Cleanup if early return from opj_j2k_copy_default_tcp_and_create_tcd().

The opj_j2k_copy_default_tcp_and_create_tcp() function memcpy's a top-level
struct, and then replaces pointers to memory owned by the original struct
with new blocks of memory. Unfortunately, an early return can leave the
copy with pointers to memory it doesn't own, which causes problems when
cleaning up the partially-initialized struct.

The referenced bug is triggered when we get a return at original
line 7969 or 7385 due to OOM.

Moral of the story: creating a "copy constructor" equivalent
based on memcpy() instead of copying field by field for structs
containing pointers is usually a bad idea.

BUG=486538
R=jun_fang@foxitsoftware.com

Review URL: https://codereview.chromium.org/1138033007

1 files changed, 10 insertions, 0 deletions

diff --git a/core/src/fxcodec/fx_libopenjpeg/libopenjpeg20/j2k.c b/core/src/fxcodec/fx_libopenjpeg/libopenjpeg20/j2k.c
index 73dc5ab6fd..c40ecc370d 100644
--- a/core/src/fxcodec/fx_libopenjpeg/libopenjpeg20/j2k.c
+++ b/core/src/fxcodec/fx_libopenjpeg/libopenjpeg20/j2k.c
@@ -7352,6 +7352,12 @@ static OPJ_BOOL opj_j2k_copy_default_tcp_and_create_tcd (       opj_j2k_t * p_j2
                 /* Initialize some values of the current tile coding parameters*/
                 l_tcp->ppt = 0;
                 l_tcp->ppt_data = 00;
+                /* Remove memory not owned by this tile in case of early error return. */
+                l_tcp->m_mct_decoding_matrix = 00;
+                l_tcp->m_nb_max_mct_records = 0;
+                l_tcp->m_mct_records = 00;
+                l_tcp->m_nb_max_mcc_records = 0;
+                l_tcp->m_mcc_records = 00;
                 /* Reconnect the tile-compo coding parameters pointer to the current tile coding parameters*/
                 l_tcp->tccps = l_current_tccp;
 
@@ -7389,6 +7395,9 @@ static OPJ_BOOL opj_j2k_copy_default_tcp_and_create_tcd (       opj_j2k_t * p_j2
 
                         ++l_src_mct_rec;
                         ++l_dest_mct_rec;
+
+                        /* Update with each pass to free exactly what has been allocated on early return. */
+                        l_tcp->m_nb_max_mct_records += 1;
                 }
 
                 /* Get the mcc_record of the dflt_tile_cp and copy them into the current tile cp*/
@@ -7398,6 +7407,7 @@ static OPJ_BOOL opj_j2k_copy_default_tcp_and_create_tcd (       opj_j2k_t * p_j2
                         return OPJ_FALSE;
                 }
                 memcpy(l_tcp->m_mcc_records,l_default_tcp->m_mcc_records,l_mcc_records_size);
+                l_tcp->m_nb_max_mcc_records = l_default_tcp->m_nb_max_mcc_records;
 
                 /* Copy the mcc record data from dflt_tile_cp to the current tile*/
                 l_src_mcc_rec = l_default_tcp->m_mcc_records;