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

Vulnerability Description

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.

References

• https://git.kernel.org/stable/c/7bcc090c81116c66936a7415f2c6b1483a4bcfd9
• https://git.kernel.org/stable/c/4f37d3a7e004bbf560c21441ca9c022168017ec4
• https://git.kernel.org/stable/c/8eebff95ce9558be66a36aa7cfb43223f3ab4699
• https://git.kernel.org/stable/c/8ffcd3ccdbda0c918c4a0f922ef1c17010f1b598
• https://git.kernel.org/stable/c/cf7d8cba639ae792a42c2a137b495eac262ac36c
• https://git.kernel.org/stable/c/3a9f78b297e08ca8e88ae3ecff1f6fe2766dc5eb
• https://git.kernel.org/stable/c/c51f8b6930db3f259b8820b589f2459d2df3fc68
• https://git.kernel.org/stable/c/44f9f1abb0ecc43023225ab9539167facbabf0ec
• https://git.kernel.org/stable/c/d27e2da94a42655861ca4baea30c8cd65546f25d