We wish to be able to audit when a uid=500 task accesses a file which is
uid=0. Or vice versa. This patch introduces a new audit filter type
AUDIT_FIELD_COMPARE which takes as an 'enum' which indicates which fields
should be compared. At this point we only define the task->uid vs
inode->uid, but other comparisons can be added.
Signed-off-by: Eric Paris <eparis@redhat.com>
Just a code cleanup really. We don't need to make a function call just for
it to return on error. This also makes the VFS function even easier to follow
and removes a conditional on a hot path.
Signed-off-by: Eric Paris <eparis@redhat.com>
At the moment we allow tasks to set their loginuid if they have
CAP_AUDIT_CONTROL. In reality we want tasks to set the loginuid when they
log in and it be impossible to ever reset. We had to make it mutable even
after it was once set (with the CAP) because on update and admin might have
to restart sshd. Now sshd would get his loginuid and the next user which
logged in using ssh would not be able to set his loginuid.
Systemd has changed how userspace works and allowed us to make the kernel
work the way it should. With systemd users (even admins) are not supposed
to restart services directly. The system will restart the service for
them. Thus since systemd is going to loginuid==-1, sshd would get -1, and
sshd would be allowed to set a new loginuid without special permissions.
If an admin in this system were to manually start an sshd he is inserting
himself into the system chain of trust and thus, logically, it's his
loginuid that should be used! Since we have old systems I make this a
Kconfig option.
Signed-off-by: Eric Paris <eparis@redhat.com>
The function always deals with current. Don't expose an option
pretending one can use it for something. You can't.
Signed-off-by: Eric Paris <eparis@redhat.com>
Much like the ability to filter audit on the uid of an inode collected, we
should be able to filter on the gid of the inode.
Signed-off-by: Eric Paris <eparis@redhat.com>
Allow syscall exit filter matching based on the uid of the owner of an
inode used in a syscall. aka:
auditctl -a always,exit -S open -F obj_uid=0 -F perm=wa
Signed-off-by: Eric Paris <eparis@redhat.com>
Audit entry,always rules are not allowed and are automatically changed in
exit,always rules in userspace. The kernel refuses to load such rules.
Thus a task in the middle of a syscall (and thus in audit_finish_fork())
can only be in one of two states: AUDIT_BUILD_CONTEXT or AUDIT_DISABLED.
Since the current task cannot be in AUDIT_RECORD_CONTEXT we aren't every
going to actually use the code in audit_finish_fork() since it will
return without doing anything. Thus drop the code.
Signed-off-by: Eric Paris <eparis@redhat.com>
A number of audit hooks make function calls before they determine that
auxilary records do not need to be collected. Do those checks as static
inlines since the most common case is going to be that records are not
needed and we can skip the function call overhead.
Signed-off-by: Eric Paris <eparis@redhat.com>
The audit code makes heavy use of likely() and unlikely() macros, but they
don't always make sense. Drop any that seem questionable and let the
computer do it's thing.
Signed-off-by: Eric Paris <eparis@redhat.com>
Every arch calls:
if (unlikely(current->audit_context))
audit_syscall_entry()
which requires knowledge about audit (the existance of audit_context) in
the arch code. Just do it all in static inline in audit.h so that arch's
can remain blissfully ignorant.
Signed-off-by: Eric Paris <eparis@redhat.com>
The audit system previously expected arches calling to audit_syscall_exit to
supply as arguments if the syscall was a success and what the return code was.
Audit also provides a helper AUDITSC_RESULT which was supposed to simplify things
by converting from negative retcodes to an audit internal magic value stating
success or failure. This helper was wrong and could indicate that a valid
pointer returned to userspace was a failed syscall. The fix is to fix the
layering foolishness. We now pass audit_syscall_exit a struct pt_reg and it
in turns calls back into arch code to collect the return value and to
determine if the syscall was a success or failure. We also define a generic
is_syscall_success() macro which determines success/failure based on if the
value is < -MAX_ERRNO. This works for arches like x86 which do not use a
separate mechanism to indicate syscall failure.
