Chang S. Bae 74569cb9ed x86/signal: Detect and prevent an alternate signal stack overflow ... [ Upstream commit 2beb4a53fc3f1081cedc1c1a198c7f56cc4fc60c ] The kernel pushes context on to the userspace stack to prepare for the user's signal handler. When the user has supplied an alternate signal stack, via sigaltstack(2), it is easy for the kernel to verify that the stack size is sufficient for the current hardware context. Check if writing the hardware context to the alternate stack will exceed it's size. If yes, then instead of corrupting user-data and proceeding with the original signal handler, an immediate SIGSEGV signal is delivered. Refactor the stack pointer check code from on_sig_stack() and use the new helper. While the kernel allows new source code to discover and use a sufficient alternate signal stack size, this check is still necessary to protect binaries with insufficient alternate signal stack size from data corruption. Fixes: c2bc11f10a ("x86, AVX-512: Enable AVX-512 States Context Switch") Reported-by: Florian Weimer <fweimer@redhat.com> Suggested-by: Jann Horn <jannh@google.com> Suggested-by: Andy Lutomirski <luto@kernel.org> Signed-off-by: Chang S. Bae <chang.seok.bae@intel.com> Signed-off-by: Borislav Petkov <bp@suse.de> Reviewed-by: Len Brown <len.brown@intel.com> Acked-by: Thomas Gleixner <tglx@linutronix.de> Link: https://lkml.kernel.org/r/20210518200320.17239-6-chang.seok.bae@intel.com Link: https://bugzilla.kernel.org/show_bug.cgi?id=153531 Signed-off-by: Sasha Levin <sashal@kernel.org>		2021-07-20 16:05:50 +02:00
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acpi
asm-generic
clocksource
crypto
drm
dt-bindings
keys
kunit
kvm
linux	x86/signal: Detect and prevent an alternate signal stack overflow	2021-07-20 16:05:50 +02:00
math-emu
media	media: subdev: disallow ioctl for saa6588/davinci	2021-07-19 09:45:02 +02:00
memory
misc
net	sctp: validate from_addr_param return	2021-07-19 09:44:55 +02:00
pcmcia
ras
rdma
scsi	scsi: iscsi: Fix conn use after free during resets	2021-07-20 16:05:41 +02:00
soc
sound
target
trace
uapi	net: fix mistake path for netdev_features_strings	2021-07-19 09:44:51 +02:00
vdso
video
xen