From 18cd0a9c7aaf880502e4aff3ea30022f97d6c103 Mon Sep 17 00:00:00 2001 From: PIYUSH CHOUDHARY Date: Mon, 20 Oct 2025 00:05:08 +0530 Subject: video: fb: Fix typo in comment in fb.h Fix typo: "verical" -> "vertical" in macro description Signed-off-by: PIYUSH CHOUDHARY Signed-off-by: Helge Deller Cc: stable@vger.kernel.org --- include/uapi/linux/fb.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/include/uapi/linux/fb.h b/include/uapi/linux/fb.h index cde8f173f566..22acaaec7b1c 100644 --- a/include/uapi/linux/fb.h +++ b/include/uapi/linux/fb.h @@ -319,7 +319,7 @@ enum { #define FB_VBLANK_HAVE_VCOUNT 0x020 /* the vcount field is valid */ #define FB_VBLANK_HAVE_HCOUNT 0x040 /* the hcount field is valid */ #define FB_VBLANK_VSYNCING 0x080 /* currently in a vsync */ -#define FB_VBLANK_HAVE_VSYNC 0x100 /* verical syncs can be detected */ +#define FB_VBLANK_HAVE_VSYNC 0x100 /* vertical syncs can be detected */ struct fb_vblank { __u32 flags; /* FB_VBLANK flags */ -- cgit v1.2.3 From eb53368f8d6e2dfba84c8a94d245719bcf9ae270 Mon Sep 17 00:00:00 2001 From: Miaoqian Lin Date: Mon, 27 Oct 2025 16:43:37 +0800 Subject: fbdev: valkyriefb: Fix reference count leak in valkyriefb_init 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 --- drivers/video/fbdev/valkyriefb.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/drivers/video/fbdev/valkyriefb.c b/drivers/video/fbdev/valkyriefb.c index 91d070ef6989..6ff059ee1694 100644 --- a/drivers/video/fbdev/valkyriefb.c +++ b/drivers/video/fbdev/valkyriefb.c @@ -329,11 +329,13 @@ static int __init valkyriefb_init(void) if (of_address_to_resource(dp, 0, &r)) { printk(KERN_ERR "can't find address for valkyrie\n"); + of_node_put(dp); return 0; } frame_buffer_phys = r.start; cmap_regs_phys = r.start + 0x304000; + of_node_put(dp); } #endif /* ppc (!CONFIG_MAC) */ -- cgit v1.2.3 From 5f566c0ac51cd2474e47da68dbe719d3acf7d999 Mon Sep 17 00:00:00 2001 From: Florian Fuchs Date: Sun, 26 Oct 2025 00:38:50 +0200 Subject: fbdev: pvr2fb: Fix leftover reference to ONCHIP_NR_DMA_CHANNELS 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 --- drivers/video/fbdev/pvr2fb.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/video/fbdev/pvr2fb.c b/drivers/video/fbdev/pvr2fb.c index cbdb1caf61bd..0b8d23c12b77 100644 --- a/drivers/video/fbdev/pvr2fb.c +++ b/drivers/video/fbdev/pvr2fb.c @@ -192,7 +192,7 @@ static unsigned long pvr2fb_map; #ifdef CONFIG_PVR2_DMA static unsigned int shdma = PVR2_CASCADE_CHAN; -static unsigned int pvr2dma = ONCHIP_NR_DMA_CHANNELS; +static unsigned int pvr2dma = CONFIG_NR_ONCHIP_DMA_CHANNELS; #endif static struct fb_videomode pvr2_modedb[] = { -- cgit v1.2.3 From 18c4ef4e765a798b47980555ed665d78b71aeadf Mon Sep 17 00:00:00 2001 From: Junjie Cao Date: Mon, 20 Oct 2025 21:47:01 +0800 Subject: fbdev: bitblit: bound-check glyph index in bit_putcs* 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 --- drivers/video/fbdev/core/bitblit.c | 16 ++++++++++++---- 1 file changed, 12 insertions(+), 4 deletions(-) diff --git a/drivers/video/fbdev/core/bitblit.c b/drivers/video/fbdev/core/bitblit.c index a9ec7f488522..dc5ad3fcc7be 100644 --- a/drivers/video/fbdev/core/bitblit.c +++ b/drivers/video/fbdev/core/bitblit.c @@ -79,12 +79,16 @@ static inline void bit_putcs_aligned(struct vc_data *vc, struct fb_info *info, struct fb_image *image, u8 *buf, u8 *dst) { u16 charmask = vc->vc_hi_font_mask ? 0x1ff : 0xff; + unsigned int charcnt = vc->vc_font.charcount; u32 idx = vc->vc_font.width >> 3; u8 *src; while (cnt--) { - src = vc->vc_font.data + (scr_readw(s++)& - charmask)*cellsize; + u16 ch = scr_readw(s++) & charmask; + + if (ch >= charcnt) + ch = 0; + src = vc->vc_font.data + (unsigned int)ch * cellsize; if (attr) { update_attr(buf, src, attr, vc); @@ -112,14 +116,18 @@ static inline void bit_putcs_unaligned(struct vc_data *vc, u8 *dst) { u16 charmask = vc->vc_hi_font_mask ? 