5:41 ` Alexei Starovoitov 2020-06-26 6:20 ` Tetsuo Handa 2020-06-26 6:39 ` Alexei Starovoitov 2020-06-26 12:51 ` [PATCH 00/14] Make the user mode driver code a better citizen Eric W. Biederman 2020-06-26 12:53 ` [PATCH 01/14] umh: Capture the pid in umh_pipe_setup Eric W. Biederman 2020-06-26 12:53 ` [PATCH 02/14] umh: Move setting PF_UMH into umh_pipe_setup Eric W. Biederman 2020-06-26 12:54 ` [PATCH 03/14] umh: Rename the user mode driver helpers for clarity Eric W. Biederman 2020-06-26 12:54 ` [PATCH 04/14] umh: Remove call_usermodehelper_setup_file Eric W. Biederman 2020-06-26 12:55 ` [PATCH 05/14] umh: Separate the user mode driver and the user mode helper support Eric W. Biederman 2020-06-26 16:22 ` Tetsuo Handa 2020-06-26 16:45 ` Eric W. Biederman 2020-06-27 1:26 ` Tetsuo Handa 2020-06-27 4:21 ` Eric W. Biederman 2020-06-27 4:36 ` Tetsuo Handa 2020-06-26 12:55 ` [PATCH 06/14] umd: For clarity rename umh_info umd_info Eric W. Biederman 2020-06-26 15:37 ` Kees Cook 2020-06-26 16:31 ` Eric W. Biederman 2020-06-26 12:56 ` [PATCH 07/14] umd: Rename umd_info.cmdline umd_info.driver_name Eric W. Biederman 2020-06-26 12:56 ` [PATCH 08/14] umd: Transform fork_usermode_blob into fork_usermode_driver Eric W. Biederman 2020-06-26 12:57 ` [PATCH 09/14] umh: Stop calling do_execve_file Eric W. Biederman 2020-06-26 12:57 ` [PATCH 10/14] exec: Remove do_execve_file Eric W. Biederman 2020-06-26 12:58 ` [PATCH 11/14] bpfilter: Move bpfilter_umh back into init data Eric W. Biederman 2020-06-26 12:58 ` [PATCH 12/14] umd: Track user space drivers with struct pid Eric W. Biederman 2020-06-26 12:59 ` [PATCH 13/14] bpfilter: Take advantage of the facilities of " Eric W. Biederman 2020-06-26 12:59 ` [PATCH 14/14] umd: Remove exit_umh Eric W. Biederman 2020-06-26 13:48 ` [PATCH 00/14] Make the user mode driver code a better citizen Eric W. Biederman 2020-06-29 19:55 ` [PATCH v2 00/15] " Eric W. Biederman 2020-06-29 19:56 ` [PATCH v2 01/15] umh: Capture the pid in umh_pipe_setup Eric W. Biederman 2020-06-29 19:57 ` [PATCH v2 02/15] umh: Move setting PF_UMH into umh_pipe_setup Eric W. Biederman 2020-06-29 19:57 ` [PATCH v2 03/15] umh: Rename the user mode driver helpers for clarity Eric W. Biederman 2020-06-29 19:59 ` [PATCH v2 04/15] umh: Remove call_usermodehelper_setup_file Eric W. Biederman 2020-06-29 20:00 ` [PATCH v2 05/15] umh: Separate the user mode driver and the user mode helper support Eric W. Biederman 2020-06-30 16:58 ` Linus Torvalds 2020-07-01 17:18 ` Eric W. Biederman 2020-07-01 17:42 ` Alexei Starovoitov 2020-06-29 20:01 ` [PATCH v2 06/15] umd: For clarity rename umh_info umd_info Eric W. Biederman 2020-06-29 20:02 ` [PATCH v2 07/15] umd: Rename umd_info.cmdline umd_info.driver_name Eric W. Biederman 2020-06-29 20:03 ` [PATCH v2 08/15] umd: Transform fork_usermode_blob into fork_usermode_driver Eric W. Biederman 2020-06-29 20:03 ` [PATCH v2 09/15] umh: Stop calling do_execve_file Eric W. Biederman 2020-06-29 20:04 ` [PATCH v2 10/15] exec: Remove do_execve_file Eric W. Biederman 2020-06-30 5:43 ` Christoph Hellwig 2020-06-30 12:14 ` Eric W. Biederman 2020-06-30 13:38 ` Christoph Hellwig 2020-06-30 14:28 ` Eric W. Biederman 2020-06-30 16:55 ` Alexei Starovoitov 2020-06-29 20:05 ` [PATCH v2 11/15] bpfilter: Move bpfilter_umh back into init data Eric W. Biederman 2020-06-29 20:06 ` [PATCH v2 12/15] umd: Track user space drivers with struct pid Eric W. Biederman 2020-06-29 20:06 ` [PATCH v2 13/15] bpfilter: Take advantage of the facilities of " Eric W. Biederman 2020-06-29 20:07 ` [PATCH v2 14/15] umd: Remove exit_umh Eric W. Biederman 2020-06-29 20:08 ` [PATCH v2 15/15] umd: Stop using split_argv Eric W. Biederman 2020-06-29 22:12 ` [PATCH v2 00/15] Make the user mode driver code a better citizen Alexei