kernel/linux.git/drivers/video/fbdev/core/fbcon.c, branch v6.1.87

fbcon: always restore the old font data in fbcon_do_set_font()

2024-03-06T14:45:09+00:00

[ Upstream commit 00d6a284fcf3fad1b7e1b5bc3cd87cbfb60ce03f ] Commit a5a923038d70 (fbdev: fbcon: Properly revert changes when vc_resize() failed) started restoring old font data upon failure (of vc_resize()). But it performs so only for user fonts. It means that the "system"/internal fonts are not restored at all. So in result, the very first call to fbcon_do_set_font() performs no restore at all upon failing vc_resize(). This can be reproduced by Syzkaller to crash the system on the next invocation of font_get(). It's rather hard to hit the allocation failure in vc_resize() on the first font_set(), but not impossible. Esp. if fault injection is used to aid the execution/failure. It was demonstrated by Sirius: BUG: unable to handle page fault for address: fffffffffffffff8 #PF: supervisor read access in kernel mode #PF: error_code(0x0000) - not-present page PGD cb7b067 P4D cb7b067 PUD cb7d067 PMD 0 Oops: 0000 [#1] PREEMPT SMP KASAN CPU: 1 PID: 8007 Comm: poc Not tainted 6.7.0-g9d1694dc91ce #20 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.15.0-1 04/01/2014 RIP: 0010:fbcon_get_font+0x229/0x800 drivers/video/fbdev/core/fbcon.c:2286 Call Trace: con_font_get drivers/tty/vt/vt.c:4558 [inline] con_font_op+0x1fc/0xf20 drivers/tty/vt/vt.c:4673 vt_k_ioctl drivers/tty/vt/vt_ioctl.c:474 [inline] vt_ioctl+0x632/0x2ec0 drivers/tty/vt/vt_ioctl.c:752 tty_ioctl+0x6f8/0x1570 drivers/tty/tty_io.c:2803 vfs_ioctl fs/ioctl.c:51 [inline] ... So restore the font data in any case, not only for user fonts. Note the later 'if' is now protected by 'old_userfont' and not 'old_data' as the latter is always set now. (And it is supposed to be non-NULL. Otherwise we would see the bug above again.) Signed-off-by: Jiri Slaby (SUSE) Fixes: a5a923038d70 ("fbdev: fbcon: Properly revert changes when vc_resize() failed") Reported-and-tested-by: Ubisectech Sirius Cc: Ubisectech Sirius Cc: Daniel Vetter Cc: Helge Deller Cc: linux-fbdev@vger.kernel.org Cc: dri-devel@lists.freedesktop.org Signed-off-by: Daniel Vetter Link: https://patchwork.freedesktop.org/patch/msgid/20240208114411.14604-1-jirislaby@kernel.org Signed-off-by: Sasha Levin

fbcon: set_con2fb_map needs to set con2fb_map!

2023-04-20T10:35:07+00:00

commit fffb0b52d5258554c645c966c6cbef7de50b851d upstream. I got really badly confused in d443d9386472 ("fbcon: move more common code into fb_open()") because we set the con2fb_map before the failure points, which didn't look good. But in trying to fix that I moved the assignment into the wrong path - we need to do it for _all_ vc we take over, not just the first one (which additionally requires the call to con2fb_acquire_newinfo). I've figured this out because of a KASAN bug report, where the fbcon_registered_fb and fbcon_display arrays went out of sync in fbcon_mode_deleted() because the con2fb_map pointed at the old fb_info, but the modes and everything was updated for the new one. Signed-off-by: Daniel Vetter Reviewed-by: Javier Martinez Canillas Acked-by: Helge Deller Tested-by: Xingyuan Mo Fixes: d443d9386472 ("fbcon: move more common code into fb_open()") Reported-by: Xingyuan Mo Cc: Thomas Zimmermann Cc: Sam Ravnborg Cc: Xingyuan Mo Cc: Thomas Zimmermann Cc: Helge Deller Cc: # v5.19+ Signed-off-by: Greg Kroah-Hartman