0x1ff : 0xff; + unsigned int charcnt = vc->vc_font.charcount; u32 shift_low = 0, mod = vc->vc_font.width % 8; u32 shift_high = 8; u32 idx = vc->vc_font.width >> 3; u8 *src; while (cnt--) { - src = vc->vc_font.data + (scr_readw(s++)& - charmask)*cellsize; + u16 ch = scr_readw(s++) & charmask; + + if (ch >= charcnt) + ch = 0; + src = vc->vc_font.data + (unsigned int)ch * cellsize; if (attr) { update_attr(buf, src, attr, vc); -- cgit v1.2.3 From a1f3058930745d2b938b6b4f5bd9630dc74b26b7 Mon Sep 17 00:00:00 2001 From: Quanmin Yan Date: Fri, 10 Oct 2025 16:16:59 +0800 Subject: fbcon: Set fb_display[i]->mode to NULL when the mode is released 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 --- drivers/video/fbdev/core/fbcon.c | 19 +++++++++++++++++++ drivers/video/fbdev/core/fbmem.c | 1 + include/linux/fbcon.h | 2 ++ 3 files changed, 22 insertions(+) diff --git a/drivers/video/fbdev/core/fbcon.c b/drivers/video/fbdev/core/fbcon.c index 96cc9b389246..9bd3c3814b5c 100644 --- a/drivers/video/fbdev/core/fbcon.c +++ b/drivers/video/fbdev/core/fbcon.c @@ -2810,6 +2810,25 @@ int fbcon_mode_deleted(struct fb_info *info, return found; } +static void fbcon_delete_mode(struct fb_videomode *m) +{ + struct fbcon_display *p; + + for (int i = first_fb_vc; i <= last_fb_vc; i++) { + p = &fb_display[i]; + if (p->mode == m) + p->mode = NULL; + } +} + +void fbcon_delete_modelist(struct list_head *head) +{ + struct fb_modelist *modelist; + + list_for_each_entry(modelist, head, list) + fbcon_delete_mode(&modelist->mode); +} + #ifdef CONFIG_VT_HW_CONSOLE_BINDING static void fbcon_unbind(void) { diff --git a/drivers/video/fbdev/core/fbmem.c b/drivers/video/fbdev/core/fbmem.c index 53f1719b1ae1..eff757ebbed1 100644 --- a/drivers/video/fbdev/core/fbmem.c +++ b/drivers/video/fbdev/core/fbmem.c @@ -544,6 +544,7 @@ static void do_unregister_framebuffer(struct fb_info *fb_info) fb_info->pixmap.addr = NULL; } + fbcon_delete_modelist(&fb_info->modelist); fb_destroy_modelist(&fb_info->modelist); registered_fb[fb_info->node] = NULL; num_registered_fb--; diff --git a/include/linux/fbcon.h b/include/linux/fbcon.h index 81f0e698acbf..f206370060e1 100644 --- a/include/linux/fbcon.h +++ b/include/linux/fbcon.h @@ -18,6 +18,7 @@ void fbcon_suspended(struct fb_info *info); void fbcon_resumed(struct fb_info *info); int fbcon_mode_deleted(struct fb_info *info, struct fb_videomode *mode); +void fbcon_delete_modelist(struct list_head *head); void fbcon_new_modelist(struct fb_info *info); void fbcon_get_requirement(struct fb_info *info, struct fb_blit_caps *caps); @@ -38,6 +39,7 @@ static inline void fbcon_suspended(struct fb_info *info) {} static inline void fbcon_resumed(struct fb_info *info) {} static inline int fbcon_mode_deleted(struct fb_info *info, struct fb_videomode *mode) { return 0; } +static inline void fbcon_delete_modelist(struct list_head *head) {} static inline void fbcon_new_modelist(struct fb_info *info) {} static inline void fbcon_get_requirement(struct fb_info *info, struct fb_blit_caps *caps) {} -- cgit v1.2.3 From 7073c7fc8d8ba47194e5fc58fcafc0efe7586e9b Mon Sep 17 00:00:00 2001 From: Daniel Palmer Date: Fri, 24 Oct 2025 18:37:15 +0900 Subject: fbdev: atyfb: Check if pll_ops->init_pll failed 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 --- drivers/video/fbdev/aty/atyfb_base.c | 8 ++++++-- 1 file changed, 6 insertions(+), 2 deletions(-) diff --git a/drivers/video/fbdev/aty/atyfb_base.c b/drivers/video/fbdev/aty/atyfb_base.c index 210fd3ac18a4..56ef1d88e003 100644 --- a/drivers/video/fbdev/aty/atyfb_base.c +++ b/drivers/video/fbdev/aty/atyfb_base.c @@ -2614,8 +2614,12 @@ static int aty_init(struct fb_info *info) pr_cont("\n"); } #endif - if (par->pll_ops->init_pll) - par->pll_ops->init_pll(info, &par->pll); + if (par->pll_ops->init_pll) { + ret = par->pll_ops->init_pll(info, &par->pll); + if (ret) + return ret; + } + if (par->pll_ops->resume_pll) par->pll_ops->resume_pll(info, &par->pll); -- cgit v1.2.3