From: Hoang Le hoang.h.le@dektech.com.au
[ Upstream commit f20a46c3044c3f75232b3d0e2d09af9b25efaf45 ]
When enabling a bearer by name, we don't sanity check its name with higher slot in bearer list. This may have the effect that the name of an already enabled bearer bypasses the check.
To fix the above issue, we just perform an extra checking with all existing bearers.
Fixes: cb30a63384bc9 ("tipc: refactor function tipc_enable_bearer()") Cc: stable@vger.kernel.org Acked-by: Jon Maloy jmaloy@redhat.com Signed-off-by: Hoang Le hoang.h.le@dektech.com.au Signed-off-by: David S. Miller davem@davemloft.net Signed-off-by: Sasha Levin sashal@kernel.org --- net/tipc/bearer.c | 46 +++++++++++++++++++++++++++------------------- 1 file changed, 27 insertions(+), 19 deletions(-)
diff --git a/net/tipc/bearer.c b/net/tipc/bearer.c index 4d0e11623e5c..12e535b43d88 100644 --- a/net/tipc/bearer.c +++ b/net/tipc/bearer.c @@ -246,6 +246,7 @@ static int tipc_enable_bearer(struct net *net, const char *name, int bearer_id = 0; int res = -EINVAL; char *errstr = ""; + u32 i;
if (!bearer_name_validate(name, &b_names)) { errstr = "illegal name"; @@ -270,31 +271,38 @@ static int tipc_enable_bearer(struct net *net, const char *name, prio = m->priority;
/* Check new bearer vs existing ones and find free bearer id if any */ - while (bearer_id < MAX_BEARERS) { - b = rtnl_dereference(tn->bearer_list[bearer_id]); - if (!b) - break; + bearer_id = MAX_BEARERS; + i = MAX_BEARERS; + while (i-- != 0) { + b = rtnl_dereference(tn->bearer_list[i]); + if (!b) { + bearer_id = i; + continue; + } if (!strcmp(name, b->name)) { errstr = "already enabled"; NL_SET_ERR_MSG(extack, "Already enabled"); goto rejected; } - bearer_id++; - if (b->priority != prio) - continue; - if (++with_this_prio <= 2) - continue; - pr_warn("Bearer <%s>: already 2 bearers with priority %u\n", - name, prio); - if (prio == TIPC_MIN_LINK_PRI) { - errstr = "cannot adjust to lower"; - NL_SET_ERR_MSG(extack, "Cannot adjust to lower"); - goto rejected; + + if (b->priority == prio && + (++with_this_prio > 2)) { + pr_warn("Bearer <%s>: already 2 bearers with priority %u\n", + name, prio); + + if (prio == TIPC_MIN_LINK_PRI) { + errstr = "cannot adjust to lower"; + NL_SET_ERR_MSG(extack, "Cannot adjust to lower"); + goto rejected; + } + + pr_warn("Bearer <%s>: trying with adjusted priority\n", + name); + prio--; + bearer_id = MAX_BEARERS; + i = MAX_BEARERS; + with_this_prio = 1; } - pr_warn("Bearer <%s>: trying with adjusted priority\n", name); - prio--; - bearer_id = 0; - with_this_prio = 1; }
if (bearer_id >= MAX_BEARERS) {