This commit fixes the deadlock introduced by commit
0980764dee. The call getgrouplist() of
the glibc library isn't safe to be called in between fork and
exec (see commit 75c125641a).
Signed-off-by: Marc Hartmayer <mhartmay@linux.vnet.ibm.com>
Fixes: 0980764dee ("util: share code between virExec and virCommandExec")
Reviewed-by: Bjoern Walk <bwalk@linux.vnet.ibm.com>
Reviewed-by: Boris Fiuczynski <fiuczy@linux.vnet.ibm.com>
There is no "node driver" as there was before, drivers have to do
their own ACL checking anyway, so they all specify their functions and
nodeinfo is basically just extending conf/capablities. Hence moving
the code to src/conf/ is the right way to go.
Also that way we can de-duplicate some code that is in virsysfs and/or
virhostcpu that got duplicated during the virhostcpu.c split. And
Some cleanup is done throughout the changes, like adding the vir*
prefix etc.
Signed-off-by: Martin Kletzander <mkletzan@redhat.com>
Commit ca10bb040f introduced a new test that fails to build
on at least some architectures:
commandtest.c: In function 'test25':
commandtest.c:1121:5: error: comparison is always true due to
limited range of data type [-Werror=type-limits]
if (rv >= 0) {
^
Change the type of 'rv' from char to int, which is the proper
return type for virCommandExec() anyway.
In an unlikely event of execve() failing, the virCommandExec()
function does not report any error, even though checks that are
at the beginning of the function are verbose when failing.
Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
We have macros for both positive and negative string matching.
Therefore there is no need to use !STREQ or !STRNEQ. At the same
time as we are dropping this, new syntax-check rule is
introduced to make sure we won't introduce it again.
Signed-off-by: Ishmanpreet Kaur Khera <khera.ishman@gmail.com>
Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
That sets a new flag, but that flag does mean the child will get
LISTEN_FDS and LISTEN_PID environment variables properly set and
passed FDs reordered so that it corresponds with LISTEN_FDS (they must
start right after STDERR_FILENO).
Signed-off-by: Martin Kletzander <mkletzan@redhat.com>
Recent changes in the module seemed to have caused Coverity to reanalyze
certain parts of the code. Previously the code was modified via commit
id '11a11812' to resolve a different error (perhaps DEADCODE). Up through
commit id '7b3f1f8c' there were no issues.
The new error indicats the 'outbuf' was checked for NULL and then complains
because of the dereference. Adding checks for non-NULL prior to the deref
resulted in a DEADCODE message.
So, resolve using an sa_assert() to keep Coverity quiet especially since
it doesn't understand that outbuf will change as a result of a successful
virCommandRun() call.
Commit a1cbe4b5 added a check for spaces around assignments and this
patch extends it to checks for spaces around '=='. One exception is
virAssertCmpInt where comma after '==' is acceptable (since it is a
macro and '==' is its argument).
Signed-off-by: Martin Kletzander <mkletzan@redhat.com>
Commit 631923e used a few macros from sys/wait.h without including
it. On Linux, they were also defined in stdlib.h, but on FreeBSD
the build failed:
../../tests/commandtest.c: In function 'test1':
warning: implicit declaration of function 'WIFEXITED'
warning: nested extern declaration of 'WIFEXITED' [-Wnested-externs]
The old semantics of virFork() violates the priciple of good
usability: it requires the caller to check the pid argument
after use, *even when virFork returned -1*, in order to properly
abort a child process that failed setup done immediately after
fork() - that is, the caller must call _exit() in the child.
While uses in virfile.c did this correctly, uses in 'virsh
lxc-enter-namespace' and 'virt-login-shell' would happily return
from the calling function in both the child and the parent,
leading to very confusing results. [Thankfully, I found the
problem by inspection, and can't actually trigger the double
return on error without an LD_PRELOAD library.]
It is much better if the semantics of virFork are impossible
to abuse. Looking at virFork(), the parent could only ever
return -1 with a non-negative pid if it misused pthread_sigmask,
but this never happens. Up until this patch series, the child
could return -1 with non-negative pid if it fails to set up
signals correctly, but we recently fixed that to make the child
call _exit() at that point instead of forcing the caller to do
it. Thus, the return value and contents of the pid argument are
now redundant (a -1 return now happens only for failure to fork,
a child 0 return only happens for a successful 0 pid, and a
parent 0 return only happens for a successful non-zero pid),
so we might as well return the pid directly rather than an
integer of whether it succeeded or failed; this is also good
from the interface design perspective as users are already
familiar with fork() semantics.
