pf: Send syncookies from the receiving thread
pf sends outbound packets by offloading them to a single per-vnet SWI handler
through the `V_pf_sendqueue` mbuf queue. A large DDoS attack may overwhelm
that per-vnet queue with syncookie packets and cause contention in the SWI
handler that negatively affects other pf operations.
Fix this by sending the initial syncookie challenge from the context
of the receiving thread. This avoids the syncookie-induced contention on
the `pf_intr` mbuf queue.
Sponsored by: Klara, Inc.
Sponsored by: Entersekt
MFC after: 3 weeks
Reviewed by: kp
Differential Revision: https://reviews.freebsd.org/D59068
sys/tests/kern/pdopenpid: pdopenpid(2) is allowed in cap mode
Adjust test to check for ECAPMODE using grandchild instead of child.
Childrens can be opened even in cap mode. Add test for the later.
Reviewed by: markj
Sponsored by: The FreeBSD Foundation
MFC after: 1 week
Differential revision: https://reviews.freebsd.org/D58989
pdptrace(2): allow debugging in capability mode
The pdopenpid(2) syscall is allowed in capability mode. Add the chicken
switch security.bsd.ptrace_in_cap_mode, which disables it without
reboot, if needed.
The descriptor passed to pdptrace(2) must have the CAP_PTRACE
capability enabled. This capability is not enabled by default by
pdfork()/pdopenpid(), and the calls do not return a procdesc suitable
for debugging. The opening code must prepare for debugging in advance by
passing the PD_PTRACE_CAP flag to pdfork()/pdopenpid().
For ptrace(2), allow PT_CLEARSTEP and PT_GET_CHILDREN for the current
thread and process in cap mode as well.
Reviewed by: markj
Sponsored by: The FreeBSD Foundation
MFC after: 1 week
Differential revision: https://reviews.freebsd.org/D58989
pdopenpid(2): allow in capability mode with restrictions
The pdopenpid() syscall is allowed to open processes which are either
direct children of the caller, or are debuggees already attached to the
calling process. This is reasonable because we could have controlled the
child on fork anyway.
The procdesc-less debuggee can legitimately appear due to ptrace
FOLLOW-FORK mode.
Reviewed by: markj
Sponsored by: The FreeBSD Foundation
MFC after: 1 week
Differential revision: https://reviews.freebsd.org/D58989
kern: add p_canopen()
The function defines the policy for allowing to open a pid.
Reviewed by: markj
Sponsored by: The FreeBSD Foundation
MFC after: 1 week
Differential revision: https://reviews.freebsd.org/D58989
tests/sys/kern/pdwait: adjust test for the addition of CAP_PTRACE
Reviewed by: markj
Sponsored by: The FreeBSD Foundation
MFC after: 1 week
Differential revision: https://reviews.freebsd.org/D58586
ptrace: split sys_ptrace()/freebsd32_ptrace()
The code to handle copyin and copyout of the structured parameters is
moved into the helpers.
Reviewed by: markj
Sponsored by: The FreeBSD Foundation
MFC after: 1 week
Differential revision: https://reviews.freebsd.org/D58586
capsicum: add CAP_PTRACE
The capability will allow the ptrace(2) on the procdesc.
Reviewed by: markj
Sponsored by: The FreeBSD Foundation
MFC after: 1 week
Differential revision: https://reviews.freebsd.org/D58586
pdfork(2): add PD_PTRACE_CAP flag
If the flag is not specified, the process descriptor returned by either
pdfork(2) or pdopenpid(2) has the CAP_PTRACE capability disabled.
Reviewed by: markj
Sponsored by: The FreeBSD Foundation
MFC after: 1 week
Differential revision: https://reviews.freebsd.org/D58586
unix: Fix a socket leak
When connecting a unix domain stream socket, we
1. look up the peer (listening) socket,
2. allocate a new socket
3. add the new socket to the listening socket's queue
Prior to commit 26147c51546e, this sequence of operations was
synchronized by a pool mutex, also acquired in uipc_close().
After commit 26147c51546e, we drop the vnode pool lock immediately after
finding the peer socket via a filesystem lookup. This creates a window
where it's possible for a connection to add a new socket to the
listening queue after the listening queue has been aborted.
Fix the race by restoring the old behaviour of holding the pool lock
across the solisten_enqueue() call. This is a bit ugly since we need to
pass a mutex lock and a vnode through a couple of layers, but it seems
like a low-risk solution. Alternately we could add some flag to the
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nullfs: Allow VSOCK to be mounted on top of another VSOCK
In the world of containers, mounting a unix(4) socket is a common
practice to allow communication between processes within containers.
For example, both Podman and Docker can expose a unix(4) socket,
and that same unix(4) socket can be mounted as a file accessible
to a process inside a container, allowing that application to control
Podman or Docker. Another example is PHP-FPM with NGINX, where,
instead of using TCP/IP for communication between containers, a
unix(4) socket is sufficient.
However, nullfs(4) and all related components do not allow mounting
a VSOCK on top of another. The current workaround involves creating
the socket in a directory and mounting that directory. This is an
option, though it does not provide a good user experience compared
to directly mounting a VSOCK on top of another, since the application
that creates the socket may create other sockets in that directory,
and the user may not wish to share them, or, worse yet, applications
that create unix(4) sockets may not provide any authentication at
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iflib: Initialize the VFLR task unconditionally
The VFLR task was initialized only from drivers MSI-X interrupt
assignment paths. ixl's legacy interrupt handler can nevertheless defer
VFLR work, leaving an uninitialized task. Even with MSI-X, the admin
interrupt was established before the task was initialized.
