kernel/git/stable/linux.git/drivers/video/fbdev, branch linux-6.17.y

fbdev: ssd1307fb: fix potential page leak in ssd1307fb_probe()

2025-12-18T13:00:07+00:00

[ Upstream commit 164312662ae9764b83b84d97afb25c42eb2be473 ] The page allocated for vmem using __get_free_pages() is not freed on the error paths after it. Fix that by adding a corresponding __free_pages() call to the error path. Fixes: facd94bc458a ("fbdev: ssd1307fb: Allocate page aligned video memory.") Signed-off-by: Abdun Nihaal Signed-off-by: Helge Deller Signed-off-by: Sasha Levin

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

2025-12-06T21:27:36+00:00

commit eb76d0f5553575599561010f24c277cc5b31d003 upstream. 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 Signed-off-by: Greg Kroah-Hartman

fbdev: Add bounds checking in bit_putcs to fix vmalloc-out-of-bounds

2025-11-13T20:37:38+00:00

[ Upstream commit 3637d34b35b287ab830e66048841ace404382b67 ] Add bounds checking to prevent writes past framebuffer boundaries when rendering text near screen edges. Return early if the Y position is off-screen and clip image height to screen boundary. Break from the rendering loop if the X position is off-screen. When clipping image width to fit the screen, update the character count to match the clipped width to prevent buffer size mismatches. Without the character count update, bit_putcs_aligned and bit_putcs_unaligned receive mismatched parameters where the buffer is allocated for the clipped width but cnt reflects the original larger count, causing out-of-bounds writes. Reported-by: syzbot+48b0652a95834717f190@syzkaller.appspotmail.com Closes: https://syzkaller.appspot.com/bug?extid=48b0652a95834717f190 Suggested-by: Helge Deller Tested-by: syzbot+48b0652a95834717f190@syzkaller.appspotmail.com Signed-off-by: Albin Babu Varghese Signed-off-by: Helge Deller Signed-off-by: Sasha Levin

fbdev: core: Fix ubsan warning in pixel_to_pat

2025-11-13T20:37:38+00:00

[ Upstream commit aad1d99beaaf132e2024a52727c24894cdf9474a ] It could be triggered on 32 bit big endian machines at 32 bpp in the pattern realignment. In this case just return early as the result is an identity. Signed-off-by: Zsolt Kajtar Signed-off-by: Helge Deller Signed-off-by: Sasha Levin

fbdev: valkyriefb: Fix reference count leak in valkyriefb_init

2025-11-13T20:36:37+00:00

commit eb53368f8d6e2dfba84c8a94d245719bcf9ae270 upstream. The of_find_node_by_name() function returns a device tree node with its reference count incremented. The caller is responsible for calling of_node_put() to release this reference when done. Found via static analysis. Fixes: cc5d0189b9ba ("[PATCH] powerpc: Remove device_node addrs/n_addr") Cc: stable@vger.kernel.org Signed-off-by: Miaoqian Lin Signed-off-by: Helge Deller Signed-off-by: Greg Kroah-Hartman

fbdev: pvr2fb: Fix leftover reference to ONCHIP_NR_DMA_CHANNELS

2025-11-13T20:36:37+00:00

commit 5f566c0ac51cd2474e47da68dbe719d3acf7d999 upstream. Commit e24cca19babe ("sh: Kill off MAX_DMA_ADDRESS leftovers.") removed the define ONCHIP_NR_DMA_CHANNELS. So that the leftover reference needs to be replaced by CONFIG_NR_ONCHIP_DMA_CHANNELS to compile successfully with CONFIG_PVR2_DMA enabled. Signed-off-by: Florian Fuchs Reviewed-by: John Paul Adrian Glaubitz Signed-off-by: Helge Deller Cc: stable@vger.kernel.org Signed-off-by: Greg Kroah-Hartman

fbdev: bitblit: bound-check glyph index in bit_putcs*

2025-11-13T20:36:37+00:00

commit 18c4ef4e765a798b47980555ed665d78b71aeadf upstream. bit_putcs_aligned()/unaligned() derived the glyph pointer from the character value masked by 0xff/0x1ff, which may exceed the actual font's glyph count and read past the end of the built-in font array. Clamp the index to the actual glyph count before computing the address. This fixes a global out-of-bounds read reported by syzbot. Reported-by: syzbot+793cf822d213be1a74f2@syzkaller.appspotmail.com Closes: https://syzkaller.appspot.com/bug?extid=793cf822d213be1a74f2 Tested-by: syzbot+793cf822d213be1a74f2@syzkaller.appspotmail.com Signed-off-by: Junjie Cao Reviewed-by: Thomas Zimmermann Signed-off-by: Helge Deller Cc: stable@vger.kernel.org Signed-off-by: Greg Kroah-Hartman

