Subject: CVE-2024-26859: net/bnx2x: Prevent access to a freed page in page_pool

From: Greg Kroah-Hartman <[email-masked]>

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.

The Linux kernel CVE team has assigned CVE-2024-26859 to this issue.

Affected and fixed versions
===========================

	Issue introduced in 4.2 with commit 4cace675d687 and fixed in 4.19.311 with commit 7bcc090c8111
	Issue introduced in 4.2 with commit 4cace675d687 and fixed in 5.4.273 with commit 4f37d3a7e004
	Issue introduced in 4.2 with commit 4cace675d687 and fixed in 5.10.214 with commit 8eebff95ce95
	Issue introduced in 4.2 with commit 4cace675d687 and fixed in 5.15.153 with commit 8ffcd3ccdbda
	Issue introduced in 4.2 with commit 4cace675d687 and fixed in 6.1.83 with commit cf7d8cba639a
	Issue introduced in 4.2 with commit 4cace675d687 and fixed in 6.6.23 with commit 3a9f78b297e0
	Issue introduced in 4.2 with commit 4cace675d687 and fixed in 6.7.11 with commit c51f8b6930db
	Issue introduced in 4.2 with commit 4cace675d687 and fixed in 6.8.2 with commit 44f9f1abb0ec
	Issue introduced in 4.2 with commit 4cace675d687 and fixed in 6.9 with commit d27e2da94a42

Please see https://www.kernel.org for a full list of currently supported
kernel versions by the kernel community.

Unaffected versions might change over time as fixes are backported to
older supported kernel versions.  The official CVE entry at
	https://cve.org/CVERecord/?id=CVE-2024-26859
will be updated if fixes are backported, please check that for the most
up to date information about this issue.

Affected files
==============

The file(s) affected by this issue are:
	drivers/net/ethernet/broadcom/bnx2x/bnx2x_cmn.h

Mitigation
==========

The Linux kernel CVE team recommends that you update to the latest
stable kernel version for this, and many other bugfixes.  Individual
changes are never tested alone, but rather are part of a larger kernel
release.  Cherry-picking individual commits is not recommended or
supported by the Linux kernel community at all.  If however, updating to
the latest release is impossible, the individual changes to resolve this
issue can be found at these commits:
	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