Subject: CVE-2024-26656: drm/amdgpu: fix use-after-free bug

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

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

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

drm/amdgpu: fix use-after-free bug

The bug can be triggered by sending a single amdgpu_gem_userptr_ioctl
to the AMDGPU DRM driver on any ASICs with an invalid address and size.
The bug was reported by Joonkyo Jung <[email-masked]>.
For example the following code:

static void Syzkaller1(int fd)
{
	struct drm_amdgpu_gem_userptr arg;
	int ret;

	arg.addr = 0xffffffffffff0000;
	arg.size = 0x80000000; /*2 Gb*/
	arg.flags = 0x7;
	ret = drmIoctl(fd, 0xc1186451/*amdgpu_gem_userptr_ioctl*/, &arg);
}

Due to the address and size are not valid there is a failure in
amdgpu_hmm_register->mmu_interval_notifier_insert->__mmu_interval_notifier_insert->
check_shl_overflow, but we even the amdgpu_hmm_register failure we still call
amdgpu_hmm_unregister into  amdgpu_gem_object_free which causes access to a bad address.
The following stack is below when the issue is reproduced when Kazan is enabled:

[  +0.000014] Hardware name: ASUS System Product Name/ROG STRIX B550-F GAMING (WI-FI), BIOS 1401 12/03/2020
[  +0.000009] RIP: 0010:mmu_interval_notifier_remove+0x327/0x340
[  +0.000017] Code: ff ff 49 89 44 24 08 48 b8 00 01 00 00 00 00 ad de 4c 89 f7 49 89 47 40 48 83 c0 22 49 89 47 48 e8 ce d1 2d 01 e9 32 ff ff ff <0f> 0b e9 16 ff ff ff 4c 89 ef e8 fa 14 b3 ff e9 36 ff ff ff e8 80
[  +0.000014] RSP: 0018:ffffc90002657988 EFLAGS: 00010246
[  +0.000013] RAX: 0000000000000000 RBX: 1ffff920004caf35 RCX: ffffffff8160565b
[  +0.000011] RDX: dffffc0000000000 RSI: 0000000000000004 RDI: ffff8881a9f78260
[  +0.000010] RBP: ffffc90002657a70 R08: 0000000000000001 R09: fffff520004caf25
[  +0.000010] R10: 0000000000000003 R11: ffffffff8161d1d6 R12: ffff88810e988c00
[  +0.000010] R13: ffff888126fb5a00 R14: ffff88810e988c0c R15: ffff8881a9f78260
[  +0.000011] FS:  00007ff9ec848540(0000) GS:ffff8883cc880000(0000) knlGS:0000000000000000
[  +0.000012] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[  +0.000010] CR2: 000055b3f7e14328 CR3: 00000001b5770000 CR4: 0000000000350ef0
[  +0.000010] Call Trace:
[  +0.000006]  <TASK>
[  +0.000007]  ? show_regs+0x6a/0x80
[  +0.000018]  ? __warn+0xa5/0x1b0
[  +0.000019]  ? mmu_interval_notifier_remove+0x327/0x340
[  +0.000018]  ? report_bug+0x24a/0x290
[  +0.000022]  ? handle_bug+0x46/0x90
[  +0.000015]  ? exc_invalid_op+0x19/0x50
[  +0.000016]  ? asm_exc_invalid_op+0x1b/0x20
[  +0.000017]  ? kasan_save_stack+0x26/0x50
[  +0.000017]  ? mmu_interval_notifier_remove+0x23b/0x340
[  +0.000019]  ? mmu_interval_notifier_remove+0x327/0x340
[  +0.000019]  ? mmu_interval_notifier_remove+0x23b/0x340
[  +0.000020]  ? __pfx_mmu_interval_notifier_remove+0x10/0x10
[  +0.000017]  ? kasan_save_alloc_info+0x1e/0x30
[  +0.000018]  ? srso_return_thunk+0x5/0x5f
[  +0.000014]  ? __kasan_kmalloc+0xb1/0xc0
[  +0.000018]  ? srso_return_thunk+0x5/0x5f
[  +0.000013]  ? __kasan_check_read+0x11/0x20
[  +0.000020]  amdgpu_hmm_unregister+0x34/0x50 [amdgpu]
[  +0.004695]  amdgpu_gem_object_free+0x66/0xa0 [amdgpu]
[  +0.004534]  ? __pfx_amdgpu_gem_object_free+0x10/0x10 [amdgpu]
[  +0.004291]  ? do_syscall_64+0x5f/0xe0
[  +0.000023]  ? srso_return_thunk+0x5/0x5f
[  +0.000017]  drm_gem_object_free+0x3b/0x50 [drm]
[  +0.000489]  amdgpu_gem_userptr_ioctl+0x306/0x500 [amdgpu]