fbcon: Fix error paths in set_con2fb_map

2023-04-20T10:35:07+00:00

commit edf79dd2172233452ff142dcc98b19d955fc8974 upstream. This is a regressoin introduced in b07db3958485 ("fbcon: Ditch error handling for con2fb_release_oldinfo"). I failed to realize what the if (!err) checks. The mentioned commit was dropping the con2fb_release_oldinfo() return value but the if (!err) was also checking whether the con2fb_acquire_newinfo() function call above failed or not. Fix this with an early return statement. Note that there's still a difference compared to the orginal state of the code, the below lines are now also skipped on error: if (!search_fb_in_map(info_idx)) info_idx = newidx; These are only needed when we've actually thrown out an old fb_info from the console mappings, which only happens later on. Also move the fbcon_add_cursor_work() call into the same if block, it's all protected by console_lock so doesn't matter when we set up the blinking cursor delayed work anyway. This further simplifies the control flow and allows us to ditch the found local variable. v2: Clarify commit message (Javier) Signed-off-by: Daniel Vetter Reviewed-by: Javier Martinez Canillas Acked-by: Helge Deller Tested-by: Xingyuan Mo Fixes: b07db3958485 ("fbcon: Ditch error handling for con2fb_release_oldinfo") Cc: Thomas Zimmermann Cc: Sam Ravnborg Cc: Xingyuan Mo Cc: Thomas Zimmermann Cc: Helge Deller Cc: # v5.19+ Signed-off-by: Greg Kroah-Hartman

Revert "fbcon: don't lose the console font across generic->chip driver switch"

2023-03-10T08:33:56+00:00

[ Upstream commit 12d5796d55f9fd9e4b621003127c99e176665064 ] This reverts commit ae1287865f5361fa138d4d3b1b6277908b54eac9. Always free the console font when deinitializing the framebuffer console. Subsequent framebuffer consoles will then use the default font. Rely on userspace to load any user-configured font for these consoles. Commit ae1287865f53 ("fbcon: don't lose the console font across generic->chip driver switch") was introduced to work around losing the font during graphics-device handover. [1][2] It kept a dangling pointer with the font data between loading the two consoles, which is fairly adventurous hack. It also never covered cases when the other consoles, such as VGA text mode, where involved. The problem has meanwhile been solved in userspace. Systemd comes with a udev rule that re-installs the configured font when a console comes up. [3] So the kernel workaround can be removed. This also removes one of the two special cases triggered by setting FBINFO_MISC_FIRMWARE in an fbdev driver. Tested during device handover from efifb and simpledrm to radeon. Udev reloads the configured console font for the new driver's terminal. Signed-off-by: Thomas Zimmermann Link: https://bugzilla.redhat.com/show_bug.cgi?id=892340 # 1 Link: https://bugzilla.redhat.com/show_bug.cgi?id=1074624 # 2 Link: https://cgit.freedesktop.org/systemd/systemd/tree/src/vconsole/90-vconsole.rules.in?h=v222 # 3 Reviewed-by: Javier Martinez Canillas Link: https://patchwork.freedesktop.org/patch/msgid/20221219160516.23436-3-tzimmermann@suse.de Signed-off-by: Sasha Levin

fbcon: Check font dimension limits

2023-02-09T10:28:15+00:00

commit 2b09d5d364986f724f17001ccfe4126b9b43a0be upstream. blit_x and blit_y are u32, so fbcon currently cannot support fonts larger than 32x32. The 32x32 case also needs shifting an unsigned int, to properly set bit 31, otherwise we get "UBSAN: shift-out-of-bounds in fbcon_set_font", as reported on: http://lore.kernel.org/all/IA1PR07MB98308653E259A6F2CE94A4AFABCE9@IA1PR07MB9830.namprd07.prod.outlook.com Kernel Branch: 6.2.0-rc5-next-20230124 Kernel config: https://drive.google.com/file/d/1F-LszDAizEEH0ZX0HcSR06v5q8FPl2Uv/view?usp=sharing Reproducer: https://drive.google.com/file/d/1mP1jcLBY7vWCNM60OMf-ogw-urQRjNrm/view?usp=sharing Reported-by: Sanan Hasanov Signed-off-by: Samuel Thibault Fixes: 2d2699d98492 ("fbcon: font setting should check limitation of driver") Cc: stable@vger.kernel.org Tested-by: Miko Larsson Reviewed-by: Greg Kroah-Hartman Signed-off-by: Helge Deller Signed-off-by: Greg Kroah-Hartman

