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2025-08-28vt: defkeymap: Map keycodes above 127 to K_HOLEMyrrh Periwinkle1-0/+112
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 <myrrhperiwinkle@qtmlabs.xyz> Cc: stable <stable@kernel.org> Reviewed-by: Jiri Slaby <jirislaby@kernel.org> Link: https://lore.kernel.org/r/20250702-vt-misc-unicode-fixes-v1-2-c27e143cc2eb@qtmlabs.xyz Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-08-28vt: keyboard: Don't process Unicode characters in K_OFF modeMyrrh Periwinkle1-1/+1
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 <myrrhperiwinkle@qtmlabs.xyz> Cc: stable <stable@kernel.org> Reviewed-by: Jiri Slaby <jirislaby@kernel.org> Link: https://lore.kernel.org/r/20250702-vt-misc-unicode-fixes-v1-1-c27e143cc2eb@qtmlabs.xyz Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-07-17vt: add missing notification when switching back to text modeNicolas Pitre1-0/+1
[ 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 <npitre@baylibre.com> Link: https://lore.kernel.org/r/9o5ro928-0pp4-05rq-70p4-ro385n21n723@onlyvoer.pbz Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2025-06-27vt: remove VT_RESIZE and VT_RESIZEX from vt_compat_ioctl()Nicolas Pitre1-2/+0
[ 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 <npitre@baylibre.com> Reviewed-by: Jiri Slaby <jirislaby@kernel.org> Link: https://lore.kernel.org/r/pr214s15-36r8-6732-2pop-159nq85o48r7@syhkavp.arg Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-11-08vt: prevent kernel-infoleak in con_font_get()Jeongjun Park1-1/+1
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 <aha310510@gmail.com> Link: https://lore.kernel.org/r/20241010174619.59662-1-aha310510@gmail.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-04-13vt: fix unicode buffer corruption when deleting charactersNicolas Pitre1-1/+1
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 <nico@fluxnic.net> Fixes: 81732c3b2fed ("tty vt: Fix line garbage in virtual console on command line edition") Cc: stable <stable@kernel.org> Link: https://lore.kernel.org/r/sn184on2-3p0q-0qrq-0218-895349s4753o@syhkavp.arg Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-03-27tty: vt: fix 20 vs 0x20 typo in EScsiignoreJiri Slaby (SUSE)1-1/+1
[ 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)" <jirislaby@kernel.org> Fixes: 7a99565f8732 ("vt: ignore csi sequences with intermediate characters.") Cc: Martin Hostettler <textshell@uchuujin.de> Link: https://lore.kernel.org/all/ZaP45QY2WEsDqoxg@neutronstar.dyndns.org/ Tested-by: Helge Deller <deller@gmx.de> # parisc STI console Link: https://lore.kernel.org/r/20240122110401.7289-4-jirislaby@kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2023-05-30vc_screen: reload load of struct vc_data pointer in vcs_write() to avoid UAFGeorge Kennedy1-2/+9
commit 8fb9ea65c9d1338b0d2bb0a9122dc942cdd32357 upstream. After a call to console_unlock() in vcs_write() the vc_data struct can be freed by vc_port_destruct(). Because of that, the struct vc_data pointer must be reloaded in the while loop in vcs_write() after console_lock() to avoid a UAF when vcs_size() is called. Syzkaller reported a UAF in vcs_size(). BUG: KASAN: slab-use-after-free in vcs_size (drivers/tty/vt/vc_screen.c:215) Read of size 4 at addr ffff8880beab89a8 by task repro_vcs_size/4119 Call Trace: <TASK> __asan_report_load4_noabort (mm/kasan/report_generic.c:380) vcs_size (drivers/tty/vt/vc_screen.c:215) vcs_write (drivers/tty/vt/vc_screen.c:664) vfs_write (fs/read_write.c:582 fs/read_write.c:564) ... <TASK> Allocated by task 1213: kmalloc_trace (mm/slab_common.c:1064) vc_allocate (./include/linux/slab.h:559 ./include/linux/slab.h:680 drivers/tty/vt/vt.c:1078 drivers/tty/vt/vt.c:1058) con_install (drivers/tty/vt/vt.c:3334) tty_init_dev (drivers/tty/tty_io.c:1303 drivers/tty/tty_io.c:1415 drivers/tty/tty_io.c:1392) tty_open (drivers/tty/tty_io.c:2082 drivers/tty/tty_io.c:2128) chrdev_open (fs/char_dev.c:415) do_dentry_open (fs/open.c:921) vfs_open (fs/open.c:1052) ... Freed by task 4116: kfree (mm/slab_common.c:1016) vc_port_destruct (drivers/tty/vt/vt.c:1044) tty_port_destructor (drivers/tty/tty_port.c:296) tty_port_put (drivers/tty/tty_port.c:312) vt_disallocate_all (drivers/tty/vt/vt_ioctl.c:662 (discriminator 2)) vt_ioctl (drivers/tty/vt/vt_ioctl.c:903) tty_ioctl (drivers/tty/tty_io.c:2778) ... The buggy address belongs to the object at ffff8880beab8800 which belongs to the cache kmalloc-1k of size 1024 The buggy address is located 424 bytes inside of freed 1024-byte region [ffff8880beab8800, ffff8880beab8c00) The buggy address belongs to the physical page: page:00000000afc77580 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0xbeab8 head:00000000afc77580 order:3 entire_mapcount:0 nr_pages_mapped:0 