| Message ID | 20220131171023.2836753-1-brauner@kernel.org (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | generic/633: adapt execveat() invocations | expand |
On Mon, Jan 31, 2022 at 06:10:23PM +0100, Christian Brauner wrote: > There's a push by Ariadne to enforce that argv[0] cannot be NULL. So far > we've allowed this. Fix the execveat() invocations to set argv[0] to the > name of the file we're about to execute. To be clear, these tests are also trying to launch set-id binaries with argc == 0, so narrowing the kernel check to only set-id binaries wouldn't help here, yes? -Kees > > Cc: Ariadne Conill <ariadne@dereferenced.org> > Cc: Kees Cook <keescook@chromium.org> > Cc: Rich Felker <dalias@libc.org> > Cc: Eryu Guan <guaneryu@gmail.com> > Cc: Michael Kerrisk <mtk.manpages@gmail.com> > Cc: Andrew Morton <akpm@linux-foundation.org> > Cc: Matthew Wilcox <willy@infradead.org> > Cc: fstests@vger.kernel.org > Cc: linux-fsdevel@vger.kernel.org > Cc: linux-kernel@vger.kernel.org > Link: https://lore.kernel.org/lkml/20220127000724.15106-1-ariadne@dereferenced.org > Signed-off-by: Christian Brauner <brauner@kernel.org> > --- > src/idmapped-mounts/idmapped-mounts.c | 16 ++++++++-------- > 1 file changed, 8 insertions(+), 8 deletions(-) > > diff --git a/src/idmapped-mounts/idmapped-mounts.c b/src/idmapped-mounts/idmapped-mounts.c > index 4cf6c3bb..76b559ae 100644 > --- a/src/idmapped-mounts/idmapped-mounts.c > +++ b/src/idmapped-mounts/idmapped-mounts.c > @@ -3598,7 +3598,7 @@ static int setid_binaries(void) > NULL, > }; > static char *argv[] = { > - NULL, > + "", > }; > > if (!expected_uid_gid(t_dir1_fd, FILE1, 0, 5000, 5000)) > @@ -3726,7 +3726,7 @@ static int setid_binaries_idmapped_mounts(void) > NULL, > }; > static char *argv[] = { > - NULL, > + "", > }; > > if (!expected_uid_gid(open_tree_fd, FILE1, 0, 15000, 15000)) > @@ -3865,7 +3865,7 @@ static int setid_binaries_idmapped_mounts_in_userns(void) > NULL, > }; > static char *argv[] = { > - NULL, > + "", > }; > > if (!switch_userns(attr.userns_fd, 0, 0, false)) > @@ -3924,7 +3924,7 @@ static int setid_binaries_idmapped_mounts_in_userns(void) > NULL, > }; > static char *argv[] = { > - NULL, > + "", > }; > > if (!caps_supported()) { > @@ -3992,7 +3992,7 @@ static int setid_binaries_idmapped_mounts_in_userns(void) > NULL, > }; > static char *argv[] = { > - NULL, > + "", > }; > > if (!switch_userns(attr.userns_fd, 0, 0, false)) > @@ -4150,7 +4150,7 @@ static int setid_binaries_idmapped_mounts_in_userns_separate_userns(void) > NULL, > }; > static char *argv[] = { > - NULL, > + "", > }; > > userns_fd = get_userns_fd(0, 10000, 10000); > @@ -4214,7 +4214,7 @@ static int setid_binaries_idmapped_mounts_in_userns_separate_userns(void) > NULL, > }; > static char *argv[] = { > - NULL, > + "", > }; > > userns_fd = get_userns_fd(0, 10000, 10000); > @@ -4286,7 +4286,7 @@ static int setid_binaries_idmapped_mounts_in_userns_separate_userns(void) > NULL, > }; > static char *argv[] = { > - NULL, > + "", > }; > > userns_fd = get_userns_fd(0, 10000, 10000); > > base-commit: d8dee1222ecdfa1cff1386a61248e587eb3b275d > -- > 2.32.0 >
On Mon, Jan 31, 2022 at 12:46:27PM -0800, Kees Cook wrote: > On Mon, Jan 31, 2022 at 06:10:23PM +0100, Christian Brauner wrote: > > There's a push by Ariadne to enforce that argv[0] cannot be NULL. So far > > we've allowed this. Fix the execveat() invocations to set argv[0] to the > > name of the file we're about to execute. > > To be clear, these tests are also trying to launch set-id binaries with > argc == 0, so narrowing the kernel check to only set-id binaries > wouldn't help here, yes? Yes, that wouldn't help. The new approach of mutating argv { NULL } into { "", NULL } is better.