Starovoitov 2020-06-30 1:13 ` Eric W. Biederman 2020-06-30 6:16 ` Tetsuo Handa 2020-06-30 12:29 ` Eric W. Biederman 2020-06-30 13:21 ` Tetsuo Handa 2020-07-02 13:08 ` Eric W. Biederman 2020-07-02 13:40 ` Tetsuo Handa 2020-07-02 16:02 ` Eric W. Biederman 2020-07-03 13:19 ` Tetsuo Handa 2020-07-03 22:25 ` Eric W. Biederman 2020-07-04 6:57 ` Tetsuo Handa 2020-07-08 4:46 ` Eric W. Biederman 2020-06-30 16:52 ` Alexei Starovoitov 2020-07-01 17:12 ` Eric W. Biederman 2020-07-02 16:40 ` [PATCH v3 00/16] " Eric W. Biederman 2020-07-02 16:41 ` [PATCH v3 01/16] umh: Capture the pid in umh_pipe_setup Eric W. Biederman 2020-07-02 16:41 ` [PATCH v3 02/16] umh: Move setting PF_UMH into umh_pipe_setup Eric W. Biederman 2020-07-02 16:41 ` [PATCH v3 03/16] umh: Rename the user mode driver helpers for clarity Eric W. Biederman 2020-07-02 16:41 ` [PATCH v3 04/16] umh: Remove call_usermodehelper_setup_file Eric W. Biederman 2020-07-02 16:41 ` [PATCH v3 05/16] umh: Separate the user mode driver and the user mode helper support Eric W. Biederman 2020-07-02 16:41 ` [PATCH v3 06/16] umd: For clarity rename umh_info umd_info Eric W. Biederman 2020-07-02 16:41 ` [PATCH v3 07/16] umd: Rename umd_info.cmdline umd_info.driver_name Eric W. Biederman 2020-07-02 16:41 ` [PATCH v3 08/16] umd: Transform fork_usermode_blob into fork_usermode_driver Eric W. Biederman 2020-07-02 16:41 ` [PATCH v3 09/16] umh: Stop calling do_execve_file Eric W. Biederman 2020-07-02 16:41 ` [PATCH v3 10/16] exec: Remove do_execve_file Eric W. Biederman 2020-07-08 6:35 ` Luis Chamberlain 2020-07-08 12:41 ` Luis Chamberlain 2020-07-08 13:08 ` Eric W. Biederman 2020-07-08 13:32 ` Luis Chamberlain 2020-07-12 21:02 ` Pavel Machek 2020-07-02 16:41 ` [PATCH v3 11/16] bpfilter: Move bpfilter_umh back into init data Eric W. Biederman 2020-07-02 16:41 ` [PATCH v3 12/16] umd: Track user space drivers with struct pid Eric W. Biederman 2020-07-02 16:41 ` [PATCH v3 13/16] exit: Factor thread_group_exited out of pidfd_poll Eric W. Biederman 2020-07-03 20:30 ` Alexei Starovoitov 2020-07-03 21:37 ` Eric W. Biederman 2020-07-04 0:03 ` Alexei Starovoitov 2020-07-04 15:50 ` Christian Brauner 2020-07-07 17:09 ` Eric W. Biederman 2020-07-08 0:05 ` Daniel Borkmann 2020-07-08 3:50 ` Eric W. Biederman 2020-07-04 16:00 ` Christian Brauner 2020-07-02 16:41 ` [PATCH v3 14/16] bpfilter: Take advantage of the facilities of struct pid Eric W. Biederman 2020-07-02 16:41 ` [PATCH v3 15/16] umd: Remove exit_umh Eric W. Biederman 2020-07-02 16:41 ` [PATCH v3 16/16] umd: Stop using split_argv Eric W. Biederman 2020-07-02 23:51 ` [PATCH v3 00/16] Make the user mode driver code a better citizen Tetsuo Handa 2020-07-09 22:05 ` [merged][PATCH " Eric W. Biederman 2020-07-14 19:42 ` Alexei Starovoitov 2020-07-08 5:20 ` [PATCH v2 00/15] " Luis Chamberlain 2020-06-26 14:10 ` [PATCH 00/14] " Greg Kroah-Hartman 2020-06-26 16:40 ` Alexei Starovoitov 2020-06-26 17:17 ` Eric W. Biederman 2020-06-26 18:22 ` Alexei Starovoitov 2020-06-27 11:38 ` Tetsuo Handa 2020-06-27 12:59 ` Eric W. Biederman 2020-06-27 13:57 ` Tetsuo Handa 2020-06-28 19:44 ` Alexei Starovoitov 2020-06-29 2:20 ` Tetsuo Handa [this message] 2020-06-29 20:19 ` Eric W. Biederman 2020-06-30 6:28 ` Tetsuo Handa 2020-06-30 12:32 ` Eric W. Biederman 2020-06-30 16:48 ` Alexei Starovoitov 2020-06-30 21:54 ` Tetsuo Handa 2020-06-30 21:57 ` Alexei Starovoitov 2020-06-30 22:58 ` Tetsuo Handa 2020-06-25 12:56 ` [RFC][PATCH] net/bpfilter: Remove this broken and apparently unmantained Stephen Smalley 2020-06-25 13:25 ` Greg Kroah-Hartman 2020-06-25 14:26 ` Stephen Smalley 2020-06-25 14:36 ` Stephen Smalley 2020-06-25 15:21 ` Tetsuo Handa 2020-06-25 16:03 ` Stephen Smalley 2020-06-25 16:06 ` Casey Schaufler
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