We make both the is_syscall_success() and regs_return_value() static inlines
instead of macros. The reason is because the audit function must take a void*
for the regs. (uml calls theirs struct uml_pt_regs instead of just struct
pt_regs so audit_syscall_exit can't take a struct pt_regs). Since the audit
function takes a void* we need to use static inlines to cast it back to the
arch correct structure to dereference it.
The other major change is that on some arches, like ia64, MIPS and ppc, we
change regs_return_value() to give us the negative value on syscall failure.
THE only other user of this macro, kretprobe_example.c, won't notice and it
makes the value signed consistently for the audit functions across all archs.
In arch/sh/kernel/ptrace_64.c I see that we were using regs[9] in the old
audit code as the return value. But the ptrace_64.h code defined the macro
regs_return_value() as regs[3]. I have no idea which one is correct, but this
patch now uses the regs_return_value() function, so it now uses regs[3].
For powerpc we previously used regs->result but now use the
regs_return_value() function which uses regs->gprs[3]. regs->gprs[3] is
always positive so the regs_return_value(), much like ia64 makes it negative
before calling the audit code when appropriate.
Signed-off-by: Eric Paris <eparis@redhat.com>
Acked-by: H. Peter Anvin <hpa@zytor.com> [for x86 portion]
Acked-by: Tony Luck <tony.luck@intel.com> [for ia64]
Acked-by: Richard Weinberger <richard@nod.at> [for uml]
Acked-by: David S. Miller <davem@davemloft.net> [for sparc]
Acked-by: Ralf Baechle <ralf@linux-mips.org> [for mips]
Acked-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> [for ppc]
The audit system likes to collect information about processes that end
abnormally (SIGSEGV) as this may me useful intrusion detection information.
This patch adds audit support to collect information when seccomp forces a
task to exit because of misbehavior in a similar way.
Signed-off-by: Eric Paris <eparis@redhat.com>
The audit system has the ability to filter on the major and minor number of
the device containing the inode being operated upon. Lets say that
/dev/sda1 has major,minor 8,1 and that we mount /dev/sda1 on /boot. Now lets
say we add a watch with a filter on 8,1. If we proceed to open an inode
inside /boot, such as /vboot/vmlinuz, we will match the major,minor filter.
Lets instead assume that one were to use a tool like debugfs and were to
open /dev/sda1 directly and to modify it's contents. We might hope that
this would also be logged, but it isn't. The rules will check the
major,minor of the device containing /dev/sda1. In other words the rule
would match on the major/minor of the tmpfs mounted at /dev.
I believe these rules should trigger on either device. The man page is
devoid of useful information about the intended semantics. It only seems
logical that if you want to know everything that happened on a major,minor
that would include things that happened to the device itself...
Signed-off-by: Eric Paris <eparis@redhat.com>
This patch does 2 things. First it reduces the number of audit_names
allocated in every audit context from 20 to 5. 5 should be enough for all
'normal' syscalls (rename being the worst). Some syscalls can still touch
more the 5 inodes such as mount. When rpc filesystem is mounted it will
create inodes and those can exceed 5. To handle that problem this patch will
dynamically allocate audit_names if it needs more than 5. This should
decrease the typicall memory usage while still supporting all the possible
kernel operations.
Signed-off-by: Eric Paris <eparis@redhat.com>
Every other filter that matches part of the inodes list collected by audit
will match against any of the inodes on that list. The filetype matching
however had a strange way of doing things. It allowed userspace to
indicated if it should match on the first of the second name collected by
the kernel. Name collection ordering seems like a kernel internal and
making userspace rules get that right just seems like a bad idea. As it
turns out the userspace audit writers had no idea it was doing this and
thus never overloaded the value field. The kernel always checked the first
name collected which for the tested rules was always correct.
This patch just makes the filetype matching like the major, minor, inode,
and LSM rules in that it will match against any of the names collected. It
also changes the rule validation to reject the old unused rule types.
Noone knew it was there. Noone used it. Why keep around the extra code?