One last change in this patch: before returning the pid directly,
I found cases where using virProcessWait unconditionally on a
cleanup path of a virFork's -1 pid return would be nicer if there
were a way to avoid it overwriting an earlier message. While
such paths are a bit harder to come by with my change to a direct
pid return, I decided to keep the virProcessWait change in this
patch.
* src/util/vircommand.h (virFork): Change signature.
* src/util/vircommand.c (virFork): Guarantee that child will only
return on success, to simplify callers. Return pid rather than
status, now that the situations are always the same.
(virExec): Adjust caller, also avoid open-coding process death.
* src/util/virprocess.c (virProcessWait): Tweak semantics when pid
is -1.
(virProcessRunInMountNamespace): Adjust caller.
* src/util/virfile.c (virFileAccessibleAs, virFileOpenForked)
(virDirCreate): Likewise.
* tools/virt-login-shell.c (main): Likewise.
* tools/virsh-domain.c (cmdLxcEnterNamespace): Likewise.
* tests/commandtest.c (test23): Likewise.
Signed-off-by: Eric Blake <eblake@redhat.com>
Auditing all callers of virCommandRun and virCommandWait that
passed a non-NULL pointer for exit status turned up some
interesting observations. Many callers were merely passing
a pointer to avoid the overall command dying, but without
caring what the exit status was - but these callers would
be better off treating a child death by signal as an abnormal
exit. Other callers were actually acting on the status, but
not all of them remembered to filter by WIFEXITED and convert
with WEXITSTATUS; depending on the platform, this can result
in a status being reported as 256 times too big. And among
those that correctly parse the output, it gets rather verbose.
Finally, there were the callers that explicitly checked that
the status was 0, and gave their own message, but with fewer
details than what virCommand gives for free.
So the best idea is to move the complexity out of callers and
into virCommand - by default, we return the actual exit status
already cleaned through WEXITSTATUS and treat signals as a
failed command; but the few callers that care can ask for raw
status and act on it themselves.
* src/util/vircommand.h (virCommandRawStatus): New prototype.
* src/libvirt_private.syms (util/command.h): Export it.
* docs/internals/command.html.in: Document it.
* src/util/vircommand.c (virCommandRawStatus): New function.
(virCommandWait): Adjust semantics.
* tests/commandtest.c (test1): Test it.
* daemon/remote.c (remoteDispatchAuthPolkit): Adjust callers.
* src/access/viraccessdriverpolkit.c (virAccessDriverPolkitCheck):
Likewise.
* src/fdstream.c (virFDStreamCloseInt): Likewise.
* src/lxc/lxc_process.c (virLXCProcessStart): Likewise.
* src/qemu/qemu_command.c (qemuCreateInBridgePortWithHelper):
Likewise.
* src/xen/xen_driver.c (xenUnifiedXendProbe): Simplify.
* tests/reconnect.c (mymain): Likewise.
* tests/statstest.c (mymain): Likewise.
* src/bhyve/bhyve_process.c (virBhyveProcessStart)
(virBhyveProcessStop): Don't overwrite virCommand error.
* src/libvirt.c (virConnectAuthGainPolkit): Likewise.
* src/openvz/openvz_driver.c (openvzDomainGetBarrierLimit)
(openvzDomainSetBarrierLimit): Likewise.
* src/util/virebtables.c (virEbTablesOnceInit): Likewise.
* src/util/viriptables.c (virIpTablesOnceInit): Likewise.
* src/util/virnetdevveth.c (virNetDevVethCreate): Fix debug
message.
* src/qemu/qemu_capabilities.c (virQEMUCapsInitQMP): Add comment.
* src/storage/storage_backend_iscsi.c
(virStorageBackendISCSINodeUpdate): Likewise.
Signed-off-by: Eric Blake <eblake@redhat.com>
Right now, a caller waiting for a child process either requires
the child to have status 0, or must use WIFEXITED() and friends
itself. But in many cases, we want the middle ground of treating
fatal signals as an error, and directly accessing the normal exit
value without having to use WEXITSTATUS(), in order to easily
detect an expected non-zero exit status. This adds the middle
ground to the low-level virProcessWait; the next patch will add
it to virCommand.
* src/util/virprocess.h (virProcessWait): Alter signature.
* src/util/virprocess.c (virProcessWait): Add parameter.
(virProcessRunInMountNamespace): Adjust caller.
