Fix a race condition between ice_free_tx_tstamp_ring() and ice_tx_map()
that can cause a NULL pointer dereference.
ice_free_tx_tstamp_ring currently clears the ICE_TX_FLAGS_TXTIME flag
after NULLing the tstamp_ring. This could allow a concurrent ice_tx_map
call on another CPU to dereference the tstamp_ring, which could lead to
a NULL pointer dereference.
CPU A:ice_free_tx_tstamp_ring() | CPU B:ice_tx_map()
--------------------------------|---------------------------------
tx_ring->tstamp_ring = NULL |
| ice_is_txtime_cfg() -> true
| tstamp_ring = tx_ring->tstamp_ring
| tstamp_ring->count // NULL deref!
flags &= ~ICE_TX_FLAGS_TXTIME |
Fix by:
1. Reordering ice_free_tx_tstamp_ring() to clear the flag before
NULLing the pointer, with smp_wmb() to ensure proper ordering.
2. Adding smp_rmb() in ice_tx_map() after the flag check to order the
flag read before the pointer read, using READ_ONCE() for the
pointer, and adding a NULL check as a safety net.
3. Converting tx_ring->flags from u8 to DECLARE_BITMAP() and using
atomic bitops (set_bit(), clear_bit(), test_bit()) for all flag
operations throughout the driver:
- ICE_TX_RING_FLAGS_XDP
- ICE_TX_RING_FLAGS_VLAN_L2TAG1
- ICE_TX_RING_FLAGS_VLAN_L2TAG2
- ICE_TX_RING_FLAGS_TXTIME
Fixes: ccde82e909467 ("ice: add E830 Earliest TxTime First Offload support")
Signed-off-by: Keita Morisaki <[email protected]>
Reviewed-by: Aleksandr Loktionov <[email protected]>
---
Changes in v2:
- Convert tx_ring->flags from u8 to DECLARE_BITMAP() and use atomic
bitops (set_bit(), clear_bit(), test_bit()) for all flag operations
instead of WRITE_ONCE() for flag updates
- Rename flags from ICE_TX_FLAGS_RING_* to ICE_TX_RING_FLAGS_* to
distinguish from per-packet flags (ICE_TX_FLAGS_*)
drivers/net/ethernet/intel/ice/ice.h | 4 ++--
drivers/net/ethernet/intel/ice/ice_dcb_lib.c | 2 +-
drivers/net/ethernet/intel/ice/ice_lib.c | 4 ++--
drivers/net/ethernet/intel/ice/ice_txrx.c | 23 ++++++++++++++------
drivers/net/ethernet/intel/ice/ice_txrx.h | 16 +++++++++-----
5 files changed, 31 insertions(+), 18 deletions(-)
diff --git a/drivers/net/ethernet/intel/ice/ice.h
b/drivers/net/ethernet/intel/ice/ice.h
index 00f75d87c73f9..5baeca824cd99 100644
--- a/drivers/net/ethernet/intel/ice/ice.h
+++ b/drivers/net/ethernet/intel/ice/ice.h
@@ -753,7 +753,7 @@ static inline bool ice_is_xdp_ena_vsi(struct ice_vsi *vsi)
static inline void ice_set_ring_xdp(struct ice_tx_ring *ring)
{
- ring->flags |= ICE_TX_FLAGS_RING_XDP;
+ set_bit(ICE_TX_RING_FLAGS_XDP, ring->flags);
}
/**
@@ -778,7 +778,7 @@ static inline bool ice_is_txtime_ena(const struct
