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

drm/i915/gem: Really move i915_gem_context.link under ref protection

i915_perf assumes that it can use the i915_gem_context reference to protect its i915->gem.contexts.list iteration. However, this requires that we do not remove the context from the list until after we drop the final reference and release the struct. If, as currently, we remove the context from the list during context_close(), the link.next pointer may be poisoned while we are holding the context reference and cause a GPF:

[ 4070.573157] i915 0000:00:02.0: [drm:i915_perf_open_ioctl [i915]] filtering on ctx_id=0x1fffff ctx_id_mask=0x1fffff [ 4070.574881] general protection fault, probably for non-canonical address 0xdead000000000100: 0000 [#1] PREEMPT SMP [ 4070.574897] CPU: 1 PID: 284392 Comm: amd_performance Tainted: G E 5.17.9 #180 [ 4070.574903] Hardware name: Intel Corporation NUC7i5BNK/NUC7i5BNB, BIOS BNKBL357.86A.0052.2017.0918.1346 09/18/2017 [ 4070.574907] RIP: 0010:oa_configure_all_contexts.isra.0+0x222/0x350 [i915] [ 4070.574982] Code: 08 e8 32 6e 10 e1 4d 8b 6d 50 b8 ff ff ff ff 49 83 ed 50 f0 41 0f c1 04 24 83 f8 01 0f 84 e3 00 00 00 85 c0 0f 8e fa 00 00 00 <49> 8b 45 50 48 8d 70 b0 49 8d 45 50 48 39 44 24 10 0f 85 34 fe ff [ 4070.574990] RSP: 0018:ffffc90002077b78 EFLAGS: 00010202 [ 4070.574995] RAX: 0000000000000002 RBX: 0000000000000002 RCX: 0000000000000000 [ 4070.575000] RDX: 0000000000000001 RSI: ffffc9000…

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

drm/i915/gem: Really move i915_gem_context.link under ref protection

i915_perf assumes that it can use the i915_gem_context reference to protect its i915->gem.contexts.list iteration. However, this requires that we do not remove the context from the list until after we drop the final reference and release the struct. If, as currently, we remove the context from the list during context_close(), the link.next pointer may be poisoned while we are holding the context reference and cause a GPF:

[ 4070.573157] i915 0000:00:02.0: [drm:i915_perf_open_ioctl [i915]] filtering on ctx_id=0x1fffff ctx_id_mask=0x1fffff [ 4070.574881] general protection fault, probably for non-canonical address 0xdead000000000100: 0000 [#1] PREEMPT SMP [ 4070.574897] CPU: 1 PID: 284392 Comm: amd_performance Tainted: G E 5.17.9 #180 [ 4070.574903] Hardware name: Intel Corporation NUC7i5BNK/NUC7i5BNB, BIOS BNKBL357.86A.0052.2017.0918.1346 09/18/2017 [ 4070.574907] RIP: 0010:oa_configure_all_contexts.isra.0+0x222/0x350 [i915] [ 4070.574982] Code: 08 e8 32 6e 10 e1 4d 8b 6d 50 b8 ff ff ff ff 49 83 ed 50 f0 41 0f c1 04 24 83 f8 01 0f 84 e3 00 00 00 85 c0 0f 8e fa 00 00 00 <49> 8b 45 50 48 8d 70 b0 49 8d 45 50 48 39 44 24 10 0f 85 34 fe ff [ 4070.574990] RSP: 0018:ffffc90002077b78 EFLAGS: 00010202 [ 4070.574995] RAX: 0000000000000002 RBX: 0000000000000002 RCX: 0000000000000000 [ 4070.575000] RDX: 0000000000000001 RSI: ffffc9000…

Security update for the Linux Kernel

Affected: Ubuntu:16.04:LTS: linux-hwe-edge, Ubuntu:18.04:LTS: linux-aws-5.0, Ubuntu:18.04:LTS: linux-aws-5.3, Ubuntu:18.04:LTS: linux-azure, Ubuntu:18.04:LTS: linux-azure-5.3, Ubuntu:18.04:LTS: linux-azure-edge, Ubuntu:18.04:LTS: linux-gcp, Ubuntu:18.04:LTS: linux-gcp-5.3, Ubuntu:18.04:LTS: linux-gke-4.15, Ubuntu:18.04:LTS: linux-gke-5.4 and 81 more

In the Linux kernel, the following vulnerability has been resolved: drm/i915/gem: Really move i915_gem_context.link under ref protection i915_perf assumes that it can use the i915_gem_context reference to protect its i915->gem.contexts.list iteration. However, this requires that we do not remove the context from the list until after we drop the final reference and release the struct. If, as currently, we remove the context from the list during context_close(), the link.next pointer may be poisoned while we are holding the context reference and cause a GPF: [ 4070.573157] i915 0000:00:02.0: [drm:i915_perf_open_ioctl [i915]] filtering on ctx_id=0x1fffff ctx_id_mask=0x1fffff [ 4070.574881] general protection fault, probably for non-canonical address 0xdead000000000100: 0000 [#1] PREEMPT SMP [ 4070.574897] CPU: 1 PID: 284392 Comm: amd_performance Tainted: G E 5.17.9 #180 [ 4070.574903] Hardware name: Intel Corporation NUC7i5BNK/NUC7i5BNB, BIOS BNKBL357.86A.0052.2017.0918.1346 09/18/2017 [ 4070.574907] RIP: 0010:oa_configure_all_contexts.isra.0+0x222/0x350 [i915] [ 4070.574982] Code: 08 e8 32 6e 10 e1 4d 8b 6d 50 b8 ff ff ff ff 49 83 ed 50 f0 41 0f c1 04 24 83 f8 01 0f 84 e3 00 00 00 85 c0 0f 8e fa 00 00 00 <49> 8b 45 50 48 8d 70 b0 49 8d 45 50 48 39 44 24 10 0f 85 34 fe ff [ 4070.574990] RSP: 0018:ffffc90002077b78 EFLAGS: 00010202 [ 4070.574995] RAX: 0000000000000002 RBX: 0000000000000002 RCX: 0000000000000000 [ 4070.575000] RDX: 0000000000000001 RSI: ffffc90002077b20 RDI:…

Ein lokaler Angreifer kann diese Schwachstellen ausnutzen, um einen Denial-of-Service-Zustand herbeizuführen oder einen nicht spezifizierten Angriff durchzuführen.