In the Linux kernel, the following vulnerability has been resolved:
drm/vc4: dont check if plane->state->fb == state->fb
Currently, when using non-blocking commits, we can see the following kernel warning:
[ 110.908514] ————[ cut here ]———— [ 110.908529] refcount_t: underflow; use-after-free. [ 110.908620] WARNING: CPU: 0 PID: 1866 at lib/refcount.c:87 refcount_dec_not_one+0xb8/0xc0 [ 110.908664] Modules linked in: rfcomm snd_seq_dummy snd_hrtimer snd_seq snd_seq_device cmac algif_hash aes_arm64 aes_generic algif_skcipher af_alg bnep hid_logitech_hidpp vc4 brcmfmac hci_uart btbcm brcmutil bluetooth snd_soc_hdmi_codec cfg80211 cec drm_display_helper drm_dma_helper drm_kms_helper snd_soc_core snd_compress snd_pcm_dmaengine fb_sys_fops sysimgblt syscopyarea sysfillrect raspberrypi_hwmon ecdh_generic ecc rfkill libaes i2c_bcm2835 binfmt_misc joydev snd_bcm2835(C) bcm2835_codec(C) bcm2835_isp(C) v4l2_mem2mem videobuf2_dma_contig snd_pcm bcm2835_v4l2(C) raspberrypi_gpiomem bcm2835_mmal_vchiq(C) videobuf2_v4l2 snd_timer videobuf2_vmalloc videobuf2_memops videobuf2_common snd videodev vc_sm_cma(C) mc hid_logitech_dj uio_pdrv_genirq uio i2c_dev drm fuse dm_mod drm_panel_orientation_quirks backlight ip_tables x_tables ipv6 [ 110.909086] CPU: 0 PID: 1866 Comm: kodi.bin Tainted: G C 6.1.66-v8+ #32 [ 110.909104] Hardware name: Raspberry Pi 3 Model B Rev 1.2 (DT) [ 110.909114] pstate: 60000005 (nZCv daif -PAN -UAO -TCO -DIT -SSBS BTYPE=–) [ 110.909132] pc : refcount_dec_not_one+0xb8/0xc0 [ 110.909152] lr : refcount_dec_not_one+0xb4/0xc0 [ 110.909170] sp : ffffffc00913b9c0 [ 110.909177] x29: ffffffc00913b9c0 x28: 000000556969bbb0 x27: 000000556990df60 [ 110.909205] x26: 0000000000000002 x25: 0000000000000004 x24: ffffff8004448480 [ 110.909230] x23: ffffff800570b500 x22: ffffff802e03a7bc x21: ffffffecfca68c78 [ 110.909257] x20: ffffff8002b42000 x19: ffffff802e03a600 x18: 0000000000000000 [ 110.909283] x17: 0000000000000011 x16: ffffffffffffffff x15: 0000000000000004 [ 110.909308] x14: 0000000000000fff x13: ffffffed577e47e0 x12: 0000000000000003 [ 110.909333] x11: 0000000000000000 x10: 0000000000000027 x9 : c912d0d083728c00 [ 110.909359] x8 : c912d0d083728c00 x7 : 65646e75203a745f x6 : 746e756f63666572 [ 110.909384] x5 : ffffffed579f62ee x4 : ffffffed579eb01e x3 : 0000000000000000 [ 110.909409] x2 : 0000000000000000 x1 : ffffffc00913b750 x0 : 0000000000000001 [ 110.909434] Call trace: [ 110.909441] refcount_dec_not_one+0xb8/0xc0 [ 110.909461] vc4_bo_dec_usecnt+0x4c/0x1b0 [vc4] [ 110.909903] vc4_cleanup_fb+0x44/0x50 [vc4] [ 110.910315] drm_atomic_helper_cleanup_planes+0x88/0xa4 [drm_kms_helper] [ 110.910669] vc4_atomic_commit_tail+0x390/0x9dc [vc4] [ 110.911079] commit_tail+0xb0/0x164 [drm_kms_helper] [ 110.911397] drm_atomic_helper_commit+0x1d0/0x1f0 [drm_kms_helper] [ 110.911716] drm_atomic_commit+0xb0/0xdc [drm] [ 110.912569] drm_mode_atomic_ioctl+0x348/0x4b8 [drm] [ 110.913330] drm_ioctl_kernel+0xec/0x15c [drm] [ 110.914091] drm_ioctl+0x24c/0x3b0 [drm] [ 110.914850] __arm64_sys_ioctl+0x9c/0xd4 [ 110.914873] invoke_syscall+0x4c/0x114 [ 110.914897] el0_svc_common+0xd0/0x118 [ 110.914917] do_el0_svc+0x38/0xd0 [ 110.914936] el0_svc+0x30/0x8c [ 110.914958] el0t_64_sync_handler+0x84/0xf0 [ 110.914979] el0t_64_sync+0x18c/0x190 [ 110.914996] —[ end trace 0000000000000000 ]—
This happens because, although prepare_fb
and cleanup_fb
are
perfectly balanced, we cannot guarantee consistency in the check
plane->state->fb == state->fb. This means that sometimes we can increase
the refcount in prepare_fb
and dont decrease it in cleanup_fb
. The
opposite can also be true.