ice_tx_ring *ring)
*/
static inline bool ice_is_txtime_cfg(const struct ice_tx_ring *ring)
{
- return !!(ring->flags & ICE_TX_FLAGS_TXTIME);
+ return test_bit(ICE_TX_RING_FLAGS_TXTIME, ring->flags);
}
/**
diff --git a/drivers/net/ethernet/intel/ice/ice_dcb_lib.c
b/drivers/net/ethernet/intel/ice/ice_dcb_lib.c
index 9fc8681cc58ea..bd74344271f3f 100644
--- a/drivers/net/ethernet/intel/ice/ice_dcb_lib.c
+++ b/drivers/net/ethernet/intel/ice/ice_dcb_lib.c
@@ -943,7 +943,7 @@ ice_tx_prepare_vlan_flags_dcb(struct ice_tx_ring *tx_ring,
/* if this is not already set it means a VLAN 0 + priority needs
* to be offloaded
*/
- if (tx_ring->flags & ICE_TX_FLAGS_RING_VLAN_L2TAG2)
+ if (test_bit(ICE_TX_RING_FLAGS_VLAN_L2TAG2, tx_ring->flags))
first->tx_flags |= ICE_TX_FLAGS_HW_OUTER_SINGLE_VLAN;
else
first->tx_flags |= ICE_TX_FLAGS_HW_VLAN;
diff --git a/drivers/net/ethernet/intel/ice/ice_lib.c
b/drivers/net/ethernet/intel/ice/ice_lib.c
index d47af94f31a99..55ff0708d136e 100644
--- a/drivers/net/ethernet/intel/ice/ice_lib.c
+++ b/drivers/net/ethernet/intel/ice/ice_lib.c
@@ -1412,9 +1412,9 @@ static int ice_vsi_alloc_rings(struct ice_vsi *vsi)
ring->count = vsi->num_tx_desc;
ring->txq_teid = ICE_INVAL_TEID;
if (dvm_ena)
- ring->flags |= ICE_TX_FLAGS_RING_VLAN_L2TAG2;
+ set_bit(ICE_TX_RING_FLAGS_VLAN_L2TAG2, ring->flags);
else
- ring->flags |= ICE_TX_FLAGS_RING_VLAN_L2TAG1;
+ set_bit(ICE_TX_RING_FLAGS_VLAN_L2TAG1, ring->flags);
WRITE_ONCE(vsi->tx_rings[i], ring);
}
diff --git a/drivers/net/ethernet/intel/ice/ice_txrx.c
b/drivers/net/ethernet/intel/ice/ice_txrx.c
index ad76768a42323..564e4e33ecbc3 100644
--- a/drivers/net/ethernet/intel/ice/ice_txrx.c
+++ b/drivers/net/ethernet/intel/ice/ice_txrx.c
@@ -190,9 +190,10 @@ void ice_free_tstamp_ring(struct ice_tx_ring *tx_ring)
void ice_free_tx_tstamp_ring(struct ice_tx_ring *tx_ring)
{
ice_free_tstamp_ring(tx_ring);
+ clear_bit(ICE_TX_RING_FLAGS_TXTIME, tx_ring->flags);
+ smp_wmb(); /* order flag clear before pointer NULL */
kfree_rcu(tx_ring->tstamp_ring, rcu);
- tx_ring->tstamp_ring = NULL;
- tx_ring->flags &= ~ICE_TX_FLAGS_TXTIME;
+ WRITE_ONCE(tx_ring->tstamp_ring, NULL);
}
/**
@@ -405,7 +406,7 @@ static int ice_alloc_tstamp_ring(struct ice_tx_ring
*tx_ring)
tx_ring->tstamp_ring = tstamp_ring;
tstamp_ring->desc = NULL;
tstamp_ring->count = ice_calc_ts_ring_count(tx_ring);
- tx_ring->flags |= ICE_TX_FLAGS_TXTIME;
+ set_bit(ICE_TX_RING_FLAGS_TXTIME, tx_ring->flags);
return 0;
}
@@ -1519,13 +1520,20 @@ ice_tx_map(struct ice_tx_ring *tx_ring, struct
ice_tx_buf *first,
return;
if (ice_is_txtime_cfg(tx_ring)) {
