aboutsummaryrefslogtreecommitdiff
path: root/drivers/video/console/vgacon.c
AgeCommit message (Collapse)AuthorFilesLines
2025-08-02Revert "vgacon: Add check for vc_origin address range in vgacon_scroll()"Helge Deller1-1/+1
This reverts commit 864f9963ec6b4b76d104d595ba28110b87158003. The patch is wrong as it checks vc_origin against vc_screenbuf, while in text mode it should compare against vga_vram_base. As such it broke VGA text scrolling, which can be reproduced like this: (1) boot a kernel that is configured to use text mode VGA-console (2) type commands: ls -l /usr/bin | less -S (3) scroll up/down with cursor-down/up keys Reported-by: Jari Ruusu <jariruusu@protonmail.com> Cc: stable@vger.kernel.org Cc: Yi Yang <yiyang13@huawei.com> Cc: GONG Ruiqi <gongruiqi1@huawei.com> Signed-off-by: Helge Deller <deller@gmx.de>
2025-05-31vgacon: Add check for vc_origin address range in vgacon_scroll()GONG Ruiqi1-1/+1
Our in-house Syzkaller reported the following BUG (twice), which we believed was the same issue with [1]: ================================================================== BUG: KASAN: slab-out-of-bounds in vcs_scr_readw+0xc2/0xd0 drivers/tty/vt/vt.c:4740 Read of size 2 at addr ffff88800f5bef60 by task syz.7.2620/12393 ... Call Trace: <TASK> __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0x72/0xa0 lib/dump_stack.c:106 print_address_description.constprop.0+0x6b/0x3d0 mm/kasan/report.c:364 print_report+0xba/0x280 mm/kasan/report.c:475 kasan_report+0xa9/0xe0 mm/kasan/report.c:588 vcs_scr_readw+0xc2/0xd0 drivers/tty/vt/vt.c:4740 vcs_write_buf_noattr drivers/tty/vt/vc_screen.c:493 [inline] vcs_write+0x586/0x840 drivers/tty/vt/vc_screen.c:690 vfs_write+0x219/0x960 fs/read_write.c:584 ksys_write+0x12e/0x260 fs/read_write.c:639 do_syscall_x64 arch/x86/entry/common.c:51 [inline] do_syscall_64+0x59/0x110 arch/x86/entry/common.c:81 entry_SYSCALL_64_after_hwframe+0x78/0xe2 ... </TASK> Allocated by task 5614: kasan_save_stack+0x20/0x40 mm/kasan/common.c:45 kasan_set_track+0x25/0x30 mm/kasan/common.c:52 ____kasan_kmalloc mm/kasan/common.c:374 [inline] __kasan_kmalloc+0x8f/0xa0 mm/kasan/common.c:383 kasan_kmalloc include/linux/kasan.h:201 [inline] __do_kmalloc_node mm/slab_common.c:1007 [inline] __kmalloc+0x62/0x140 mm/slab_common.c:1020 kmalloc include/linux/slab.h:604 [inline] kzalloc include/linux/slab.h:721 [inline] vc_do_resize+0x235/0xf40 drivers/tty/vt/vt.c:1193 vgacon_adjust_height+0x2d4/0x350 drivers/video/console/vgacon.c:1007 vgacon_font_set+0x1f7/0x240 drivers/video/console/vgacon.c:1031 con_font_set drivers/tty/vt/vt.c:4628 [inline] con_font_op+0x4da/0xa20 drivers/tty/vt/vt.c:4675 vt_k_ioctl+0xa10/0xb30 drivers/tty/vt/vt_ioctl.c:474 vt_ioctl+0x14c/0x1870 drivers/tty/vt/vt_ioctl.c:752 tty_ioctl+0x655/0x1510 drivers/tty/tty_io.c:2779 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:871 [inline] __se_sys_ioctl+0x12d/0x190 fs/ioctl.c:857 do_syscall_x64 arch/x86/entry/common.c:51 [inline] do_syscall_64+0x59/0x110 arch/x86/entry/common.c:81 entry_SYSCALL_64_after_hwframe+0x78/0xe2 Last potentially related work creation: kasan_save_stack+0x20/0x40 mm/kasan/common.c:45 __kasan_record_aux_stack+0x94/0xa0 mm/kasan/generic.c:492 __call_rcu_common.constprop.0+0xc3/0xa10 kernel/rcu/tree.c:2713 netlink_release+0x620/0xc20 net/netlink/af_netlink.c:802 __sock_release+0xb5/0x270 net/socket.c:663 sock_close+0x1e/0x30 net/socket.c:1425 __fput+0x408/0xab0 fs/file_table.c:384 __fput_sync+0x4c/0x60 fs/file_table.c:465 __do_sys_close fs/open.c:1580 [inline] __se_sys_close+0x68/0xd0 fs/open.c:1565 do_syscall_x64 arch/x86/entry/common.c:51 [inline] do_syscall_64+0x59/0x110 arch/x86/entry/common.c:81 entry_SYSCALL_64_after_hwframe+0x78/0xe2 Second to last potentially related work creation: kasan_save_stack+0x20/0x40 mm/kasan/common.c:45 __kasan_record_aux_stack+0x94/0xa0 mm/kasan/generic.c:492 __call_rcu_common.constprop.0+0xc3/0xa10 kernel/rcu/tree.c:2713 netlink_release+0x620/0xc20 net/netlink/af_netlink.c:802 __sock_release+0xb5/0x270 net/socket.c:663 sock_close+0x1e/0x30 net/socket.c:1425 __fput+0x408/0xab0 fs/file_table.c:384 task_work_run+0x154/0x240 kernel/task_work.c:239 exit_task_work include/linux/task_work.h:45 [inline] do_exit+0x8e5/0x1320 kernel/exit.c:874 do_group_exit+0xcd/0x280 kernel/exit.c:1023 get_signal+0x1675/0x1850 kernel/signal.c:2905 arch_do_signal_or_restart+0x80/0x3b0 arch/x86/kernel/signal.c:310 exit_to_user_mode_loop kernel/entry/common.c:111 [inline] exit_to_user_mode_prepare include/linux/entry-common.h:328 [inline] __syscall_exit_to_user_mode_work kernel/entry/common.c:207 [inline] syscall_exit_to_user_mode+0x1b3/0x1e0 kernel/entry/common.c:218 do_syscall_64+0x66/0x110 arch/x86/entry/common.c:87 entry_SYSCALL_64_after_hwframe+0x78/0xe2 The buggy address belongs to the object at ffff88800f5be000 which belongs to the cache kmalloc-2k of size 2048 The buggy address is located 2656 bytes to the right of allocated 1280-byte region [ffff88800f5be000, ffff88800f5be500) ... Memory state around the buggy address: ffff88800f5bee00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff88800f5bee80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc >ffff88800f5bef00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ^ ffff88800f5bef80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff88800f5bf000: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ================================================================== By analyzing the vmcore, we found that vc->vc_origin was somehow placed one line prior to vc->vc_screenbuf when vc was in KD_TEXT mode, and further writings to /dev/vcs caused out-of-bounds reads (and writes right after) in vcs_write_buf_noattr(). Our further experiments show that in most cases, vc->vc_origin equals to vga_vram_base when the console is in KD_TEXT mode, and it's around vc->vc_screenbuf for the KD_GRAPHICS mode. But via triggerring a TIOCL_SETVESABLANK ioctl beforehand, we can make vc->vc_origin be around vc->vc_screenbuf while the console is in KD_TEXT mode, and then by writing the special 'ESC M' control sequence to the tty certain times (depends on the value of `vc->state.y - vc->vc_top`), we can eventually move vc->vc_origin prior to vc->vc_screenbuf. Here's the PoC, tested on QEMU: ``` int main() { const int RI_NUM = 10; // should be greater than `vc->state.y - vc->vc_top` int tty_fd, vcs_fd; const char *tty_path = "/dev/tty0"; const char *vcs_path = "/dev/vcs"; const char escape_seq[] = "\x1bM"; // ESC + M const char trigger_seq[] = "Let's trigger an OOB write."; struct vt_sizes vt_size = { 70, 2 }; int blank = TIOCL_BLANKSCREEN; tty_fd = open(tty_path, O_RDWR); char vesa_mode[] = { TIOCL_SETVESABLANK, 1 }; ioctl(tty_fd, TIOCLINUX, vesa_mode); ioctl(tty_fd, TIOCLINUX, &blank); ioctl(tty_fd, VT_RESIZE, &vt_size); for (int i = 0; i < RI_NUM; ++i) write(tty_fd, escape_seq, sizeof(escape_seq) - 1); vcs_fd = open(vcs_path, O_RDWR); write(vcs_fd, trigger_seq, sizeof(trigger_seq)); close(vcs_fd); close(tty_fd); return 0; } ``` To solve this problem, add an address range validation check in vgacon_scroll(), ensuring vc->vc_origin never precedes vc_screenbuf. Reported-by: syzbot+9c09fda97a1a65ea859b@syzkaller.appspotmail.com Closes: https://syzkaller.appspot.com/bug?extid=9c09fda97a1a65ea859b [1] Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Cc: stable@vger.kernel.org Co-developed-by: Yi Yang <yiyang13@huawei.com> Signed-off-by: Yi Yang <yiyang13@huawei.com> Signed-off-by: GONG Ruiqi <gongruiqi1@huawei.com> Signed-off-by: Helge Deller <deller@gmx.de>
2024-06-22video: console: add missing MODULE_DESCRIPTION() macrosJeff Johnson1-0/+1
With ARCH=i386, make allmodconfig && make W=1 C=1 reports: WARNING: modpost: missing MODULE_DESCRIPTION() in drivers/video/console/mdacon.o Add the missing invocation of the MODULE_DESCRIPTION() macro to all files which have a MODULE_LICENSE(). This includes three other files which, although they did not produce a warning with the i386 allmodconfig configuration, may cause this warning with other configurations. Signed-off-by: Jeff Johnson <quic_jjohnson@quicinc.com> Signed-off-by: Helge Deller <deller@gmx.de>
2024-01-27tty: vt: change consw::con_set_origin() return typeJiri Slaby (SUSE)1-4/+4
The return value of consw::con_set_origin() is only true/false, meaining if vc->vc_origin is set to vc->vc_screenbuf or not. So switch the type and returned values accordingly. And document the hook. Signed-off-by: "Jiri Slaby (SUSE)" <jirislaby@kernel.org> Cc: Helge Deller <deller@gmx.de> Cc: linux-fbdev@vger.kernel.org Cc: dri-devel@lists.freedesktop.org Tested-by: Helge Deller <deller@gmx.de> # parisc STI console Link: https://lore.kernel.org/r/20240122110401.7289-39-jirislaby@kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-01-27tty: vt: make font of consw::con_font_set() constJiri Slaby (SUSE)1-1/+1
Provided the font parameter of consw::con_font_set() is not supposed to be changed, make it const. Signed-off-by: "Jiri Slaby (SUSE)" <jirislaby@kernel.org> Cc: Helge Deller <deller@gmx.de> Cc: "James E.J. Bottomley" <James.Bottomley@HansenPartnership.com> Cc: Daniel Vetter <daniel@ffwll.ch> Cc: linux-fbdev@vger.kernel.org Cc: dri-devel@lists.freedesktop.org Cc: linux-parisc@vger.kernel.org Tested-by: Helge Deller <deller@gmx.de> # parisc STI console Link: https://lore.kernel.org/r/20240122110401.7289-37-jirislaby@kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-01-27tty: vt: make types around consw::con_blank() boolJiri Slaby (SUSE)1-2/+2
Both the mode_switch parameter and the return value (a redraw needed) are true/false. So switch them to bool, so that users won't return -Eerrors or anything else. And document the hook. Signed-off-by: "Jiri Slaby (SUSE)" <jirislaby@kernel.org> Cc: Helge Deller <deller@gmx.de> Cc: "James E.J. Bottomley" <James.Bottomley@HansenPartnership.com> Cc: Daniel Vetter <daniel@ffwll.ch> Cc: linux-fbdev@vger.kernel.org Cc: dri-devel@lists.freedesktop.org Cc: linux-parisc@vger.kernel.org Tested-by: Helge Deller <deller@gmx.de> # parisc STI console Link: https://lore.kernel.org/r/20240122110401.7289-36-jirislaby@kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-01-27tty: vt: use enum constants for VESA blanking modesJiri Slaby (SUSE)1-3/+4
