This is a note to let you know that I've just added the patch titled
powerpc/lib: Validate size for vector operations
to the 5.4-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
powerpc-lib-validate-size-for-vector-operations.patch
and it can be found in the queue-5.4 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit ae072cd756ed11a06b7eb08ce7f9ebe7917ed543
Author: Naveen N Rao <naveen@xxxxxxxxxx>
Date: Thu Nov 23 12:47:05 2023 +0530
powerpc/lib: Validate size for vector operations
[ Upstream commit 8f9abaa6d7de0a70fc68acaedce290c1f96e2e59 ]
Some of the fp/vmx code in sstep.c assume a certain maximum size for the
instructions being emulated. The size of those operations however is
determined separately in analyse_instr().
Add a check to validate the assumption on the maximum size of the
operations, so as to prevent any unintended kernel stack corruption.
Signed-off-by: Naveen N Rao <naveen@xxxxxxxxxx>
Reviewed-by: Gustavo A. R. Silva <gustavoars@xxxxxxxxxx>
Build-tested-by: Gustavo A. R. Silva <gustavoars@xxxxxxxxxx>
Signed-off-by: Michael Ellerman <mpe@xxxxxxxxxxxxxx>
Link: https://msgid.link/20231123071705.397625-1-naveen@xxxxxxxxxx
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/arch/powerpc/lib/sstep.c b/arch/powerpc/lib/sstep.c
index 27650cd5857f..490162fb0893 100644
--- a/arch/powerpc/lib/sstep.c
+++ b/arch/powerpc/lib/sstep.c
@@ -469,6 +469,8 @@ static int do_fp_load(struct instruction_op *op, unsigned long ea,
} u;
nb = GETSIZE(op->type);
+ if (nb > sizeof(u))
+ return -EINVAL;
if (!address_ok(regs, ea, nb))
return -EFAULT;
rn = op->reg;
@@ -519,6 +521,8 @@ static int do_fp_store(struct instruction_op *op, unsigned long ea,
} u;
nb = GETSIZE(op->type);
+ if (nb > sizeof(u))
+ return -EINVAL;
if (!address_ok(regs, ea, nb))
return -EFAULT;
rn = op->reg;
@@ -563,6 +567,9 @@ static nokprobe_inline int do_vec_load(int rn, unsigned long ea,
u8 b[sizeof(__vector128)];
} u = {};
+ if (size > sizeof(u))
+ return -EINVAL;
+
if (!address_ok(regs, ea & ~0xfUL, 16))
return -EFAULT;
/* align to multiple of size */
@@ -590,6 +597,9 @@ static nokprobe_inline int do_vec_store(int rn, unsigned long ea,
u8 b[sizeof(__vector128)];
} u;
+ if (size > sizeof(u))
+ return -EINVAL;
+
if (!address_ok(regs, ea & ~0xfUL, 16))
return -EFAULT;
/* align to multiple of size */
