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| author | Chris Bainbridge <chris.bainbridge@gmail.com> | 2025-01-11 19:59:45 +0100 |
|---|---|---|
| committer | Rafael J. Wysocki <rafael.j.wysocki@intel.com> | 2025-01-13 21:09:10 +0100 |
| commit | 14578923e8c251091d2bb8a2756cde3b662ac316 (patch) | |
| tree | f04b3e2444e7b0bf0d0d0b7201c5c91c58d17230 /drivers/gpu/drm/nouveau/nouveau_acpi.c | |
| parent | Linux 6.13-rc7 (diff) | |
| download | linux-14578923e8c251091d2bb8a2756cde3b662ac316.tar.xz linux-14578923e8c251091d2bb8a2756cde3b662ac316.zip | |
ACPI: video: Fix random crashes due to bad kfree()
Commit c6a837088bed ("drm/amd/display: Fetch the EDID from _DDC if
available for eDP") added function dm_helpers_probe_acpi_edid(), which
fetches the EDID from the BIOS by calling acpi_video_get_edid().
acpi_video_get_edid() returns a pointer to the EDID, but this pointer
does not originate from kmalloc() - it is actually the internal
"pointer" field from an acpi_buffer struct (which did come from
kmalloc()).
dm_helpers_probe_acpi_edid() then attempts to kfree() the EDID pointer,
resulting in memory corruption which leads to random, intermittent
crashes (e.g. 4% of boots will fail with some Oops).
Fix this by allocating a new array (which can be safely freed) for the
EDID data, and correctly freeing the acpi_buffer pointer.
The only other caller of acpi_video_get_edid() is nouveau_acpi_edid():
remove the extraneous kmemdup() here as the EDID data is now copied in
acpi_video_device_EDID().
Signed-off-by: Chris Bainbridge <chris.bainbridge@gmail.com>
Fixes: c6a837088bed ("drm/amd/display: Fetch the EDID from _DDC if available for eDP")
Reviewed-by: Hans de Goede <hdegoede@redhat.com>
Reviewed-by: Mario Limonciello <mario.limonciello@amd.com>
Reported-by: Borislav Petkov (AMD) <bp@alien8.de>
Tested-by: Borislav Petkov (AMD) <bp@alien8.de>
Closes: https://lore.kernel.org/amd-gfx/20250110175252.GBZ4FedNKqmBRaY4T3@fat_crate.local/T/#m324a23eb4c4c32fa7e89e31f8ba96c781e496fb1
Link: https://patch.msgid.link/Z4K_oQL7eA9Owkbs@debian.local
[ rjw: Changed function description comment into a kerneldoc one ]
[ rjw: Subject and changelog edits ]
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Diffstat (limited to '')
| -rw-r--r-- | drivers/gpu/drm/nouveau/nouveau_acpi.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/drivers/gpu/drm/nouveau/nouveau_acpi.c b/drivers/gpu/drm/nouveau/nouveau_acpi.c index 8f0c69aad248..21b56cc7605c 100644 --- a/drivers/gpu/drm/nouveau/nouveau_acpi.c +++ b/drivers/gpu/drm/nouveau/nouveau_acpi.c @@ -384,7 +384,7 @@ nouveau_acpi_edid(struct drm_device *dev, struct drm_connector *connector) if (ret < 0) return NULL; - return kmemdup(edid, EDID_LENGTH, GFP_KERNEL); + return edid; } bool nouveau_acpi_video_backlight_use_native(void) |