Use the new enum for VESA constants. This improves type checking in consw::con_blank(). Signed-off-by: "Jiri Slaby (SUSE)" <jirislaby@kernel.org> Cc: Helge Deller <deller@gmx.de> Cc: "James E.J. Bottomley" <James.Bottomley@HansenPartnership.com> Cc: Daniel Vetter <daniel@ffwll.ch> Cc: linux-fbdev@vger.kernel.org Cc: dri-devel@lists.freedesktop.org Cc: linux-parisc@vger.kernel.org Tested-by: Helge Deller <deller@gmx.de> # parisc STI console Link: https://lore.kernel.org/r/20240122110401.7289-35-jirislaby@kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-01-27tty: vt: use VESA blanking constantsJiri Slaby (SUSE)1-3/+3
There are VESA blanking constants defined in vesa.h. So use them in the console code instead of constant values. Signed-off-by: "Jiri Slaby (SUSE)" <jirislaby@kernel.org> Cc: Helge Deller <deller@gmx.de> Cc: "James E.J. Bottomley" <James.Bottomley@HansenPartnership.com> Cc: linux-fbdev@vger.kernel.org Cc: dri-devel@lists.freedesktop.org Cc: linux-parisc@vger.kernel.org Tested-by: Helge Deller <deller@gmx.de> # parisc STI console Link: https://lore.kernel.org/r/20240122110401.7289-34-jirislaby@kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-01-27tty: vt: stop using -1 for blank mode in consw::con_blank()Jiri Slaby (SUSE)1-1/+0
-1 is the same as VESA_VSYNC_SUSPEND in all con_blank() implementations. So we can remove this special case from vgacon now too. Despite con_blank() of fbcon looks complicated, the "if (!fbcon_is_inactive(vc, info))" branch is not taken as we set "ops->graphics = 1;" few lines above. So what matters there (as in all other blank implementations except vgacon) is if 'blank' is zero or not. Signed-off-by: "Jiri Slaby (SUSE)" <jirislaby@kernel.org> Cc: Helge Deller <deller@gmx.de> Cc: linux-fbdev@vger.kernel.org Cc: dri-devel@lists.freedesktop.org Tested-by: Helge Deller <deller@gmx.de> # parisc STI console Link: https://lore.kernel.org/r/20240122110401.7289-32-jirislaby@kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-01-27tty: vt: make consw::con_switch() return a boolJiri Slaby (SUSE)1-2/+2
The non-zero (true) return value from consw::con_switch() means a redraw is needed. So make this return type a bool explicitly instead of int. The latter might imply that -Eerrors are expected. They are not. And document the hook. Signed-off-by: "Jiri Slaby (SUSE)" <jirislaby@kernel.org> Cc: Helge Deller <deller@gmx.de> Cc: "James E.J. Bottomley" <James.Bottomley@HansenPartnership.com> Cc: Daniel Vetter <daniel@ffwll.ch> Cc: linux-fbdev@vger.kernel.org Cc: dri-devel@lists.freedesktop.org Cc: linux-parisc@vger.kernel.org Tested-by: Helge Deller <deller@gmx.de> # parisc STI console Link: https://lore.kernel.org/r/20240122110401.7289-31-jirislaby@kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-01-27tty: vt: remove CM_* constantsJiri Slaby (SUSE)1-3/+3
There is no difference between CM_MOVE and CM_DRAW. Either of them enables the cursor. CM_ERASE then disables cursor. So get rid of all of them and use simple "bool enable". Note that this propagates down to the fbcon code. And document the hook. Signed-off-by: "Jiri Slaby (SUSE)" <jirislaby@kernel.org> Cc: Helge Deller <deller@gmx.de> Cc: "James E.J. Bottomley" <James.Bottomley@HansenPartnership.com> Cc: Daniel Vetter <daniel@ffwll.ch> Cc: linux-fbdev@vger.kernel.org Cc: dri-devel@lists.freedesktop.org Cc: linux-parisc@vger.kernel.org Tested-by: Helge Deller <deller@gmx.de> # parisc STI console Link: https://lore.kernel.org/r/20240122110401.7289-30-jirislaby@kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-01-27consoles: use if instead of switch-case in consw::con_cursor()Jiri Slaby (SUSE)1-36/+30
This is only a preparation for the following cleanup patch to make it easier. Provided CM_ERASE is the only different, use 'if' instead of 'switch+case' in all those. Signed-off-by: "Jiri Slaby (SUSE)" <jirislaby@kernel.org> Cc: Helge Deller <deller@gmx.de> Cc: linux-fbdev@vger.kernel.org Cc: dri-devel@lists.freedesktop.org Tested-by: Helge Deller <deller@gmx.de> # parisc STI console Link: https://lore.kernel.org/r/20240122110401.7289-28-jirislaby@kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-01-27tty: vt: sanitize consw::con_putcs() parametersJiri Slaby (SUSE)1-2/+2
Similar to con_putc() in the previous patch: * make the pointer to charattr a pointer to u16, and * make x, y, and count unsigned as they are strictly non-negative. And again, document that hook. Signed-off-by: "Jiri Slaby (SUSE)" <jirislaby@kernel.org> Tested-by: Helge Deller <deller@gmx.de> # parisc STI console Link: https://lore.kernel.org/r/20240122110401.7289-27-jirislaby@kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-01-27tty: vt: eliminate unneeded consw::con_putc() implementationsJiri Slaby (SUSE)1-2/+0
All these consw::con_putc() implementations do the same as consw::con_putcs() (only for one charattr) or even call consw::con_putcs() on their own. Drop them, as thanks to the new con_putc() helper in the previous patch, the console code performs this already -- exactly if consw::con_putc() is missing (NULL). Signed-off-by: "Jiri Slaby (SUSE)" <jirislaby@kernel.org> Cc: Helge Deller <deller@gmx.de> Cc: "James E.J. Bottomley" <James.Bottomley@HansenPartnership.com> Cc: Daniel Vetter <daniel@ffwll.ch> Cc: linux-fbdev@vger.kernel.org Cc: dri-devel@lists.freedesktop.org Cc: linux-parisc@vger.kernel.org Tested-by: Helge Deller <deller@gmx.de> # parisc STI console Link: https://lore.kernel.org/r/20240122110401.7289-25-jirislaby@kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-01-27tty: vt: sanitize arguments of consw::con_clear()Jiri Slaby (SUSE)1-2/+2
