Affected: Alpaquita:25: linux-lts, Alpaquita:stream: linux-lts

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

drm/imagination: acquire vm_ctx->lock before mapping memory to GPU VM

The drm gpuvm code doesn't protect find operation against map operation, and the driver needs to ensure a map operation shouldn't happen when a find operation is in progress.

In some cases a find operation will be in progress when doing map/unmap operations, and the find operation will do a NULL pointer dereference.

An example of the stack trace of such NULL dereference is shown below:

``` Unable to handle kernel access to user memory without uaccess routines at virtual address 0000000000000010

[<ffffffff01e989d4>] drm_gpuva_find+0x28/0x6c [drm_gpuvm] [<ffffffff01ed3a40>] pvr_vm_unmap+0x34/0x68 [powervr] [<ffffffff01ec69da>] pvr_ioctl_vm_unmap+0x2e/0x50 [powervr] [<ffffffff8080ce0a>] drm_ioctl_kernel+0x8e/0xdc [<ffffffff8080d016>] drm_ioctl+0x1be/0x3e0 [<ffffffff802bec3e>] __riscv_sys_ioctl+0xba/0xc4 [<ffffffff80d858b2>] do_trap_ecall_u+0x23e/0x3f4 [<ffffffff80d92288>] handle_exception+0x168/0x174 ```

As all occurences of drm_gpuva_find*() are already guarded by vm_ctx->lock, make pvr_vm_map() to acquire this lock to prevent disturbing any find operation. This fixes the NULL deference problem in drm_gpuva_find*().

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

drm/imagination: acquire vm_ctx->lock before mapping memory to GPU VM

The drm gpuvm code doesn't protect find operation against map operation, and the driver needs to ensure a map operation shouldn't happen when a find operation is in progress.

In some cases a find operation will be in progress when doing map/unmap operations, and the find operation will do a NULL pointer dereference.

An example of the stack trace of such NULL dereference is shown below:

``` Unable to handle kernel access to user memory without uaccess routines at virtual address 0000000000000010

[<ffffffff01e989d4>] drm_gpuva_find+0x28/0x6c [drm_gpuvm] [<ffffffff01ed3a40>] pvr_vm_unmap+0x34/0x68 [powervr] [<ffffffff01ec69da>] pvr_ioctl_vm_unmap+0x2e/0x50 [powervr] [<ffffffff8080ce0a>] drm_ioctl_kernel+0x8e/0xdc [<ffffffff8080d016>] drm_ioctl+0x1be/0x3e0 [<ffffffff802bec3e>] __riscv_sys_ioctl+0xba/0xc4 [<ffffffff80d858b2>] do_trap_ecall_u+0x23e/0x3f4 [<ffffffff80d92288>] handle_exception+0x168/0x174 ```

As all occurences of drm_gpuva_find*() are already guarded by vm_ctx->lock, make pvr_vm_map() to acquire this lock to prevent disturbing any find operation. This fixes the NULL deference problem in drm_gpuva_find*().

Security update for the Linux Kernel

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 154 more

In the Linux kernel, the following vulnerability has been resolved: drm/imagination: acquire vm_ctx->lock before mapping memory to GPU VM The drm gpuvm code doesn't protect find operation against map operation, and the driver needs to ensure a map operation shouldn't happen when a find operation is in progress. In some cases a find operation will be in progress when doing map/unmap operations, and the find operation will do a NULL pointer dereference. An example of the stack trace of such NULL dereference is shown below: ``` Unable to handle kernel access to user memory without uaccess routines at virtual address 0000000000000010 [<ffffffff01e989d4>] drm_gpuva_find+0x28/0x6c [drm_gpuvm] [<ffffffff01ed3a40>] pvr_vm_unmap+0x34/0x68 [powervr] [<ffffffff01ec69da>] pvr_ioctl_vm_unmap+0x2e/0x50 [powervr] [<ffffffff8080ce0a>] drm_ioctl_kernel+0x8e/0xdc [<ffffffff8080d016>] drm_ioctl+0x1be/0x3e0 [<ffffffff802bec3e>] __riscv_sys_ioctl+0xba/0xc4 [<ffffffff80d858b2>] do_trap_ecall_u+0x23e/0x3f4 [<ffffffff80d92288>] handle_exception+0x168/0x174 ``` As all occurences of drm_gpuva_find*() are already guarded by vm_ctx->lock, make pvr_vm_map() to acquire this lock to prevent disturbing any find operation. This fixes the NULL deference problem in drm_gpuva_find*().

Ein Angreifer kann mehrere Schwachstellen im Linux Kernel ausnutzen, um einen nicht näher spezifizierten Angriff durchzuführen, darunter möglicherweise die Ausführung von beliebigem Code, die Ausweitung von Berechtigungen, die Offenlegung von Informationen, die Manipulation von Daten oder Denial-of-Service-Zustände.