In fact, the struct drm_plane .state shouldnt be accessed directly
but instead, the drm_atomic_get_new_plane_state()
helper function should
be used. So, we could stick to this check, but using
drm_atomic_get_new_plane_state()
. But actually, this check is not re
—truncated—
Name | Vendor | Start Version | End Version |
---|---|---|---|
Linux | Ubuntu | devel | * |
Linux | Ubuntu | esm-infra-legacy/trusty | * |
Linux | Ubuntu | esm-infra/bionic | * |
Linux | Ubuntu | esm-infra/xenial | * |
Linux | Ubuntu | focal | * |
Linux | Ubuntu | jammy | * |
Linux | Ubuntu | mantic | * |
Linux | Ubuntu | noble | * |
Linux | Ubuntu | trusty/esm | * |
Linux | Ubuntu | upstream | * |
Linux-allwinner-5.19 | Ubuntu | jammy | * |
Linux-allwinner-5.19 | Ubuntu | upstream | * |
Linux-aws | Ubuntu | devel | * |
Linux-aws | Ubuntu | esm-infra-legacy/trusty | * |
Linux-aws | Ubuntu | esm-infra/bionic | * |
Linux-aws | Ubuntu | esm-infra/xenial | * |
Linux-aws | Ubuntu | focal | * |
Linux-aws | Ubuntu | jammy | * |
Linux-aws | Ubuntu | mantic | * |
Linux-aws | Ubuntu | noble | * |
Linux-aws | Ubuntu | trusty/esm | * |
Linux-aws | Ubuntu | upstream | * |
Linux-aws-5.0 | Ubuntu | esm-infra/bionic | * |
Linux-aws-5.0 | Ubuntu | upstream | * |
Linux-aws-5.11 | Ubuntu | focal | * |
Linux-aws-5.11 | Ubuntu | upstream | * |
Linux-aws-5.13 | Ubuntu | focal | * |
Linux-aws-5.13 | Ubuntu | upstream | * |
Linux-aws-5.15 | Ubuntu | focal | * |
Linux-aws-5.15 | Ubuntu | upstream | * |
Linux-aws-5.19 | Ubuntu | jammy | * |
Linux-aws-5.19 | Ubuntu | upstream | * |
Linux-aws-5.3 | Ubuntu | esm-infra/bionic | * |
Linux-aws-5.3 | Ubuntu | upstream | * |
Linux-aws-5.4 | Ubuntu | esm-infra/bionic | * |
Linux-aws-5.4 | Ubuntu | upstream | * |
Linux-aws-5.8 | Ubuntu | focal | * |
Linux-aws-5.8 | Ubuntu | upstream | * |
Linux-aws-6.2 | Ubuntu | jammy | * |
Linux-aws-6.2 | Ubuntu | upstream | * |
Linux-aws-6.5 | Ubuntu | jammy | * |
Linux-aws-6.5 | Ubuntu | upstream | * |
Linux-aws-fips | Ubuntu | fips-updates/bionic | * |
Linux-aws-fips | Ubuntu | fips-updates/focal | * |
Linux-aws-fips | Ubuntu | fips/bionic | * |
Linux-aws-fips | Ubuntu | fips/focal | * |
Linux-aws-fips | Ubuntu | upstream | * |
Linux-aws-hwe | Ubuntu | esm-infra/xenial | * |
Linux-aws-hwe | Ubuntu | upstream | * |
Linux-azure | Ubuntu | devel | * |
Linux-azure | Ubuntu | esm-infra-legacy/trusty | * |
Linux-azure | Ubuntu | esm-infra/bionic | * |
Linux-azure | Ubuntu | esm-infra/xenial | * |
Linux-azure | Ubuntu | focal | * |
Linux-azure | Ubuntu | jammy | * |
Linux-azure | Ubuntu | mantic | * |
Linux-azure | Ubuntu | noble | * |
