In the Linux kernel, the following vulnerability has been resolved:<\/p>\n
drm\/virtio: fix NULL pointer dereference on fence allocation failure<\/p>\n
virtio_gpu_fence_alloc() can fail due to memory pressure and return NULL,
\nbut its caller like virtio_gpu_init_submit() never checks it. Later,
\nvirtio_gpu_init_submit() passes the NULL fence to
\nvirtio_gpu_fence_event_create(), which unconditionally dereferences it.<\/p>\n
Found when fuzzing the virtio driver with Syzkaller:<\/p>\n
\tOops: general protection fault, probably for non-canonical address 0xdffffc0000000012: 0000 [#1] SMP KASAN NOPTI
\n\tKASAN: null-ptr-deref in range [0x0000000000000090-0x0000000000000097]
\n\tCPU: 1 UID: 0 PID: 9991 Comm: syz.0.121 Not tainted 7.2.0 #4 PREEMPT(full)
\n\tHardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS rel-1.17.0-0-gb52ca86e094d-prebuilt.qemu.org 04\/01\/2014
\n\tRIP: 0010:virtio_gpu_fence_event_create drivers\/gpu\/drm\/virtio\/virtgpu_submit.c:295 [inline]
\n\tRIP: 0010:virtio_gpu_init_submit drivers\/gpu\/drm\/virtio\/virtgpu_submit.c:398 [inline]
\n\tRIP: 0010:virtio_gpu_execbuffer_ioctl+0xc78\/0x1aa0 drivers\/gpu\/drm\/virtio\/virtgpu_submit.c:505
\n\tCode: 85 ed 0f 85 21 09 00 00 e8 05 5a c9 fb 48 8b 44 24 10 48 8d b8 90 00 00 00 48 b8 00 00 00 00 00 fc ff df 48 89 fa 48 c1 ea 03 3c 02 00 0f 85 9a 0d 00 00 48 8b 44 24 10 4c 89 b0 90 00 00 00
\n\tRSP: 0018:ffffc900039dfad0 EFLAGS: 00010216
\n\tRAX: dffffc0000000000 RBX: ffffc900039dfdd8 RCX: ffffffff85f6fd3d
\n\tRDX: 0000000000000012 RSI: ffffffff85f6fd4b RDI: 0000000000000090
\n\tRBP: 0000000000000000 R0virtio_gpu_virgl_process_cmd: ctrl 0x102, error 0x1203
\n\tR10: 0000000000000000 R11: 0000000000000000 R12: ffff8880132c4000
\n\tR13: 0000000000000000 R14: ffff888073b6c700 R15: 000000000000003b
\n\tFS: 00007fab480b96c0(0000) GS:ffff8880eb6e9000(0000) knlGS:0000000000000000
\n\tCS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
\n\tCR2: 00007effbf5e55a8 CR3: 0000000048d19000 CR4: 0000000000350ef0
\n\tCall Trace:<\/p>\n
\tdrm_ioctl_kernel+0x1f4\/0x3e0 drivers\/gpu\/drm\/drm_ioctl.c:817
\n\tdrm_ioctl+0x5f4\/0xc70 drivers\/gpu\/drm\/drm_ioctl.c:914
\n\tvfs_ioctl fs\/ioctl.c:51 [inline]
\n\t__do_sys_ioctl fs\/ioctl.c:597 [inline]
\n\t__se_sys_ioctl fs\/ioctl.c:583 [inline]
\n\t__x64_sys_ioctl+0x18e\/0x210 fs\/ioctl.c:583
\n\tdo_syscall_x64 arch\/x86\/entry\/syscall_64.c:63 [inline]
\n\tdo_syscall_64+0x116\/0x800 arch\/x86\/entry\/syscall_64.c:94
\n\tentry_SYSCALL_64_after_hwframe+0x77\/0x7f
\n\tRIP: 0033:0x7fab471a82bd
\n\tCode: ff c3 66 2e 0f 1f 84 00 00 00 00 00 90 f3 0f 1e fa 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 3d 01 f0 ff ff 73 01 c3 48 c7 c1 b0 ff ff ff f7 d8 64 89 01 48
\n\tRSP: 002b:00007fab480b9018 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
\n\tRAX: ffffffffffffffda RBX: 00007fab47435fa0 RCX: 00007fab471a82bd
\n\tRDX: 00002000000000c0 RSI: 00000000c0406442 RDI: 0000000000000003
\n\tRBP: 00007fab480b9080 R08: 0000000000000000 R09: 0000000000000000
\n\tR10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000001
\n\tR13: 00007fab47436038 R14: 00007fab47435fa0 R15: 00007ffe85ab0740<\/p>\n
\tModules linked in:
\n\t—[ end trace 0000000000000000 ]—
\n\tRIP: 0010:virtio_gpu_fence_event_create drivers\/gpu\/drm\/virtio\/virtgpu_submit.c:295 [inline]
\n\tRIP: 0010:virtio_gpu_init_submit drivers\/gpu\/drm\/virtio\/virtgpu_submit.c:398 [inline]
\n\tRIP: 0010:virtio_gpu_execbuffer_ioctl+0xc78\/0x1aa0 drivers\/gpu\/drm\/virtio\/virtgpu_submit.c:505
\n\tCode: 85 ed 0f 85 21 09 00 00 e8 05 5a c9 fb 48 8b 44 24 10 48 8d b8 90 00 00 00 48 b8 00 00 00 00 00 fc ff df 48 89 fa 48 c1 ea 03 3c 02 00 0f 85 9a 0d 00 00 48 8b 44 24 10 4c 89 b0 90 00 00 00
\n\tRSP: 0018:ffffc900039dfad0 EFLAGS: 00010216
\n\tRAX: dffffc0000000000 RBX: ffffc900039dfdd8 RCX: ffffffff85f6fd3d
\n\tRDX: 0000000000000012 RSI: ffffffff85f6fd4b RDI: 0000000000000090
\n\tRBP: 0000000000000000 R08: 0000000000000005 R09: 0000000000000000
\n\tR10: 0000000000000000 R11: 0000000000000000 R12: ffff8880132c4000
\n\tR13: 0000000000000000 R14: ffff888073b6c700 R15: 000000000000003b
\n\tFS: 00007fab480b96c0(0000) GS:ffff888098ae9000(0000) knlGS:00000000
\n—truncated—<\/p>\n","protected":false},"excerpt":{"rendered":"
In the Linux kernel, the following vulnerability has been resolved:<\/p>\n
drm\/virtio: fix NULL pointer dereference on fence allocation failure<\/p>\n
virtio_gpu_fence_alloc() can fail due to memory pressure and <\/p>\n","protected":false},"template":"","meta":[],"categories":[],"tags":[],"class_list":["post-40980","vuln","type-vuln","status-publish","hentry"],"_links":{"self":[{"href":"https:\/\/www.54iter.cn\/index.php?rest_route=\/wp\/v2\/vuln\/40980","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.54iter.cn\/index.php?rest_route=\/wp\/v2\/vuln"}],"about":[{"href":"https:\/\/www.54iter.cn\/index.php?rest_route=\/wp\/v2\/types\/vuln"}],"wp:attachment":[{"href":"https:\/\/www.54iter.cn\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=40980"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.54iter.cn\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=40980"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.54iter.cn\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=40980"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}