CVE-2024-26859

In the Linux kernel, the following vulnerability has been resolved:

net/bnx2x: Prevent access to a freed page in page_pool

Fix race condition leading to system crash during EEH error handling

During EEH error recovery, the bnx2x driver's transmit timeout logic

could cause a race condition when handling reset tasks. The

bnx2x_tx_timeout() schedules reset tasks via bnx2x_sp_rtnl_task(),

which ultimately leads to bnx2x_nic_unload(). In bnx2x_nic_unload()

SGEs are freed using bnx2x_free_rx_sge_range(). However, this could

overlap with the EEH driver's attempt to reset the device using

bnx2x_io_slot_reset(), which also tries to free SGEs. This race

condition can result in system crashes due to accessing freed memory

locations in bnx2x_free_rx_sge()

799 static inline void bnx2x_free_rx_sge(struct bnx2x *bp,

800 struct bnx2x_fastpath *fp, u16 index)

801 {

802 struct sw_rx_page *sw_buf = &fp->rx_page_ring[index];

803 struct page *page = sw_buf->page;

....

where sw_buf was set to NULL after the call to dma_unmap_page()

by the preceding thread.

EEH: Beginning: 'slot_reset'

PCI 0011:01:00.0#10000: EEH: Invoking bnx2x->slot_reset()

bnx2x: [bnx2x_io_slot_reset:14228(eth1)]IO slot reset initializing...

bnx2x 0011:01:00.0: enabling device (0140 -> 0142)

bnx2x: [bnx2x_io_slot_reset:14244(eth1)]IO slot reset --> driver unload

Kernel attempted to read user page (0) - exploit attempt? (uid: 0)

BUG: Kernel NULL pointer dereference on read at 0x00000000

Faulting instruction address: 0xc0080000025065fc

Oops: Kernel access of bad area, sig: 11 [#1]

.....

Call Trace:

[c000000003c67a20] [c00800000250658c] bnx2x_io_slot_reset+0x204/0x610 [bnx2x] (unreliable)

[c000000003c67af0] [c0000000000518a8] eeh_report_reset+0xb8/0xf0

[c000000003c67b60] [c000000000052130] eeh_pe_report+0x180/0x550

[c000000003c67c70] [c00000000005318c] eeh_handle_normal_event+0x84c/0xa60

[c000000003c67d50] [c000000000053a84] eeh_event_handler+0xf4/0x170

[c000000003c67da0] [c000000000194c58] kthread+0x1c8/0x1d0

[c000000003c67e10] [c00000000000cf64] ret_from_kernel_thread+0x5c/0x64

To solve this issue, we need to verify page pool allocations before

freeing.