In consw::con_clear(): * Height is always 1, so drop it. * Offsets and width are always unsigned values, so re-type them as such. This needs a new __fbcon_clear() in the fbcon code to still handle height which might not be 1 when called internally. Note that tests for negative count/width are left in place -- they are taken care of in the next patches. And document the hook. Signed-off-by: "Jiri Slaby (SUSE)" <jirislaby@kernel.org> Cc: Helge Deller <deller@gmx.de> Cc: "James E.J. Bottomley" <James.Bottomley@HansenPartnership.com> Cc: Daniel Vetter <daniel@ffwll.ch> Cc: linux-fbdev@vger.kernel.org Cc: dri-devel@lists.freedesktop.org Cc: linux-parisc@vger.kernel.org Tested-by: Helge Deller <deller@gmx.de> # parisc STI console Link: https://lore.kernel.org/r/20240122110401.7289-22-jirislaby@kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-01-27tty: vt: make init parameter of consw::con_init() a boolJiri Slaby (SUSE)1-2/+2
The 'init' parameter of consw::con_init() is true for the first call of the hook on a particular console. So make the parameter a bool. And document the hook. Signed-off-by: "Jiri Slaby (SUSE)" <jirislaby@kernel.org> Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be> Cc: Helge Deller <deller@gmx.de> Cc: "James E.J. Bottomley" <James.Bottomley@HansenPartnership.com> Cc: Daniel Vetter <daniel@ffwll.ch> Cc: linux-fbdev@vger.kernel.org Cc: dri-devel@lists.freedesktop.org Cc: linux-parisc@vger.kernel.org Tested-by: Helge Deller <deller@gmx.de> # parisc STI console Link: https://lore.kernel.org/r/20240122110401.7289-21-jirislaby@kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-01-27tty: vt: pass vc_resize_user as a parameterJiri Slaby (SUSE)1-2/+2
It is pretty unfortunate to set vc_data::vc_resize_user in two callers of vc_do_resize(). vc_resize_user is immediately reset there (while remembering it). So instead of this back and forth, pass 'from_user' as a parameter. Notes on 'int user': * The name changes from 'user' to 'from_user' on some places to be consistent. * The type is bool now as 'int user' might evoke user's uid or whatever. Provided vc_resize() is called on many places and they need not to care about this parameter, its prototype is kept unchanged. Instead, it is now an inline calling a new __vc_resize() which implements the above. This patch makes the situation much more obvious. Signed-off-by: "Jiri Slaby (SUSE)" <jirislaby@kernel.org> Cc: Helge Deller <deller@gmx.de> Cc: Daniel Vetter <daniel@ffwll.ch> Cc: linux-fbdev@vger.kernel.org Cc: dri-devel@lists.freedesktop.org Tested-by: Helge Deller <deller@gmx.de> # parisc STI console Link: https://lore.kernel.org/r/20240122110401.7289-8-jirislaby@kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-01-27vgacon: inline vc_scrolldelta_helper() into vgacon_scrolldelta()Jiri Slaby (SUSE)1-2/+34
Since commit 74d58cd48a8f ("USB: sisusbvga: remove console support"), vgacon_scrolldelta() is the only user of vc_scrolldelta_helper(). Inline the helper into vgacon_scrolldelta() and drop it. Signed-off-by: "Jiri Slaby (SUSE)" <jirislaby@kernel.org> Cc: Helge Deller <deller@gmx.de> Cc: linux-fbdev@vger.kernel.org Cc: dri-devel@lists.freedesktop.org Tested-by: Helge Deller <deller@gmx.de> # parisc STI console Link: https://lore.kernel.org/r/20240122110401.7289-2-jirislaby@kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-10-17vgacon: remove screen_info dependencyArnd Bergmann1-28/+40
The vga console driver is fairly self-contained, and only used by architectures that explicitly initialize the screen_info settings. Chance every instance that picks the vga console by setting conswitchp to call a function instead, and pass a reference to the screen_info there. Reviewed-by: Javier Martinez Canillas <javierm@redhat.com> Acked-by: Khalid Azzi <khalid@gonehiking.org> Acked-by: Helge Deller <deller@gmx.de> Signed-off-by: Arnd Bergmann <arnd@arndb.de> Link: https://lore.kernel.org/r/20231009211845.3136536-6-arnd@kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-07-20vgacon: cache vc_cell_height in vgacon_cursor()Jiri Slaby (SUSE)1-19/+15
There are many places c->vc_cell_height is used in the code of vgacon_cursor(). Caching the value to a local variable makes the code much easier to follow. Signed-off-by: "Jiri Slaby (SUSE)" <jirislaby@kernel.org> Cc: Helge Deller <deller@gmx.de> Cc: linux-fbdev@vger.kernel.org Cc: dri-devel@lists.freedesktop.org Signed-off-by: Helge Deller <deller@gmx.de>
2023-07-20vgacon: let vgacon_doresize() return voidJiri Slaby (SUSE)1-2/+1
The return value is neither used, nor vgacon_doresize() returns an error. So change the reurn type to void. Signed-off-by: "Jiri Slaby (SUSE)" <jirislaby@kernel.org> Cc: Helge Deller <deller@gmx.de> Cc: linux-fbdev@vger.kernel.org Cc: dri-devel@lists.freedesktop.org Signed-off-by: Helge Deller <deller@gmx.de>
2023-07-20vgacon: remove unused xpos from vgacon_set_cursor_size()Jiri Slaby (SUSE)1-15/+10
xpos is unused, remove it. Signed-off-by: "Jiri Slaby (SUSE)" <jirislaby@kernel.org> Cc: Helge Deller <deller@gmx.de> Cc: linux-fbdev@vger.kernel.org Cc: dri-devel@lists.freedesktop.org Signed-off-by: Helge Deller <deller@gmx.de>
