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

nouveau/firmware: use dma non-coherent allocator

Currently, enabling SG_DEBUG in the kernel will cause nouveau to hit a
BUG() on startup, when the iommu is enabled:

kernel BUG at include/linux/scatterlist.h:187!
invalid opcode: 0000 [#1] PREEMPT SMP NOPTI
CPU: 7 PID: 930 Comm: (udev-worker) Not tainted 6.9.0-rc3Lyude-Test+ #30
Hardware name: MSI MS-7A39/A320M GAMING PRO (MS-7A39), BIOS 1.I0 01/22/2019
RIP: 0010:sg_init_one+0x85/0xa0
Code: 69 88 32 01 83 e1 03 f6 c3 03 75 20 a8 01 75 1e 48 09 cb 41 89 54
24 08 49 89 1c 24 41 89 6c 24 0c 5b 5d 41 5c e9 7b b9 88 00 <0f> 0b 0f 0b
0f 0b 48 8b 05 5e 46 9a 01 eb b2 66 66 2e 0f 1f 84 00
RSP: 0018:ffffa776017bf6a0 EFLAGS: 00010246
RAX: 0000000000000000 RBX: ffffa77600d87000 RCX: 000000000000002b
RDX: 0000000000000001 RSI: 0000000000000000 RDI: ffffa77680d87000
RBP: 000000000000e000 R08: 0000000000000000 R09: 0000000000000000
R10: ffff98f4c46aa508 R11: 0000000000000000 R12: ffff98f4c46aa508
R13: ffff98f4c46aa008 R14: ffffa77600d4a000 R15: ffffa77600d4a018
FS: 00007feeb5aae980(0000) GS:ffff98f5c4dc0000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f22cb9a4520 CR3: 00000001043ba000 CR4: 00000000003506f0
Call Trace:
<TASK>
? die+0x36/0x90
? do_trap+0xdd/0x100
? sg_init_one+0x85/0xa0
? do_error_trap+0x65/0x80
? sg_init_one+0x85/0xa0
? exc_invalid_op+0x50/0x70
? sg_init_one+0x85/0xa0
? asm_exc_invalid_op+0x1a/0x20
? sg_init_one+0x85/0xa0
nvkm_firmware_ctor+0x14a/0x250 [nouveau]
nvkm_falcon_fw_ctor+0x42/0x70 [nouveau]
ga102_gsp_booter_ctor+0xb4/0x1a0 [nouveau]
r535_gsp_oneinit+0xb3/0x15f0 [nouveau]
? srso_return_thunk+0x5/0x5f
? srso_return_thunk+0x5/0x5f
? nvkm_udevice_new+0x95/0x140 [nouveau]
? srso_return_thunk+0x5/0x5f
? srso_return_thunk+0x5/0x5f
? ktime_get+0x47/0xb0

Fix this by using the non-coherent allocator instead, I think there
might be a better answer to this, but it involve ripping up some of
APIs using sg lists.