Linux-azure | Ubuntu | trusty/esm | * |
Linux-azure | Ubuntu | upstream | * |
Linux-azure-4.15 | Ubuntu | esm-infra/bionic | * |
Linux-azure-4.15 | Ubuntu | upstream | * |
Linux-azure-5.11 | Ubuntu | focal | * |
Linux-azure-5.11 | Ubuntu | upstream | * |
Linux-azure-5.13 | Ubuntu | focal | * |
Linux-azure-5.13 | Ubuntu | upstream | * |
Linux-azure-5.15 | Ubuntu | focal | * |
Linux-azure-5.15 | Ubuntu | upstream | * |
Linux-azure-5.19 | Ubuntu | jammy | * |
Linux-azure-5.19 | Ubuntu | upstream | * |
Linux-azure-5.3 | Ubuntu | esm-infra/bionic | * |
Linux-azure-5.3 | Ubuntu | upstream | * |
Linux-azure-5.4 | Ubuntu | esm-infra/bionic | * |
Linux-azure-5.4 | Ubuntu | upstream | * |
Linux-azure-5.8 | Ubuntu | focal | * |
Linux-azure-5.8 | Ubuntu | upstream | * |
Linux-azure-6.2 | Ubuntu | jammy | * |
Linux-azure-6.2 | Ubuntu | upstream | * |
Linux-azure-6.5 | Ubuntu | jammy | * |
Linux-azure-6.5 | Ubuntu | upstream | * |
Linux-azure-edge | Ubuntu | esm-infra/bionic | * |
Linux-azure-edge | Ubuntu | upstream | * |
Linux-azure-fde | Ubuntu | focal | * |
Linux-azure-fde | Ubuntu | jammy | * |
Linux-azure-fde | Ubuntu | upstream | * |
Linux-azure-fde-5.15 | Ubuntu | focal | * |
Linux-azure-fde-5.15 | Ubuntu | upstream | * |
Linux-azure-fde-5.19 | Ubuntu | jammy | * |
Linux-azure-fde-5.19 | Ubuntu | upstream | * |
Linux-azure-fde-6.2 | Ubuntu | jammy | * |
Linux-azure-fde-6.2 | Ubuntu | upstream | * |
Linux-azure-fips | Ubuntu | fips-updates/bionic | * |
Linux-azure-fips | Ubuntu | fips-updates/focal | * |
Linux-azure-fips | Ubuntu | fips/bionic | * |
Linux-azure-fips | Ubuntu | fips/focal | * |
Linux-azure-fips | Ubuntu | upstream | * |
Linux-bluefield | Ubuntu | focal | * |
Linux-bluefield | Ubuntu | upstream | * |
Linux-fips | Ubuntu | fips-updates/bionic | * |
Linux-fips | Ubuntu | fips-updates/focal | * |
Linux-fips | Ubuntu | fips-updates/xenial | * |
Linux-fips | Ubuntu | fips/bionic | * |
Linux-fips | Ubuntu | fips/focal | * |
Linux-fips | Ubuntu | fips/xenial | * |
Linux-fips | Ubuntu | upstream | * |
Linux-gcp | Ubuntu | devel | * |
Linux-gcp | Ubuntu | esm-infra/bionic | * |
Linux-gcp | Ubuntu | esm-infra/xenial | * |
Linux-gcp | Ubuntu | focal | * |
Linux-gcp | Ubuntu | jammy | * |
Linux-gcp | Ubuntu | mantic | * |
Linux-gcp | Ubuntu | noble | * |
Linux-gcp | Ubuntu | upstream | * |
Linux-gcp-4.15 | Ubuntu | esm-infra/bionic | * |
Linux-gcp-4.15 | Ubuntu | upstream | * |
Linux-gcp-5.11 | Ubuntu | focal | * |
Linux-gcp-5.11 | Ubuntu | upstream | * |
Linux-gcp-5.13 | Ubuntu | focal | * |
Linux-gcp-5.13 | Ubuntu | upstream | * |
