Fix memory corruption when a compound variable is unset #49
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JohnoKing
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The following set of commands ends with a memory fault under certain circumstances because ksh attempts to free memory twice, causing memory corruption: $ testarray=(1 2) $ compound testarray $ unset testarray $ eval testarray= The fix is to make sure 'np->nvfun' is a valid pointer before attempting to free memory in 'put_tree'. This patch is from OpenSUSE: https://build.opensuse.org/package/view_file/shells/ksh/ksh93-nvtree-free.dif?expand=1 src/cmd/ksh93/sh/nvtree.c: - Do not try to free memory when 'np->nvfun' and 'val' are false. src/cmd/ksh93/tests/comvar.sh: - Add a regression test for the double free problem. The reproducer must be run from an executable script with 'ksh -c'.
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The following set of commands sometimes ends with a memory fault because ksh attempts to free memory twice, causing memory corruption:
The fix is to make sure
np->nvfunis a valid pointer before attempting to free memory input_tree. This patch is from OpenSUSE: https://build.opensuse.org/package/view_file/shells/ksh/ksh93-nvtree-free.dif?expand=1