From: Christian Brauner > Sent: 31 January 2022 17:10 > > There's a push by Ariadne to enforce that argv[0] cannot be NULL. So far > we've allowed this. Fix the execveat() invocations to set argv[0] to the > name of the file we're about to execute. > ... > src/idmapped-mounts/idmapped-mounts.c | 16 ++++++++-------- > 1 file changed, 8 insertions(+), 8 deletions(-) > > diff --git a/src/idmapped-mounts/idmapped-mounts.c b/src/idmapped-mounts/idmapped-mounts.c > index 4cf6c3bb..76b559ae 100644 > --- a/src/idmapped-mounts/idmapped-mounts.c > +++ b/src/idmapped-mounts/idmapped-mounts.c > @@ -3598,7 +3598,7 @@ static int setid_binaries(void) > NULL, > }; > static char *argv[] = { > - NULL, > + "", > }; Isn't that just plain wrong? argv[] needs to be terminated by a NULL so you need to add the "" before the NULL not replace the NULL by it. Quite how this matches the patch description is another matter... David - Registered Address Lakeside, Bramley Road, Mount Farm, Milton Keynes, MK1 1PT, UK Registration No: 1397386 (Wales)
On Wed, Feb 02, 2022 at 08:36:05AM +0000, David Laight wrote: > From: Christian Brauner > > Sent: 31 January 2022 17:10 > > > > There's a push by Ariadne to enforce that argv[0] cannot be NULL. So far > > we've allowed this. Fix the execveat() invocations to set argv[0] to the > > name of the file we're about to execute. > > > ... > > src/idmapped-mounts/idmapped-mounts.c | 16 ++++++++-------- > > 1 file changed, 8 insertions(+), 8 deletions(-) > > > > diff --git a/src/idmapped-mounts/idmapped-mounts.c b/src/idmapped-mounts/idmapped-mounts.c > > index 4cf6c3bb..76b559ae 100644 > > --- a/src/idmapped-mounts/idmapped-mounts.c > > +++ b/src/idmapped-mounts/idmapped-mounts.c > > @@ -3598,7 +3598,7 @@ static int setid_binaries(void) > > NULL, > > }; > > static char *argv[] = { > > - NULL, > > + "", > > }; > > Isn't that just plain wrong? > argv[] needs to be terminated by a NULL so you need to add the "" > before the NULL not replace the NULL by it. > > Quite how this matches the patch description is another matter... Bah, braino. I fired that too quickly.
diff --git a/src/idmapped-mounts/idmapped-mounts.c b/src/idmapped-mounts/idmapped-mounts.c index 4cf6c3bb..76b559ae 100644 --- a/src/idmapped-mounts/idmapped-mounts.c +++ b/src/idmapped-mounts/idmapped-mounts.c @@ -3598,7 +3598,7 @@ static int setid_binaries(void) NULL, }; static char *argv[] = { - NULL, + "", }; if (!expected_uid_gid(t_dir1_fd, FILE1, 0, 5000, 5000)) @@ -3726,7 +3726,7 @@ static int setid_binaries_idmapped_mounts(void) NULL, }; static char *argv[] = { - NULL, + "", }; if (!expected_uid_gid(open_tree_fd, FILE1, 0, 15000, 15000)) @@ -3865,7 +3865,7 @@ static int setid_binaries_idmapped_mounts_in_userns(void) NULL, }; static char *argv[] = { - NULL, + "", }; if (!switch_userns(attr.userns_fd, 0, 0, false)) @@ -3924,7 +3924,7 @@ static int setid_binaries_idmapped_mounts_in_userns(void) NULL, }; static char *argv[] = { - NULL, + "", }; if (!caps_supported()) { @@ -3992,7 +3992,7 @@ static int setid_binaries_idmapped_mounts_in_userns(void) NULL, }; static char *argv[] = { - NULL, + "", }; if (!switch_userns(attr.userns_fd, 0, 0, false)) @@ -4150,7 +4150,7 @@ static int setid_binaries_idmapped_mounts_in_userns_separate_userns(void) NULL, }; static char *argv[] = { - NULL, + "", }; userns_fd = get_userns_fd(0, 10000, 10000); @@ -4214,7 +4214,7 @@ static int setid_binaries_idmapped_mounts_in_userns_separate_userns(void) NULL, }; static char *argv[] = { - NULL, + "", }; userns_fd = get_userns_fd(0, 10000, 10000); @@ -4286,7 +4286,7 @@ static int setid_binaries_idmapped_mounts_in_userns_separate_userns(void) NULL, }; static char *argv[] = { - NULL, + "", }; userns_fd = get_userns_fd(0, 10000, 10000);
There's a push by Ariadne to enforce that argv[0] cannot be NULL. So far we've allowed this. Fix the execveat() invocations to set argv[0] to the name of the file we're about to execute. Cc: Ariadne Conill <ariadne@dereferenced.org> Cc: Kees Cook <keescook@chromium.org> Cc: Rich Felker <dalias@libc.org> Cc: Eryu Guan <guaneryu@gmail.com> Cc: Michael Kerrisk <mtk.manpages@gmail.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Matthew Wilcox <willy@infradead.org> Cc: fstests@vger.kernel.org Cc: linux-fsdevel@vger.kernel.org Cc: linux-kernel@vger.kernel.org Link: https://lore.kernel.org/lkml/20220127000724.15106-1-ariadne@dereferenced.org Signed-off-by: Christian Brauner <brauner@kernel.org> --- src/idmapped-mounts/idmapped-mounts.c | 16 ++++++++-------- 1 file changed, 8 insertions(+), 8 deletions(-) base-commit: d8dee1222ecdfa1cff1386a61248e587eb3b275d