UBUNTU-CVE-2024-26984
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.
02 / AFFECTED SOFTWARE
Affected packages
6 explicit affected versions
8 explicit affected versions
143 explicit affected versions
5 explicit affected versions
1 explicit affected versions
8 explicit affected versions
1 explicit affected versions
10 explicit affected versions
11 explicit affected versions
31 explicit affected versions
45 explicit affected versions
50 explicit affected versions
14 explicit affected versions
10 explicit affected versions
12 explicit affected versions
12 explicit affected versions
19 explicit affected versions
6 explicit affected versions
54 explicit affected versions
6 explicit affected versions
40 explicit affected versions
61 explicit affected versions
51 explicit affected versions
40 explicit affected versions
10 explicit affected versions
47 explicit affected versions
7 explicit affected versions
46 explicit affected versions
1 explicit affected versions
88 explicit affected versions
13 explicit affected versions
64 explicit affected versions
2 explicit affected versions
35 explicit affected versions
7 explicit affected versions
18 explicit affected versions
9 explicit affected versions
95 explicit affected versions
34 explicit affected versions
6 explicit affected versions
90 explicit affected versions
13 explicit affected versions
4 explicit affected versions
23 explicit affected versions
9 explicit affected versions
1 explicit affected versions
21 explicit affected versions
16 explicit affected versions
10 explicit affected versions
45 explicit affected versions
7 explicit affected versions
7 explicit affected versions
12 explicit affected versions
38 explicit affected versions
12 explicit affected versions
14 explicit affected versions
7 explicit affected versions
78 explicit affected versions
12 explicit affected versions
93 explicit affected versions
101 explicit affected versions
12 explicit affected versions
89 explicit affected versions
10 explicit affected versions
2 explicit affected versions
10 explicit affected versions
37 explicit affected versions
13 explicit affected versions
10 explicit affected versions
27 explicit affected versions
31 explicit affected versions
26 explicit affected versions
13 explicit affected versions
6 explicit affected versions
93 explicit affected versions
1 explicit affected versions
29 explicit affected versions
81 explicit affected versions
13 explicit affected versions
51 explicit affected versions
1 explicit affected versions
77 explicit affected versions
49 explicit affected versions
11 explicit affected versions
33 explicit affected versions
23 explicit affected versions
10 explicit affected versions
93 explicit affected versions
11 explicit affected versions
12 explicit affected versions
116 explicit affected versions
32 explicit affected versions
7 explicit affected versions
12 explicit affected versions
92 explicit affected versions
39 explicit affected versions
109 explicit affected versions
48 explicit affected versions
129 explicit affected versions
10 explicit affected versions
26 explicit affected versions
7 explicit affected versions
8 explicit affected versions
27 explicit affected versions
1 explicit affected versions
8 explicit affected versions
13 explicit affected versions
116 explicit affected versions
51 explicit affected versions
16 explicit affected versions
51 explicit affected versions
73 explicit affected versions
40 explicit affected versions
3 explicit affected versions
70 explicit affected versions
1 explicit affected versions
2 explicit affected versions
58 explicit affected versions
51 explicit affected versions
69 explicit affected versions
5 explicit affected versions
12 explicit affected versions
37 explicit affected versions
27 explicit affected versions
23 explicit affected versions
1 explicit affected versions
1 explicit affected versions
12 explicit affected versions
5 explicit affected versions
2 explicit affected versions
8 explicit affected versions
1 explicit affected versions
4 explicit affected versions
13 explicit affected versions
81 explicit affected versions
13 explicit affected versions
52 explicit affected versions
45 explicit affected versions
7 explicit affected versions
71 explicit affected versions
43 explicit affected versions
12 explicit affected versions
80 explicit affected versions
44 explicit affected versions
16 explicit affected versions
3 explicit affected versions
13 explicit affected versions
26 explicit affected versions
37 explicit affected versions
37 explicit affected versions
8 explicit affected versions
14 explicit affected versions
38 explicit affected versions
40 explicit affected versions
9 explicit affected versions
40 explicit affected versions
11 explicit affected versions
48 explicit affected versions
7 explicit affected versions
21 explicit affected versions
120 explicit affected versions
99 explicit affected versions
4 explicit affected versions
1 explicit affected versions
1 explicit affected versions
46 explicit affected versions
92 explicit affected versions
13 explicit affected versions
43 explicit affected versions
46 explicit affected versions
10 explicit affected versions
8 explicit affected versions
3 explicit affected versions
14 explicit affected versions
81 explicit affected versions
4 explicit affected versions
70 explicit affected versions
11 explicit affected versions
1 explicit affected versions
46 explicit affected versions
2 explicit affected versions
03 / CONNECTIONS
Connected vulnerabilities
04 / EVIDENCE
Source records
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.
05 / REFERENCES
Further evidence
- https://git.kernel.org/linus/fff1386cc889d8fb4089d285f883f8cba62d82ce
- https://git.kernel.org/stable/c/21ca9539f09360fd83654f78f2c361f2f5ddcb52
- https://git.kernel.org/stable/c/3ab056814cd8ab84744c9a19ef51360b2271c572
- https://git.kernel.org/stable/c/a019b44b1bc6ed224c46fb5f88a8a10dd116e525
- https://git.kernel.org/stable/c/ad74d208f213c06d860916ad40f609ade8c13039
- https://git.kernel.org/stable/c/fff1386cc889d8fb4089d285f883f8cba62d82ce
- https://ubuntu.com/security/CVE-2024-26984
- https://ubuntu.com/security/notices/USN-6893-1
- https://ubuntu.com/security/notices/USN-6893-2
- https://ubuntu.com/security/notices/USN-6893-3
- https://ubuntu.com/security/notices/USN-6896-1
- https://ubuntu.com/security/notices/USN-6896-2
- https://ubuntu.com/security/notices/USN-6896-3
- https://ubuntu.com/security/notices/USN-6896-4
- https://ubuntu.com/security/notices/USN-6896-5
- https://ubuntu.com/security/notices/USN-6898-1
- https://ubuntu.com/security/notices/USN-6898-2
- https://ubuntu.com/security/notices/USN-6898-3
- https://ubuntu.com/security/notices/USN-6898-4
- https://ubuntu.com/security/notices/USN-6917-1
- https://ubuntu.com/security/notices/USN-6918-1
- https://ubuntu.com/security/notices/USN-6919-1
- https://ubuntu.com/security/notices/USN-6927-1
- https://ubuntu.com/security/notices/USN-7019-1
- https://ubuntu.com/security/notices/USN-7028-1
- https://ubuntu.com/security/notices/USN-7028-2
- https://www.cve.org/CVERecord?id=CVE-2024-26984