kernel/linux.git/drivers/video, branch v6.6.143

fbdev/vt8500lcdfb: Initialize fb_ops with fbdev macros

2026-06-19T11:39:38+00:00

commit 63a11adaceb8b77d70bcce0890197fa9462ce160 upstream. Initialize the instance of struct fb_ops with fbdev initializer macros for framebuffers in DMA-able virtual address space. Set the read/write, draw and mmap callbacks to the correct implementation and avoid implicit defaults. Also select the necessary helpers in Kconfig. Fbdev drivers sometimes rely on the callbacks being NULL for a default I/O-memory-based implementation to be invoked; hence requiring the I/O helpers to be built in any case. Setting all callbacks in all drivers explicitly will allow to make the I/O helpers optional. This benefits systems that do not use these functions. Signed-off-by: Thomas Zimmermann Reviewed-by: Javier Martinez Canillas Link: https://patchwork.freedesktop.org/patch/msgid/20231127131655.4020-23-tzimmermann@suse.de Cc: Ben Hutchings Signed-off-by: Greg Kroah-Hartman

drm, fbcon, vga_switcheroo: Avoid race condition in fbcon setup

2026-06-19T11:39:13+00:00

[ Upstream commit eb76d0f5553575599561010f24c277cc5b31d003 ] Protect vga_switcheroo_client_fb_set() with console lock. Avoids OOB access in fbcon_remap_all(). Without holding the console lock the call races with switching outputs. VGA switcheroo calls fbcon_remap_all() when switching clients. The fbcon function uses struct fb_info.node, which is set by register_framebuffer(). As the fb-helper code currently sets up VGA switcheroo before registering the framebuffer, the value of node is -1 and therefore not a legal value. For example, fbcon uses the value within set_con2fb_map() [1] as an index into an array. Moving vga_switcheroo_client_fb_set() after register_framebuffer() can result in VGA switching that does not switch fbcon correctly. Therefore move vga_switcheroo_client_fb_set() under fbcon_fb_registered(), which already holds the console lock. Fbdev calls fbcon_fb_registered() from within register_framebuffer(). Serializes the helper with VGA switcheroo's call to fbcon_remap_all(). Although vga_switcheroo_client_fb_set() takes an instance of struct fb_info as parameter, it really only needs the contained fbcon state. Moving the call to fbcon initialization is therefore cleaner than before. Only amdgpu, i915, nouveau and radeon support vga_switcheroo. For all other drivers, this change does nothing. Signed-off-by: Thomas Zimmermann Link: https://elixir.bootlin.com/linux/v6.17/source/drivers/video/fbdev/core/fbcon.c#L2942 # [1] Fixes: 6a9ee8af344e ("vga_switcheroo: initial implementation (v15)") Acked-by: Javier Martinez Canillas Acked-by: Alex Deucher Cc: dri-devel@lists.freedesktop.org Cc: nouveau@lists.freedesktop.org Cc: amd-gfx@lists.freedesktop.org Cc: linux-fbdev@vger.kernel.org Cc: # v2.6.34+ Link: https://patch.msgid.link/20251105161549.98836-1-tzimmermann@suse.de [ Minor context conflict resolved. ] Signed-off-by: Wenshan Lan Signed-off-by: Sasha Levin

fbdev: offb: fix PCI device reference leak on probe failure

2026-05-23T11:03:26+00:00

[ Upstream commit 869b93ba04088713596e68453c1146f52f713290 ] offb_init_nodriver() gets a referenced PCI device with pci_get_device(). If pci_enable_device() fails, the function returns without dropping that reference. Release the PCI device reference before returning from the pci_enable_device() failure path. Fixes: 5bda8f7b5468 ("video: fbdev: offb: Call pci_enable_device() before using the PCI VGA device") Co-developed-by: Myeonghun Pak Signed-off-by: Myeonghun Pak Co-developed-by: Ijae Kim Signed-off-by: Ijae Kim Co-developed-by: Taegyu Kim Signed-off-by: Taegyu Kim Signed-off-by: Yuho Choi Signed-off-by: Helge Deller Signed-off-by: Sasha Levin

backlight: sky81452-backlight: Check return value of devm_gpiod_get_optional() in sky81452_bl_parse_dt()