Linux-gcp-5.15 | Ubuntu | focal | * |
Linux-gcp-5.15 | Ubuntu | upstream | * |
Linux-gcp-5.19 | Ubuntu | jammy | * |
Linux-gcp-5.19 | Ubuntu | upstream | * |
Linux-gcp-5.3 | Ubuntu | esm-infra/bionic | * |
Linux-gcp-5.3 | Ubuntu | upstream | * |
Linux-gcp-5.4 | Ubuntu | esm-infra/bionic | * |
Linux-gcp-5.4 | Ubuntu | upstream | * |
Linux-gcp-5.8 | Ubuntu | focal | * |
Linux-gcp-5.8 | Ubuntu | upstream | * |
Linux-gcp-6.2 | Ubuntu | jammy | * |
Linux-gcp-6.2 | Ubuntu | upstream | * |
Linux-gcp-6.5 | Ubuntu | jammy | * |
Linux-gcp-6.5 | Ubuntu | upstream | * |
Linux-gcp-fips | Ubuntu | fips-updates/bionic | * |
Linux-gcp-fips | Ubuntu | fips-updates/focal | * |
Linux-gcp-fips | Ubuntu | fips/bionic | * |
Linux-gcp-fips | Ubuntu | fips/focal | * |
Linux-gcp-fips | Ubuntu | upstream | * |
Linux-gke | Ubuntu | devel | * |
Linux-gke | Ubuntu | focal | * |
Linux-gke | Ubuntu | jammy | * |
Linux-gke | Ubuntu | noble | * |
Linux-gke | Ubuntu | upstream | * |
Linux-gke-4.15 | Ubuntu | esm-infra/bionic | * |
Linux-gke-4.15 | Ubuntu | upstream | * |
Linux-gke-5.15 | Ubuntu | focal | * |
Linux-gke-5.15 | Ubuntu | upstream | * |
Linux-gke-5.4 | Ubuntu | esm-infra/bionic | * |
Linux-gke-5.4 | Ubuntu | upstream | * |
Linux-gkeop | Ubuntu | focal | * |
Linux-gkeop | Ubuntu | jammy | * |
Linux-gkeop | Ubuntu | upstream | * |
Linux-gkeop-5.15 | Ubuntu | focal | * |
Linux-gkeop-5.15 | Ubuntu | upstream | * |
Linux-gkeop-5.4 | Ubuntu | esm-infra/bionic | * |
Linux-gkeop-5.4 | Ubuntu | upstream | * |
Linux-hwe | Ubuntu | esm-infra/bionic | * |
Linux-hwe | Ubuntu | esm-infra/xenial | * |
Linux-hwe | Ubuntu | upstream | * |
Linux-hwe-5.11 | Ubuntu | focal | * |
Linux-hwe-5.11 | Ubuntu | upstream | * |
Linux-hwe-5.13 | Ubuntu | focal | * |
Linux-hwe-5.13 | Ubuntu | upstream | * |
Linux-hwe-5.15 | Ubuntu | focal | * |
Linux-hwe-5.15 | Ubuntu | upstream | * |
Linux-hwe-5.19 | Ubuntu | jammy | * |
Linux-hwe-5.19 | Ubuntu | upstream | * |
Linux-hwe-5.4 | Ubuntu | esm-infra/bionic | * |
Linux-hwe-5.4 | Ubuntu | upstream | * |
Linux-hwe-5.8 | Ubuntu | focal | * |
Linux-hwe-5.8 | Ubuntu | upstream | * |
Linux-hwe-6.2 | Ubuntu | jammy | * |
Linux-hwe-6.2 | Ubuntu | upstream | * |
Linux-hwe-6.5 | Ubuntu | jammy | * |
Linux-hwe-6.5 | Ubuntu | upstream | * |
Linux-hwe-edge | Ubuntu | esm-infra/bionic | * |
Linux-hwe-edge | Ubuntu | esm-infra/xenial | * |
Linux-hwe-edge | Ubuntu | upstream | * |
Linux-ibm | Ubuntu | devel | * |
Linux-ibm | Ubuntu | focal | * |
Linux-ibm | Ubuntu | jammy | * |
Linux-ibm | Ubuntu | mantic | * |
Linux-ibm | Ubuntu | noble | * |
