[PATCH] Avoid secmem leaking capability state

[Mike Crowe]

The capability state returned by cap_from_text needs to be freed after it
has been used.

Valgrind reports this as:

 36 bytes in 1 blocks are definitely lost in loss record 132 of 242
    at 0x4027938: malloc (vg_replace_malloc.c:270)
    by 0x4C0B2CF: cap_init (cap_alloc.c:19)
    by 0x4C0BE0F: cap_from_text (cap_text.c:122)
    by 0x4573413: secmem_init (secmem.c:243)
    by 0x4573691: _gcry_secmem_malloc_internal (secmem.c:517)
    by 0x4573869: _gcry_secmem_malloc (secmem.c:554)
    by 0x4573007: _gcry_private_malloc_secure (stdmem.c:147)
    by 0x456F0F4: do_malloc.constprop.4 (global.c:774)
    by 0x456FAEF: _gcry_malloc_secure (global.c:813)
    by 0x45841AB: md_open (md.c:491)
    by 0x4584861: _gcry_md_open (md.c:534)
    by 0x456D1D8: gcry_md_open (visibility.c:777)

 36 bytes in 1 blocks are definitely lost in loss record 133 of 242
    at 0x4027938: malloc (vg_replace_malloc.c:270)
    by 0x4C0B2CF: cap_init (cap_alloc.c:19)
    by 0x4C0BE0F: cap_from_text (cap_text.c:122)
    by 0x4573505: secmem_init (secmem.c:247)
    by 0x4573691: _gcry_secmem_malloc_internal (secmem.c:517)
    by 0x4573869: _gcry_secmem_malloc (secmem.c:554)
    by 0x4573007: _gcry_private_malloc_secure (stdmem.c:147)
    by 0x456F0F4: do_malloc.constprop.4 (global.c:774)
    by 0x456FAEF: _gcry_malloc_secure (global.c:813)
    by 0x45841AB: md_open (md.c:491)
    by 0x4584861: _gcry_md_open (md.c:534)
    by 0x456D1D8: gcry_md_open (visibility.c:777)

Signed-off-by: Mike Crowe <mac at mcrowe.com>
---
 src/secmem.c |    9 +++++++--
 1 file changed, 7 insertions(+), 2 deletions(-)

diff --git a/src/secmem.c b/src/secmem.c
index c350bc9..2d76858 100644
--- a/src/secmem.c
+++ b/src/secmem.c
@@ -242,12 +242,17 @@ lock_pool (void *p, size_t n)
 {
 #if defined(USE_CAPABILITIES) && defined(HAVE_MLOCK)
   int err;
+  cap_t cap;
 
-  cap_set_proc (cap_from_text ("cap_ipc_lock+ep"));
+  cap = cap_from_text ("cap_ipc_lock+ep");
+  cap_set_proc (cap);
+  cap_free(cap);
   err = no_mlock? 0 : mlock (p, n);
   if (err && errno)
     err = errno;
-  cap_set_proc (cap_from_text ("cap_ipc_lock+p"));
+  cap = cap_from_text ("cap_ipc_lock+p");
+  cap_set_proc (cap);
+  cap_free(cap);
 
   if (err)
     {
-- 
1.7.10.4