ghsa-w8h9-x2qc-v5qf
Vulnerability from github
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.
{
"affected": [],
"aliases": [
"CVE-2024-26984"
],
"database_specific": {
"cwe_ids": [
"CWE-362"
],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2024-05-01T06:15:15Z",
"severity": "MODERATE"
},
"details": "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 \u003c48\u003e 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-\u003ememory-\u003eptrs 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\u0027t 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\u0027s write followed by a read.\n\nv2: use paired smp_rmb/smp_wmb.",
"id": "GHSA-w8h9-x2qc-v5qf",
"modified": "2024-07-03T18:38:01Z",
"published": "2024-05-01T06:31:42Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2024-26984"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/13d76b2f443dc371842916dd8768009ff1594716"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/1bc4825d4c3ec6abe43cf06c3c39d664d044cbf7"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/21ca9539f09360fd83654f78f2c361f2f5ddcb52"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/3ab056814cd8ab84744c9a19ef51360b2271c572"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/a019b44b1bc6ed224c46fb5f88a8a10dd116e525"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/ad74d208f213c06d860916ad40f609ade8c13039"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/bba8ec5e9b16649d85bc9e9086bf7ae5b5716ff9"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/fff1386cc889d8fb4089d285f883f8cba62d82ce"
},
{
"type": "WEB",
"url": "https://lists.debian.org/debian-lts-announce/2024/06/msg00017.html"
},
{
"type": "WEB",
"url": "https://lists.debian.org/debian-lts-announce/2024/06/msg00020.html"
},
{
"type": "WEB",
"url": "https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/4EZ6PJW7VOZ224TD7N4JZNU6KV32ZJ53"
},
{
"type": "WEB",
"url": "https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/DAMSOZXJEPUOXW33WZYWCVAY7Z5S7OOY"
},
{
"type": "WEB",
"url": "https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/GCBZZEC7L7KTWWAS2NLJK6SO3IZIL4WW"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H",
"type": "CVSS_V3"
}
]
}