linux-stable.git/drivers/video/fbdev/core, branch v5.4.192 Linux kernel stable tree video: fbdev: fbcvt.c: fix printing in fb_cvt_print_name() 2022-04-15T12:18:07+00:00 Dan Carpenter dan.carpenter@oracle.com 2021-09-16T13:29:19+00:00 547d36fa4100764a2b03c59301c4fab7cedfda4c [ Upstream commit 78482af095abd9f4f29f1aa3fe575d25c6ae3028 ] This code has two bugs: 1) "cnt" is 255 but the size of the buffer is 256 so the last byte is not used. 2) If we try to print more than 255 characters then "cnt" will be negative and that will trigger a WARN() in snprintf(). The fix for this is to use scnprintf() instead of snprintf(). We can re-write this code to be cleaner: 1) Rename "offset" to "off" because that's shorter. 2) Get rid of the "cnt" variable and just use "size - off" directly. 3) Get rid of the "read" variable and just increment "off" directly. Fixes: 96fe6a2109db ("fbdev: Add VESA Coordinated Video Timings (CVT) support") Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> Signed-off-by: Helge Deller <deller@gmx.de> Signed-off-by: Sasha Levin <sashal@kernel.org> 
[ Upstream commit 78482af095abd9f4f29f1aa3fe575d25c6ae3028 ]

This code has two bugs:
1) "cnt" is 255 but the size of the buffer is 256 so the last byte is
   not used.
2) If we try to print more than 255 characters then "cnt" will be
   negative and that will trigger a WARN() in snprintf(). The fix for
   this is to use scnprintf() instead of snprintf().

We can re-write this code to be cleaner:
1) Rename "offset" to "off" because that's shorter.
2) Get rid of the "cnt" variable and just use "size - off" directly.
3) Get rid of the "read" variable and just increment "off" directly.

Fixes: 96fe6a2109db ("fbdev: Add VESA Coordinated Video Timings (CVT) support")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Helge Deller <deller@gmx.de>
Signed-off-by: Sasha Levin <sashal@kernel.org>
fbmem: don't allow too huge resolutions 2021-09-15T07:47:41+00:00 Tetsuo Handa penguin-kernel@i-love.sakura.ne.jp 2021-09-08T10:27:49+00:00 5de2ee621bc48fc527f0ed51265eea4bed8b769a commit 8c28051cdcbe9dfcec6bd0a4709d67a09df6edae upstream. syzbot is reporting page fault at vga16fb_fillrect() [1], for vga16fb_check_var() is failing to detect multiplication overflow. if (vxres * vyres > maxmem) { vyres = maxmem / vxres; if (vyres < yres) return -ENOMEM; } Since no module would accept too huge resolutions where multiplication overflow happens, let's reject in the common path. Link: https://syzkaller.appspot.com/bug?extid=04168c8063cfdde1db5e [1] Reported-by: syzbot <syzbot+04168c8063cfdde1db5e@syzkaller.appspotmail.com> Debugged-by: Randy Dunlap <rdunlap@infradead.org> Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be> Cc: stable@vger.kernel.org Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch> Link: https://patchwork.freedesktop.org/patch/msgid/185175d6-227a-7b55-433d-b070929b262c@i-love.sakura.ne.jp Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit 8c28051cdcbe9dfcec6bd0a4709d67a09df6edae upstream.

syzbot is reporting page fault at vga16fb_fillrect() [1], for
vga16fb_check_var() is failing to detect multiplication overflow.

  if (vxres * vyres > maxmem) {
    vyres = maxmem / vxres;
    if (vyres < yres)
      return -ENOMEM;
  }

Since no module would accept too huge resolutions where multiplication
overflow happens, let's reject in the common path.

