fix bug in race condition of calling nflog_open from different threads at same timeHEADmaster

This patch addresses a bug that occurs when the nflog_open function is
called concurrently from different threads within an application. The
function nflog_open internally invokes nflog_open_nfnl. Within this
function, a static global variable pkt_cb (static struct nfnl_callback
pkt_cb) is used. This variable is assigned a pointer to a newly created
structure (pkt_cb.data = h;) and is passed to nfnl_callback_register.
The issue arises with concurrent execution of pkt_cb.data = h;, as only
one of the simultaneously created nflog_handle structures is retained
due to the callback function.
Subsequently, the callback function __nflog_rcv_pkt is invoked for all
the nflog_open structures, but only references one of them.
Consequently, the callbacks registered by the end-user of the library
through nflog_callback_register fail to trigger in sessions where the
incorrect reference was recorded.
This patch corrects this behavior by creating the structure locally on
the stack for each call to nflog_open_nfnl. Since the
nfnl_callback_register function simply copies the data into its internal
structures, there is no need to retain pkt_cb beyond this point.

Signed-off-by: Evgenii Bendyak <jman.box@gmail.com>
Signed-off-by: Phil Sutter <phil@nwl.cc>

0 files changed, 0 insertions, 0 deletions