From: Tetsuo Handa <penguin-kernel@i-love.sakura.ne.jp>
To: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>,
David Miller <davem@davemloft.net>,
Greg Kroah-Hartman <greg@kroah.com>,
Alexei Starovoitov <alexei.starovoitov@gmail.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: Sat, 27 Jun 2020 20:38:33 +0900 [thread overview]
Message-ID: <40720db5-92f0-4b5b-3d8a-beb78464a57f@i-love.sakura.ne.jp> (raw)
In-Reply-To: <87pn9mgfc2.fsf_-_@x220.int.ebiederm.org>
On 2020/06/26 21:51, Eric W. Biederman wrote:
> Please let me know if you see any bugs. Once the code review is
> finished I plan to take this through my tree.
This series needs some sanity checks.
diff --git a/kernel/umd.c b/kernel/umd.c
index de2f542191e5..f3e0227a3012 100644
--- a/kernel/umd.c
+++ b/kernel/umd.c
@@ -47,15 +47,18 @@ static struct vfsmount *blob_to_mnt(const void *data, size_t len, const char *na
/**
* umd_load_blob - Remember a blob of bytes for fork_usermode_driver
- * @info: information about usermode driver
- * @data: a blob of bytes that can be executed as a file
- * @len: The lentgh of the blob
+ * @info: information about usermode driver (shouldn't be NULL)
+ * @data: a blob of bytes that can be executed as a file (shouldn't be NULL)
+ * @len: The lentgh of the blob (shouldn't be 0)
*
*/
int umd_load_blob(struct umd_info *info, const void *data, size_t len)
{
struct vfsmount *mnt;
+ if (!info || !info->driver_name || !data || !len)
+ return -EINVAL;
+
if (WARN_ON_ONCE(info->wd.dentry || info->wd.mnt))
return -EBUSY;
@@ -158,6 +161,9 @@ int fork_usermode_driver(struct umd_info *info)
char **argv = NULL;
int err;
+ if (!info || !info->driver_name)
+ return -EINVAL;
+
if (WARN_ON_ONCE(info->tgid))
return -EBUSY;
But loading
----- test.c -----
#include <linux/slab.h>
#include <linux/module.h>
#include <linux/umd.h>
static int __init test_init(void)
{
const char blob[464] = {
"\x7f\x45\x4c\x46\x02\x01\x01\x00\x00\x00\x00\x00\x00\x00\x00\x00"
"\x02\x00\x3e\x00\x01\x00\x00\x00\x80\x00\x40\x00\x00\x00\x00\x00"
"\x40\x00\x00\x00\x00\x00\x00\x00\xd0\x00\x00\x00\x00\x00\x00\x00"
"\x00\x00\x00\x00\x40\x00\x38\x00\x01\x00\x40\x00\x04\x00\x03\x00"
"\x01\x00\x00\x00\x05\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00"
"\x00\x00\x40\x00\x00\x00\x00\x00\x00\x00\x40\x00\x00\x00\x00\x00"
"\xb4\x00\x00\x00\x00\x00\x00\x00\xb4\x00\x00\x00\x00\x00\x00\x00"
"\x00\x00\x20\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00"
"\xb8\x01\x00\x00\x00\xbf\x01\x00\x00\x00\x48\xbe\xa8\x00\x40\x00"
"\x00\x00\x00\x00\xba\x0c\x00\x00\x00\x0f\x05\xb8\xe7\x00\x00\x00"
"\xbf\x00\x00\x00\x00\x0f\x05\x00\x48\x65\x6c\x6c\x6f\x20\x77\x6f"
"\x72\x6c\x64\x0a\x00\x2e\x73\x68\x73\x74\x72\x74\x61\x62\x00\x2e"
"\x74\x65\x78\x74\x00\x2e\x72\x6f\x64\x61\x74\x61\x00\x00\x00\x00"
"\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00"
"\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00"
"\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00"
"\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00"
"\x0b\x00\x00\x00\x01\x00\x00\x00\x06\x00\x00\x00\x00\x00\x00\x00"
"\x80\x00\x40\x00\x00\x00\x00\x00\x80\x00\x00\x00\x00\x00\x00\x00"
"\x27\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00"
"\x10\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00"
"\x11\x00\x00\x00\x01\x00\x00\x00\x02\x00\x00\x00\x00\x00\x00\x00"
"\xa8\x00\x40\x00\x00\x00\x00\x00\xa8\x00\x00\x00\x00\x00\x00\x00"
"\x0c\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00"
"\x04\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00"
"\x01\x00\x00\x00\x03\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00"
"\x00\x00\x00\x00\x00\x00\x00\x00\xb4\x00\x00\x00\x00\x00\x00\x00"
"\x19\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00"
"\x01\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00"
};
struct umd_info *info = kzalloc(sizeof(*info), GFP_KERNEL);
if (!info)
return -ENOMEM;
info->driver_name = kstrdup("my test driver", GFP_KERNEL);
printk("umd_load_blob()=%d\n", umd_load_blob(info, blob, 464));
//printk("fork_usermode_driver()=%d\n", fork_usermode_driver(info));
return -EINVAL;
}
module_init(test_init);
MODULE_LICENSE("GPL");
----- test.c -----
causes
BUG_ON(!(task->flags & PF_KTHREAD));
in __fput_sync(). Do we want to forbid umd_load_blob() from process context (e.g.
upon module initialization time) ?
Also, since umd_load_blob() uses info->driver_name as filename, info->driver_name has to
satisfy strchr(info->driver_name, '/') == NULL && strlen(info->driver_name) <= NAME_MAX
in order to avoid -ENOENT failure. On the other hand, since fork_usermode_driver() uses
info->driver_name as argv[], info->driver_name has to use ' ' within this constraint.
This might be inconvenient...
next prev parent reply other threads:[~2020-06-27 11:39 UTC|newest]
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 [this message]
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
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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