linux/include
Jori Koolstra fd8756fa14 net: af_unix: useful handling of LSM denials on SCM_RIGHTS
Right now if some LSM such as Smack denies an AF_UNIX socket peer to
receive an SCM_RIGHTS fd, the SCM_RIGHTS fd array will be cut short at
that point, and MSG_CTRUNC is set on return of recvmsg(). This is
highly problematic behaviour, because it leaves the receiver
wondering what happened. As per man page MSG_CTRUNC is supposed to
indicate that the control buffer was sized too short, but suddenly
a permission error might result in the exact same flag being set.
Moreover, the receiver has no chance to determine how many fds got
originally sent and how many were suppressed.[1]

Add a SO_RIGHTS_NOTRUNC option to UNIX sockets to enable more useful
handling of LSM denials when receiving SCM_RIGHTS messages: instead of
truncating the message at the first blocked fd, keep every fd slot
and store the LSM errno in the blocked slot. The socket option is
inherited by the child accept() socket if set on the listen() socket.

[1]: https://github.com/uapi-group/kernel-features#useful-handling-of-lsm-denials-on-scm_rights

Reviewed-by: Christian Brauner (Amutable) <brauner@kernel.org>
Signed-off-by: Jori Koolstra <jkoolstra@xs4all.nl>
Link: https://patch.msgid.link/20260813162818.149248-4-jkoolstra@xs4all.nl
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-08-17 18:14:52 -07:00
..
acpi ACPI: CPPC: Check all controls for fast switching 2026-07-22 15:09:14 +02:00
asm-generic mm.git review status for mm-hotfixes-stable..mm-nonmm-stable 2026-06-21 13:20:19 -07:00
clocksource
crypto Networking changes for 7.2. 2026-06-17 08:17:00 +01:00
cxl cxl: Support dpa without a mailbox 2026-06-29 10:55:47 -07:00
drm drm-misc-fixes for v7.2-rc5: 2026-07-24 18:30:29 +10:00
dt-bindings SoC fixes for 7.2 2026-07-17 08:52:09 -07:00
hyperv mshv: fix hv_input_get_system_property struct 2026-07-22 21:58:21 +00:00
keys keys: Pin request_key_auth payload in instantiate paths 2026-06-15 15:19:13 +03:00
kunit linux_kselftest-kunit-7.2-rc1 2026-06-16 16:33:57 +05:30
kvm KVM: arm64: vgic: Fix race between LPI release and re-registration 2026-07-23 09:56:57 +01:00
linux Merge branch '200GbE' of git://git.kernel.org/pub/scm/linux/kernel/git/tnguy/next-queue 2026-08-17 18:01:55 -07:00
math-emu
media
memory
misc
net net: af_unix: useful handling of LSM denials on SCM_RIGHTS 2026-08-17 18:14:52 -07:00
pcmcia Replace <linux/mod_devicetable.h> by more specific <linux/device-id/*.h> (headers) 2026-07-03 07:38:16 +02:00
ras
rdma RDMA v7.2 merge window 2026-06-18 08:16:21 -07:00
rv
scsi SCSI fixes on 20260812 2026-08-12 08:03:31 -07:00
soc soc/tegra: pmc: Fixes for v7.2 2026-07-10 14:40:52 +02:00
sound ASoC/soundwire: Intel: reset the PCMSyCM registers in hda_sdw_bpt_close 2026-07-31 13:23:10 +01:00
target
trace mptcp: remove unused data_ack from struct mptcp_ext 2026-08-17 17:25:49 -07:00
uapi net: af_unix: useful handling of LSM denials on SCM_RIGHTS 2026-08-17 18:14:52 -07:00
ufs Merge branch 7.1/scsi-fixes into 7.2/scsi-staging 2026-06-15 21:01:30 -04:00
vdso
video
xen xen: Replace __ASSEMBLY__ with __ASSEMBLER__ in header files 2026-07-01 09:49:52 +02:00
Kbuild