{"cve":"CVE-2024-26984","nvd":{"published":"2024-05-01T06:15:15.880","modified":"2026-06-17T07:18:51.640","status":"Modified","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nnouveau: fix instmem race condition around ptr stores\n\nRunning a lot of VK CTS in parallel against nouveau, once every\nfew hours you might see something like this crash.\n\nBUG: kernel NULL pointer dereference, address: 0000000000000008\nPGD 8000000114e6e067 P4D 8000000114e6e067 PUD 109046067 PMD 0\nOops: 0000 [#1] PREEMPT SMP PTI\nCPU: 7 PID: 53891 Comm: deqp-vk Not tainted 6.8.0-rc6+ #27\nHardware name: Gigabyte Technology Co., Ltd. Z390 I AORUS PRO WIFI/Z390 I AORUS PRO WIFI-CF, BIOS F8 11/05/2021\nRIP: 0010:gp100_vmm_pgt_mem+0xe3/0x180 [nouveau]\nCode: 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\nRSP: 0000:ffffac20c5857838 EFLAGS: 00010202\nRAX: 0000000000000000 RBX: 00000000004d8001 RCX: 0000000000000001\nRDX: 00000000004d8001 RSI: 00000000000006d8 RDI: ffffa07afe332180\nRBP: 00000000000006d8 R08: ffffac20c5857ad0 R09: 0000000000ffff10\nR10: 0000000000000001 R11: ffffa07af27e2de0 R12: 000000000000001c\nR13: ffffac20c5857ad0 R14: ffffa07a96fe9040 R15: 000000000000001c\nFS:  00007fe395eed7c0(0000) GS:ffffa07e2c980000(0000) knlGS:0000000000000000\nCS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033\nCR2: 0000000000000008 CR3: 000000011febe001 CR4: 00000000003706f0\nDR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000\nDR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400\nCall Trace:\n\n...\n\n ? gp100_vmm_pgt_mem+0xe3/0x180 [nouveau]\n ? gp100_vmm_pgt_mem+0x37/0x180 [nouveau]\n nvkm_vmm_iter+0x351/0xa20 [nouveau]\n ? __pfx_nvkm_vmm_ref_ptes+0x10/0x10 [nouveau]\n ? __pfx_gp100_vmm_pgt_mem+0x10/0x10 [nouveau]\n ? __pfx_gp100_vmm_pgt_mem+0x10/0x10 [nouveau]\n ? __lock_acquire+0x3ed/0x2170\n ? __pfx_gp100_vmm_pgt_mem+0x10/0x10 [nouveau]\n nvkm_vmm_ptes_get_map+0xc2/0x100 [nouveau]\n ? __pfx_nvkm_vmm_ref_ptes+0x10/0x10 [nouveau]\n ? __pfx_gp100_vmm_pgt_mem+0x10/0x10 [nouveau]\n nvkm_vmm_map_locked+0x224/0x3a0 [nouveau]\n\nAdding any sort of useful debug usually makes it go away, so I hand\nwrote the function in a line, and debugged the asm.\n\nEvery so often pt->memory->ptrs is NULL. This ptrs ptr is set in\nthe nv50_instobj_acquire called from nvkm_kmap.\n\nIf Thread A and Thread B both get to nv50_instobj_acquire around\nthe same time, and Thread A hits the refcount_set line, and in\nlockstep thread B succeeds at refcount_inc_not_zero, there is a\nchance the ptrs value won't have been stored since refcount_set\nis unordered. Force a memory barrier here, I picked smp_mb, since\nwe want it on all CPUs and it's write followed by a read.\n\nv2: use paired smp_rmb/smp_wmb.","cvss_v4":null,"cvss_v3":{"version":"3.1","vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H","score":5.5},"cwes":["CWE-362"],"references":["https://git.kernel.org/stable/c/13d76b2f443dc371842916dd8768009ff1594716","https://git.kernel.org/stable/c/1bc4825d4c3ec6abe43cf06c3c39d664d044cbf7","https://git.kernel.org/stable/c/21ca9539f09360fd83654f78f2c361f2f5ddcb52","https://git.kernel.org/stable/c/3ab056814cd8ab84744c9a19ef51360b2271c572","https://git.kernel.org/stable/c/a019b44b1bc6ed224c46fb5f88a8a10dd116e525"],"products":["debian:debian_linux","linux:linux_kernel"],"source":"nvd","synced_at":"2026-10-19T21:49:08.435428910+00:00"},"epss":{"cve":"CVE-2024-26984","score":0.00202,"percentile":0.10245,"date":"2026-10-31"},"kev":null,"osv":[],"attribution":["This product uses the NVD API but is not endorsed or certified by the NVD.","EPSS scores: FIRST Exploit Prediction Scoring System, https://www.first.org/epss","Known exploited vulnerabilities: CISA Known Exploited Vulnerabilities Catalog, https://www.cisa.gov/known-exploited-vulnerabilities-catalog","Package advisories: OSV (https://osv.dev), from the GitHub Advisory Database, PyPA, Go, RustSec and other ecosystem databases, under CC-BY 4.0 or CC0","CVE records: the CVE Program's CVE List (https://www.cve.org), under its terms of use (https://www.cve.org/Legal/TermsOfUse). CVE is a registered trademark of The MITRE Corporation; this product is not affiliated with the CVE Program."]}