Signed-off-by: Eric Paris <eparis@redhat.com>
The changed files were only including linux/module.h for the
EXPORT_SYMBOL infrastructure, and nothing else. Revector them
onto the isolated export header for faster compile times.
Nothing to see here but a whole lot of instances of:
-#include <linux/module.h>
+#include <linux/export.h>
This commit is only changing the kernel dir; next targets
will probably be mm, fs, the arch dirs, etc.
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
This allows us to move duplicated code in <asm/atomic.h>
(atomic_inc_not_zero() for now) to <linux/atomic.h>
Signed-off-by: Arun Sharma <asharma@fb.com>
Reviewed-by: Eric Dumazet <eric.dumazet@gmail.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: David Miller <davem@davemloft.net>
Cc: Eric Dumazet <eric.dumazet@gmail.com>
Acked-by: Mike Frysinger <vapier@gentoo.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Commit c69e8d9c01 ("CRED: Use RCU to access another task's creds and to
release a task's own creds") added calls to get_task_cred and put_cred in
audit_filter_rules. Profiling with a large number of audit rules active
on the exit chain shows that we are spending upto 48% in this routine for
syscall intensive tests, most of which is in the atomic ops.
1. The code should be accessing tsk->cred rather than tsk->real_cred.
2. Since tsk is current (or tsk is being created by copy_process) access to
tsk->cred without rcu read lock is possible. At the request of the audit
maintainer, a new flag has been added to audit_filter_rules in order to make
this explicit and guide future code.
Signed-off-by: Tony Jones <tonyj@suse.de>
Acked-by: Eric Paris <eparis@redhat.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
Normal syscall audit doesn't catch 5th argument of syscall. It also
doesn't catch the contents of userland structures pointed to be
syscall argument, so for both old and new mmap(2) ABI it doesn't
record the descriptor we are mapping. For old one it also misses
flags.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Add three helpers that retrieve a refcounted copy of the root and cwd
from the supplied fs_struct.
get_fs_root()
get_fs_pwd()
get_fs_root_and_pwd()
Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Simply switch audit_trees from using inotify to using fsnotify for it's
inode pinning and disappearing act information.
Signed-off-by: Eric Paris <eparis@redhat.com>
No real changes, just cleanup to the audit_watch split patch which we done
with minimal code changes for easy review. Now fix interfaces to make
things work better.
Signed-off-by: Eric Paris <eparis@redhat.com>
There have been a number of reports of people seeing the message:
"name_count maxed, losing inode data: dev=00:05, inode=3185"
in dmesg. These usually lead to people reporting problems to the filesystem
group who are in turn clueless what they mean.
Eventually someone finds me and I explain what is going on and that
these come from the audit system. The basics of the problem is that the
audit subsystem never expects a single syscall to 'interact' (for some
wish washy meaning of interact) with more than 20 inodes. But in fact
some operations like loading kernel modules can cause changes to lots of
inodes in debugfs.
There are a couple real fixes being bandied about including removing the
fixed compile time limit of 20 or not auditing changes in debugfs (or
both) but neither are small and obvious so I am not sending them for
immediate inclusion (I hope Al forwards a real solution next devel
window).
In the meantime this patch simply adds 'audit' to the beginning of the
crap message so if a user sees it, they come blame me first and we can
talk about what it means and make sure we understand all of the reasons
it can happen and make sure this gets solved correctly in the long run.
Signed-off-by: Eric Paris <eparis@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
percpu.h is included by sched.h and module.h and thus ends up being
included when building most .c files. percpu.h includes slab.h which
in turn includes gfp.h making everything defined by the two files
universally available and complicating inclusion dependencies.
percpu.h -> slab.h dependency is about to be removed. Prepare for
this change by updating users of gfp and slab facilities include those
headers directly instead of assuming availability. As this conversion
needs to touch large number of source files, the following script is
used as the basis of conversion.
http://userweb.kernel.org/~tj/misc/slabh-sweep.py
The script does the followings.
* Scan files for gfp and slab usages and update includes such that
only the necessary includes are there. ie. if only gfp is used,
gfp.h, if slab is used, slab.h.
