[libcamera-devel] [RFC/PATCH] libcamera: ipa_module: Relax ipaModuleInfo symbol size check

[Laurent Pinchart]

When an IPA module is loaded, the loadIPAModuleInfo() function validates
the ipaModuleInfo structure. As part of that process, it checks that the
ipaModuleInfo symbol size matches the expected structure size. This
check breaks with clang and ASan, as the LLVM's address sanitizer
implementation includes the redzone after the structure in the symbol
size, currently growing it by 156 bytes (on x86-64). This causes all IPA
modules to fail to load.

Fix the problem by relaxing the size check to only ensure that the
symbol is large enough to contain the structure.

Signed-off-by: Laurent Pinchart <laurent.pinchart at ideasonboard.com>
---
Relaxing checks increases the chance of false negatives, but I think
it's totally safe in this case. If we want to validate the structure
size, we should add a size field within the data. Other candidates for
new fields would be a magic number.
---
 src/libcamera/ipa_module.cpp | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/src/libcamera/ipa_module.cpp b/src/libcamera/ipa_module.cpp
index c9ff7de30e21..c152153c180f 100644
--- a/src/libcamera/ipa_module.cpp
+++ b/src/libcamera/ipa_module.cpp
@@ -288,12 +288,12 @@ int IPAModule::loadIPAModuleInfo()
 	}
 
 	Span<const uint8_t> info = elfLoadSymbol(data, "ipaModuleInfo");
-	if (info.size() != sizeof(info_)) {
+	if (info.size() < sizeof(info_)) {
 		LOG(IPAModule, Error) << "IPA module has no valid info";
 		return -EINVAL;
 	}
 
-	memcpy(&info_, info.data(), info.size());
+	memcpy(&info_, info.data(), sizeof(info_));
 
 	if (info_.moduleAPIVersion != IPA_MODULE_API_VERSION) {
 		LOG(IPAModule, Error) << "IPA module API version mismatch";

base-commit: f66a5c447b65bce774a1bc2d01034f437bf764b5
-- 
Regards,

Laurent Pinchart