2023-07-20vgacon: remove unneeded forward declarationsJiri Slaby (SUSE)1-9/+1
Most of the forward declarations in vgacon are not needed. Drop them. Signed-off-by: "Jiri Slaby (SUSE)" <jirislaby@kernel.org> Cc: Helge Deller <deller@gmx.de> Cc: linux-fbdev@vger.kernel.org Cc: dri-devel@lists.freedesktop.org Signed-off-by: Helge Deller <deller@gmx.de>
2023-07-20vgacon: switch vgacon_scrolldelta() and vgacon_restore_screen()Jiri Slaby (SUSE)1-6/+6
Switch vgacon_scrolldelta() and vgacon_restore_screen() positions, so that the former is not needed to be forward-declared. Signed-off-by: "Jiri Slaby (SUSE)" <jirislaby@kernel.org> Cc: Helge Deller <deller@gmx.de> Cc: linux-fbdev@vger.kernel.org Cc: dri-devel@lists.freedesktop.org Signed-off-by: Helge Deller <deller@gmx.de>
2023-01-19VT: Bump font size limitation to 64x128 pixelsSamuel Thibault1-1/+1
This moves 32x32 font size limitation checking down to drivers, so that fbcon can allow large fonts. We still keep a limitation to 64x128 pixels so as to have a simple bounded allocation for con_font_get and in the userland kbd tool. That glyph size will however be enough to have 128x36 characters on a "16/9 8K display". Signed-off-by: Samuel Thibault <samuel.thibault@ens-lyon.org> Link: https://lore.kernel.org/r/20230119151935.112415738@ens-lyon.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-01-19VT: Add height parameter to con_font_get/set consw operationsSamuel Thibault1-4/+4
The current con_font_get/set API currently hardcodes a 32-pixel-tall limitation, which only dates from the old VGA hardware which could not handle taller fonts than that. This change just adds a vpitch parameter to release this constraint. Drivers which do not support vpitch != 32 can just return EINVAL when it is not 32, font loading tools will revert to trying 32 and succeed. This change makes the fbcon driver consider vpitch appropriately, thus making it able to load large fonts. Signed-off-by: Samuel Thibault <samuel.thibault@ens-lyon.org> Link: https://lore.kernel.org/r/20230119151934.932642243@ens-lyon.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-06-27tty/vt: consolemap: rename struct vc_data::vc_uni_pagedir*Jiri Slaby1-4/+4
As a follow-up to the commit 4173f018aae1 (tty/vt: consolemap: rename and document struct uni_pagedir), rename also the members of struct vc_data. I.e. pagedir -> pagedict. And while touching all the places, remove also the unnecessary vc_ prefix. Suggested-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com> Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com> Signed-off-by: Jiri Slaby <jslaby@suse.cz> Link: https://lore.kernel.org/r/20220614090537.15557-5-jslaby@suse.cz Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-06-10tty/vt: consolemap: rename and document struct uni_pagedirJiri Slaby1-2/+2
struct uni_pagedir contains 32 unicode page directories, so the name of the structure is a bit misleading. Rename the structure to uni_pagedict, so it looks like this: struct uni_pagedict -> 32 page dirs -> 32 rows -> 64 glyphs Signed-off-by: Jiri Slaby <jslaby@suse.cz> Link: https://lore.kernel.org/r/20220607104946.18710-2-jslaby@suse.cz Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-12-14Merge v5.16-rc5 into drm-nextDaniel Vetter1-5/+9
Thomas Zimmermann requested a fixes backmerge, specifically also for 96c5f82ef0a1 ("drm/vc4: fix error code in vc4_create_object()") Just a bunch of adjacent changes conflicts, even the big pile of them in vc4. Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
2021-11-27drm: Move nomodeset kernel parameter to the DRM subsystemJavier Martinez Canillas1-21/+0
The "nomodeset" kernel cmdline parameter is handled by the vgacon driver but the exported vgacon_text_force() symbol is only used by DRM drivers. It makes much more sense for the parameter logic to be in the subsystem of the drivers that are making use of it. Let's move the vgacon_text_force() function and related logic to the DRM subsystem. While doing that, rename it to drm_firmware_drivers_only() and make it return true if "nomodeset" was used and false otherwise. This is a better description of the condition that the drivers are testing for. Suggested-by: Daniel Vetter <daniel.vetter@ffwll.ch> Signed-off-by: Javier Martinez Canillas <javierm@redhat.com> Acked-by: Thomas Zimmermann <tzimmermann@suse.de> Acked-by: Jani Nikula <jani.nikula@intel.com> Acked-by: Pekka Paalanen <pekka.paalanen@collabora.com> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Link: https://patchwork.freedesktop.org/patch/msgid/20211112133230.1595307-4-javierm@redhat.com
2021-11-25vgacon: Propagate console boot parameters before calling `vc_resize'Maciej W. Rozycki1-5/+9
