In the Linux kernel, the following vulnerability has been resolved:
drm/mediatek: Fix a null pointer crash in mtk_drm_crtc_finish_page_flip
It’s possible that mtk_crtc->event is NULL in
mtk_drm_crtc_finish_page_flip().
pending_needs_vblank value is set by mtk_crtc->event, but in
mtk_drm_crtc_atomic_flush(), it’s is not guarded by the same
lock in mtk_drm_finish_page_flip(), thus a race condition happens.
Consider the following case:
CPU1 CPU2
step 1:
mtk_drm_crtc_atomic_begin()
mtk_crtc->event is not null,
step 1:
mtk_drm_crtc_atomic_flush:
mtk_drm_crtc_update_config(
!!mtk_crtc->event)
step 2:
mtk_crtc_ddp_irq ->
mtk_drm_finish_page_flip:
lock
mtk_crtc->event set to null,
pending_needs_vblank set to false
unlock
pending_needs_vblank set to true,
step 2:
mtk_crtc_ddp_irq ->
mtk_drm_finish_page_flip called again,
pending_needs_vblank is still true
//null pointer
Instead of guarding the entire mtk_drm_crtc_atomic_flush(), it’s more
efficient to just check if mtk_crtc->event is null before use.
Vendor | Product | Version | CPE |
---|---|---|---|
linux | linux_kernel | * | cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* |
linux | linux_kernel | * | cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* |
linux | linux_kernel | * | cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* |
linux | linux_kernel | * | cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* |
linux | linux_kernel | * | cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* |
linux | linux_kernel | * | cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* |
linux | linux_kernel | * | cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* |
linux | linux_kernel | * | cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* |
linux | linux_kernel | * | cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* |
[
{
"product": "Linux",
"vendor": "Linux",
"defaultStatus": "unaffected",
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"programFiles": [
"drivers/gpu/drm/mediatek/mtk_drm_crtc.c"
],
"versions": [
{
"version": "119f5173628a",
"lessThan": "accdac6b71d5",
"status": "affected",
"versionType": "git"
},
{
"version": "119f5173628a",
"lessThan": "dfde84cc6c58",
"status": "affected",
"versionType": "git"
},
{
"version": "119f5173628a",
"lessThan": "4688be96d20f",
"status": "affected",
"versionType": "git"
},
{
"version": "119f5173628a",
"lessThan": "9beec711a172",
"status": "affected",
"versionType": "git"
},
{
"version": "119f5173628a",
"lessThan": "d2bd30c71047",
"status": "affected",
"versionType": "git"
},
{
"version": "119f5173628a",
"lessThan": "a3dd12b64ae8",
"status": "affected",
"versionType": "git"
},
{
"version": "119f5173628a",
"lessThan": "9acee29a38b4",
"status": "affected",
"versionType": "git"
},
{
"version": "119f5173628a",
"lessThan": "3fc88b246a2f",
"status": "affected",
"versionType": "git"
},
{
"version": "119f5173628a",
"lessThan": "c958e86e9cc1",
"status": "affected",
"versionType": "git"
}
]
},
{
"product": "Linux",
"vendor": "Linux",
"defaultStatus": "affected",
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"programFiles": [
"drivers/gpu/drm/mediatek/mtk_drm_crtc.c"
],
"versions": [
{
"version": "4.7",
"status": "affected"
},
{
"version": "0",
"lessThan": "4.7",
"status": "unaffected",
"versionType": "custom"
},
{
"version": "4.19.311",
"lessThanOrEqual": "4.19.*",
"status": "unaffected",
"versionType": "custom"
},
{
"version": "5.4.273",
"lessThanOrEqual": "5.4.*",
"status": "unaffected",
"versionType": "custom"
},
{
"version": "5.10.214",
"lessThanOrEqual": "5.10.*",
"status": "unaffected",
"versionType": "custom"
},
{
"version": "5.15.153",
"lessThanOrEqual": "5.15.*",
"status": "unaffected",
"versionType": "custom"
},
{
"version": "6.1.83",
"lessThanOrEqual": "6.1.*",
"status": "unaffected",
"versionType": "custom"
},
{
"version": "6.6.23",
"lessThanOrEqual": "6.6.*",
"status": "unaffected",
"versionType": "custom"
},
{
"version": "6.7.11",
"lessThanOrEqual": "6.7.*",
"status": "unaffected",
"versionType": "custom"
},
{
"version": "6.8.2",
"lessThanOrEqual": "6.8.*",
"status": "unaffected",
"versionType": "custom"
},
{
"version": "6.9",
"lessThanOrEqual": "*",
"status": "unaffected",
"versionType": "original_commit_for_fix"
}
]
}
]
git.kernel.org/stable/c/3fc88b246a2fc16014e374040fc15af1d3752535
git.kernel.org/stable/c/4688be96d20ffa49d2186523ee84f475f316fd49
git.kernel.org/stable/c/9acee29a38b4d4b70f1f583e5ef9a245db4db710
git.kernel.org/stable/c/9beec711a17245b853d64488fd5b739031612340
git.kernel.org/stable/c/a3dd12b64ae8373a41a216a0b621df224210860a
git.kernel.org/stable/c/accdac6b71d5a2b84040c3d2234f53a60edc398e
git.kernel.org/stable/c/c958e86e9cc1b48cac004a6e245154dfba8e163b
git.kernel.org/stable/c/d2bd30c710475b2e29288827d2c91f9e6e2b91d7
git.kernel.org/stable/c/dfde84cc6c589f2a9f820f12426d97365670b731
lists.debian.org/debian-lts-announce/2024/06/msg00017.html
lists.debian.org/debian-lts-announce/2024/06/msg00020.html