* When the script inserts a new include, it looks at the include
blocks and try to put the new include such that its order conforms
to its surrounding. It's put in the include block which contains
core kernel includes, in the same order that the rest are ordered -
alphabetical, Christmas tree, rev-Xmas-tree or at the end if there
doesn't seem to be any matching order.
* If the script can't find a place to put a new include (mostly
because the file doesn't have fitting include block), it prints out
an error message indicating which .h file needs to be added to the
file.
The conversion was done in the following steps.
1. The initial automatic conversion of all .c files updated slightly
over 4000 files, deleting around 700 includes and adding ~480 gfp.h
and ~3000 slab.h inclusions. The script emitted errors for ~400
files.
2. Each error was manually checked. Some didn't need the inclusion,
some needed manual addition while adding it to implementation .h or
embedding .c file was more appropriate for others. This step added
inclusions to around 150 files.
3. The script was run again and the output was compared to the edits
from #2 to make sure no file was left behind.
4. Several build tests were done and a couple of problems were fixed.
e.g. lib/decompress_*.c used malloc/free() wrappers around slab
APIs requiring slab.h to be added manually.
5. The script was run on all .h files but without automatically
editing them as sprinkling gfp.h and slab.h inclusions around .h
files could easily lead to inclusion dependency hell. Most gfp.h
inclusion directives were ignored as stuff from gfp.h was usually
wildly available and often used in preprocessor macros. Each
slab.h inclusion directive was examined and added manually as
necessary.
6. percpu.h was updated not to include slab.h.
7. Build test were done on the following configurations and failures
were fixed. CONFIG_GCOV_KERNEL was turned off for all tests (as my
distributed build env didn't work with gcov compiles) and a few
more options had to be turned off depending on archs to make things
build (like ipr on powerpc/64 which failed due to missing writeq).
* x86 and x86_64 UP and SMP allmodconfig and a custom test config.
* powerpc and powerpc64 SMP allmodconfig
* sparc and sparc64 SMP allmodconfig
* ia64 SMP allmodconfig
* s390 SMP allmodconfig
* alpha SMP allmodconfig
* um on x86_64 SMP allmodconfig
8. percpu.h modifications were reverted so that it could be applied as
a separate patch and serve as bisection point.
Given the fact that I had only a couple of failures from tests on step
6, I'm fairly confident about the coverage of this conversion patch.
If there is a breakage, it's likely to be something in one of the arch
headers which should be easily discoverable easily on most builds of
the specific arch.
Signed-off-by: Tejun Heo <tj@kernel.org>
Guess-its-ok-by: Christoph Lameter <cl@linux-foundation.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>
* pull ACC_MODE to fs.h; we have several copies all over the place
* nightmarish expression calculating f_mode by f_flags deserves a helper
too (OPEN_FMODE(flags))
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
pahole pointed out that on x86_64 struct audit_context can be rearrainged
to save 16 bytes per struct. Since we have an audit_context per task this
can acually be a pretty significant gain.
Signed-off-by: Eric Paris <eparis@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
If syscall removes the root of subtree being watched, we
definitely do not want the rules refering that subtree
to be destroyed without the syscall in question having
a chance to match them.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
A number of places in the audit system we send an op= followed by a string
that includes spaces. Somehow this works but it's just wrong. This patch
moves all of those that I could find to be quoted.
Example:
Change From: type=CONFIG_CHANGE msg=audit(1244666690.117:31): auid=0 ses=1
subj=unconfined_u:unconfined_r:auditctl_t:s0-s0:c0.c1023 op=remove rule
key="number2" list=4 res=0
Change To: type=CONFIG_CHANGE msg=audit(1244666690.117:31): auid=0 ses=1
subj=unconfined_u:unconfined_r:auditctl_t:s0-s0:c0.c1023 op="remove rule"
key="number2" list=4 res=0
Signed-off-by: Eric Paris <eparis@redhat.com>
In preparation for converting audit to use fsnotify instead of inotify we
seperate the inode watching code into it's own file. This is similar to
how the audit tree watching code is already seperated into audit_tree.c
Signed-off-by: Eric Paris <eparis@redhat.com>
The audit execve record splitting code estimates the length of the message
generated. But it forgot to include the "" that wrap each string in its
estimation. This means that execve messages with lots of tiny (1-2 byte)
arguments could still cause records greater than 8k to be emitted. Simply
fix the estimate.
