[PATCH net-next 1/4] cnic: Fix occasional NULL pointer dereference during reboot.
From: "Michael Chan" <mchan@broadcom.com>
Date: 2012-06-28 00:57:26
Subsystem:
networking drivers, the rest · Maintainers:
Andrew Lunn, "David S. Miller", Eric Dumazet, Jakub Kicinski, Paolo Abeni, Linus Torvalds
We register with bnx2x before we allocate ctx_tbl structure, so it is possible for bnx2x to call cnic_ctl before the structure is allocated. This can sometimes cause NULL pointer dereference of cp->ctx_tbl. We fix this by adding simple checking for valid state before proceeding. The cnic_ctl call is RCU protected so we don't have to deal with race conditions. Because of the additional checking, we need to finish the shutdown before clearing the CNIC_UP flag. Signed-off-by: Michael Chan <mchan@broadcom.com> --- drivers/net/ethernet/broadcom/cnic.c | 9 +++++++-- 1 files changed, 7 insertions(+), 2 deletions(-)
diff --git a/drivers/net/ethernet/broadcom/cnic.c b/drivers/net/ethernet/broadcom/cnic.c
index 0e9be2b..31b05ad 100644
--- a/drivers/net/ethernet/broadcom/cnic.c
+++ b/drivers/net/ethernet/broadcom/cnic.c@@ -291,6 +291,9 @@ static int cnic_get_l5_cid(struct cnic_local *cp, u32 cid, u32 *l5_cid) { u32 i; + if (!cp->ctx_tbl) + return -EINVAL; + for (i = 0; i < cp->max_cid_space; i++) { if (cp->ctx_tbl[i].cid == cid) { *l5_cid = i;
@@ -3220,6 +3223,9 @@ static int cnic_ctl(void *data, struct cnic_ctl_info *info) u32 l5_cid; struct cnic_local *cp = dev->cnic_priv; + if (!test_bit(CNIC_F_CNIC_UP, &dev->flags)) + break; + if (cnic_get_l5_cid(cp, cid, &l5_cid) == 0) { struct cnic_context *ctx = &cp->ctx_tbl[l5_cid];
@@ -4253,8 +4259,6 @@ static int cnic_cm_shutdown(struct cnic_dev *dev) struct cnic_local *cp = dev->cnic_priv; int i; - cp->stop_cm(dev); - if (!cp->csk_tbl) return 0;
@@ -5290,6 +5294,7 @@ static void cnic_stop_hw(struct cnic_dev *dev) i++; } cnic_shutdown_rings(dev); + cp->stop_cm(dev); clear_bit(CNIC_F_CNIC_UP, &dev->flags); RCU_INIT_POINTER(cp->ulp_ops[CNIC_ULP_L4], NULL); synchronize_rcu();
--
1.7.1