kernel/linux.git/drivers/tty/vt, branch v5.10.268

vt: stabilize tty reference in kbd_keycode with tty_port_tty_get

2026-08-19T15:12:13+00:00

commit e25d47a526939ad44b75f778b8a7500562b84fc1 upstream. kbd_keycode() reads vc->port.tty without acquiring a tty reference, racing against con_shutdown() which clears port.tty under a different lock. Use tty_port_tty_get()/tty_kref_put() to hold a proper reference for the duration the tty pointer is needed. Assisted-by: AISLE:Snapshot Signed-off-by: Joshua Rogers Cc: stable Link: https://patch.msgid.link/20260731-tty-vt-stuff-v1-1-be99b9da8e30@linuxfoundation.org Signed-off-by: Greg Kroah-Hartman Signed-off-by: Greg Kroah-Hartman

vt: add permission check for KDSKBMETA ioctl

2026-08-19T15:12:13+00:00

commit a7ad0034453ba4c353f9b8f810ee2569de33d283 upstream. KDSKBMETA modifies keyboard meta mode but lacks the !perm check that all other keyboard setter ioctls in vt_k_ioctl() enforce, allowing a process to change meta mode on a non-controlling console without authorization. Assisted-by: AISLE:Snapshot Cc: stable Signed-off-by: Joshua Rogers Link: https://patch.msgid.link/20260731-tty-vt-stuff-v1-2-be99b9da8e30@linuxfoundation.org Signed-off-by: Greg Kroah-Hartman Signed-off-by: Greg Kroah-Hartman

vc_screen: fix null-ptr-deref in vcs_notifier() during concurrent vcs_write

2026-07-04T11:38:38+00:00

commit a287620312dc6dcb9a093417a0e589bf30fcf38a upstream. A KASAN null-ptr-deref was observed in vcs_notifier(): BUG: KASAN: null-ptr-deref in vcs_notifier+0x98/0x130 Read of size 2 at addr qmp_cmd_name: qmp_capabilities, arguments: {} The issue is a race condition in vcs_write(). When the console_lock is temporarily dropped (to copy data from userspace), the vc_data pointer obtained from vcs_vc() may become stale. After re-acquiring the lock, vcs_vc() is called again to re-validate the pointer. If the vc has been deallocated in the meantime, vcs_vc() returns NULL, and the while loop breaks (with written > 0). However, after the loop, vcs_scr_updated(vc) is still called with the now-NULL vc pointer, leading to a null pointer dereference in the notifier chain (vcs_notifier dereferences param->vc). Fix this by adding a NULL check for vc before calling vcs_scr_updated(). Fixes: 8fb9ea65c9d1 ("vc_screen: reload load of struct vc_data pointer in vcs_write() to avoid UAF") Cc: stable@vger.kernel.org Signed-off-by: Yi Yang Reviewed-by: Jiri Slaby Link: https://patch.msgid.link/20260604060734.2914976-1-yiyang13@huawei.com Signed-off-by: Greg Kroah-Hartman

vt: defkeymap: Map keycodes above 127 to K_HOLE

2025-08-28T14:22:49+00:00

commit b43cb4ff85da5cf29c4cd351ef1d7dd8210780f7 upstream. The maximum number of keycodes got bumped to 256 a very long time ago, but the default keymaps were never adjusted to match. This is causing the kernel to interpret keycodes above 127 as U+0000 if the shipped generated keymap is used. Fix this by mapping all keycodes above 127 to K_HOLE so the kernel ignores them. The contents of this patche were generated by rerunning `loadkeys --mktable --unicode` and only including the changes to map keycodes above 127 to K_HOLE. Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Signed-off-by: Myrrh Periwinkle Cc: stable Reviewed-by: Jiri Slaby Link: https://lore.kernel.org/r/20250702-vt-misc-unicode-fixes-v1-2-c27e143cc2eb@qtmlabs.xyz Signed-off-by: Greg Kroah-Hartman

vt: keyboard: Don't process Unicode characters in K_OFF mode

2025-08-28T14:22:49+00:00

commit b1cc2092ea7a52e2c435aee6d2b1bcb773202663 upstream. We don't process Unicode characters if the virtual terminal is in raw mode, so there's no reason why we shouldn't do the same for K_OFF (especially since people would expect K_OFF to actually turn off all VT key processing). Fixes: 9fc3de9c8356 ("vt: Add virtual console keyboard mode OFF") Signed-off-by: Myrrh Periwinkle Cc: stable Reviewed-by: Jiri Slaby Link: https://lore.kernel.org/r/20250702-vt-misc-unicode-fixes-v1-1-c27e143cc2eb@qtmlabs.xyz Signed-off-by: Greg Kroah-Hartman