Signed-off-by: Eric Paris <eparis@redhat.com>
audit_log_d_path had spaces in the strings which would be emitted on the
error paths. This patch simply replaces those spaces with an _ or removes
the needless spaces entirely.
Signed-off-by: Eric Paris <eparis@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
after 0590b9335a audit_set_auditable() is now only
used by the audit tree code. If CONFIG_AUDIT_TREE is unset it will be defined
but unused. This patch simply moves the function inside a CONFIG_AUDIT_TREE
block.
cc1: warnings being treated as errors
/home/acme_unencrypted/git/linux-2.6-tip/kernel/auditsc.c:745: error: ‘audit_set_auditable’ defined but not used
make[2]: *** [kernel/auditsc.o] Error 1
make[1]: *** [kernel] Error 2
make[1]: *** Waiting for unfinished jobs....
Signed-off-by: Eric Paris <eparis@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
The audit subsystem treats syscall return codes as type long, unfortunately
the audit_get_context() function mistakenly converts the return code to an
int type in the parameters which could cause problems on systems where the
sizeof(int) != sizeof(long).
Signed-off-by: Paul Moore <paul.moore@hp.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Fix auditsc kernel-doc notation:
Warning(linux-2.6.28-git7//kernel/auditsc.c:2156): No description found for parameter 'attr'
Warning(linux-2.6.28-git7//kernel/auditsc.c:2156): Excess function parameter 'u_attr' description in '__audit_mq_open'
Warning(linux-2.6.28-git7//kernel/auditsc.c:2204): No description found for parameter 'notification'
Warning(linux-2.6.28-git7//kernel/auditsc.c:2204): Excess function parameter 'u_notification' description in '__audit_mq_notify'
Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com>
cc: Al Viro <viro@zeniv.linux.org.uk>
cc: Eric Paris <eparis@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
(updated)
Added hunk that changes the comment, the rest is the same.
EXECVE records contain a newline after every argument. auditd converts
"\n" to " " so you cannot see newlines even in raw logs, but they're
there nevertheless. If you're not using auditd, you need to work round
them. These '\n' chars are can be easily replaced by spaces when
creating record in kernel. Note there is no need for trailing '\n' in
an audit record.
record before this patch:
"type=EXECVE msg=audit(1231421801.566:31): argc=4 a0=\"./test\"\na1=\"a\"\na2=\"b\"\na3=\"c\"\n"
record after this patch:
"type=EXECVE msg=audit(1231421801.566:31): argc=4 a0=\"./test\" a1=\"a\" a2=\"b\" a3=\"c\""
Signed-off-by: Jiri Pirko <jpirko@redhat.com>
Acked-by: Eric Paris <eparis@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Don't pull it in sched.h; very few files actually need it and those
can include directly. sched.h itself only needs forward declaration
of struct fs_struct;
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Problem: ordering between the rules on exit chain is currently lost;
all watch and inode rules are listed after everything else _and_
exit,never on one kind doesn't stop exit,always on another from
being matched.
Solution: assign priorities to rules, keep track of the current
highest-priority matching rule and its result (always/never).
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* don't bother with allocations
* don't do double copy_from_user()
* don't duplicate parts of check for audit_dummy_context()
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* logging the original value of *msg_prio in mq_timedreceive(2)
is insane - the argument is write-only (i.e. syscall always
ignores the original value and only overwrites it).
* merge __audit_mq_timed{send,receive}
* don't do copy_from_user() twice
* don't mess with allocations in auditsc part
* ... and don't bother checking !audit_enabled and !context in there -
we'd already checked for audit_dummy_context().
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