fbdev: atyfb: Check if pll_ops->init_pll failed

2025-11-13T20:36:36+00:00

commit 7073c7fc8d8ba47194e5fc58fcafc0efe7586e9b upstream. Actually check the return value from pll_ops->init_pll() as it can return an error. If the card's BIOS didn't run because it's not the primary VGA card the fact that the xclk source is unsupported is printed as shown below but the driver continues on regardless and on my machine causes a hard lock up. [ 61.470088] atyfb 0000:03:05.0: enabling device (0080 -> 0083) [ 61.476191] atyfb: using auxiliary register aperture [ 61.481239] atyfb: 3D RAGE XL (Mach64 GR, PCI-33) [0x4752 rev 0x27] [ 61.487569] atyfb: 512K SGRAM (1:1), 14.31818 MHz XTAL, 230 MHz PLL, 83 Mhz MCLK, 63 MHz XCLK [ 61.496112] atyfb: Unsupported xclk source: 5. Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Signed-off-by: Daniel Palmer Signed-off-by: Helge Deller Cc: stable@vger.kernel.org Signed-off-by: Greg Kroah-Hartman

fbcon: Set fb_display[i]->mode to NULL when the mode is released

2025-11-13T20:36:36+00:00

commit a1f3058930745d2b938b6b4f5bd9630dc74b26b7 upstream. Recently, we discovered the following issue through syzkaller: BUG: KASAN: slab-use-after-free in fb_mode_is_equal+0x285/0x2f0 Read of size 4 at addr ff11000001b3c69c by task syz.xxx ... Call Trace: dump_stack_lvl+0xab/0xe0 print_address_description.constprop.0+0x2c/0x390 print_report+0xb9/0x280 kasan_report+0xb8/0xf0 fb_mode_is_equal+0x285/0x2f0 fbcon_mode_deleted+0x129/0x180 fb_set_var+0xe7f/0x11d0 do_fb_ioctl+0x6a0/0x750 fb_ioctl+0xe0/0x140 __x64_sys_ioctl+0x193/0x210 do_syscall_64+0x5f/0x9c0 entry_SYSCALL_64_after_hwframe+0x76/0x7e Based on experimentation and analysis, during framebuffer unregistration, only the memory of fb_info->modelist is freed, without setting the corresponding fb_display[i]->mode to NULL for the freed modes. This leads to UAF issues during subsequent accesses. Here's an example of reproduction steps: 1. With /dev/fb0 already registered in the system, load a kernel module to register a new device /dev/fb1; 2. Set fb1's mode to the global fb_display[] array (via FBIOPUT_CON2FBMAP); 3. Switch console from fb to VGA (to allow normal rmmod of the ko); 4. Unload the kernel module, at this point fb1's modelist is freed, leaving a wild pointer in fb_display[]; 5. Trigger the bug via system calls through fb0 attempting to delete a mode from fb0. Add a check in do_unregister_framebuffer(): if the mode to be freed exists in fb_display[], set the corresponding mode pointer to NULL. Signed-off-by: Quanmin Yan Reviewed-by: Thomas Zimmermann Signed-off-by: Helge Deller Cc: stable@vger.kernel.org Signed-off-by: Greg Kroah-Hartman

fbdev: Fix logic error in "offb" name match

2025-10-19T14:37:25+00:00

commit 15df28699b28d6b49dc305040c4e26a9553df07a upstream. A regression was reported to me recently whereby /dev/fb0 had disappeared from a PowerBook G3 Series "Wallstreet". The problem shows up when the "video=ofonly" parameter is passed to the kernel, which is what the bootloader does when "no video driver" is selected. The cause of the problem is the "offb" string comparison, which got mangled when it got refactored. Fix it. Cc: stable@vger.kernel.org Fixes: 93604a5ade3a ("fbdev: Handle video= parameter in video/cmdline.c") Reported-and-tested-by: Stan Johnson Signed-off-by: Finn Thain Signed-off-by: Helge Deller Signed-off-by: Greg Kroah-Hartman