Cc'ing Patrick & Peter for similar patch:
https://lore.kernel.org/qemu-devel/aCUDxEQVACn5CY8f@x1.local/
On 28/7/25 19:25, Thomas Huth wrote:
From: Thomas Huth <th...@redhat.com>
When compiling QEMU with --enable-ubsan there is a undefined behavior
warning when running the bios-tables-test for example:
.../system/physmem.c:3243:13: runtime error: applying non-zero offset 262144
to null pointer
#0 0x55ac1df5fbc4 in address_space_write_rom_internal
.../system/physmem.c:3243:13
The problem is that buf is indeed NULL if the function is e.g. called
with type == FLUSH_CACHE. Add a check to fix the issue.
Signed-off-by: Thomas Huth <th...@redhat.com>
---
system/physmem.c | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)
diff --git a/system/physmem.c b/system/physmem.c
index 130c148ffb5..00333ffa7f7 100644
--- a/system/physmem.c
+++ b/system/physmem.c
@@ -3240,8 +3240,10 @@ static inline MemTxResult
address_space_write_rom_internal(AddressSpace *as,
}
}
len -= l;
- buf += l;
addr += l;
+ if (buf) {
+ buf += l;
+ }
}
return MEMTX_OK;
}
