From: Daniel Hoffman <dhoff749@gmail.com>
To: qemu-devel@nongnu.org
Cc: qemu-trivial@nongnu.org, Daniel Hoffman <dhoff749@gmail.com>,
Alexey Kardashevskiy <aik@ozlabs.ru>,
David Gibson <david@gibson.dropbear.id.au>,
qemu-ppc@nongnu.org (open list:Virtual Open Firm...)
Subject: [PATCH] ppc/spapr: Fix ubsan warning with unaligned pointer access
Date: Sat, 16 Dec 2023 16:14:40 -0800 [thread overview]
Message-ID: <20231217001441.146344-1-dhoff749@gmail.com> (raw)
Found while running QTest with UBsan. Unaligned pointers appear to be
valid, so moving the read to an explicit memcpy to an intermediate.
---
hw/ppc/vof.c | 5 ++++-
1 file changed, 4 insertions(+), 1 deletion(-)
diff --git a/hw/ppc/vof.c b/hw/ppc/vof.c
index e3b430a81f4..609a51c645d 100644
--- a/hw/ppc/vof.c
+++ b/hw/ppc/vof.c
@@ -646,7 +646,10 @@ static void vof_dt_memory_available(void *fdt, GArray *claimed, uint64_t base)
mem0_reg = fdt_getprop(fdt, offset, "reg", &proplen);
g_assert(mem0_reg && proplen == sizeof(uint32_t) * (ac + sc));
if (sc == 2) {
- mem0_end = be64_to_cpu(*(uint64_t *)(mem0_reg + sizeof(uint32_t) * ac));
+ /* Pointer may be unaligned */
+ uint64_t mem0_end_copy;
+ memcpy(&mem0_end_copy, mem0_reg + sizeof(uint32_t) * ac, sizeof(mem0_end_copy));
+ mem0_end = be64_to_cpu(mem0_end_copy);
} else {
mem0_end = be32_to_cpu(*(uint32_t *)(mem0_reg + sizeof(uint32_t) * ac));
}
--
2.40.1
next reply other threads:[~2023-12-17 0:16 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-12-17 0:14 Daniel Hoffman [this message]
2023-12-20 1:45 ` [PATCH] ppc/spapr: Fix ubsan warning with unaligned pointer access Richard Henderson
2023-12-22 3:47 ` Alexey Kardashevskiy
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