[PATCH 2/3] libcamera: shared_mem_object: Prevent memfd from shrinking or growing

[Laurent Pinchart]

The memfd underlying the SharedMem object must not shrink, or memory
corruption will happen. Prevent this by setting the shrink seal on the
file. As there's no valid use case for growing the memory either, set
the grow seal as well.

Signed-off-by: Laurent Pinchart <laurent.pinchart at ideasonboard.com>
---
 src/libcamera/shared_mem_object.cpp | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/src/libcamera/shared_mem_object.cpp b/src/libcamera/shared_mem_object.cpp
index 022645e71a35..d4c7991ad16a 100644
--- a/src/libcamera/shared_mem_object.cpp
+++ b/src/libcamera/shared_mem_object.cpp
@@ -58,7 +58,8 @@ SharedMem::SharedMem() = default;
  */
 SharedMem::SharedMem(const std::string &name, std::size_t size)
 {
-	UniqueFD memfd = MemFd::create(name.c_str(), size);
+	UniqueFD memfd = MemFd::create(name.c_str(), size, MemFd::Seal::Shrink |
+				       MemFd::Seal::Grow);
 	if (!memfd.isValid())
 		return;
 
-- 
Regards,

Laurent Pinchart