Link: https://syzkaller.appspot.com/bug?extid=04168c8063cfdde1db5e [1]
Reported-by: syzbot <syzbot+04168c8063cfdde1db5e@syzkaller.appspotmail.com>
Debugged-by: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
Cc: stable@vger.kernel.org
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: https://patchwork.freedesktop.org/patch/msgid/185175d6-227a-7b55-433d-b070929b262c@i-love.sakura.ne.jp
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
fbmem: Do not delete the mode that is still in use 2021-07-20T14:10:40+00:00 Zhen Lei thunder.leizhen@huawei.com 2021-07-12T08:55:44+00:00 359311b85ebec7c07c3a08ae2f3def946cad33fa commit 0af778269a522c988ef0b4188556aba97fb420cc upstream. The execution of fb_delete_videomode() is not based on the result of the previous fbcon_mode_deleted(). As a result, the mode is directly deleted, regardless of whether it is still in use, which may cause UAF. ================================================================== BUG: KASAN: use-after-free in fb_mode_is_equal+0x36e/0x5e0 \ drivers/video/fbdev/core/modedb.c:924 Read of size 4 at addr ffff88807e0ddb1c by task syz-executor.0/18962 CPU: 2 PID: 18962 Comm: syz-executor.0 Not tainted 5.10.45-rc1+ #3 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS ... Call Trace: __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0x137/0x1be lib/dump_stack.c:118 print_address_description+0x6c/0x640 mm/kasan/report.c:385 __kasan_report mm/kasan/report.c:545 [inline] kasan_report+0x13d/0x1e0 mm/kasan/report.c:562 fb_mode_is_equal+0x36e/0x5e0 drivers/video/fbdev/core/modedb.c:924 fbcon_mode_deleted+0x16a/0x220 drivers/video/fbdev/core/fbcon.c:2746 fb_set_var+0x1e1/0xdb0 drivers/video/fbdev/core/fbmem.c:975 do_fb_ioctl+0x4d9/0x6e0 drivers/video/fbdev/core/fbmem.c:1108 vfs_ioctl fs/ioctl.c:48 [inline] __do_sys_ioctl fs/ioctl.c:753 [inline] __se_sys_ioctl+0xfb/0x170 fs/ioctl.c:739 do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46 entry_SYSCALL_64_after_hwframe+0x44/0xa9 Freed by task 18960: kasan_save_stack mm/kasan/common.c:48 [inline] kasan_set_track+0x3d/0x70 mm/kasan/common.c:56 kasan_set_free_info+0x17/0x30 mm/kasan/generic.c:355 __kasan_slab_free+0x108/0x140 mm/kasan/common.c:422 slab_free_hook mm/slub.c:1541 [inline] slab_free_freelist_hook+0xd6/0x1a0 mm/slub.c:1574 slab_free mm/slub.c:3139 [inline] kfree+0xca/0x3d0 mm/slub.c:4121 fb_delete_videomode+0x56a/0x820 drivers/video/fbdev/core/modedb.c:1104 fb_set_var+0x1f3/0xdb0 drivers/video/fbdev/core/fbmem.c:978 do_fb_ioctl+0x4d9/0x6e0 drivers/video/fbdev/core/fbmem.c:1108 vfs_ioctl fs/ioctl.c:48 [inline] __do_sys_ioctl fs/ioctl.c:753 [inline] __se_sys_ioctl+0xfb/0x170 fs/ioctl.c:739 do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46 entry_SYSCALL_64_after_hwframe+0x44/0xa9 Fixes: 13ff178ccd6d ("fbcon: Call fbcon_mode_deleted/new_modelist directly") Signed-off-by: Zhen Lei <thunder.leizhen@huawei.com> Cc: <stable@vger.kernel.org> # v5.3+ Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch> Link: https://patchwork.freedesktop.org/patch/msgid/20210712085544.2828-1-thunder.leizhen@huawei.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit 0af778269a522c988ef0b4188556aba97fb420cc upstream.

The execution of fb_delete_videomode() is not based on the result of the
previous fbcon_mode_deleted(). As a result, the mode is directly deleted,
regardless of whether it is still in use, which may cause UAF.

==================================================================
BUG: KASAN: use-after-free in fb_mode_is_equal+0x36e/0x5e0 \
drivers/video/fbdev/core/modedb.c:924
Read of size 4 at addr ffff88807e0ddb1c by task syz-executor.0/18962

CPU: 2 PID: 18962 Comm: syz-executor.0 Not tainted 5.10.45-rc1+ #3
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS ...
Call Trace:
 __dump_stack lib/dump_stack.c:77 [inline]
 dump_stack+0x137/0x1be lib/dump_stack.c:118
 print_address_description+0x6c/0x640 mm/kasan/report.c:385
 __kasan_report mm/kasan/report.c:545 [inline]
 kasan_report+0x13d/0x1e0 mm/kasan/report.c:562
 fb_mode_is_equal+0x36e/0x5e0 drivers/video/fbdev/core/modedb.c:924
 fbcon_mode_deleted+0x16a/0x220 drivers/video/fbdev/core/fbcon.c:2746
 fb_set_var+0x1e1/0xdb0 drivers/video/fbdev/core/fbmem.c:975
 do_fb_ioctl+0x4d9/0x6e0 drivers/video/fbdev/core/fbmem.c:1108
 vfs_ioctl fs/ioctl.c:48 [inline]
 __do_sys_ioctl fs/ioctl.c:753 [inline]
 __se_sys_ioctl+0xfb/0x170 fs/ioctl.c:739
 do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