Linux-ibm | Ubuntu | upstream | * |
Linux-ibm-5.15 | Ubuntu | focal | * |
Linux-ibm-5.15 | Ubuntu | upstream | * |
Linux-ibm-5.4 | Ubuntu | esm-infra/bionic | * |
Linux-ibm-5.4 | Ubuntu | upstream | * |
Linux-intel | Ubuntu | noble | * |
Linux-intel | Ubuntu | upstream | * |
Linux-intel-5.13 | Ubuntu | focal | * |
Linux-intel-5.13 | Ubuntu | upstream | * |
Linux-intel-iotg | Ubuntu | jammy | * |
Linux-intel-iotg | Ubuntu | upstream | * |
Linux-intel-iotg-5.15 | Ubuntu | focal | * |
Linux-intel-iotg-5.15 | Ubuntu | upstream | * |
Linux-iot | Ubuntu | focal | * |
Linux-iot | Ubuntu | upstream | * |
Linux-kvm | Ubuntu | esm-infra/bionic | * |
Linux-kvm | Ubuntu | esm-infra/xenial | * |
Linux-kvm | Ubuntu | focal | * |
Linux-kvm | Ubuntu | jammy | * |
Linux-kvm | Ubuntu | upstream | * |
Linux-laptop | Ubuntu | mantic | * |
Linux-laptop | Ubuntu | upstream | * |
Linux-lowlatency | Ubuntu | devel | * |
Linux-lowlatency | Ubuntu | jammy | * |
Linux-lowlatency | Ubuntu | mantic | * |
Linux-lowlatency | Ubuntu | noble | * |
Linux-lowlatency | Ubuntu | upstream | * |
Linux-lowlatency-hwe-5.15 | Ubuntu | focal | * |
Linux-lowlatency-hwe-5.15 | Ubuntu | upstream | * |
Linux-lowlatency-hwe-5.19 | Ubuntu | jammy | * |
Linux-lowlatency-hwe-5.19 | Ubuntu | upstream | * |
Linux-lowlatency-hwe-6.2 | Ubuntu | jammy | * |
Linux-lowlatency-hwe-6.2 | Ubuntu | upstream | * |
Linux-lowlatency-hwe-6.5 | Ubuntu | jammy | * |
Linux-lowlatency-hwe-6.5 | Ubuntu | upstream | * |
Linux-lts-xenial | Ubuntu | esm-infra-legacy/trusty | * |
Linux-lts-xenial | Ubuntu | trusty/esm | * |
Linux-lts-xenial | Ubuntu | upstream | * |
Linux-nvidia | Ubuntu | jammy | * |
Linux-nvidia | Ubuntu | noble | * |
Linux-nvidia | Ubuntu | upstream | * |
Linux-nvidia-6.2 | Ubuntu | jammy | * |
Linux-nvidia-6.2 | Ubuntu | upstream | * |
Linux-nvidia-6.5 | Ubuntu | jammy | * |
Linux-nvidia-6.5 | Ubuntu | upstream | * |
Linux-oem | Ubuntu | esm-infra/bionic | * |
Linux-oem | Ubuntu | upstream | * |
Linux-oem-5.10 | Ubuntu | focal | * |
Linux-oem-5.10 | Ubuntu | upstream | * |
Linux-oem-5.13 | Ubuntu | focal | * |
Linux-oem-5.13 | Ubuntu | upstream | * |
Linux-oem-5.14 | Ubuntu | focal | * |
Linux-oem-5.14 | Ubuntu | upstream | * |
Linux-oem-5.17 | Ubuntu | jammy | * |
Linux-oem-5.17 | Ubuntu | upstream | * |
Linux-oem-5.6 | Ubuntu | focal | * |
Linux-oem-5.6 | Ubuntu | upstream | * |
Linux-oem-6.0 | Ubuntu | jammy | * |
Linux-oem-6.0 | Ubuntu | upstream | * |
Linux-oem-6.1 | Ubuntu | jammy | * |
Linux-oem-6.1 | Ubuntu | upstream | * |
Linux-oem-6.5 | Ubuntu | jammy | * |
Linux-oem-6.5 | Ubuntu | upstream | * |
