5.15-stable review patch. If anyone has any objections, please let me know.
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From: Christophe Leroy christophe.leroy@csgroup.eu
[ Upstream commit 3091f5fc5f1df7741ddf326561384e0997eca2a1 ]
.opd section contains function descriptors used to locate functions in the kernel. If someone is able to modify a function descriptor he will be able to run arbitrary kernel function instead of another.
To avoid that, move .opd section inside read-only memory.
Signed-off-by: Christophe Leroy christophe.leroy@csgroup.eu Signed-off-by: Michael Ellerman mpe@ellerman.id.au Link: https://lore.kernel.org/r/3cd40b682fb6f75bb40947b55ca0bac20cb3f995.163413622... Stable-dep-of: 1b1e38002648 ("powerpc: add crtsavres.o to always-y instead of extra-y") Signed-off-by: Sasha Levin sashal@kernel.org --- arch/powerpc/kernel/vmlinux.lds.S | 12 ++++++------ 1 file changed, 6 insertions(+), 6 deletions(-)
diff --git a/arch/powerpc/kernel/vmlinux.lds.S b/arch/powerpc/kernel/vmlinux.lds.S index d4531902d8c6..d8301ce7c675 100644 --- a/arch/powerpc/kernel/vmlinux.lds.S +++ b/arch/powerpc/kernel/vmlinux.lds.S @@ -148,6 +148,12 @@ SECTIONS SOFT_MASK_TABLE(8) RESTART_TABLE(8)
+ .opd : AT(ADDR(.opd) - LOAD_OFFSET) { + __start_opd = .; + KEEP(*(.opd)) + __end_opd = .; + } + . = ALIGN(8); __stf_entry_barrier_fixup : AT(ADDR(__stf_entry_barrier_fixup) - LOAD_OFFSET) { __start___stf_entry_barrier_fixup = .; @@ -346,12 +352,6 @@ SECTIONS *(.branch_lt) }
- .opd : AT(ADDR(.opd) - LOAD_OFFSET) { - __start_opd = .; - KEEP(*(.opd)) - __end_opd = .; - } - . = ALIGN(256); .got : AT(ADDR(.got) - LOAD_OFFSET) { __toc_start = .;