Freed by task 18960:
 kasan_save_stack mm/kasan/common.c:48 [inline]
 kasan_set_track+0x3d/0x70 mm/kasan/common.c:56
 kasan_set_free_info+0x17/0x30 mm/kasan/generic.c:355
 __kasan_slab_free+0x108/0x140 mm/kasan/common.c:422
 slab_free_hook mm/slub.c:1541 [inline]
 slab_free_freelist_hook+0xd6/0x1a0 mm/slub.c:1574
 slab_free mm/slub.c:3139 [inline]
 kfree+0xca/0x3d0 mm/slub.c:4121
 fb_delete_videomode+0x56a/0x820 drivers/video/fbdev/core/modedb.c:1104
 fb_set_var+0x1f3/0xdb0 drivers/video/fbdev/core/fbmem.c:978
 do_fb_ioctl+0x4d9/0x6e0 drivers/video/fbdev/core/fbmem.c:1108
 vfs_ioctl fs/ioctl.c:48 [inline]
 __do_sys_ioctl fs/ioctl.c:753 [inline]
 __se_sys_ioctl+0xfb/0x170 fs/ioctl.c:739
 do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

Fixes: 13ff178ccd6d ("fbcon: Call fbcon_mode_deleted/new_modelist directly")
Signed-off-by: Zhen Lei <thunder.leizhen@huawei.com>
Cc: <stable@vger.kernel.org> # v5.3+
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: https://patchwork.freedesktop.org/patch/msgid/20210712085544.2828-1-thunder.leizhen@huawei.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
tty: vt: always invoke vc->vc_sw->con_resize callback 2021-05-26T10:05:20+00:00 Tetsuo Handa penguin-kernel@I-love.SAKURA.ne.jp 2021-05-15T03:00:37+00:00 2dea1e9ae5cf12202cf276aa1c36d32823060571 commit ffb324e6f874121f7dce5bdae5e05d02baae7269 upstream. syzbot is reporting OOB write at vga16fb_imageblit() [1], for resize_screen() from ioctl(VT_RESIZE) returns 0 without checking whether requested rows/columns fit the amount of memory reserved for the graphical screen if current mode is KD_GRAPHICS. ---------- #include <sys/types.h> #include <sys/stat.h> #include <fcntl.h> #include <sys/ioctl.h> #include <linux/kd.h> #include <linux/vt.h> int main(int argc, char *argv[]) { const int fd = open("/dev/char/4:1", O_RDWR); struct vt_sizes vt = { 0x4100, 2 }; ioctl(fd, KDSETMODE, KD_GRAPHICS); ioctl(fd, VT_RESIZE, &vt); ioctl(fd, KDSETMODE, KD_TEXT); return 0; } ---------- Allow framebuffer drivers to return -EINVAL, by moving vc->vc_mode != KD_GRAPHICS check from resize_screen() to fbcon_resize(). Link: https://syzkaller.appspot.com/bug?extid=1f29e126cf461c4de3b3 [1] Reported-by: syzbot <syzbot+1f29e126cf461c4de3b3@syzkaller.appspotmail.com> Suggested-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> Tested-by: syzbot <syzbot+1f29e126cf461c4de3b3@syzkaller.appspotmail.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit ffb324e6f874121f7dce5bdae5e05d02baae7269 upstream.

syzbot is reporting OOB write at vga16fb_imageblit() [1], for
resize_screen() from ioctl(VT_RESIZE) returns 0 without checking whether
requested rows/columns fit the amount of memory reserved for the graphical
screen if current mode is KD_GRAPHICS.

----------
  #include <sys/types.h>
  #include <sys/stat.h>
  #include <fcntl.h>
  #include <sys/ioctl.h>
  #include <linux/kd.h>
  #include <linux/vt.h>

  int main(int argc, char *argv[])
  {
        const int fd = open("/dev/char/4:1", O_RDWR);
        struct vt_sizes vt = { 0x4100, 2 };

        ioctl(fd, KDSETMODE, KD_GRAPHICS);
        ioctl(fd, VT_RESIZE, &vt);
        ioctl(fd, KDSETMODE, KD_TEXT);
        return 0;
  }
----------

Allow framebuffer drivers to return -EINVAL, by moving vc->vc_mode !=
KD_GRAPHICS check from resize_screen() to fbcon_resize().

