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

drm/xe/vf: Add drmdev guards when detaching CCS read/write buffers

CCS read/write buffers are freed during BO destruction. In some cases, BOs may be destroyed after the device is unbound but while the DRM structure remains valid, leading to NULL pointer dereferences when accessing device resources.

BUG: kernel NULL pointer dereference, address: 0000000000000000 PGD 0 P4D 0 Oops: Oops: 0000 [#1] SMP NOPTI CPU: 0 UID: 0 PID: 9376 Comm: xepat Not tainted 7.2.0-rc2+ #1 PREEMPT(lazy) RIP: 0010:xesriovvfccsrwupdatebbaddr+0x4d/0xa0 [xe] RSP: 0018:ffffcf304110b9c8 EFLAGS: 00010246 RAX: ffff8a85c38a0a00 RBX: 00000000810ef000 RCX: 0000000000000000 RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffff8a85c39c1888 RBP: ffffcf304110b9e8 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000000 R12: ffff8a85c39c1888 R13: 0000000000000000 R14: ffff8a85c39b4f28 R15: ffff8a85c3885000 FS: 0000000000000000(0000) GS:ffff8a878b809000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000000000000 CR3: 000000010314a002 CR4: 0000000000772ef0 PKRU: 55555554 Call Trace: <TASK> xemigrateccsrwcopyclear+0x98/0x120 [xe] xesriovvfccsdetachbo+0x2c/0x60 [xe] xettmbodeletememnotify+0xc8/0xe0 [xe] ttmbocleanupmemtypeuse+0x26/0x80 [ttm] ttmborelease+0x29e/0x2d0 [ttm] ttmbofini+0x39/0x70 [ttm] xegemobjectfree+0x1f/0x30 [xe] drmgemobjectfree+0x1d/0x40 ttmbovmclose+0x5f/0x90 [ttm] removevma+0x2c/0x70 teardownvmas+0x63/0xf0 exitmmap+0x20d/0x3f0 mmput+0x45/0x170 mmput+0x31/0x40 doexit+0x2ba/0xac0 dogroupexit+0x2d/0xb0 x64sysexitgroup+0x18/0x20 x64syscall+0x14a0/0x2390 dosyscall64+0xdd/0x640 ? countmemcgevents+0xea/0x240 ? handlemmfault+0x1ec/0x2f0

(cherry picked from commit 1ae415a6eefe5004954a1d352b1718faca8844ef)