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

nouveau: fix instmem race condition around ptr stores

Running a lot of VK CTS in parallel against nouveau, once every
few hours you might see something like this crash.

BUG: kernel NULL pointer dereference, address: 0000000000000008
PGD 8000000114e6e067 P4D 8000000114e6e067 PUD 109046067 PMD 0
Oops: 0000 [#1] PREEMPT SMP PTI
CPU: 7 PID: 53891 Comm: deqp-vk Not tainted 6.8.0-rc6+ #27
Hardware name: Gigabyte Technology Co., Ltd. Z390 I AORUS PRO WIFI/Z390 I AORUS PRO WIFI-CF, BIOS F8 11/05/2021
RIP: 0010:gp100_vmm_pgt_mem+0xe3/0x180 [nouveau]
Code: c7 48 01 c8 49 89 45 58 85 d2 0f 84 95 00 00 00 41 0f b7 46 12 49 8b 7e 08 89 da 42 8d 2c f8 48 8b 47 08 41 83 c7 01 48 89 ee <48> 8b 40 08 ff d0 0f 1f 00 49 8b 7e 08 48 89 d9 48 8d 75 04 48 c1
RSP: 0000:ffffac20c5857838 EFLAGS: 00010202
RAX: 0000000000000000 RBX: 00000000004d8001 RCX: 0000000000000001
RDX: 00000000004d8001 RSI: 00000000000006d8 RDI: ffffa07afe332180
RBP: 00000000000006d8 R08: ffffac20c5857ad0 R09: 0000000000ffff10
R10: 0000000000000001 R11: ffffa07af27e2de0 R12: 000000000000001c
R13: ffffac20c5857ad0 R14: ffffa07a96fe9040 R15: 000000000000001c
FS: 00007fe395eed7c0(0000) GS:ffffa07e2c980000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000000008 CR3: 000000011febe001 CR4: 00000000003706f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:

...

? gp100_vmm_pgt_mem+0xe3/0x180 [nouveau]
? gp100_vmm_pgt_mem+0x37/0x180 [nouveau]
nvkm_vmm_iter+0x351/0xa20 [nouveau]
? __pfx_nvkm_vmm_ref_ptes+0x10/0x10 [nouveau]
? __pfx_gp100_vmm_pgt_mem+0x10/0x10 [nouveau]
? __pfx_gp100_vmm_pgt_mem+0x10/0x10 [nouveau]
? __lock_acquire+0x3ed/0x2170
? __pfx_gp100_vmm_pgt_mem+0x10/0x10 [nouveau]
nvkm_vmm_ptes_get_map+0xc2/0x100 [nouveau]
? __pfx_nvkm_vmm_ref_ptes+0x10/0x10 [nouveau]
? __pfx_gp100_vmm_pgt_mem+0x10/0x10 [nouveau]
nvkm_vmm_map_locked+0x224/0x3a0 [nouveau]

Adding any sort of useful debug usually makes it go away, so I hand
wrote the function in a line, and debugged the asm.

Every so often pt->memory->ptrs is NULL. This ptrs ptr is set in
the nv50_instobj_acquire called from nvkm_kmap.

If Thread A and Thread B both get to nv50_instobj_acquire around
the same time, and Thread A hits the refcount_set line, and in
lockstep thread B succeeds at refcount_inc_not_zero, there is a
chance the ptrs value won't have been stored since refcount_set
is unordered. Force a memory barrier here, I picked smp_mb, since
we want it on all CPUs and it's write followed by a read.

v2: use paired smp_rmb/smp_wmb.
Fixes

Solution

No solution given by the vendor.


Workaround

No workaround given by the vendor.

History

Tue, 08 Apr 2025 19:00:00 +0000

Type Values Removed Values Added
First Time appeared Debian
Debian debian Linux
CPEs cpe:2.3:o:debian:debian_linux:10.0:*:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:6.9:rc1:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:6.9:rc2:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:6.9:rc3:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:6.9:rc4:*:*:*:*:*:*
Vendors & Products Debian
Debian debian Linux

Wed, 04 Dec 2024 15:00:00 +0000

Type Values Removed Values Added
CPEs cpe:/a:redhat:rhel_eus:9.2
cpe:/a:redhat:rhel_eus:9.2::nfv

Fri, 22 Nov 2024 12:00:00 +0000


Sat, 16 Nov 2024 03:00:00 +0000

Type Values Removed Values Added
First Time appeared Redhat rhel Eus
CPEs cpe:/a:redhat:rhel_eus:9.4
Vendors & Products Redhat rhel Eus

Wed, 13 Nov 2024 02:45:00 +0000

Type Values Removed Values Added
First Time appeared Redhat
Redhat enterprise Linux
CPEs cpe:/a:redhat:enterprise_linux:9
cpe:/o:redhat:enterprise_linux:9
Vendors & Products Redhat
Redhat enterprise Linux

Tue, 05 Nov 2024 10:45:00 +0000


Wed, 16 Oct 2024 02:45:00 +0000

Type Values Removed Values Added
Weaknesses CWE-476

cve-icon MITRE

Status: PUBLISHED

Assigner: Linux

Published:

Updated: 2025-05-04T09:01:29.153Z

Reserved: 2024-02-19T14:20:24.204Z

Link: CVE-2024-26984

cve-icon Vulnrichment

Updated: 2024-08-02T00:21:05.854Z

cve-icon NVD

Status : Analyzed

Published: 2024-05-01T06:15:15.880

Modified: 2025-04-08T18:45:02.520

Link: CVE-2024-26984

cve-icon Redhat

Severity : Moderate

Publid Date: 2024-05-01T00:00:00Z

Links: CVE-2024-26984 - Bugzilla

cve-icon OpenCVE Enrichment

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