[  +0.004295]  ? __pfx_amdgpu_gem_userptr_ioctl+0x10/0x10 [amdgpu]
[  +0.004270]  ? srso_return_thunk+0x5/0x5f
[  +0.000014]  ? __this_cpu_preempt_check+0x13/0x20
[  +0.000015]  ? srso_return_thunk+0x5/0x5f
[  +0.000013]  ? sysvec_apic_timer_interrupt+0x57/0xc0
[  +0.000020]  ? srso_return_thunk+0x5/0x5f
[  +0.000014]  ? asm_sysvec_apic_timer_interrupt+0x1b/0x20
[  +0.000022]  ? drm_ioctl_kernel+0x17b/0x1f0 [drm]
[  +0.000496]  ? __pfx_amdgpu_gem_userptr_ioctl+0x10/0x10 [amdgpu]
[  +0.004272]  ? drm_ioctl_kernel+0x190/0x1f0 [drm]
[  +0.000492]  drm_ioctl_kernel+0x140/0x1f0 [drm]
[  +0.000497]  ? __pfx_amdgpu_gem_userptr_ioctl+0x10/0x10 [amdgpu]
[  +0.004297]  ? __pfx_drm_ioctl_kernel+0x10/0x10 [drm]
[  +0.000489]  ? srso_return_thunk+0x5/0x5f
[  +0.000011]  ? __kasan_check_write+0x14/0x20
[  +0.000016]  drm_ioctl+0x3da/0x730 [drm]
[  +0.000475]  ? __pfx_amdgpu_gem_userptr_ioctl+0x10/0x10 [amdgpu]
[  +0.004293]  ? __pfx_drm_ioctl+0x10/0x10 [drm]
[  +0.000506]  ? __pfx_rpm_resume+0x10/0x10
[  +0.000016]  ? srso_return_thunk+0x5/0x5f
[  +0.000011]  ? __kasan_check_write+0x14/0x20
[  +0.000010]  ? srso_return_thunk+0x5/0x5f
[  +0.000011]  ? _raw_spin_lock_irqsave+0x99/0x100
[  +0.000015]  ? __pfx__raw_spin_lock_irqsave+0x10/0x10
[  +0.000014]  ? srso_return_thunk+0x5/0x5f
[  +0.000013]  ? srso_return_thunk+0x5/0x5f
[  +0.000011]  ? srso_return_thunk+0x5/0x5f
[  +0.000011]  ? preempt_count_sub+0x18/0xc0
[  +0.000013]  ? srso_return_thunk+0x5/0x5f
[  +0.000010]  ? _raw_spin_unlock_irqrestore+0x27/0x50
[  +0.000019]  amdgpu_drm_ioctl+0x7e/0xe0 [amdgpu]
[  +0.004272]  __x64_sys_ioctl+0xcd/0x110
[  +0.000020]  do_syscall_64+0x5f/0xe0
[  +0.000021]  entry_SYSCALL_64_after_hwframe+0x6e/0x76
[  +0.000015] RIP: 0033:0x7ff9ed31a94f
[  +0.000012] Code: 00 48 89 44 24 18 31 c0 48 8d 44 24 60 c7 04 24 10 00 00 00 48 89 44 24 08 48 8d 44 24 20 48 89 44 24 10 b8 10 00 00 00 0f 05 <41> 89 c0 3d 00 f0 ff ff 77 1f 48 8b 44 24 18 64 48 2b 04 25 28 00
[  +0.000013] RSP: 002b:00007fff25f66790 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
[  +0.000016] RAX: ffffffffffffffda RBX: 000055b3f7e133e0 RCX: 00007ff9ed31a94f
[  +0.000012] RDX: 000055b3f7e133e0 RSI: 00000000c1186451 RDI: 0000000000000003
[  +0.000010] RBP: 00000000c1186451 R08: 0000000000000000 R09: 0000000000000000
[  +0.000009] R10: 0000000000000008 R11: 0000000000000246 R12: 00007fff25f66ca8
[  +0.000009] R13: 0000000000000003 R14: 000055b3f7021ba8 R15: 00007ff9ed7af040
[  +0.000024]  </TASK>
[  +0.000007] ---[ end trace 0000000000000000 ]---

v2: Consolidate any error handling into amdgpu_hmm_register
    which applied to kfd_bo also. (Christian)
v3: Improve syntax and comment (Christian)

The Linux kernel CVE team has assigned CVE-2024-26656 to this issue.

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

	Fixed in 6.6.24 with commit e87e08c94c95
	Fixed in 6.7.12 with commit af054a5fb24a
	Fixed in 6.8.3 with commit 22f665ecfd12
	Fixed in 6.9 with commit 22207fd5c801

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-2024-26656
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/gpu/drm/amd/amdgpu/amdgpu_hmm.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/e87e08c94c9541b4e18c4c13f2f605935f512605
	https://git.kernel.org/stable/c/af054a5fb24a144f99895afce9519d709891894c
	https://git.kernel.org/stable/c/22f665ecfd1225afa1309ace623157d12bb9bb0c
	https://git.kernel.org/stable/c/22207fd5c80177b860279653d017474b2812af5e