Fix a division by zero in `vgacon_resize' with a backtrace like: vgacon_resize vc_do_resize vgacon_init do_bind_con_driver do_unbind_con_driver fbcon_fb_unbind do_unregister_framebuffer do_register_framebuffer register_framebuffer __drm_fb_helper_initial_config_and_unlock drm_helper_hpd_irq_event dw_hdmi_irq irq_thread kthread caused by `c->vc_cell_height' not having been initialized. This has only started to trigger with commit 860dafa90259 ("vt: Fix character height handling with VT_RESIZEX"), however the ultimate offender is commit 50ec42edd978 ("[PATCH] Detaching fbcon: fix vgacon to allow retaking of the console"). Said commit has added a call to `vc_resize' whenever `vgacon_init' is called with the `init' argument set to 0, which did not happen before. And the call is made before a key vgacon boot parameter retrieved in `vgacon_startup' has been propagated in `vgacon_init' for `vc_resize' to use to the console structure being worked on. Previously the parameter was `c->vc_font.height' and now it is `c->vc_cell_height'. In this particular scenario the registration of fbcon has failed and vt resorts to vgacon. Now fbcon does have initialized `c->vc_font.height' somehow, unlike `c->vc_cell_height', which is why this code did not crash before, but either way the boot parameters should have been copied to the console structure ahead of the call to `vc_resize' rather than afterwards, so that first the call has a chance to use them and second they do not change the console structure to something possibly different from what was used by `vc_resize'. Move the propagation of the vgacon boot parameters ahead of the call to `vc_resize' then. Adjust the comment accordingly. Fixes: 50ec42edd978 ("[PATCH] Detaching fbcon: fix vgacon to allow retaking of the console") Cc: stable@vger.kernel.org # v2.6.18+ Reported-by: Wim Osterholt <wim@djo.tudelft.nl> Reported-by: Pavel V. Panteleev <panteleev_p@mcst.ru> Signed-off-by: Maciej W. Rozycki <macro@orcam.me.uk> Link: https://lore.kernel.org/r/alpine.DEB.2.21.2110252317110.58149@angie.orcam.me.uk Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-05-13Merge branch 'resizex' (patches from Maciej)Linus Torvalds1-24/+32
Merge VT_RESIZEX fixes from Maciej Rozycki: "I got to the bottom of the issue with VT_RESIZEX recently discussed and came up with this small patch series, fixing an additional issue that I originally thought might be broken VGA hardware emulation with my laptop, which however turned out to be intertwined with the original problem and also a regression introduced somewhat later. The fix for that because the first patch, and then to make backporting feasible I had to put a revert of the offending change from last September next, followed by a proper fix for the framebuffer issue that change had tried to address. See individual change descriptions for details. These have been verified with true VGA hardware (a Trident TVGA8900 ISA video adapter) using various combinations of `svgatextmode' and `setfont' command invocations to change both the VT size and the font size, and also switching between the text console and X11, both by starting/stopping the X server and by switching between VTs. All this to ensure bringing the behaviour of VGA text console back to correct operation as it used to be with Linux 2.6.18" * emailed patches from Maciej W. Rozycki <macro@orcam.me.uk>: vt: Fix character height handling with VT_RESIZEX vt_ioctl: Revert VT_RESIZEX parameter handling removal vgacon: Record video mode changes with VT_RESIZEX
2021-05-13vt: Fix character height handling with VT_RESIZEXMaciej W. Rozycki1-22/+22
Restore the original intent of the VT_RESIZEX ioctl's `v_clin' parameter which is the number of pixel rows per character (cell) rather than the height of the font used. For framebuffer devices the two values are always the same, because the former is inferred from the latter one. For VGA used as a true text mode device these two parameters are independent from each other: the number of pixel rows per character is set in the CRT controller, while font height is in fact hardwired to 32 pixel rows and fonts of heights below that value are handled by padding their data with blanks when loaded to hardware for use by the character generator. One can change the setting in the CRT controller and it will update the screen contents accordingly regardless of the font loaded. The `v_clin' parameter is used by the `vgacon' driver to set the height of the character cell and then the cursor position within. Make the parameter explicit then, by defining a new `vc_cell_height' struct member of `vc_data', set it instead of `vc_font.height' from `v_clin' in the VT_RESIZEX ioctl, and then use it throughout the `vgacon' driver except where actual font data is accessed which as noted above is independent from the CRTC setting. This way the framebuffer console driver is free to ignore the `v_clin' parameter as irrelevant, as it always should have, avoiding any issues attempts to give the parameter a meaning there could have caused, such as one that has led to commit 988d0763361b ("vt_ioctl: make VT_RESIZEX behave like VT_RESIZE"): "syzbot is reporting UAF/OOB read at bit_putcs()/soft_cursor() [1][2], for vt_resizex() from ioctl(VT_RESIZEX) allows setting font height larger than actual font height calculated by con_font_set() from ioctl(PIO_FONT). Since fbcon_set_font() from con_font_set() allocates minimal amount of memory based on actual font height calculated by con_font_set(), use of vt_resizex() can cause UAF/OOB read for font data." The problem first appeared around Linux 2.5.66 which predates our repo history, but the