Re: [edk2-devel] [edk2-libc Patch v2 1/1] edk2-libc/StdLib: Fix uninitialized global variable

["Jayaprakash, N" <n.jayaprakash@intel.com>]

Reviewed-by: Jayaprakash N <n.jayaprakash@intel.com>

Regards,
JP
-----Original Message-----
From: devel@edk2.groups.io <devel@edk2.groups.io> On Behalf Of Jayaprakash, N
Sent: Wednesday, July 26, 2023 9:09 PM
To: devel@edk2.groups.io
Cc: Jayaprakash, N <n.jayaprakash@intel.com>; Rebecca Cran <rebecca@bsdio.com>; Kinney, Michael D <michael.d.kinney@intel.com>; Kloper, Dimitry <dimitry.kloper@intel.com>
Subject: [edk2-devel] [edk2-libc Patch v2 1/1] edk2-libc/StdLib: Fix uninitialized global variable

REF: https://bugzilla.tianocore.org/show_bug.cgi?id=4506

res_init() is called from different places in sockets library. It depends on global _res variable containing a state.
The problem is that if __BIND_RES_TEXT macro is not defined, _res is not initialized.
Depending on compiler and build optimization this can fill the variable with garbage that is later used by res_init().
Fix is trivial - explicitly initialize _res.

Cc: Rebecca Cran <rebecca@bsdio.com>
Cc: Michael D Kinney <michael.d.kinney@intel.com>
Cc: Jayaprakash N <n.jayaprakash@intel.com>
Signed-off-by: Kloper Dimitry <dimitry.kloper@intel.com>
---
 StdLib/BsdSocketLib/res_init.c | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/StdLib/BsdSocketLib/res_init.c b/StdLib/BsdSocketLib/res_init.c index 613a76a..9df7d4f 100644
--- a/StdLib/BsdSocketLib/res_init.c
+++ b/StdLib/BsdSocketLib/res_init.c
@@ -121,9 +121,11 @@ static u_int32_t net_mask __P((struct in_addr));
  */
 
 struct __res_state _res
-# if defined(__BIND_RES_TEXT)
+#if defined(__BIND_RES_TEXT)
     = { RES_TIMEOUT, }  /* Motorola, et al. */ -# endif
+#else
+    = {0}
+#endif
     ;
 
 
--
2.40.0.windows.1








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