fbdev: fbcon: release buffer when fbcon_do_set_font() failed

2022-12-31T12:33:11+00:00

commit 3c3bfb8586f848317ceba5d777e11204ba3e5758 upstream. syzbot is reporting memory leak at fbcon_do_set_font() [1], for commit a5a923038d70 ("fbdev: fbcon: Properly revert changes when vc_resize() failed") missed that the buffer might be newly allocated by fbcon_set_font(). Link: https://syzkaller.appspot.com/bug?extid=25bdb7b1703639abd498 [1] Reported-by: syzbot Signed-off-by: Tetsuo Handa Tested-by: syzbot Fixes: a5a923038d70 ("fbdev: fbcon: Properly revert changes when vc_resize() failed") CC: stable@vger.kernel.org # 5.15+ Signed-off-by: Helge Deller Signed-off-by: Greg Kroah-Hartman

fbcon: Use kzalloc() in fbcon_prepare_logo()

2022-11-22T14:48:02+00:00

A kernel built with syzbot's config file reported that scr_memcpyw(q, save, array3_size(logo_lines, new_cols, 2)) causes uninitialized "save" to be copied. ---------- [drm] Initialized vgem 1.0.0 20120112 for vgem on minor 0 [drm] Initialized vkms 1.0.0 20180514 for vkms on minor 1 Console: switching to colour frame buffer device 128x48 ===================================================== BUG: KMSAN: uninit-value in do_update_region+0x4b8/0xba0 do_update_region+0x4b8/0xba0 update_region+0x40d/0x840 fbcon_switch+0x3364/0x35e0 redraw_screen+0xae3/0x18a0 do_bind_con_driver+0x1cb3/0x1df0 do_take_over_console+0x11cb/0x13f0 fbcon_fb_registered+0xacc/0xfd0 register_framebuffer+0x1179/0x1320 __drm_fb_helper_initial_config_and_unlock+0x23ad/0x2b40 drm_fbdev_client_hotplug+0xbea/0xda0 drm_fbdev_generic_setup+0x65e/0x9d0 vkms_init+0x9f3/0xc76 (...snipped...) Uninit was stored to memory at: fbcon_prepare_logo+0x143b/0x1940 fbcon_init+0x2c1b/0x31c0 visual_init+0x3e7/0x820 do_bind_con_driver+0x14a4/0x1df0 do_take_over_console+0x11cb/0x13f0 fbcon_fb_registered+0xacc/0xfd0 register_framebuffer+0x1179/0x1320 __drm_fb_helper_initial_config_and_unlock+0x23ad/0x2b40 drm_fbdev_client_hotplug+0xbea/0xda0 drm_fbdev_generic_setup+0x65e/0x9d0 vkms_init+0x9f3/0xc76 (...snipped...) Uninit was created at: __kmem_cache_alloc_node+0xb69/0x1020 __kmalloc+0x379/0x680 fbcon_prepare_logo+0x704/0x1940 fbcon_init+0x2c1b/0x31c0 visual_init+0x3e7/0x820 do_bind_con_driver+0x14a4/0x1df0 do_take_over_console+0x11cb/0x13f0 fbcon_fb_registered+0xacc/0xfd0 register_framebuffer+0x1179/0x1320 __drm_fb_helper_initial_config_and_unlock+0x23ad/0x2b40 drm_fbdev_client_hotplug+0xbea/0xda0 drm_fbdev_generic_setup+0x65e/0x9d0 vkms_init+0x9f3/0xc76 (...snipped...) CPU: 2 PID: 1 Comm: swapper/0 Not tainted 6.1.0-rc4-00356-g8f2975c2bb4c #924 Hardware name: innotek GmbH VirtualBox/VirtualBox, BIOS VirtualBox 12/01/2006 ---------- Signed-off-by: Tetsuo Handa Signed-off-by: Daniel Vetter Link: https://patchwork.freedesktop.org/patch/msgid/cad03d25-0ea0-32c4-8173-fd1895314bce@I-love.SAKURA.ne.jp