Link: https://syzkaller.appspot.com/bug?extid=1f29e126cf461c4de3b3 [1]
Reported-by: syzbot <syzbot+1f29e126cf461c4de3b3@syzkaller.appspotmail.com>
Suggested-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Tested-by: syzbot <syzbot+1f29e126cf461c4de3b3@syzkaller.appspotmail.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
fbdev: zero-fill colormap in fbcmap.c 2021-05-11T12:04:04+00:00 Phillip Potter phil@philpotter.co.uk 2021-03-31T22:07:19+00:00 4928d3b02083c88a8089562469e4e250b4fe864c commit 19ab233989d0f7ab1de19a036e247afa4a0a1e9c upstream. Use kzalloc() rather than kmalloc() for the dynamically allocated parts of the colormap in fb_alloc_cmap_gfp, to prevent a leak of random kernel data to userspace under certain circumstances. Fixes a KMSAN-found infoleak bug reported by syzbot at: https://syzkaller.appspot.com/bug?id=741578659feabd108ad9e06696f0c1f2e69c4b6e Reported-by: syzbot+47fa9c9c648b765305b9@syzkaller.appspotmail.com Cc: stable <stable@vger.kernel.org> Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be> Signed-off-by: Phillip Potter <phil@philpotter.co.uk> Link: https://lore.kernel.org/r/20210331220719.1499743-1-phil@philpotter.co.uk Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit 19ab233989d0f7ab1de19a036e247afa4a0a1e9c upstream.

Use kzalloc() rather than kmalloc() for the dynamically allocated parts
of the colormap in fb_alloc_cmap_gfp, to prevent a leak of random kernel
data to userspace under certain circumstances.

Fixes a KMSAN-found infoleak bug reported by syzbot at:
https://syzkaller.appspot.com/bug?id=741578659feabd108ad9e06696f0c1f2e69c4b6e

Reported-by: syzbot+47fa9c9c648b765305b9@syzkaller.appspotmail.com
Cc: stable <stable@vger.kernel.org>
Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Phillip Potter <phil@philpotter.co.uk>
Link: https://lore.kernel.org/r/20210331220719.1499743-1-phil@philpotter.co.uk
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
drivers: video: fbcon: fix NULL dereference in fbcon_cursor() 2021-04-07T12:47:44+00:00 Du Cheng ducheng2@gmail.com 2021-03-12T08:14:21+00:00 cde4e338c2b2dda998dd480ecf9df55a1624820d commit 01faae5193d6190b7b3aa93dae43f514e866d652 upstream. add null-check on function pointer before dereference on ops->cursor Reported-by: syzbot+b67aaae8d3a927f68d20@syzkaller.appspotmail.com Cc: stable <stable@vger.kernel.org> Signed-off-by: Du Cheng <ducheng2@gmail.com> Link: https://lore.kernel.org/r/20210312081421.452405-1-ducheng2@gmail.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit 01faae5193d6190b7b3aa93dae43f514e866d652 upstream.

add null-check on function pointer before dereference on ops->cursor

Reported-by: syzbot+b67aaae8d3a927f68d20@syzkaller.appspotmail.com
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Du Cheng <ducheng2@gmail.com>
Link: https://lore.kernel.org/r/20210312081421.452405-1-ducheng2@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
fbmem: add margin check to fb_check_caps() 2020-10-29T08:58:08+00:00 George Kennedy george.kennedy@oracle.com 2020-07-07T19:26:03+00:00 e80b7ebcfda70d5c10b050fddcd45c5e38af7176 [ Upstream commit a49145acfb975d921464b84fe00279f99827d816 ] A fb_ioctl() FBIOPUT_VSCREENINFO call with invalid xres setting or yres setting in struct fb_var_screeninfo will result in a KASAN: vmalloc-out-of-bounds failure in bitfill_aligned() as the margins are being cleared. The margins are cleared in chunks and if the xres setting or yres setting is a value of zero upto the chunk size, the failure will occur. Add a margin check to validate xres and yres settings. Signed-off-by: George Kennedy <george.kennedy@oracle.com> Reported-by: syzbot+e5fd3e65515b48c02a30@syzkaller.appspotmail.com Reviewed-by: Dan Carpenter <dan.carpenter@oracle.com> Cc: Dhaval Giani <dhaval.giani@oracle.com> Signed-off-by: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com> Link: https://patchwork.freedesktop.org/patch/msgid/1594149963-13801-1-git-send-email-george.kennedy@oracle.com Signed-off-by: Sasha Levin <sashal@kernel.org> 
[ Upstream commit a49145acfb975d921464b84fe00279f99827d816 ]