2026-05-23T11:03:20+00:00

[ Upstream commit 797cc011ae02bda26f93d25a4442d7a1a77d84df ] The devm_gpiod_get_optional() function may return an ERR_PTR in case of genuine GPIO acquisition errors, not just NULL which indicates the legitimate absence of an optional GPIO. Add an IS_ERR() check after the call in sky81452_bl_parse_dt(). On error, return the error code to ensure proper failure handling rather than proceeding with invalid pointers. Fixes: e1915eec54a6 ("backlight: sky81452: Convert to GPIO descriptors") Signed-off-by: Chen Ni Reviewed-by: Linus Walleij Reviewed-by: Daniel Thompson (RISCstar) Link: https://patch.msgid.link/20260203021625.578678-1-nichen@iscas.ac.cn Signed-off-by: Lee Jones Signed-off-by: Sasha Levin

fbdev: matroxfb: Mark variable with __maybe_unused to avoid W=1 build break

2026-05-23T11:03:11+00:00

[ Upstream commit caf6144053b4e1c815aa56afb54745a176f999df ] Clang is not happy about set but unused variable: drivers/video/fbdev/matrox/g450_pll.c:412:18: error: variable 'mnp' set but not used 412 | unsigned int mnp; | ^ 1 error generated. Since the commit 7b987887f97b ("video: fbdev: matroxfb: remove dead code and set but not used variable") the 'mnp' became unused, but eliminating that code might have side-effects. The question here is what should we do with 'mnp'? The easiest way out is just mark it with __maybe_unused which will shut the compiler up and won't change any possible IO flow. So does this change. A dive into the history of the driver: The problem was revealed when the #if 0 guarded code along with unused pixel_vco variable was removed. That code was introduced in the original commit 213d22146d1f ("[PATCH] (1/3) matroxfb for 2.5.3"). And then guarded in the commit 705e41f82988 ("matroxfb DVI updates: Handle DVI output on G450/G550. Powerdown unused portions of G450/G550 DAC. Split G450/G550 DAC from older DAC1064 handling. Modify PLL setting when both CRTCs use same pixel clocks."). NOTE: The two commits mentioned above pre-date Git era and available in history.git repository for archaeological purposes. Even without that guard the modern compilers may see that the pixel_vco wasn't ever used and seems a leftover after some debug or review made 25 years ago. The g450_mnp2vco() doesn't have any IO and as Jason said doesn't seem to have any side effects either than some unneeded CPU processing during runtime. I agree that's unlikely that timeout (or heating up the CPU) has any effect on the HW (GPU/display) functionality. Fixes: 7b987887f97b ("video: fbdev: matroxfb: remove dead code and set but not used variable") Signed-off-by: Andy Shevchenko Reviewed-by: Jason Yan Signed-off-by: Helge Deller Signed-off-by: Sasha Levin

fbcon: Avoid OOB font access if console rotation fails

2026-05-17T15:13:52+00:00

[ Upstream commit e4ef723d8975a2694cc90733a6b888a5e2841842 ] Clear the font buffer if the reallocation during console rotation fails in fbcon_rotate_font(). The putcs implementations for the rotated buffer will return early in this case. See [1] for an example. Currently, fbcon_rotate_font() keeps the old buffer, which is too small for the rotated font. Printing to the rotated console with a high-enough character code will overflow the font buffer. v2: - fix typos in commit message Signed-off-by: Thomas Zimmermann Fixes: 6cc50e1c5b57 ("[PATCH] fbcon: Console Rotation - Add support to rotate font bitmap") Cc: stable@vger.kernel.org # v2.6.15+ Link: https://elixir.bootlin.com/linux/v6.19/source/drivers/video/fbdev/core/fbcon_ccw.c#L144 # [1] Signed-off-by: Helge Deller [ renamed `par` to `ops` to match the 6.12 local pointer name ] Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman

