Re: Can we audit writing to character device?
Steve Grubb wrote:
The rule matcher only uses the information readily at hand during a
syscall.
Ah, the rule matcher does not solve f_path.dentry->d_inode->i_mode etc. from
the FD argument. Then, I see that it is impossible.
-a exit,always -w /dev/watchdog -p wa -k watchdog
It will detect the opening with write permissions, but not the individual
writes.
What I wanted to do is to record the timestamp of the individual writes, for
what I want to do is to determine whether watchdog NMI is raised by error or
by timeout. To determine it, I need to know when the last write syscall on
/dev/watchdog was.
If you have to watch writes and you know with some certainty which
descriptor
the program always uses and which selinux type it uses (assuming hpwdt_t
below), you might be able to do something like:
-a exit,always -F arch=b64 -S write -F a0=4 -F subj_type=hpwdt_t
If you know the buffer size used in the program, you might add -F a2=X where X
is the buffer size to help identify writes to the correct descriptor if the
descriptor gets reused.
Yes, I'll try a0= and a2= conditions.
Thank you.