In the Linux kernel, the following vulnerability has been resolved: 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.
| Vendor | Product | Versions |
|---|---|---|
| linux | linux kernel | 3a616b92a9d17448d96a33bf58e69f01457fd43a, 3a616b92a9d17448d96a33bf58e69f01457fd43a, 3a616b92a9d17448d96a33bf58e69f01457fd43a, 3a616b92a9d17448d96a33bf58e69f01457fd43a, 3a616b92a9d17448d96a33bf58e69f01457fd43a, 3a616b92a9d17448d96a33bf58e69f01457fd43a, 5.12, 6.1.167, 6.6.130, 6.12.78, 6.18.20, 6.19.10, 7.0-rc5 |
Updated severity to CRITICAL, removed patch availability, and added new CVE ID CVE-2026-23438.
Updated description with detailed technical information, added new affected versions, changed severity to HIGH, and marked the vulnerability as actively exploited.
Initial creation
