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authorMark Wielaard <mark@klomp.org>2019-04-28 13:21:50 +0200
committerMark Wielaard <mark@klomp.org>2019-04-28 13:21:50 +0200
commit6d055c058dc6880f75a1936efa5bea3c49216119 (patch)
treee12a455c459622a304839f2c14e88da668775677 /libdwfl
parent4ec3ce577c74938a686ce2231032615756d0f6ae (diff)
downloadelfutils-6d055c058dc6880f75a1936efa5bea3c49216119.tar.gz
libdwfl: Don't call realloc with zero in cu.c addraranges.
Calling realloc when naranges is zero will result is trying to free aranges. If realloc does free aranges it returns NULL, which means aranges is still assigned. This is likely not a problem, because in most cases aranges will be NULL already. But if it was not and naranges does turn out to be zero after reduction (which would be invalid DWARF) we are left with a dangling pointer. Signed-off-by: Mark Wielaard <mark@klomp.org>
Diffstat (limited to 'libdwfl')
-rw-r--r--libdwfl/ChangeLog4
-rw-r--r--libdwfl/cu.c7
2 files changed, 9 insertions, 2 deletions
diff --git a/libdwfl/ChangeLog b/libdwfl/ChangeLog
index 1da888f6..3e19d9bd 100644
--- a/libdwfl/ChangeLog
+++ b/libdwfl/ChangeLog
@@ -1,3 +1,7 @@
+2019-04-28 Mark Wielaard <mark@klomp.org>
+
+ * cu.c (addrarange): Only call realloc when naranges is not zero.
+
2019-03-27 Mark Wielaard <mark@klomp.org>
* dwfl_segment_report_module.c (dwfl_segment_report_module): Check
diff --git a/libdwfl/cu.c b/libdwfl/cu.c
index 94bfad8d..4de66248 100644
--- a/libdwfl/cu.c
+++ b/libdwfl/cu.c
@@ -83,8 +83,11 @@ addrarange (Dwfl_Module *mod, Dwarf_Addr addr, struct dwfl_arange **arange)
/* Store the final array, which is probably much smaller than before. */
mod->naranges = naranges;
- mod->aranges = (realloc (aranges, naranges * sizeof aranges[0])
- ?: aranges);
+ if (naranges > 0)
+ mod->aranges = (realloc (aranges, naranges * sizeof aranges[0])
+ ?: aranges);
+ else if (aranges != NULL)
+ free (aranges);
mod->lazycu += naranges;
}