A fb_ioctl() FBIOPUT_VSCREENINFO call with invalid xres setting
or yres setting in struct fb_var_screeninfo will result in a
KASAN: vmalloc-out-of-bounds failure in bitfill_aligned() as
the margins are being cleared. The margins are cleared in
chunks and if the xres setting or yres setting is a value of
zero upto the chunk size, the failure will occur.

Add a margin check to validate xres and yres settings.

Signed-off-by: George Kennedy <george.kennedy@oracle.com>
Reported-by: syzbot+e5fd3e65515b48c02a30@syzkaller.appspotmail.com
Reviewed-by: Dan Carpenter <dan.carpenter@oracle.com>
Cc: Dhaval Giani <dhaval.giani@oracle.com>
Signed-off-by: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>
Link: https://patchwork.freedesktop.org/patch/msgid/1594149963-13801-1-git-send-email-george.kennedy@oracle.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
fbcon: Fix global-out-of-bounds read in fbcon_get_font() 2020-10-14T08:32:56+00:00 Peilin Ye yepeilin.cs@gmail.com 2020-09-24T13:43:48+00:00 1b2fcd82c0ca23f6fa01298c0d7b59eb4efbaf48 commit 5af08640795b2b9a940c9266c0260455377ae262 upstream. fbcon_get_font() is reading out-of-bounds. A malicious user may resize `vc->vc_font.height` to a large value, causing fbcon_get_font() to read out of `fontdata`. fbcon_get_font() handles both built-in and user-provided fonts. Fortunately, recently we have added FONT_EXTRA_WORDS support for built-in fonts, so fix it by adding range checks using FNTSIZE(). This patch depends on patch "fbdev, newport_con: Move FONT_EXTRA_WORDS macros into linux/font.h", and patch "Fonts: Support FONT_EXTRA_WORDS macros for built-in fonts". Cc: stable@vger.kernel.org Reported-and-tested-by: syzbot+29d4ed7f3bdedf2aa2fd@syzkaller.appspotmail.com Link: https://syzkaller.appspot.com/bug?id=08b8be45afea11888776f897895aef9ad1c3ecfd Signed-off-by: Peilin Ye <yepeilin.cs@gmail.com> Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch> Link: https://patchwork.freedesktop.org/patch/msgid/b34544687a1a09d6de630659eb7a773f4953238b.1600953813.git.yepeilin.cs@gmail.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit 5af08640795b2b9a940c9266c0260455377ae262 upstream.

fbcon_get_font() is reading out-of-bounds. A malicious user may resize
`vc->vc_font.height` to a large value, causing fbcon_get_font() to
read out of `fontdata`.

fbcon_get_font() handles both built-in and user-provided fonts.
Fortunately, recently we have added FONT_EXTRA_WORDS support for built-in
fonts, so fix it by adding range checks using FNTSIZE().

This patch depends on patch "fbdev, newport_con: Move FONT_EXTRA_WORDS
macros into linux/font.h", and patch "Fonts: Support FONT_EXTRA_WORDS
macros for built-in fonts".

Cc: stable@vger.kernel.org
Reported-and-tested-by: syzbot+29d4ed7f3bdedf2aa2fd@syzkaller.appspotmail.com
Link: https://syzkaller.appspot.com/bug?id=08b8be45afea11888776f897895aef9ad1c3ecfd
Signed-off-by: Peilin Ye <yepeilin.cs@gmail.com>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: https://patchwork.freedesktop.org/patch/msgid/b34544687a1a09d6de630659eb7a773f4953238b.1600953813.git.yepeilin.cs@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
fbdev, newport_con: Move FONT_EXTRA_WORDS macros into linux/font.h 2020-10-14T08:32:56+00:00 Peilin Ye yepeilin.cs@gmail.com 2020-09-24T13:40:53+00:00 eebe3685701bcd4b437f2ddd2142888b1fb39aeb commit bb0890b4cd7f8203e3aa99c6d0f062d6acdaad27 upstream. drivers/video/console/newport_con.c is borrowing FONT_EXTRA_WORDS macros from drivers/video/fbdev/core/fbcon.h. To keep things simple, move all definitions into <linux/font.h>. Since newport_con now uses four extra words, initialize the fourth word in newport_set_font() properly. Cc: stable@vger.kernel.org Signed-off-by: Peilin Ye <yepeilin.cs@gmail.com> Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch> Link: https://patchwork.freedesktop.org/patch/msgid/7fb8bc9b0abc676ada6b7ac0e0bd443499357267.1600953813.git.yepeilin.cs@gmail.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit bb0890b4cd7f8203e3aa99c6d0f062d6acdaad27 upstream.

