Hi all!
Git commit e2bb55ec3b70cf45088bb73ba9ca990129328d60 (pr/108350) removes the
fallback scenario for lrealpath() when none of the #ifdef's match (in which
case the function is empty)
In this situation, there is no return statement, and hence an uninitialized
pointer value is returned. This is bad, as make_relative_prefix_1() uses this
pointer and passes it to free().
This crashes in my hobby OS (https://github.com/zhmu/dogfood) as I do not
implement any of the proper lrealpath() scenarios ;-) This is likely not an
issue for any real use case, but I'm submitting this to prevent others from
having to chase this.
I've attached a simple patch that restores the fallback behaviour (return
strdup(filename);) which it did prior to pr/108350.
Regards,
Rink
diff -rubB gcc-15.1.0-base/libiberty/lrealpath.c gcc-15.1.0/libiberty/lrealpath.c
--- gcc-15.1.0-base/libiberty/lrealpath.c 2025-04-25 10:18:04.000000000 +0200
+++ gcc-15.1.0/libiberty/lrealpath.c 2025-05-09 16:49:35.228340555 +0200
@@ -303,4 +303,7 @@
return res;
}
#endif // _WIN32
+
+ /* This system is a lost cause, just duplicate the filename. */
+ return strdup (filename);
}
