Subject: CVE-2024-35907: mlxbf_gige: call request_irq() after NAPI initialized

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

Description
===========

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

mlxbf_gige: call request_irq() after NAPI initialized

The mlxbf_gige driver encounters a NULL pointer exception in
mlxbf_gige_open() when kdump is enabled.  The sequence to reproduce
the exception is as follows:
a) enable kdump
b) trigger kdump via "echo c > /proc/sysrq-trigger"
c) kdump kernel executes
d) kdump kernel loads mlxbf_gige module
e) the mlxbf_gige module runs its open() as the
   the "oob_net0" interface is brought up
f) mlxbf_gige module will experience an exception
   during its open(), something like:

     Unable to handle kernel NULL pointer dereference at virtual address 0000000000000000
     Mem abort info:
       ESR = 0x0000000086000004
       EC = 0x21: IABT (current EL), IL = 32 bits
       SET = 0, FnV = 0
       EA = 0, S1PTW = 0
       FSC = 0x04: level 0 translation fault
     user pgtable: 4k pages, 48-bit VAs, pgdp=00000000e29a4000
     [0000000000000000] pgd=0000000000000000, p4d=0000000000000000
     Internal error: Oops: 0000000086000004 [#1] SMP
     CPU: 0 PID: 812 Comm: NetworkManager Tainted: G           OE     5.15.0-1035-bluefield #37-Ubuntu
     Hardware name: https://www.mellanox.com BlueField-3 SmartNIC Main Card/BlueField-3 SmartNIC Main Card, BIOS 4.6.0.13024 Jan 19 2024
     pstate: 80400009 (Nzcv daif +PAN -UAO -TCO -DIT -SSBS BTYPE=--)
     pc : 0x0
     lr : __napi_poll+0x40/0x230
     sp : ffff800008003e00
     x29: ffff800008003e00 x28: 0000000000000000 x27: 00000000ffffffff
     x26: ffff000066027238 x25: ffff00007cedec00 x24: ffff800008003ec8
     x23: 000000000000012c x22: ffff800008003eb7 x21: 0000000000000000
     x20: 0000000000000001 x19: ffff000066027238 x18: 0000000000000000
     x17: ffff578fcb450000 x16: ffffa870b083c7c0 x15: 0000aaab010441d0
     x14: 0000000000000001 x13: 00726f7272655f65 x12: 6769675f6662786c
     x11: 0000000000000000 x10: 0000000000000000 x9 : ffffa870b0842398
     x8 : 0000000000000004 x7 : fe5a48b9069706ea x6 : 17fdb11fc84ae0d2
     x5 : d94a82549d594f35 x4 : 0000000000000000 x3 : 0000000000400100
     x2 : 0000000000000000 x1 : 0000000000000000 x0 : ffff000066027238
     Call trace:
      0x0
      net_rx_action+0x178/0x360
      __do_softirq+0x15c/0x428
      __irq_exit_rcu+0xac/0xec
      irq_exit+0x18/0x2c
      handle_domain_irq+0x6c/0xa0
      gic_handle_irq+0xec/0x1b0
      call_on_irq_stack+0x20/0x2c
      do_interrupt_handler+0x5c/0x70
      el1_interrupt+0x30/0x50
      el1h_64_irq_handler+0x18/0x2c
      el1h_64_irq+0x7c/0x80
      __setup_irq+0x4c0/0x950
      request_threaded_irq+0xf4/0x1bc
      mlxbf_gige_request_irqs+0x68/0x110 [mlxbf_gige]
      mlxbf_gige_open+0x5c/0x170 [mlxbf_gige]
      __dev_open+0x100/0x220
      __dev_change_flags+0x16c/0x1f0
      dev_change_flags+0x2c/0x70
      do_setlink+0x220/0xa40
      __rtnl_newlink+0x56c/0x8a0
      rtnl_newlink+0x58/0x84
      rtnetlink_rcv_msg+0x138/0x3c4
      netlink_rcv_skb+0x64/0x130
      rtnetlink_rcv+0x20/0x30
      netlink_unicast+0x2ec/0x360
      netlink_sendmsg+0x278/0x490
      __sock_sendmsg+0x5c/0x6c
      ____sys_sendmsg+0x290/0x2d4
      ___sys_sendmsg+0x84/0xd0
      __sys_sendmsg+0x70/0xd0
      __arm64_sys_sendmsg+0x2c/0x40
      invoke_syscall+0x78/0x100
      el0_svc_common.constprop.0+0x54/0x184
      do_el0_svc+0x30/0xac
      el0_svc+0x48/0x160
      el0t_64_sync_handler+0xa4/0x12c
      el0t_64_sync+0x1a4/0x1a8
     Code: bad PC value
     ---[ end trace 7d1c3f3bf9d81885 ]---
     Kernel panic - not syncing: Oops: Fatal exception in interrupt
     Kernel Offset: 0x2870a7a00000 from 0xffff800008000000
     PHYS_OFFSET: 0x80000000
     CPU features: 0x0,000005c1,a3332a5a
     Memory Limit: none
     ---[ end Kernel panic - not syncing: Oops: Fatal exception in interrupt ]---

The exception happens because there is a pending RX interrupt before the
call to request_irq(RX IRQ) executes.  Then, the RX IRQ handler fires
immediately after this request_irq() completes. The RX IRQ handler runs
"napi_schedule()" before NAPI is fully initialized via "netif_napi_add()"
and "napi_enable()", both which happen later in the open() logic.

The logic in mlxbf_gige_open() must fully initialize NAPI before any calls
to request_irq() execute.

The Linux kernel CVE team has assigned CVE-2024-35907 to this issue.

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

	Issue introduced in 5.14 with commit f92e1869d74e and fixed in 5.15.154 with commit a583117668dd
	Issue introduced in 5.14 with commit f92e1869d74e and fixed in 6.1.85 with commit 24444af5ddf7
	Issue introduced in 5.14 with commit f92e1869d74e and fixed in 6.6.26 with commit 867a2f598af6
	Issue introduced in 5.14 with commit f92e1869d74e and fixed in 6.8.5 with commit 8feb1652afe9
	Issue introduced in 5.14 with commit f92e1869d74e and fixed in 6.9 with commit f7442a634ac0

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-2024-35907
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/mellanox/mlxbf_gige/mlxbf_gige_main.c

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/a583117668ddb86e98f2e11c7caa3db0e6df52a3
	https://git.kernel.org/stable/c/24444af5ddf729376b90db0f135fa19973cb5dab
	https://git.kernel.org/stable/c/867a2f598af6a645c865d1101b58c5e070c6dd9e
	https://git.kernel.org/stable/c/8feb1652afe9c5d019059a55c90f70690dce0f52
	https://git.kernel.org/stable/c/f7442a634ac06b953fc1f7418f307b25acd4cfbc