origin could be identified with the old MIPS/Linux repo also at: <git://git.kernel.org/pub/scm/linux/kernel/git/ralf/linux.git> as commit 9736a3546de7 ("Merge with Linux 2.5.66."), where VT_RESIZEX code in `vt_ioctl' was updated as follows: if (clin) - video_font_height = clin; + vc->vc_font.height = clin; making the parameter apply to framebuffer devices as well, perhaps due to the use of "font" in the name of the original `video_font_height' variable. Use "cell" in the new struct member then to avoid ambiguity. References: [1] https://syzkaller.appspot.com/bug?id=32577e96d88447ded2d3b76d71254fb855245837 [2] https://syzkaller.appspot.com/bug?id=6b8355d27b2b94fb5cedf4655e3a59162d9e48e3 Signed-off-by: Maciej W. Rozycki <macro@orcam.me.uk> Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Cc: stable@vger.kernel.org # v2.6.12+ Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-05-13vgacon: Record video mode changes with VT_RESIZEXMaciej W. Rozycki1-3/+11
Fix an issue with VGA console font size changes made after the initial video text mode has been changed with a user tool like `svgatextmode' calling the VT_RESIZEX ioctl. As it stands in that case the original screen geometry continues being used to validate further VT resizing. Consequently when the video adapter is firstly reprogrammed from the original say 80x25 text mode using a 9x16 character cell (720x400 pixel resolution) to say 80x37 text mode and the same character cell (720x592 pixel resolution), and secondly the CRTC character cell updated to 9x8 (by loading a suitable font with the KD_FONT_OP_SET request of the KDFONTOP ioctl), the VT geometry does not get further updated from 80x37 and only upper half of the screen is used for the VT, with the lower half showing rubbish corresponding to whatever happens to be there in the video memory that maps to that part of the screen. Of course the proportions change according to text mode geometries and font sizes chosen. Address the problem then, by updating the text mode geometry defaults rather than checking against them whenever the VT is resized via a user ioctl. Signed-off-by: Maciej W. Rozycki <macro@orcam.me.uk> Fixes: e400b6ec4ede ("vt/vgacon: Check if screen resize request comes from userspace") Cc: stable@vger.kernel.org # v2.6.24+ Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-03-23vgacon: drop unused vga_init_doneStephen Kitt1-3/+0
Commit 973c096f6a85 ("vgacon: remove software scrollback support") removed all uses of vga_init_done, so let's get rid of it entirely. Signed-off-by: Stephen Kitt <steve@sk2.org> Link: https://lore.kernel.org/r/20210215170837.1599706-1-steve@sk2.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-03-10vgacon: comment on vga_rolled_overJiri Slaby1-1/+1
Long time ago, I figured out what this number is good for and documented that locally. But never submitted, so do it now. Cc: dri-devel@lists.freedesktop.org Cc: linux-fbdev@vger.kernel.org Signed-off-by: Jiri Slaby <jslaby@suse.cz> Link: https://lore.kernel.org/r/20210302062214.29627-4-jslaby@suse.cz Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-01-07vgacon: drop BROKEN_GRAPHICS_PROGRAMSJiri Slaby1-19/+0
BROKEN_GRAPHICS_PROGRAMS is defined when CONFIG_VGA_CONSOLE=y. And vgacon.c is built exclusively in that case too. So the check for BROKEN_GRAPHICS_PROGRAMS is pointless in vgacon.c as it is always true. So remove the test and BROKEN_GRAPHICS_PROGRAMS completely. This also eliminates the need for vga_font_is_default global as it is only set and never read. Cc: dri-devel@lists.freedesktop.org Cc: linux-fbdev@vger.kernel.org Signed-off-by: Jiri Slaby <jslaby@suse.cz> Link: https://lore.kernel.org/r/20210105120239.28031-9-jslaby@suse.cz Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-09-14vgacon: remove software scrollback supportLinus Torvalds1-220/+1
Yunhai Zhang recently fixed a VGA software scrollback bug in commit ebfdfeeae8c0 ("vgacon: Fix for missing check in scrollback handling"), but that then made people look more closely at some of this code, and there were more problems on the vgacon side, but also the fbcon software scrollback. We don't really have anybody who maintains this code - probably because nobody actually _uses_ it any more. Sure, people still use both VGA and the framebuffer consoles, but they are no longer the main user interfaces to the kernel, and haven't been for decades, so these kinds of extra features end up bitrotting and not really being used. So rather than try to maintain a likely unused set of code, I'll just aggressively remove it, and see if anybody even notices. Maybe there are people who haven't jumped on the whole GUI badnwagon yet, and think it's just a fad. And maybe those people use the scrollback code. If that turns out to be the case, we can resurrect this again, once we've found the sucker^Wmaintainer for it who actually uses it. Reported-by: NopNop Nop <nopitydays@gmail.com> Tested-by: Willy Tarreau <w@1wt.eu> Cc: 张云海 <zhangyunhai@nsfocus.com> Acked-by: Andy Lutomirski <luto@amacapital.net> Acked-by: Willy Tarreau <w@1wt.eu> Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-08-04vgacon: Fix for missing check in scrollback handlingYunhai Zhang1-0/+4
