diff options
| author | Muhammad Hammad Ijaz <mhijaz@amazon.com> | 2026-03-16 22:31:01 +0300 |
|---|---|---|
| committer | Paolo Abeni <pabeni@redhat.com> | 2026-03-19 12:31:19 +0300 |
| commit | 8a63baadf08453f66eb582fdb6dd234f72024723 (patch) | |
| tree | a19152d06caadb46501c503b86fc6e99a15bdcfe | |
| parent | 7c46bd845d89ad4772573cfe0f2a56b93db75cc7 (diff) | |
| download | linux-8a63baadf08453f66eb582fdb6dd234f72024723.tar.xz | |
net: mvpp2: guard flow control update with global_tx_fc in buffer switching
mvpp2_bm_switch_buffers() unconditionally calls
mvpp2_bm_pool_update_priv_fc() when switching between per-cpu and
shared buffer pool modes. This function programs CM3 flow control
registers via mvpp2_cm3_read()/mvpp2_cm3_write(), which dereference
priv->cm3_base without any NULL check.
When the CM3 SRAM resource is not present in the device tree (the
third reg entry added by commit 60523583b07c ("dts: marvell: add CM3
SRAM memory to cp11x ethernet device tree")), priv->cm3_base remains
NULL and priv->global_tx_fc is false. Any operation that triggers
mvpp2_bm_switch_buffers(), for example an MTU change that crosses
the jumbo frame threshold, will crash:
Unable to handle kernel NULL pointer dereference at
virtual address 0000000000000000
Mem abort info:
ESR = 0x0000000096000006
EC = 0x25: DABT (current EL), IL = 32 bits
pc : readl+0x0/0x18
lr : mvpp2_cm3_read.isra.0+0x14/0x20
Call trace:
readl+0x0/0x18
mvpp2_bm_pool_update_fc+0x40/0x12c
mvpp2_bm_pool_update_priv_fc+0x94/0xd8
mvpp2_bm_switch_buffers.isra.0+0x80/0x1c0
mvpp2_change_mtu+0x140/0x380
__dev_set_mtu+0x1c/0x38
dev_set_mtu_ext+0x78/0x118
dev_set_mtu+0x48/0xa8
dev_ifsioc+0x21c/0x43c
dev_ioctl+0x2d8/0x42c
sock_ioctl+0x314/0x378
Every other flow control call site in the driver already guards
hardware access with either priv->global_tx_fc or port->tx_fc.
mvpp2_bm_switch_buffers() is the only place that omits this check.
Add the missing priv->global_tx_fc guard to both the disable and
re-enable calls in mvpp2_bm_switch_buffers(), consistent with the
rest of the driver.
Fixes: 3a616b92a9d1 ("net: mvpp2: Add TX flow control support for jumbo frames")
Signed-off-by: Muhammad Hammad Ijaz <mhijaz@amazon.com>
Reviewed-by: Gunnar Kudrjavets <gunnarku@amazon.com>
Link: https://patch.msgid.link/20260316193157.65748-1-mhijaz@amazon.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
| -rw-r--r-- | drivers/net/ethernet/marvell/mvpp2/mvpp2_main.c | 4 |
1 files changed, 2 insertions, 2 deletions
diff --git a/drivers/net/ethernet/marvell/mvpp2/mvpp2_main.c b/drivers/net/ethernet/marvell/mvpp2/mvpp2_main.c index d1b8650cb4b4..f442b874bb59 100644 --- a/drivers/net/ethernet/marvell/mvpp2/mvpp2_main.c +++ b/drivers/net/ethernet/marvell/mvpp2/mvpp2_main.c @@ -5016,7 +5016,7 @@ static int mvpp2_bm_switch_buffers(struct mvpp2 *priv, bool percpu) if (priv->percpu_pools) numbufs = port->nrxqs * 2; - if (change_percpu) + if (change_percpu && priv->global_tx_fc) mvpp2_bm_pool_update_priv_fc(priv, false); for (i = 0; i < numbufs; i++) @@ -5041,7 +5041,7 @@ static int mvpp2_bm_switch_buffers(struct mvpp2 *priv, bool percpu) mvpp2_open(port->dev); } - if (change_percpu) + if (change_percpu && priv->global_tx_fc) mvpp2_bm_pool_update_priv_fc(priv, true); return 0; |