Bugzilla – Bug 978814
VUL-1: CVE-2016-4488: gcc: Invalid write due to a use-after-free to array ktypevec
Last modified: 2023-02-08 16:51:17 UTC
rh#1333332 / CVE-2016-4488 A vulnerability was found in gcc. There is a variable ksize storing the amount of allocated memory for the array ktypevec. ksize being zero (0) indicates that some memory must be allocated upon the first write. When more memory is needed, both ksize and the memory are doubled during reallocation. At some point the memory for the array is freed (in squangle_mop_up) but the value of ksize remains. Since ksize is not 0, there is no indication that new memory must be allocated when there is another write to the array. This allows a malicious attacker to write arbitrary content to freed memory. External references: https://gcc.gnu.org/bugzilla/show_bug.cgi?id=70481 Upstream fix: https://gcc.gnu.org/ml/gcc-patches/2016-03/msg01687.html References: https://bugzilla.redhat.com/show_bug.cgi?id=1333332 http://web.nvd.nist.gov/view/vuln/detail?vulnId=CVE-2016-4488 http://seclists.org/oss-sec/2016/q2/240
bugbot adjusting priority
Bug in symbol name de-mangling -> VUL-1.
The cited bug affects the libstdc++ demangler and thus libstdc++.so and libsupc++.a. The bug was fixed on the GCC 5 branch after the last update to the toolchain module and the fix will be included in the GCC 6 toolchain module release upcoming (and thus the system libstdc++.so). Note that the copies in static libraries of older GCC do not get updated with the system runtime. Note that bugs in the libstdc++ demangler are not as serious as those in the libiberty demangler which gets used by various tools such as gdb or nm. Any update to GCC 5 should wait until after the GCC 6 toochain release to lessen the burden on QA (it no longer replaces the system runtime).
Fixed since a long time. (when libiberty, and hence binutils was affected: by version updates to binutils for sle-12 and sle-15 and sle-11 wontfix)