Subject: CVE-2024-40906: net/mlx5: Always stop health timer during driver removal

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

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

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

net/mlx5: Always stop health timer during driver removal

Currently, if teardown_hca fails to execute during driver removal, mlx5
does not stop the health timer. Afterwards, mlx5 continue with driver
teardown. This may lead to a UAF bug, which results in page fault
Oops[1], since the health timer invokes after resources were freed.

Hence, stop the health monitor even if teardown_hca fails.

[1]
mlx5_core 0000:18:00.0: E-Switch: Unload vfs: mode(LEGACY), nvfs(0), necvfs(0), active vports(0)
mlx5_core 0000:18:00.0: E-Switch: Disable: mode(LEGACY), nvfs(0), necvfs(0), active vports(0)
mlx5_core 0000:18:00.0: E-Switch: Disable: mode(LEGACY), nvfs(0), necvfs(0), active vports(0)
mlx5_core 0000:18:00.0: E-Switch: cleanup
mlx5_core 0000:18:00.0: wait_func:1155:(pid 1967079): TEARDOWN_HCA(0x103) timeout. Will cause a leak of a command resource
mlx5_core 0000:18:00.0: mlx5_function_close:1288:(pid 1967079): tear_down_hca failed, skip cleanup
BUG: unable to handle page fault for address: ffffa26487064230
PGD 100c00067 P4D 100c00067 PUD 100e5a067 PMD 105ed7067 PTE 0
Oops: 0000 [#1] PREEMPT SMP PTI
CPU: 0 PID: 0 Comm: swapper/0 Tainted: G           OE     -------  ---  6.7.0-68.fc38.x86_64 #1
Hardware name: Intel Corporation S2600WFT/S2600WFT, BIOS SE5C620.86B.02.01.0013.121520200651 12/15/2020
RIP: 0010:ioread32be+0x34/0x60
RSP: 0018:ffffa26480003e58 EFLAGS: 00010292
RAX: ffffa26487064200 RBX: ffff9042d08161a0 RCX: ffff904c108222c0
RDX: 000000010bbf1b80 RSI: ffffffffc055ddb0 RDI: ffffa26487064230
RBP: ffff9042d08161a0 R08: 0000000000000022 R09: ffff904c108222e8
R10: 0000000000000004 R11: 0000000000000441 R12: ffffffffc055ddb0
R13: ffffa26487064200 R14: ffffa26480003f00 R15: ffff904c108222c0
FS:  0000000000000000(0000) GS:ffff904c10800000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: ffffa26487064230 CR3: 00000002c4420006 CR4: 00000000007706f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
PKRU: 55555554
Call Trace:
 <IRQ>
 ? __die+0x23/0x70
 ? page_fault_oops+0x171/0x4e0
 ? exc_page_fault+0x175/0x180
 ? asm_exc_page_fault+0x26/0x30
 ? __pfx_poll_health+0x10/0x10 [mlx5_core]
 ? __pfx_poll_health+0x10/0x10 [mlx5_core]
 ? ioread32be+0x34/0x60
 mlx5_health_check_fatal_sensors+0x20/0x100 [mlx5_core]
 ? __pfx_poll_health+0x10/0x10 [mlx5_core]
 poll_health+0x42/0x230 [mlx5_core]
 ? __next_timer_interrupt+0xbc/0x110
 ? __pfx_poll_health+0x10/0x10 [mlx5_core]
 call_timer_fn+0x21/0x130
 ? __pfx_poll_health+0x10/0x10 [mlx5_core]
 __run_timers+0x222/0x2c0
 run_timer_softirq+0x1d/0x40
 __do_softirq+0xc9/0x2c8
 __irq_exit_rcu+0xa6/0xc0
 sysvec_apic_timer_interrupt+0x72/0x90
 </IRQ>
 <TASK>
 asm_sysvec_apic_timer_interrupt+0x1a/0x20
RIP: 0010:cpuidle_enter_state+0xcc/0x440
 ? cpuidle_enter_state+0xbd/0x440
 cpuidle_enter+0x2d/0x40
 do_idle+0x20d/0x270
 cpu_startup_entry+0x2a/0x30
 rest_init+0xd0/0xd0
 arch_call_rest_init+0xe/0x30
 start_kernel+0x709/0xa90
 x86_64_start_reservations+0x18/0x30
 x86_64_start_kernel+0x96/0xa0
 secondary_startup_64_no_verify+0x18f/0x19b
---[ end trace 0000000000000000 ]---

The Linux kernel CVE team has assigned CVE-2024-40906 to this issue.

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

	Issue introduced in 6.1 with commit 9b98d395b85d and fixed in 6.1.95 with commit e7d4485d4783
	Issue introduced in 6.1 with commit 9b98d395b85d and fixed in 6.6.35 with commit 6ccada6ffb42
	Issue introduced in 6.1 with commit 9b98d395b85d and fixed in 6.9.6 with commit e6777ae0bf6f
	Issue introduced in 6.1 with commit 9b98d395b85d and fixed in 6.10 with commit c8b3f38d2dae

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-2024-40906
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/mlx5/core/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/e7d4485d47839f4d1284592ae242c4e65b2810a9
	https://git.kernel.org/stable/c/6ccada6ffb42e0ac75e3db06d41baf5a7f483f8a
	https://git.kernel.org/stable/c/e6777ae0bf6fd5bc626bb051c8c93e3c8198a3f8
	https://git.kernel.org/stable/c/c8b3f38d2dae0397944814d691a419c451f9906f