On Thu, May 20, 2021 at 4:03 AM Christian Brauner
<christian.brauner(a)ubuntu.com> wrote:
On Wed, May 19, 2021 at 04:00:22PM -0400, Richard Guy Briggs wrote:
> Since the openat2(2) syscall uses a struct open_how pointer to communicate
> its parameters they are not usefully recorded by the audit SYSCALL record's
> four existing arguments.
>
> Add a new audit record type OPENAT2 that reports the parameters in its
> third argument, struct open_how with fields oflag, mode and resolve.
>
> The new record in the context of an event would look like:
> time->Wed Mar 17 16:28:53 2021
> type=PROCTITLE msg=audit(1616012933.531:184):
proctitle=73797363616C6C735F66696C652F6F70656E617432002F746D702F61756469742D7465737473756974652D737641440066696C652D6F70656E617432
> type=PATH msg=audit(1616012933.531:184): item=1 name="file-openat2"
inode=29 dev=00:1f mode=0100600 ouid=0 ogid=0 rdev=00:00
obj=unconfined_u:object_r:user_tmp_t:s0 nametype=CREATE cap_fp=0 cap_fi=0 cap_fe=0
cap_fver=0 cap_frootid=0
> type=PATH msg=audit(1616012933.531:184): item=0
name="/root/rgb/git/audit-testsuite/tests" inode=25 dev=00:1f mode=040700 ouid=0
ogid=0 rdev=00:00 obj=unconfined_u:object_r:user_tmp_t:s0 nametype=PARENT cap_fp=0
cap_fi=0 cap_fe=0 cap_fver=0 cap_frootid=0
> type=CWD msg=audit(1616012933.531:184):
cwd="/root/rgb/git/audit-testsuite/tests"
> type=OPENAT2 msg=audit(1616012933.531:184): oflag=0100302 mode=0600 resolve=0xa
> type=SYSCALL msg=audit(1616012933.531:184): arch=c000003e syscall=437 success=yes
exit=4 a0=3 a1=7ffe315f1c53 a2=7ffe315f1550 a3=18 items=2 ppid=528 pid=540 auid=0 uid=0
gid=0 euid=0 suid=0 fsuid=0 egid=0 sgid=0 fsgid=0 tty=ttyS0 ses=1 comm="openat2"
exe="/root/rgb/git/audit-testsuite/tests/syscalls_file/openat2"
subj=unconfined_u:unconfined_r:unconfined_t:s0-s0:c0.c1023
key="testsuite-1616012933-bjAUcEPO"
>
> Signed-off-by: Richard Guy Briggs <rgb(a)redhat.com>
> Link:
https://lore.kernel.org/r/d23fbb89186754487850367224b060e26f9b7181.162136...
> ---
> fs/open.c | 2 ++
> include/linux/audit.h | 10 ++++++++++
> include/uapi/linux/audit.h | 1 +
> kernel/audit.h | 2 ++
> kernel/auditsc.c | 18 +++++++++++++++++-
> 5 files changed, 32 insertions(+), 1 deletion(-)
...
> diff --git a/kernel/auditsc.c b/kernel/auditsc.c
> index 3f59ab209dfd..faf2485323a9 100644
> --- a/kernel/auditsc.c
> +++ b/kernel/auditsc.c
> @@ -76,7 +76,7 @@
> #include <linux/fsnotify_backend.h>
> #include <uapi/linux/limits.h>
> #include <uapi/linux/netfilter/nf_tables.h>
> -#include <uapi/linux/openat2.h>
> +#include <uapi/linux/openat2.h> // struct open_how
>
> #include "audit.h"
>
> @@ -1319,6 +1319,12 @@ static void show_special(struct audit_context *context, int
*call_panic)
> audit_log_format(ab, "fd=%d flags=0x%x",
context->mmap.fd,
> context->mmap.flags);
> break;
> + case AUDIT_OPENAT2:
> + audit_log_format(ab, "oflag=0%llo mode=0%llo
resolve=0x%llx",
Hm, should we maybe follow the struct member names for all entries, i.e.
replace s/oflag/flags?
There is some precedence for using "oflags" to refer to "open" flags,
my guess is Richard is trying to be consistent here. I agree it's a
little odd, but it looks like the right thing to me from an audit
perspective; the audit perspective is a little odd after all :)
--
paul moore
www.paul-moore.com