Linux-oem-6.8 | Ubuntu | noble | * |
Linux-oem-6.8 | Ubuntu | upstream | * |
Linux-oracle | Ubuntu | devel | * |
Linux-oracle | Ubuntu | esm-infra/bionic | * |
Linux-oracle | Ubuntu | esm-infra/xenial | * |
Linux-oracle | Ubuntu | focal | * |
Linux-oracle | Ubuntu | jammy | * |
Linux-oracle | Ubuntu | mantic | * |
Linux-oracle | Ubuntu | noble | * |
Linux-oracle | Ubuntu | upstream | * |
Linux-oracle-5.0 | Ubuntu | esm-infra/bionic | * |
Linux-oracle-5.0 | Ubuntu | upstream | * |
Linux-oracle-5.11 | Ubuntu | focal | * |
Linux-oracle-5.11 | Ubuntu | upstream | * |
Linux-oracle-5.13 | Ubuntu | focal | * |
Linux-oracle-5.13 | Ubuntu | upstream | * |
Linux-oracle-5.15 | Ubuntu | focal | * |
Linux-oracle-5.15 | Ubuntu | upstream | * |
Linux-oracle-5.3 | Ubuntu | esm-infra/bionic | * |
Linux-oracle-5.3 | Ubuntu | upstream | * |
Linux-oracle-5.4 | Ubuntu | esm-infra/bionic | * |
Linux-oracle-5.4 | Ubuntu | upstream | * |
Linux-oracle-5.8 | Ubuntu | focal | * |
Linux-oracle-5.8 | Ubuntu | upstream | * |
Linux-oracle-6.5 | Ubuntu | jammy | * |
Linux-oracle-6.5 | Ubuntu | upstream | * |
Linux-raspi | Ubuntu | devel | * |
Linux-raspi | Ubuntu | focal | * |
Linux-raspi | Ubuntu | jammy | * |
Linux-raspi | Ubuntu | mantic | * |
Linux-raspi | Ubuntu | noble | * |
Linux-raspi | Ubuntu | upstream | * |
Linux-raspi-5.4 | Ubuntu | esm-infra/bionic | * |
Linux-raspi-5.4 | Ubuntu | upstream | * |
Linux-raspi2 | Ubuntu | focal | * |
Linux-raspi2 | Ubuntu | upstream | * |
Linux-riscv | Ubuntu | devel | * |
Linux-riscv | Ubuntu | focal | * |
Linux-riscv | Ubuntu | jammy | * |
Linux-riscv | Ubuntu | mantic | * |
Linux-riscv | Ubuntu | noble | * |
Linux-riscv | Ubuntu | upstream | * |
Linux-riscv-5.11 | Ubuntu | focal | * |
Linux-riscv-5.11 | Ubuntu | upstream | * |
Linux-riscv-5.15 | Ubuntu | focal | * |
Linux-riscv-5.15 | Ubuntu | upstream | * |
Linux-riscv-5.19 | Ubuntu | jammy | * |
Linux-riscv-5.19 | Ubuntu | upstream | * |
Linux-riscv-5.8 | Ubuntu | focal | * |
Linux-riscv-5.8 | Ubuntu | upstream | * |
Linux-riscv-6.5 | Ubuntu | jammy | * |
Linux-riscv-6.5 | Ubuntu | upstream | * |
Linux-starfive | Ubuntu | mantic | * |
Linux-starfive | Ubuntu | upstream | * |
Linux-starfive-5.19 | Ubuntu | jammy | * |
Linux-starfive-5.19 | Ubuntu | upstream | * |
Linux-starfive-6.2 | Ubuntu | jammy | * |
Linux-starfive-6.2 | Ubuntu | upstream | * |
Linux-starfive-6.5 | Ubuntu | jammy | * |
Linux-starfive-6.5 | Ubuntu | upstream | * |
Linux-xilinx-zynqmp | Ubuntu | focal | * |
Linux-xilinx-zynqmp | Ubuntu | jammy | * |
Linux-xilinx-zynqmp | Ubuntu | upstream | * |