Searched hist:bbd99922d0f4518518282217159666c679c6a0d1 (Results 1 – 3 of 3) sorted by relevance
| /linux/arch/powerpc/kernel/ |
| H A D | dexcr.c | bbd99922d0f4518518282217159666c679c6a0d1 Wed Apr 17 13:23:19 CEST 2024 Benjamin Gray <bgray@linux.ibm.com> powerpc/dexcr: Reset DEXCR value across exec
Inheriting the DEXCR across exec can have security and usability
concerns. If a program is compiled with hash instructions it generally
expects to run with NPHIE enabled. But if the parent process disables
NPHIE then if it's not careful it will be disabled for any children too
and the protection offered by hash checks is basically worthless.
This patch introduces a per-process reset value that new execs in a
particular process tree are initialized with. This enables fine grained
control over what DEXCR value child processes run with by default.
For example, containers running legacy binaries that expect hash
instructions to act as NOPs could configure the reset value of the
container root to control the default reset value for all members of
the container.
Signed-off-by: Benjamin Gray <bgray@linux.ibm.com>
[mpe: Add missing SPDX tag on dexcr.c]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://msgid.link/20240417112325.728010-4-bgray@linux.ibm.com
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| H A D | Makefile | diff bbd99922d0f4518518282217159666c679c6a0d1 Wed Apr 17 13:23:19 CEST 2024 Benjamin Gray <bgray@linux.ibm.com> powerpc/dexcr: Reset DEXCR value across exec
Inheriting the DEXCR across exec can have security and usability
concerns. If a program is compiled with hash instructions it generally
expects to run with NPHIE enabled. But if the parent process disables
NPHIE then if it's not careful it will be disabled for any children too
and the protection offered by hash checks is basically worthless.
This patch introduces a per-process reset value that new execs in a
particular process tree are initialized with. This enables fine grained
control over what DEXCR value child processes run with by default.
For example, containers running legacy binaries that expect hash
instructions to act as NOPs could configure the reset value of the
container root to control the default reset value for all members of
the container.
Signed-off-by: Benjamin Gray <bgray@linux.ibm.com>
[mpe: Add missing SPDX tag on dexcr.c]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://msgid.link/20240417112325.728010-4-bgray@linux.ibm.com
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| /linux/arch/powerpc/include/asm/ |
| H A D | processor.h | diff bbd99922d0f4518518282217159666c679c6a0d1 Wed Apr 17 13:23:19 CEST 2024 Benjamin Gray <bgray@linux.ibm.com> powerpc/dexcr: Reset DEXCR value across exec
Inheriting the DEXCR across exec can have security and usability
concerns. If a program is compiled with hash instructions it generally
expects to run with NPHIE enabled. But if the parent process disables
NPHIE then if it's not careful it will be disabled for any children too
and the protection offered by hash checks is basically worthless.
This patch introduces a per-process reset value that new execs in a
particular process tree are initialized with. This enables fine grained
control over what DEXCR value child processes run with by default.
For example, containers running legacy binaries that expect hash
instructions to act as NOPs could configure the reset value of the
container root to control the default reset value for all members of
the container.
Signed-off-by: Benjamin Gray <bgray@linux.ibm.com>
[mpe: Add missing SPDX tag on dexcr.c]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://msgid.link/20240417112325.728010-4-bgray@linux.ibm.com
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