* src/util/vircommand.c (virCommandWait): Likewise.
* src/util/virfile.c (virFileAccessibleAs): Likewise.
* src/lxc/lxc_container.c (lxcContainerHasReboot)
(lxcContainerAvailable): Likewise.
* daemon/libvirtd.c (daemonForkIntoBackground): Likewise.
* tools/virt-login-shell.c (main): Likewise.
* tools/virsh-domain.c (cmdLxcEnterNamespace): Likewise.
* tests/testutils.c (virtTestCaptureProgramOutput): Likewise.
* tests/commandtest.c (test23): Likewise.
Signed-off-by: Eric Blake <eblake@redhat.com>
Thanks to namespaces, we have a couple of places in the code
base that want to reflect a child exit status, including the
ability to detect death by a signal, back to a grandparent.
Best to make it a reusable function.
* src/util/virprocess.h (virProcessExitWithStatus): New prototype.
* src/libvirt_private.syms (util/virprocess.h): Export it.
* src/util/virprocess.c (virProcessExitWithStatus): New function.
* tests/commandtest.c (test23): Test it.
Signed-off-by: Eric Blake <eblake@redhat.com>
When a child fails without exec'ing, we want a well-known status;
best is to match what env(1), nice(1), su(1), and other wrapper
programs do. This patch adds enum values that later patches will
use, and sets up virFork as the first client of EXIT_CANCELED
for errors detected prior to even attempting exec, as well as
virExec to distinguish between a missing executable vs. a binary
that cannot be executed.
This is a slight semantic change in the unlikely case of a child
process failing to restore its signal mask - we now kill the
child with a known status instead of relying on the caller to
notice and do an appropriate _exit(). A subsequent patch will
make further cleanups based on an audit of all callers.
* src/internal.h (EXIT_CANCELED, EXIT_CANNOT_INVOKE)
(EXIT_ENOENT): New enum.
* src/util/vircommand.c (virFork): Document specific exit value if
child aborts early.
(virExec): Distinguish between various exec failures.
* tests/commandtest.c (test1): Enhance test.
(test22): New test.
Signed-off-by: Eric Blake <eblake@redhat.com>
For a "newfd1" the coverity tools thinks that the fd is closed in
a "virCommandPassFD", but with "flags == 0" it cannot be closed.
The code itself is ok, but coverity tool thinks that there is
"double_close" of the "newfd1" and to prevent showing this error
we simply add a comment before the proper close.
This has been found by coverity.
Signed-off-by: Pavel Hrdina <phrdina@redhat.com>
When running setuid, we must be careful about what env vars
we allow commands to inherit from us. Replace the
virCommandAddEnvPass function with two new ones which do
filtering
virCommandAddEnvPassAllowSUID
virCommandAddEnvPassBlockSUID
And make virCommandAddEnvPassCommon use the appropriate
ones
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
The test case average timing code has not been used by any test
case ever. Delete it to remove complexity.
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
Merge the virCommandPreserveFD / virCommandTransferFD methods
into a single virCommandPasFD method, and use a new
VIR_COMMAND_PASS_FD_CLOSE_PARENT to indicate their difference
in behaviour
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
The source code base needs to be adapted as well. Some files
include virutil.h just for the string related functions (here,
the include is substituted to match the new file), some include
virutil.h without any need (here, the include is removed), and
some require both.
Commit 39c77fe triggered random failures, depending on the platform
and what other fds leak into the testsuite (for me, it passed on
RHEL 6 but failed on Fedora 18). The reason was that we were
expecting an fd that fell outside of our reserved range. By reserving
a larger range, the test once again passes on all platforms.
* tests/commandtest.c (mymain): Reserve enough fds.
This is just a basic test, so we don't break virCommand in the
future. A "Hello world\n" string is written to commanhelper,
which copies input to stdout and stderr where we read it from.
Then the read strings are compared with expected values.
The libvirt coding standard is to use 'function(...args...)'
instead of 'function (...args...)'. A non-trivial number of
places did not follow this rule and are fixed in this patch.
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
https://www.gnu.org/licenses/gpl-howto.html recommends that
the 'If not, see <url>.' phrase be a separate sentence.
* tests/securityselinuxhelper.c: Remove doubled line.
* tests/securityselinuxtest.c: Likewise.
* globally: s/; If/. If/
Without this patch, logged command executions can be ambiguous if
the command contained any shell metacharacters. This has caused
more than one person to attempt to patch clients to add unnecessary
quoting, without realizing that the command itself was run with
correct args, and only the logged output was ambiguous.