drivers/video/console/newport_con.c is borrowing FONT_EXTRA_WORDS macros
from drivers/video/fbdev/core/fbcon.h. To keep things simple, move all
definitions into <linux/font.h>.

Since newport_con now uses four extra words, initialize the fourth word in
newport_set_font() properly.

Cc: stable@vger.kernel.org
Signed-off-by: Peilin Ye <yepeilin.cs@gmail.com>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: https://patchwork.freedesktop.org/patch/msgid/7fb8bc9b0abc676ada6b7ac0e0bd443499357267.1600953813.git.yepeilin.cs@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
fbcon: Fix user font detection test at fbcon_resize(). 2020-09-23T10:40:41+00:00 Tetsuo Handa penguin-kernel@I-love.SAKURA.ne.jp 2020-09-10T22:57:06+00:00 73d58890be304f94f6787a83fab4455534edac72 [ Upstream commit ec0972adecb391a8d8650832263a4790f3bfb4df ] syzbot is reporting OOB read at fbcon_resize() [1], for commit 39b3cffb8cf31117 ("fbcon: prevent user font height or width change from causing potential out-of-bounds access") is by error using registered_fb[con2fb_map[vc->vc_num]]->fbcon_par->p->userfont (which was set to non-zero) instead of fb_display[vc->vc_num].userfont (which remains zero for that display). We could remove tricky userfont flag [2], for we can determine it by comparing address of the font data and addresses of built-in font data. But since that commit is failing to fix the original OOB read [3], this patch keeps the change minimal in case we decide to revert altogether. [1] https://syzkaller.appspot.com/bug?id=ebcbbb6576958a496500fee9cf7aa83ea00b5920 [2] https://syzkaller.appspot.com/text?tag=Patch&x=14030853900000 [3] https://syzkaller.appspot.com/bug?id=6fba8c186d97cf1011ab17660e633b1cc4e080c9 Reported-by: syzbot <syzbot+b38b1ef6edf0c74a8d97@syzkaller.appspotmail.com> Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> Fixes: 39b3cffb8cf31117 ("fbcon: prevent user font height or width change from causing potential out-of-bounds access") Cc: George Kennedy <george.kennedy@oracle.com> Link: https://lore.kernel.org/r/f6e3e611-8704-1263-d163-f52c906a4f06@I-love.SAKURA.ne.jp Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Sasha Levin <sashal@kernel.org> 
[ Upstream commit ec0972adecb391a8d8650832263a4790f3bfb4df ]

syzbot is reporting OOB read at fbcon_resize() [1], for
commit 39b3cffb8cf31117 ("fbcon: prevent user font height or width change
 from causing potential out-of-bounds access") is by error using
registered_fb[con2fb_map[vc->vc_num]]->fbcon_par->p->userfont (which was
set to non-zero) instead of fb_display[vc->vc_num].userfont (which remains
zero for that display).

We could remove tricky userfont flag [2], for we can determine it by
comparing address of the font data and addresses of built-in font data.
But since that commit is failing to fix the original OOB read [3], this
patch keeps the change minimal in case we decide to revert altogether.

[1] https://syzkaller.appspot.com/bug?id=ebcbbb6576958a496500fee9cf7aa83ea00b5920
[2] https://syzkaller.appspot.com/text?tag=Patch&x=14030853900000
[3] https://syzkaller.appspot.com/bug?id=6fba8c186d97cf1011ab17660e633b1cc4e080c9

Reported-by: syzbot <syzbot+b38b1ef6edf0c74a8d97@syzkaller.appspotmail.com>
Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Fixes: 39b3cffb8cf31117 ("fbcon: prevent user font height or width change from causing potential out-of-bounds access")
Cc: George Kennedy <george.kennedy@oracle.com>
Link: https://lore.kernel.org/r/f6e3e611-8704-1263-d163-f52c906a4f06@I-love.SAKURA.ne.jp
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>