diff options
| author | Linus Torvalds <torvalds@linux-foundation.org> | 2026-05-06 00:25:44 +0300 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2026-05-06 00:25:44 +0300 |
| commit | 13ad98eaabef611f042d49a9077be060ad03284d (patch) | |
| tree | b4ca15261014b5ba609fd574355913a69f49732a /drivers | |
| parent | 9207d47f966be9f4d52e7e0119ac2b7a7e366f3e (diff) | |
| parent | 8de779dc40d35d39fa07387b6f921eb11df0f511 (diff) | |
| download | linux-13ad98eaabef611f042d49a9077be060ad03284d.tar.xz | |
Merge tag 'fbdev-for-7.1-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/deller/linux-fbdev
Pull fbdev fixes from Helge Deller:
"Four small patches for fbdev, of which two are important: One fixes
the bitmap font generation and the other prevents a possible
use-after-free in udlfb:
- Fix rotating fonts by 180 degrees (Thomas Zimmermann)
- Drop duplicate include of linux/module.h in fb_defio (Chen Ni)
- Add vm_ops in udlfb to prevent use-after-free (Rajat Gupta)
- ipu-v3: clean up kernel-doc warnings (Randy Dunlap)"
* tag 'fbdev-for-7.1-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/deller/linux-fbdev:
fbdev: udlfb: add vm_ops to dlfb_ops_mmap to prevent use-after-free
lib/fonts: Fix bit position when rotating by 180 degrees
fbdev: defio: Remove duplicate include of linux/module.h
fbdev: ipu-v3: clean up kernel-doc warnings
Diffstat (limited to 'drivers')
| -rw-r--r-- | drivers/video/fbdev/core/fb_defio.c | 1 | ||||
| -rw-r--r-- | drivers/video/fbdev/udlfb.c | 31 |
2 files changed, 30 insertions, 2 deletions
diff --git a/drivers/video/fbdev/core/fb_defio.c b/drivers/video/fbdev/core/fb_defio.c index a12dd25ab697..fd00b86e1ae6 100644 --- a/drivers/video/fbdev/core/fb_defio.c +++ b/drivers/video/fbdev/core/fb_defio.c @@ -14,7 +14,6 @@ #include <linux/export.h> #include <linux/string.h> #include <linux/mm.h> -#include <linux/module.h> #include <linux/vmalloc.h> #include <linux/delay.h> #include <linux/interrupt.h> diff --git a/drivers/video/fbdev/udlfb.c b/drivers/video/fbdev/udlfb.c index c341d76bc564..fdbb8671a810 100644 --- a/drivers/video/fbdev/udlfb.c +++ b/drivers/video/fbdev/udlfb.c @@ -321,12 +321,32 @@ static int dlfb_set_video_mode(struct dlfb_data *dlfb, return retval; } +static void dlfb_vm_open(struct vm_area_struct *vma) +{ + struct dlfb_data *dlfb = vma->vm_private_data; + + atomic_inc(&dlfb->mmap_count); +} + +static void dlfb_vm_close(struct vm_area_struct *vma) +{ + struct dlfb_data *dlfb = vma->vm_private_data; + + atomic_dec(&dlfb->mmap_count); +} + +static const struct vm_operations_struct dlfb_vm_ops = { + .open = dlfb_vm_open, + .close = dlfb_vm_close, +}; + static int dlfb_ops_mmap(struct fb_info *info, struct vm_area_struct *vma) { unsigned long start = vma->vm_start; unsigned long size = vma->vm_end - vma->vm_start; unsigned long offset = vma->vm_pgoff << PAGE_SHIFT; unsigned long page, pos; + struct dlfb_data *dlfb = info->par; if (info->fbdefio) return fb_deferred_io_mmap(info, vma); @@ -358,6 +378,9 @@ static int dlfb_ops_mmap(struct fb_info *info, struct vm_area_struct *vma) size = 0; } + vma->vm_ops = &dlfb_vm_ops; + vma->vm_private_data = dlfb; + atomic_inc(&dlfb->mmap_count); return 0; } @@ -1176,7 +1199,6 @@ static void dlfb_deferred_vfree(struct dlfb_data *dlfb, void *mem) /* * Assumes &info->lock held by caller - * Assumes no active clients have framebuffer open */ static int dlfb_realloc_framebuffer(struct dlfb_data *dlfb, struct fb_info *info, u32 new_len) { @@ -1188,6 +1210,13 @@ static int dlfb_realloc_framebuffer(struct dlfb_data *dlfb, struct fb_info *info new_len = PAGE_ALIGN(new_len); if (new_len > old_len) { + if (atomic_read(&dlfb->mmap_count) > 0) { + dev_warn(info->dev, + "refusing realloc: %d active mmaps\n", + atomic_read(&dlfb->mmap_count)); + return -EBUSY; + } + /* * Alloc system memory for virtual framebuffer */ |