- struct ice_tstamp_ring *tstamp_ring = tx_ring->tstamp_ring;
- u32 tstamp_count = tstamp_ring->count;
- u32 j = tstamp_ring->next_to_use;
+ struct ice_tstamp_ring *tstamp_ring;
+ u32 tstamp_count, j;
struct ice_ts_desc *ts_desc;
struct timespec64 ts;
u32 tstamp;
+ smp_rmb(); /* order flag read before pointer read */
+ tstamp_ring = READ_ONCE(tx_ring->tstamp_ring);
+ if (unlikely(!tstamp_ring))
+ goto ring_kick;
+
+ tstamp_count = tstamp_ring->count;
+ j = tstamp_ring->next_to_use;
+
ts = ktime_to_timespec64(first->skb->tstamp);
tstamp = ts.tv_nsec >> ICE_TXTIME_CTX_RESOLUTION_128NS;
@@ -1553,6 +1561,7 @@ ice_tx_map(struct ice_tx_ring *tx_ring, struct ice_tx_buf
*first,
tstamp_ring->next_to_use = j;
writel_relaxed(j, tstamp_ring->tail);
} else {
+ring_kick:
writel_relaxed(i, tx_ring->tail);
}
return;
@@ -1812,7 +1821,7 @@ ice_tx_prepare_vlan_flags(struct ice_tx_ring *tx_ring,
struct ice_tx_buf *first)
*/
if (skb_vlan_tag_present(skb)) {
first->vid = skb_vlan_tag_get(skb);
- if (tx_ring->flags & ICE_TX_FLAGS_RING_VLAN_L2TAG2)
+ if (test_bit(ICE_TX_RING_FLAGS_VLAN_L2TAG2, tx_ring->flags))
first->tx_flags |= ICE_TX_FLAGS_HW_OUTER_SINGLE_VLAN;
else
first->tx_flags |= ICE_TX_FLAGS_HW_VLAN;
diff --git a/drivers/net/ethernet/intel/ice/ice_txrx.h
b/drivers/net/ethernet/intel/ice/ice_txrx.h
index e440c55d9e9f0..d35ffdc3dc84d 100644
--- a/drivers/net/ethernet/intel/ice/ice_txrx.h
+++ b/drivers/net/ethernet/intel/ice/ice_txrx.h
@@ -181,6 +181,14 @@ enum ice_rx_dtype {
ICE_RX_DTYPE_SPLIT_ALWAYS = 2,
};
+enum ice_tx_ring_flags {
+ ICE_TX_RING_FLAGS_XDP,
+ ICE_TX_RING_FLAGS_VLAN_L2TAG1,
+ ICE_TX_RING_FLAGS_VLAN_L2TAG2,
+ ICE_TX_RING_FLAGS_TXTIME,
+ ICE_TX_RING_FLAGS_NBITS,
+};
+
struct ice_pkt_ctx {
u64 cached_phctime;
__be16 vlan_proto;
@@ -333,11 +341,7 @@ struct ice_tx_ring {
u32 txq_teid; /* Added Tx queue TEID */
/* CL4 - 4th cacheline starts here */
struct ice_tstamp_ring *tstamp_ring;
-#define ICE_TX_FLAGS_RING_XDP BIT(0)
-#define ICE_TX_FLAGS_RING_VLAN_L2TAG1 BIT(1)
-#define ICE_TX_FLAGS_RING_VLAN_L2TAG2 BIT(2)
-#define ICE_TX_FLAGS_TXTIME BIT(3)
- u8 flags;
+ DECLARE_BITMAP(flags, ICE_TX_RING_FLAGS_NBITS);
u8 dcb_tc; /* Traffic class of ring */
u16 quanta_prof_id;
} ____cacheline_internodealigned_in_smp;
@@ -349,7 +353,7 @@ static inline bool ice_ring_ch_enabled(struct ice_tx_ring
*ring)
static inline bool ice_ring_is_xdp(struct ice_tx_ring *ring)
{
- return !!(ring->flags & ICE_TX_FLAGS_RING_XDP);
+ return test_bit(ICE_TX_RING_FLAGS_XDP, ring->flags);
}
enum ice_container_type {
base-commit: 18f7fcd5e69a04df57b563360b88be72471d6b62
--
2.34.1
