[binutils-gdb] libsframe: fix a memory leak in sframe_decode

[binutils-gdb] libsframe: fix a memory leak in sframe_decode

[Indu Bhagat]

https://sourceware.org/git/gitweb.cgi?p=binutils-gdb.git;h=995bc59782363e7634fe3034aa9363528cb8b2e5

commit 995bc59782363e7634fe3034aa9363528cb8b2e5
Author: Indu Bhagat <indu.bhagat@oracle.com>
Date:   Fri Dec 23 13:04:06 2022 -0800

    libsframe: fix a memory leak in sframe_decode
    
    sframe_decode () needs to malloc a temporary buffer of the same size as
    the input buffer (containing the SFrame section bytes) when endian
    flipping is needed.  The decoder keeps the endian flipped contents in
    this buffer for its usage.  This code is necessary when the target
    endianneess is not the same as host endianness.
    
    The malloc'd buffer needs to be kept track of, so that it can freed up in
    sframe_decoder_free () later.
    
    ChangeLog:
    
            * libsframe/sframe-impl.h (struct sframe_decoder_ctx): Add new
            member to keep track of the internally malloc'd buffer.
            * libsframe/sframe.c (sframe_decoder_free): Free it up.
            (sframe_decode): Update the reference to the buffer.

Diff:
---
 libsframe/sframe-impl.h | 15 +++++++++++----
 libsframe/sframe.c      |  9 +++++++++
 2 files changed, 20 insertions(+), 4 deletions(-)

diff --git a/libsframe/sframe-impl.h b/libsframe/sframe-impl.h
index 0e61c977886..340d3b35042 100644
--- a/libsframe/sframe-impl.h
+++ b/libsframe/sframe-impl.h
@@ -32,10 +32,17 @@ extern "C"
 
 struct sframe_decoder_ctx
 {
-  sframe_header sfd_header;	      /* SFrame header.  */
-  uint32_t *sfd_funcdesc;	      /* SFrame function desc entries table.  */
-  void *sfd_fres;		      /* SFrame FRE table.  */
-  int sfd_fre_nbytes;		      /* Number of bytes needed for SFrame FREs.  */
+  /* SFrame header.  */
+  sframe_header sfd_header;
+  /* SFrame function desc entries table.  */
+  uint32_t *sfd_funcdesc;
+  /* SFrame FRE table.  */
+  void *sfd_fres;
+  /* Number of bytes needed for SFrame FREs.  */
+  int sfd_fre_nbytes;
+  /* Reference to the internally malloc'd buffer, if any, for endian flipping
+     the original input buffer before decoding.  */
+  void *sfd_buf;
 };
 
 struct sframe_encoder_ctx
diff --git a/libsframe/sframe.c b/libsframe/sframe.c
index b8fde2f04f8..e41c95b9944 100644
--- a/libsframe/sframe.c
+++ b/libsframe/sframe.c
@@ -548,6 +548,11 @@ sframe_decoder_free (sframe_decoder_ctx **decoder)
 	  free (dctx->sfd_fres);
 	  dctx->sfd_fres = NULL;
 	}
+      if (dctx->sfd_buf != NULL)
+	{
+	  free (dctx->sfd_buf);
+	  dctx->sfd_buf = NULL;
+	}
 
       free (*decoder);
       *decoder = NULL;
@@ -824,6 +829,10 @@ sframe_decode (const char *sf_buf, size_t sf_size, int *errp)
 	  return sframe_ret_set_errno (errp, SFRAME_ERR_BUF_INVAL);
 	}
       frame_buf = tempbuf;
+      /* This buffer is malloc'd when endian flipping the contents of the input
+	 buffer are needed.  Keep a reference to it so it can be free'd up
+	 later in sframe_decoder_free ().  */
+      dctx->sfd_buf = tempbuf;
     }
   else
     frame_buf = (char *)sf_buf;