* src/util/command.c (virCommandToString): Add shell escapes.
* tests/commandtest.c (test16): Test new behavior.
* tests/commanddata/test16.log: Update expected output.
* tests/qemuxml2argvdata/qemuxml2argv-*.args: Likewise.
* tests/networkxml2argvdata/*.argv: Likewise.
Per the FSF address could be changed from time to time, and GNU
recommends the following now: (http://www.gnu.org/licenses/gpl-howto.html)
You should have received a copy of the GNU General Public License
along with Foobar. If not, see <http://www.gnu.org/licenses/>.
This patch removes the explicit FSF address, and uses above instead
(of course, with inserting 'Lesser' before 'General').
Except a bunch of files for security driver, all others are changed
automatically, the copyright for securify files are not complete,
that's why to do it manually:
src/security/security_selinux.h
src/security/security_driver.h
src/security/security_selinux.c
src/security/security_apparmor.h
src/security/security_apparmor.c
src/security/security_driver.c
It is possible to deadlock libvirt by having a domain with XML
longer than PIPE_BUF, and by writing a hook script that closes
stdin early. This is because libvirt was keeping a copy of the
child's stdin read fd open, which means the write fd in the
parent will never see EPIPE (remember, libvirt should always be
run with SIGPIPE ignored, so we should never get a SIGPIPE signal).
Since there is no error, libvirt blocks waiting for a write to
complete, even though the only reader is also libvirt. The
solution is to ensure that only the child can act as a reader
before the parent does any writes; and then dealing with the
fallout of dealing with EPIPE.
Thankfully, this is not a security hole - since the only way to
trigger the deadlock is to install a custom hook script, anyone
that already has privileges to install a hook script already has
privileges to do any number of other equally disruptive things
to libvirt; it would only be a security hole if an unprivileged
user could install a hook script to DoS a privileged user.
* src/util/command.c (virCommandRun): Close parent's copy of child
read fd earlier.
(virCommandProcessIO): Don't let EPIPE be fatal; the child may
be done parsing input.
* tests/commandhelper.c (main): Set up a SIGPIPE situation.
* tests/commandtest.c (test20): Trigger it.
* tests/commanddata/test20.log: New file.
More bug extermination in the category of:
Error: CHECKED_RETURN:
/libvirt/src/conf/network_conf.c:595:
check_return: Calling function "virAsprintf" without checking return value (as is done elsewhere 515 out of 543 times).
/libvirt/src/qemu/qemu_process.c:2780:
unchecked_value: No check of the return value of "virAsprintf(&msg, "was paused (%s)", virDomainPausedReasonTypeToString(reason))".
/libvirt/tests/commandtest.c:809:
check_return: Calling function "setsid" without checking return value (as is done elsewhere 4 out of 5 times).
/libvirt/tests/commandtest.c:830:
unchecked_value: No check of the return value of "virTestGetDebug()".
/libvirt/tests/commandtest.c:831:
check_return: Calling function "virTestGetVerbose" without checking return value (as is done elsewhere 41 out of 42 times).
/libvirt/tests/commandtest.c:833:
check_return: Calling function "virInitialize" without checking return value (as is done elsewhere 18 out of 21 times).
One note about the error in commandtest line 809: setsid() seems to fail when running the test -- could be removed ?
Return statements with parameter enclosed in parentheses were modified
and parentheses were removed. The whole change was scripted, here is how:
List of files was obtained using this command:
git grep -l -e '\<return\s*([^()]*\(([^()]*)[^()]*\)*)\s*;' | \
grep -e '\.[ch]$' -e '\.py$'
Found files were modified with this command:
sed -i -e \
's_^\(.*\<return\)\s*(\(\([^()]*([^()]*)[^()]*\)*\))\s*\(;.*$\)_\1 \2\4_' \
-e 's_^\(.*\<return\)\s*(\([^()]*\))\s*\(;.*$\)_\1 \2\3_'
Then checked for nonsense.
The whole command looks like this:
git grep -l -e '\<return\s*([^()]*\(([^()]*)[^()]*\)*)\s*;' | \
grep -e '\.[ch]$' -e '\.py$' | xargs sed -i -e \
's_^\(.*\<return\)\s*(\(\([^()]*([^()]*)[^()]*\)*\))\s*\(;.*$\)_\1 \2\4_' \
-e 's_^\(.*\<return\)\s*(\([^()]*\))\s*\(;.*$\)_\1 \2\3_'