Initialize it alongside the other private tasks. The existing detach
check and private-taskqueue drains then cover its lifecycle for every
interrupt mode and registration failure.
Sponsored by: BBOX.io
(cherry picked from commit b4208a67edc2eb7898a9ff2a6f3990c6852910e4)
iflib: Add an admin task detach fail point
Add an exact-device fail point immediately after the admin task checks
IFC_IN_DETACH. This makes the detach race reproducible without affecting
another interface.
Use a bounded delay to keep the task active while detach enters the
taskqueue drain. Mark the point nonsleepable as a safety backstop, and
document a one-shot test for verifying that deregistration drains an
already-running task before ether_ifdetach().
Reviewed by: gallatin, kgalazka
Sponsored by: BBOX.io
Differential Revision: https://reviews.freebsd.org/D58720
(cherry picked from commit ac56d36007a5a1a01fe69df370f272060e852e0b)
iflib: Drain configuration tasks before interface detach
iflib_device_deregister() sets IFC_IN_DETACH before removing the
interface, but a task which already passed its detach check can still
report a link change. This can re-arm if_linktask after
ether_ifdetach() has drained it and leave work pending across queue
teardown.
Drain the entire private taskqueue before ether_ifdetach(). Drivers
may register their own link-related configuration tasks there, so
draining only the framework admin task leaves the same race for those
drivers.
Differential Revision: https://reviews.freebsd.org/D58452
Co-authored-by: Andrew Gallatin <gallatin at FreeBSD.org>
Co-authored-by: Kevin Bowling <kbowling at FreeBSD.org>
(cherry picked from commit ba353c8950d575f9d15b82c92658e660935fba25)
iflib: Add registration failure injection points
Add six device-scoped fail(9) points at the registration milestones
needed to exercise each unwind path. An exact, runtime-only device
selector prevents unrelated iflib devices from consuming an armed point.
Mark the points non-sleepable because registration holds the ifnet and
context locks. Document one-shot operation and bus-address reprobe so a
failed attach can be recovered without another kernel build.
Reviewed by: gallatin
Sponsored by: BBOX.io
Differential Revision: https://reviews.freebsd.org/D58722
(cherry picked from commit 90e7dbe5e2ca47baff4e4c6d9e892a0554eec4db)
iflib: Complete registration failure cleanup
Pre-attach sysctls contain pointers into the iflib context. Any later
registration failure that frees the context must first remove that
sysctl tree.
Failures after a successful IFDI_ATTACH_PRE also did not consistently
call IFDI_DETACH or free the private taskqueue. In particular, routing
a taskqueue creation failure through the context cleanup could free the
driver softc while resources allocated by attach_pre remained live.
Track successful interrupt and queue setup and use one common unwind
path. Invoke IFDI_DETACH with IFNET_WLOCK dropped and release only
resources whose setup completed. Leave a failed IFDI_ATTACH_PRE to
unwind its own partial state, as required by the existing driver
contract.
A failed post-attach can follow driver registration of an SR-IOV
schema. Remove that registration before detaching the interface and
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iflib: drain admin task and fix teardown order on register failure
When IFDI_ATTACH_POST() fails (or netmap attach fails), iflib tears down with
ether_ifdetach(), taskqueue_free(ifc_tq), and IFDI_DETACH(). CTX_LOCK is still
held after ether_ifattach. ether_ifdetach() and taskqueue_drain(admin) must not
run under CTX_LOCK.
Teardown ordering (match iflib_device_deregister):
- Free the per-interface admin taskqueue after IFDI_DETACH / IFDI_QUEUES_FREE, not before.
- Drop IFNET_WLOCK() across IFDI_DETACH / IFDI_QUEUES_FREE so driver detach can sleep in
LinuxKPI workqueue drain, then retake IFNET_WLOCK() before iflib_free_intr_mem and fail_unlock.
Reviewed by: gallatin, kgalazka, #iflib
Differential Revision: https://reviews.freebsd.org/D56316
(cherry picked from commit 439132310ae1f623f6c0a3dc241d0a34e98e040b)
iflib: Fix panic observed while doing sysctl -a with if_bnxt unload
Observed below kernel panic calltrace while performing sysctl -a
operation while unloading the if_bnxt driver,
Fatal trap 9: general protection fault while in kernel mode
KDB: stack backtrace:
db_trace_self_wrapper() at db_trace_self_wrapper+0x2b/frame 0xfffffe02a7569940
vpanic() at vpanic+0x136/frame 0xfffffe02a7569a70
panic() at panic+0x43/frame 0xfffffe02a7569ad0
trap_fatal() at trap_fatal+0x68/frame 0xfffffe02a7569af0
calltrap() at calltrap+0x8/frame 0xfffffe02a7569af0
trap 0x9, rip = 0xffffffff80c0b411, rsp = 0xfffffe02a7569bc0, rbp = 0xfffffe02a7569be0 ---
sysctl_handle_counter_u64() at sysctl_handle_counter_u64+0x61/frame 0xfffffe02a7569be0
sysctl_root_handler_locked() at sysctl_root_handler_locked+0x9c/frame 0xfffffe02a7569c30
sysctl_root() at sysctl_root+0x22f/frame 0xfffffe02a7569cb0
userland_sysctl() at userland_sysctl+0x196/frame 0xfffffe02a7569d50
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