fbdev: fbcon: Properly revert changes when vc_resize() failed

2022-08-26T17:56:18+00:00

fbcon_do_set_font() calls vc_resize() when font size is changed. However, if if vc_resize() failed, current implementation doesn't revert changes for font size, and this causes inconsistent state. syzbot reported unable to handle page fault due to this issue [1]. syzbot's repro uses fault injection which cause failure for memory allocation, so vc_resize() failed. This patch fixes this issue by properly revert changes for font related date when vc_resize() failed. Link: https://syzkaller.appspot.com/bug?id=3443d3a1fa6d964dd7310a0cb1696d165a3e07c4 [1] Reported-by: syzbot+a168dbeaaa7778273c1b@syzkaller.appspotmail.com Signed-off-by: Shigeru Yoshida Signed-off-by: Helge Deller CC: stable@vger.kernel.org # 5.15+

fbdev: Move fbdev drivers from strlcpy to strscpy

2022-08-24T20:06:15+00:00

Follow the advice of the below link and prefer 'strscpy' in this subsystem. Conversion is 1:1 because the return value is not used. Generated by a coccinelle script. Link: https://lore.kernel.org/r/CAHk-=wgfRnXz0W3D37d01q3JFkr_i_uTL=V6A6G1oUZcprmknw@mail.gmail.com/ Signed-off-by: Wolfram Sang Signed-off-by: Helge Deller

Merge tag 'tty-6.0-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty

2022-08-08T18:31:40+00:00

Pull tty / serial driver updates from Greg KH: "Here is the big set of tty and serial driver changes for 6.0-rc1. It was delayed from last week as I wanted to make sure the last commit here got some good testing in linux-next and elsewhere as it seemed to show up only late in testing for some reason. Nothing major here, just lots of cleanups from Jiri and Ilpo to make the tty core cleaner (Jiri) and the rs485 code simpler to use (Ilpo). Also included in here is the obligatory n_gsm updates from Daniel Starke and lots of tiny driver updates and minor fixes and tweaks for other smaller serial drivers. All of these have been in linux-next for a while with no reported problems" * tag 'tty-6.0-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty: (186 commits) tty: serial: qcom-geni-serial: Fix %lu -> %u in print statements tty: amiserial: Fix comment typo tty: serial: document uart_get_console() tty: serial: serial_core, reformat kernel-doc for functions Documentation: serial: link uart_ops properly Documentation: serial: move GPIO kernel-doc to the functions Documentation: serial: dedup kernel-doc for uart functions Documentation: serial: move uart_ops documentation to the struct dt-bindings: serial: snps-dw-apb-uart: Document Rockchip RV1126 serial: mvebu-uart: uart2 error bits clearing tty: serial: fsl_lpuart: correct the count of break characters serial: stm32: make info structs static to avoid sparse warnings serial: fsl_lpuart: zero out parity bit in CS7 mode tty: serial: qcom-geni-serial: Fix get_clk_div_rate() which otherwise could return a sub-optimal clock rate. serial: 8250_bcm2835aux: Add missing clk_disable_unprepare() tty: vt: initialize unicode screen buffer serial: remove VR41XX serial driver serial: 8250: lpc18xx: Remove redundant sanity check for RS485 flags serial: 8250_dwlib: remove redundant sanity check for RS485 flags dt_bindings: rs485: Correct delay values ...