fbdev: defio: Disconnect deferred I/O from the lifetime of struct fb_info

2026-05-17T15:13:49+00:00

[ Upstream commit 9ded47ad003f09a94b6a710b5c47f4aa5ceb7429 ] Hold state of deferred I/O in struct fb_deferred_io_state. Allocate an instance as part of initializing deferred I/O and remove it only after the final mapping has been closed. If the fb_info and the contained deferred I/O meanwhile goes away, clear struct fb_deferred_io_state.info to invalidate the mapping. Any access will then result in a SIGBUS signal. Fixes a long-standing problem, where a device hot-unplug happens while user space still has an active mapping of the graphics memory. The hot- unplug frees the instance of struct fb_info. Accessing the memory will operate on undefined state. Signed-off-by: Thomas Zimmermann Fixes: 60b59beafba8 ("fbdev: mm: Deferred IO support") Cc: Helge Deller Cc: linux-fbdev@vger.kernel.org Cc: dri-devel@lists.freedesktop.org Cc: stable@vger.kernel.org # v2.6.22+ Signed-off-by: Helge Deller [ replaced `kzalloc_obj` with `kzalloc`, and dropped `mutex_destroy(&fbdefio->lock)` ] Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman

fbdev: udlfb: add vm_ops to dlfb_ops_mmap to prevent use-after-free

2026-05-17T15:13:34+00:00

commit 8de779dc40d35d39fa07387b6f921eb11df0f511 upstream. dlfb_ops_mmap() uses remap_pfn_range() to map vmalloc framebuffer pages to userspace but sets no vm_ops on the VMA. This means the kernel cannot track active mmaps. When dlfb_realloc_framebuffer() replaces the backing buffer via FBIOPUT_VSCREENINFO, existing mmap PTEs are not invalidated. On USB disconnect, dlfb_ops_destroy() calls vfree() on the old pages while userspace PTEs still reference them, resulting in a use-after-free: the process retains read/write access to freed kernel pages. Add vm_operations_struct with open/close callbacks that maintain an atomic mmap_count on struct dlfb_data. In dlfb_realloc_framebuffer(), check mmap_count and return -EBUSY if the buffer is currently mapped, preventing buffer replacement while userspace holds stale PTEs. Tested with PoC using dummy_hcd + raw_gadget USB device emulation. Signed-off-by: Rajat Gupta Acked-by: Greg Kroah-Hartman Cc: stable@vger.kernel.org Signed-off-by: Helge Deller Signed-off-by: Greg Kroah-Hartman

fbdev: udlfb: avoid divide-by-zero on FBIOPUT_VSCREENINFO

2026-04-27T13:23:31+00:00

commit a31e4518bec70333a0a98f2946a12b53b45fe5b9 upstream. Much like commit 19f953e74356 ("fbdev: fb_pm2fb: Avoid potential divide by zero error"), we also need to prevent that same crash from happening in the udlfb driver as it uses pixclock directly when dividing, which will crash. Cc: Bernie Thompson Cc: Helge Deller Fixes: 59277b679f8b ("Staging: udlfb: add dynamic modeset support") Assisted-by: gregkh_clanker_t1000 Signed-off-by: Greg Kroah-Hartman Signed-off-by: Helge Deller Signed-off-by: Greg Kroah-Hartman

fbdev: tdfxfb: avoid divide-by-zero on FBIOPUT_VSCREENINFO

2026-04-27T13:23:30+00:00

commit 8f98b81fe011e1879e6a7b1247e69e06a5e17af2 upstream. Much like commit 19f953e74356 ("fbdev: fb_pm2fb: Avoid potential divide by zero error"), we also need to prevent that same crash from happening in the udlfb driver as it uses pixclock directly when dividing, which will crash. Cc: Helge Deller Assisted-by: gregkh_clanker_t1000 Cc: stable Signed-off-by: Greg Kroah-Hartman Signed-off-by: Helge Deller Signed-off-by: Greg Kroah-Hartman