| Message ID | 20190729022956.18192-1-baijiaju1990@gmail.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | target: iscsi: iscsi_target_tpg: Fix a possible null-pointer dereference in iscsit_tpg_add_network_portal() | expand |
On Mon, 2019-07-29 at 10:29 +0800, Jia-Ju Bai wrote: > In iscsit_tpg_add_network_portal(), there is an if statement on line > 496 > to check whether tpg->tpg_tiqn is NULL: > if (tpg->tpg_tiqn) > > When tpg->tpg_tiqn is NULL, it is used on line 508: > pr_debug(..., tpg->tpg_tiqn->tiqn, ...); > > Thus, a possible null-pointer dereference may occur. > > To fix this bug, tpg->tpg_tiqn is checked before being used. > > This bug is found by a static analysis tool STCheck written by us. I don't really think this is helpful. The first question is, is the implied might be NULL check correct? The tpg_tiqn is always set by a non-dummy driver and I think network configuration is only done for the non dummy driver, so I suspect the NULL check is wrong. Secondly even if the NULL check were correct, I think there's still a need for some debugging output, so the proposed patch also looks wrong. James
diff --git a/drivers/target/iscsi/iscsi_target_tpg.c b/drivers/target/iscsi/iscsi_target_tpg.c index 8075f60fd02c..bf97be36ec1f 100644 --- a/drivers/target/iscsi/iscsi_target_tpg.c +++ b/drivers/target/iscsi/iscsi_target_tpg.c @@ -505,9 +505,11 @@ struct iscsi_tpg_np *iscsit_tpg_add_network_portal( spin_unlock(&tpg_np_parent->tpg_np_parent_lock); } - pr_debug("CORE[%s] - Added Network Portal: %pISpc,%hu on %s\n", - tpg->tpg_tiqn->tiqn, &np->np_sockaddr, tpg->tpgt, - np->np_transport->name); + if (tpg->tpg_tiqn) { + pr_debug("CORE[%s] - Added Network Portal: %pISpc,%hu on %s\n", + tpg->tpg_tiqn->tiqn, &np->np_sockaddr, tpg->tpgt, + np->np_transport->name); + } return tpg_np; }
In iscsit_tpg_add_network_portal(), there is an if statement on line 496 to check whether tpg->tpg_tiqn is NULL: if (tpg->tpg_tiqn) When tpg->tpg_tiqn is NULL, it is used on line 508: pr_debug(..., tpg->tpg_tiqn->tiqn, ...); Thus, a possible null-pointer dereference may occur. To fix this bug, tpg->tpg_tiqn is checked before being used. This bug is found by a static analysis tool STCheck written by us. Signed-off-by: Jia-Ju Bai <baijiaju1990@gmail.com> --- drivers/target/iscsi/iscsi_target_tpg.c | 8 +++++--- 1 file changed, 5 insertions(+), 3 deletions(-)