From 3a39919d31ac2362d18e1f71928c028e6ac33151 Mon Sep 17 00:00:00 2001
From: nabil Otsmane <hn_otsmane@esi.dz>
Date: Sun, 24 Nov 2024 16:24:36 +0400
Subject: [PATCH 1/2] protocols: fix shm fd size check before creating or
 resizing shm_pool

---
 src/protocols/core/Shm.cpp | 21 +++++++++++++++++++++
 1 file changed, 21 insertions(+)

diff --git a/src/protocols/core/Shm.cpp b/src/protocols/core/Shm.cpp
index a8c98bb0ed1..49dae079892 100644
--- a/src/protocols/core/Shm.cpp
+++ b/src/protocols/core/Shm.cpp
@@ -1,6 +1,7 @@
 #include "Shm.hpp"
 #include <algorithm>
 #include <sys/mman.h>
+#include <sys/stat.h>
 #include <drm_fourcc.h>
 #include "../../render/Texture.hpp"
 #include "../types/WLBuffer.hpp"
@@ -99,10 +100,25 @@ void CSHMPool::resize(size_t size_) {
         LOGM(ERR, "Couldn't mmap {} bytes from fd {} of shm client", size, fd);
 }
 
+int shmIsSizeValid(int fd, size_t size) {
+    struct stat st;
+    if (fstat(fd, &st) == -1) {
+        LOGM(ERR, "Couldn't get stat for fd {} of shm client", fd);
+        return 0;
+    }
+
+    return (size_t)st.st_size >= size;
+}
+
 CWLSHMPoolResource::CWLSHMPoolResource(SP<CWlShmPool> resource_, int fd_, size_t size_) : resource(resource_) {
     if (!good())
         return;
 
+    if (!shmIsSizeValid(fd_, size_)) {
+        resource_->error(-1, "The size of the file is not big enough for the shm pool");
+        return;
+    }
+
     pool = makeShared<CSHMPool>(fd_, size_);
 
     resource->setDestroy([this](CWlShmPool* r) { PROTO::shm->destroyResource(this); });
@@ -113,6 +129,11 @@ CWLSHMPoolResource::CWLSHMPoolResource(SP<CWlShmPool> resource_, int fd_, size_t
             r->error(-1, "Shrinking a shm pool is illegal");
             return;
         }
+        if (!shmIsSizeValid(pool->fd, size_)) {
+            r->error(-1, "The size of the file is not big enough for the shm pool");
+            return;
+        }
+
         pool->resize(size_);
     });
 

From 201ad4baad72895e567c40dc9231ff64d02769b8 Mon Sep 17 00:00:00 2001
From: nabil Otsmane <hn_otsmane@esi.dz>
Date: Sun, 24 Nov 2024 18:21:25 +0400
Subject: [PATCH 2/2] added static to function

---
 src/protocols/core/Shm.cpp | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/protocols/core/Shm.cpp b/src/protocols/core/Shm.cpp
index 49dae079892..708d41c3042 100644
--- a/src/protocols/core/Shm.cpp
+++ b/src/protocols/core/Shm.cpp
@@ -100,7 +100,7 @@ void CSHMPool::resize(size_t size_) {
         LOGM(ERR, "Couldn't mmap {} bytes from fd {} of shm client", size, fd);
 }
 
-int shmIsSizeValid(int fd, size_t size) {
+static int shmIsSizeValid(int fd, size_t size) {
     struct stat st;
     if (fstat(fd, &st) == -1) {
         LOGM(ERR, "Couldn't get stat for fd {} of shm client", fd);