vgacon_scrollback_update() always leaves enbough room in the scrollback buffer for the next call, but if the console size changed that room might not actually be enough, and so we need to re-check. The check should be in the loop since vgacon_scrollback_cur->tail is updated in the loop and count may be more than 1 when triggered by CSI M, as Jiri's PoC: #include <stdio.h> #include <stdlib.h> #include <unistd.h> #include <sys/types.h> #include <sys/stat.h> #include <sys/ioctl.h> #include <fcntl.h> int main(int argc, char** argv) { int fd = open("/dev/tty1", O_RDWR); unsigned short size[3] = {25, 200, 0}; ioctl(fd, 0x5609, size); // VT_RESIZE write(fd, "\e[1;1H", 6); for (int i = 0; i < 30; i++) write(fd, "\e[10M", 5); } It leads to various crashes as vgacon_scrollback_update writes out of the buffer: BUG: unable to handle page fault for address: ffffc900001752a0 #PF: supervisor write access in kernel mode #PF: error_code(0x0002) - not-present page RIP: 0010:mutex_unlock+0x13/0x30 ... Call Trace: n_tty_write+0x1a0/0x4d0 tty_write+0x1a0/0x2e0 Or to KASAN reports: BUG: KASAN: slab-out-of-bounds in vgacon_scroll+0x57a/0x8ed This fixes CVE-2020-14331. Reported-by: 张云海 <zhangyunhai@nsfocus.com> Reported-by: Yang Yingliang <yangyingliang@huawei.com> Reported-by: Kyungtae Kim <kt0755@gmail.com> Fixes: 15bdab959c9b ([PATCH] vgacon: Add support for soft scrollback) Cc: stable@vger.kernel.org Cc: linux-fbdev@vger.kernel.org Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Solar Designer <solar@openwall.com> Cc: "Srivatsa S. Bhat" <srivatsa@csail.mit.edu> Cc: Anthony Liguori <aliguori@amazon.com> Cc: Yang Yingliang <yangyingliang@huawei.com> Cc: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com> Cc: Jiri Slaby <jirislaby@kernel.org> Signed-off-by: Yunhai Zhang <zhangyunhai@nsfocus.com> Link: https://lore.kernel.org/r/9fb43895-ca91-9b07-ebfd-808cf854ca95@nsfocus.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-06-24vt: use newly defined CUR_* macrosJiri Slaby1-1/+1
We defined macros for all the magic constants in the previous patch. So let us use the macro in the code now. No functional change intended. Signed-off-by: Jiri Slaby <jslaby@suse.cz> Cc: Thomas Winischhofer <thomas@winischhofer.net> Cc: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com> Cc: "James E.J. Bottomley" <James.Bottomley@HansenPartnership.com> Cc: Helge Deller <deller@gmx.de> Cc: linux-usb@vger.kernel.org Cc: dri-devel@lists.freedesktop.org Cc: linux-fbdev@vger.kernel.org Cc: linux-parisc@vger.kernel.org Acked-by: Helge Deller <deller@gmx.de> Link: https://lore.kernel.org/r/20200615074910.19267-26-jslaby@suse.cz Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-06-24vc: switch state to boolJiri Slaby1-1/+2
The code currently uses bitfields to store true-false values. Switch all of that to bools. Apart from the cleanup, it saves 20B of code as many shifts, ANDs, and ORs became simple movzb's. Signed-off-by: Jiri Slaby <jslaby@suse.cz> Link: https://lore.kernel.org/r/20200615074910.19267-3-jslaby@suse.cz Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-06-24vt: introduce enum vc_intensity for intensityJiri Slaby1-4/+5
Introduce names (en enum) for 0, 1, and 2 constants. We now have VCI_HALF_BRIGHT, VCI_NORMAL, and VCI_BOLD instead. Apart from the cleanup, 1) the enum allows for better type checking, and 2) this saves some code. No more fiddling with bits is needed in assembly now. (OTOH, the structure is larger.) Signed-off-by: Jiri Slaby <jslaby@suse.cz> Link: https://lore.kernel.org/r/20200615074910.19267-2-jslaby@suse.cz Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-06-24vc: separate stateJiri Slaby1-11/+11
There are two copies of some members of struct vc_data. This is because we need to save them and restore later. Move these memebers to a separate structure called vc_state. So now instead of members like: vc_x, vc_y and vc_saved_x, vc_saved_y we have state and saved_state (of type: struct vc_state) containing state.x, state.y and saved_state.x, saved_state.y This change: * makes clear what is saved & restored * eases save & restore by using memcpy (see save_cur and restore_cur) Finally, we document the newly added struct vc_state using kernel-doc. Signed-off-by: Jiri Slaby <jslaby@suse.cz> Link: https://lore.kernel.org/r/20200615074910.19267-1-jslaby@suse.cz Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-03-06vgacon: Fix a UAF in vgacon_invert_regionZhang Xiaoxu1-0/+3
When syzkaller tests, there is a UAF: BUG: KASan: use after free in vgacon_invert_region+0x9d/0x110 at addr ffff880000100000 Read of size 2 by task syz-executor.1/16489 page:ffffea0000004000 count:0 mapcount:-127 mapping: (null) index:0x0 page flags: 0xfffff00000000() page dumped because: kasan: bad access detected CPU: 1 PID: 16489 Comm: syz-executor.1 Not tainted Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.9.3-0-ge2fc41e-prebuilt.qemu-project.org 04/01/2014 Call Trace: [<ffffffffb119f309>] dump_stack+0x1e/0x20 [<ffffffffb04af957>] kasan_report+0x577/0x950 [<ffffffffb04ae652>] __asan_load2+0x62/0x80 [<ffffffffb090f26d>] vgacon_invert_region+0x9d/0x110 [<ffffffffb0a39d95>] invert_screen+0xe5/0x470 [<ffffffffb0a21dcb>] set_selection+0x44b/0x12f0 [<ffffffffb0a3bfae>] tioclinux+0xee/0x490