Eric W. Biederman 82d43437f8 signal: Add SA_IMMUTABLE to ensure forced siganls do not get changed ... commit 00b06da29c upstream. As Andy pointed out that there are races between force_sig_info_to_task and sigaction[1] when force_sig_info_task. As Kees discovered[2] ptrace is also able to change these signals. In the case of seeccomp killing a process with a signal it is a security violation to allow the signal to be caught or manipulated. Solve this problem by introducing a new flag SA_IMMUTABLE that prevents sigaction and ptrace from modifying these forced signals. This flag is carefully made kernel internal so that no new ABI is introduced. Longer term I think this can be solved by guaranteeing short circuit delivery of signals in this case. Unfortunately reliable and guaranteed short circuit delivery of these signals is still a ways off from being implemented, tested, and merged. So I have implemented a much simpler alternative for now. [1] https://lkml.kernel.org/r/b5d52d25-7bde-4030-a7b1-7c6f8ab90660@www.fastmail.com [2] https://lkml.kernel.org/r/202110281136.5CE65399A7@keescook Cc: stable@vger.kernel.org Fixes: 307d522f5e ("signal/seccomp: Refactor seccomp signal and coredump generation") Tested-by: Andrea Righi <andrea.righi@canonical.com> Tested-by: Kees Cook <keescook@chromium.org> Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>		2021-11-18 19:16:01 +01:00
..
acpi	ACPI: tools: fix compilation error	2021-10-07 19:18:19 +02:00
asm-generic	asm-generic: build fixes for v5.15	2021-10-08 11:57:54 -07:00
clocksource
crypto
drm
dt-bindings	linux-watchdog 5.15-rc1 tag	2021-09-07 13:52:46 -07:00
keys
kunit	kunit: fix kernel-doc warnings due to mismatched arg names	2021-10-06 17:54:07 -06:00
kvm	KVM: arm64: Fix PMU probe ordering	2021-09-20 12:43:34 +01:00
linux	signal: Add SA_IMMUTABLE to ensure forced siganls do not get changed	2021-11-18 19:16:01 +01:00
math-emu
media
memory	memory: renesas-rpc-if: Correct QSPI data transfer in Manual mode	2021-11-18 19:16:01 +01:00
misc
net	mptcp: fix corrupt receiver key in MPC + data + checksum	2021-10-28 08:19:06 -07:00
pcmcia
ras
rdma
scsi	scsi: core: Avoid leaving shost->last_reset with stale value if EH does not run	2021-11-18 19:15:51 +01:00
soc	net: dsa: tag_ocelot_8021q: break circular dependency with ocelot switch lib	2021-10-12 17:35:18 -07:00
sound	ALSA: hda: intel: Allow repeatedly probing on codec configuration errors	2021-10-07 09:15:22 +02:00
target
trace	block-5.15-2021-10-17	2021-10-17 19:25:20 -10:00
uapi	signal: Add SA_IMMUTABLE to ensure forced siganls do not get changed	2021-11-18 19:16:01 +01:00
vdso
video
xen	xen/privcmd: drop "pages" parameter from xen_remap_pfn()	2021-10-05 08:20:27 +02:00