vt: add missing notification when switching back to text mode

2025-07-17T16:28:00+00:00

[ Upstream commit ff78538e07fa284ce08cbbcb0730daa91ed16722 ] Programs using poll() on /dev/vcsa to be notified when VT changes occur were missing one case: the switch from gfx to text mode. Signed-off-by: Nicolas Pitre Link: https://lore.kernel.org/r/9o5ro928-0pp4-05rq-70p4-ro385n21n723@onlyvoer.pbz Signed-off-by: Greg Kroah-Hartman Signed-off-by: Sasha Levin

vt: remove VT_RESIZE and VT_RESIZEX from vt_compat_ioctl()

2025-06-27T10:04:06+00:00

[ Upstream commit c4c7ead7b86c1e7f11c64915b7e5bb6d2e242691 ] They are listed amon those cmd values that "treat 'arg' as an integer" which is wrong. They should instead fall into the default case. Probably nobody ever relied on that code since 2009 but still. Fixes: e92166517e3c ("tty: handle VT specific compat ioctls in vt driver") Signed-off-by: Nicolas Pitre Reviewed-by: Jiri Slaby Link: https://lore.kernel.org/r/pr214s15-36r8-6732-2pop-159nq85o48r7@syhkavp.arg Signed-off-by: Greg Kroah-Hartman Signed-off-by: Sasha Levin

vt: prevent kernel-infoleak in con_font_get()

2024-11-08T15:22:04+00:00

commit f956052e00de211b5c9ebaa1958366c23f82ee9e upstream. font.data may not initialize all memory spaces depending on the implementation of vc->vc_sw->con_font_get. This may cause info-leak, so to prevent this, it is safest to modify it to initialize the allocated memory space to 0, and it generally does not affect the overall performance of the system. Cc: stable@vger.kernel.org Reported-by: syzbot+955da2d57931604ee691@syzkaller.appspotmail.com Fixes: 05e2600cb0a4 ("VT: Bump font size limitation to 64x128 pixels") Signed-off-by: Jeongjun Park Link: https://lore.kernel.org/r/20241010174619.59662-1-aha310510@gmail.com Signed-off-by: Greg Kroah-Hartman

vt: fix unicode buffer corruption when deleting characters

2024-04-13T10:58:52+00:00

commit 1581dafaf0d34bc9c428a794a22110d7046d186d upstream. This is the same issue that was fixed for the VGA text buffer in commit 39cdb68c64d8 ("vt: fix memory overlapping when deleting chars in the buffer"). The cure is also the same i.e. replace memcpy() with memmove() due to the overlaping buffers. Signed-off-by: Nicolas Pitre Fixes: 81732c3b2fed ("tty vt: Fix line garbage in virtual console on command line edition") Cc: stable Link: https://lore.kernel.org/r/sn184on2-3p0q-0qrq-0218-895349s4753o@syhkavp.arg Signed-off-by: Greg Kroah-Hartman

tty: vt: fix 20 vs 0x20 typo in EScsiignore

2024-03-26T22:22:02+00:00

[ Upstream commit 0e6a92f67c8a94707f7bb27ac29e2bdf3e7c167d ] The if (c >= 20 && c <= 0x3f) test added in commit 7a99565f8732 is wrong. 20 is DC4 in ascii and it makes no sense to consider that as the bottom limit. Instead, it should be 0x20 as in the other test in the commit above. This is supposed to NOT change anything as we handle interesting 20-0x20 asciis far before this if. So for sakeness, change to 0x20 (which is SPACE). Signed-off-by: "Jiri Slaby (SUSE)" Fixes: 7a99565f8732 ("vt: ignore csi sequences with intermediate characters.") Cc: Martin Hostettler Link: https://lore.kernel.org/all/ZaP45QY2WEsDqoxg@neutronstar.dyndns.org/ Tested-by: Helge Deller # parisc STI console Link: https://lore.kernel.org/r/20240122110401.7289-4-jirislaby@kernel.org Signed-off-by: Greg Kroah-Hartman Signed-off-by: Sasha Levin