isdn: prevent NULL ptr Oops in capi_cmsg2str()

The dereferencing of the private pointer cmsg->m in capi_cmsg2str() may
cause an Oops in case of an error, which is particularly inconvenient
as that function is typically used to format an error message. Add a
NULL pointer check to avoid this.

Impact: error handling improvement
Signed-off-by: Tilman Schmidt <tilman@imap.cc>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Tilman Schmidt 2009-06-07 09:09:24 +00:00 коммит произвёл David S. Miller
Родитель 4793d15b25
Коммит 7d31acda9f
1 изменённых файлов: 2 добавлений и 0 удалений

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@ -989,6 +989,8 @@ _cdebbuf *capi_cmsg2str(_cmsg * cmsg)
{
_cdebbuf *cdb;
if (!cmsg->m)
return NULL; /* no message */
cdb = cdebbuf_alloc();
if (!cdb)
return NULL;