comedi: Fix memory leak in compat_insnlist()
commit
bb509a6ffed2c8b0950f637ab5779aa818ed1596 upstream.
`compat_insnlist()` handles the 32-bit version of the `COMEDI_INSNLIST`
ioctl (whenwhen `CONFIG_COMPAT` is enabled). It allocates memory to
temporarily hold an array of `struct comedi_insn` converted from the
32-bit version in user space. This memory is only being freed if there
is a fault while filling the array, otherwise it is leaked.
Add a call to `kfree()` to fix the leak.
Fixes: b8d47d881305 ("comedi: get rid of compat_alloc_user_space() mess in COMEDI_INSNLIST compat")
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: linux-staging@lists.linux.dev
Cc: <stable@vger.kernel.org> # 5.13+
Signed-off-by: Ian Abbott <abbotti@mev.co.uk>
Link: https://lore.kernel.org/r/20210916145023.157479-1-abbotti@mev.co.uk
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>