pincount:0 flags: 0xfffffc0010200(slab|head|node=0|zone=1|lastcpupid=0x1fffff) page_type: 0xffffffff() raw: 000fffffc0010200 ffff888100042dc0 ffffea000426de00 dead000000000002 raw: 0000000000000000 0000000000100010 00000001ffffffff 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff8880beab8880: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff8880beab8900: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff8880beab8980: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff8880beab8a00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff8880beab8a80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ================================================================== Disabling lock debugging due to kernel taint Fixes: ac751efa6a0d ("console: rename acquire/release_console_sem() to console_lock/unlock()") Cc: stable <stable@kernel.org> Reported-by: syzkaller <syzkaller@googlegroups.com> Signed-off-by: George Kennedy <george.kennedy@oracle.com> Reviewed-by: Thomas Weißschuh <linux@weissschuh.net> Link: https://lore.kernel.org/r/1683889728-10411-1-git-send-email-george.kennedy@oracle.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-03-11vc_screen: modify vcs_size() handling in vcs_read()George Kennedy1-3/+1
[ Upstream commit 46d733d0efc79bc8430d63b57ab88011806d5180 ] Restore the vcs_size() handling in vcs_read() to what it had been in previous version. Fixes: 226fae124b2d ("vc_screen: move load of struct vc_data pointer in vcs_read() to avoid UAF") Suggested-by: Jiri Slaby <jirislaby@kernel.org> Signed-off-by: George Kennedy <george.kennedy@oracle.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2023-03-03vc_screen: don't clobber return value in vcs_readThomas Weißschuh1-3/+4
commit ae3419fbac845b4d3f3a9fae4cc80c68d82cdf6e upstream. Commit 226fae124b2d ("vc_screen: move load of struct vc_data pointer in vcs_read() to avoid UAF") moved the call to vcs_vc() into the loop. While doing this it also moved the unconditional assignment of ret = -ENXIO; This unconditional assignment was valid outside the loop but within it it clobbers the actual value of ret. To avoid this only assign "ret = -ENXIO" when actually needed. [ Also, the 'goto unlock_out" needs to be just a "break", so that it does the right thing when it exits on later iterations when partial success has happened - Linus ] Reported-by: Storm Dragon <stormdragon2976@gmail.com> Link: https://lore.kernel.org/lkml/Y%2FKS6vdql2pIsCiI@hotmail.com/ Fixes: 226fae124b2d ("vc_screen: move load of struct vc_data pointer in vcs_read() to avoid UAF") Signed-off-by: Thomas Weißschuh <linux@weissschuh.net> Link: https://lore.kernel.org/lkml/64981d94-d00c-4b31-9063-43ad0a384bde@t-8ch.de/ Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-02-15vc_screen: move load of struct vc_data pointer in vcs_read() to avoid UAFGeorge Kennedy1-4/+5
[ Upstream commit 226fae124b2dac217ea5436060d623ff3385bc34 ] After a call to console_unlock() in vcs_read() the vc_data struct can be freed by vc_deallocate(). Because of that, the struct vc_data pointer load must be done at the top of while loop in vcs_read() to avoid a UAF when vcs_size() is called. Syzkaller reported a UAF in vcs_size(). BUG: KASAN: use-after-free in vcs_size (drivers/tty/vt/vc_screen.c:215) Read of size 4 at addr ffff8881137479a8 by task 4a005ed81e27e65/1537 CPU: 0 PID: 1537 Comm: 4a005ed81e27e65 Not tainted 6.2.0-rc5 #1 Hardware name: Red Hat KVM, BIOS 1.15.0-2.module Call Trace: <TASK> __asan_report_load4_noabort (mm/kasan/report_generic.c:350) vcs_size (drivers/tty/vt/vc_screen.c:215) vcs_read (drivers/tty/vt/vc_screen.c:415) vfs_read (fs/read_write.c:468 fs/read_write.c:450) ... </TASK> Allocated by task 1191: ... kmalloc_trace (mm/slab_common.c:1069) vc_allocate (./include/linux/slab.h:580 ./include/linux/slab.h:720 drivers/tty/vt/vt.c:1128 drivers/tty/vt/vt.c:1108) con_install (drivers/tty/vt/vt.c:3383) tty_init_dev (drivers/tty/tty_io.c:1301 drivers/tty/tty_io.c:1413 drivers/tty/tty_io.c:1390) tty_open (drivers/tty/tty_io.c:2080 drivers/tty/tty_io.c:2126) chrdev_open (fs/char_dev.c:415) do_dentry_open (fs/open.c:883) vfs_open (fs/open.c:1014) ... Freed by task 1548: ... kfree (mm/slab_common.c:1021) vc_port_destruct (drivers/tty/vt/vt.c:1094) tty_port_destructor (drivers/tty/tty_port.c:296) tty_port_put (drivers/tty/tty_port.c:312) vt_disallocate_all (drivers/tty/vt/vt_ioctl.c:662 (discriminator 2)) vt_ioctl (drivers/tty/vt/vt_ioctl.c:903) tty_ioctl (drivers/tty/tty_io.c:2776) ... The buggy address belongs to the object at ffff888113747800 which belongs to the cache kmalloc-1k of size 1024 The buggy address is located 424 bytes inside of 1024-byte region [ffff888113747800, ffff888113747c00) The buggy address belongs to the physical page: page:00000000b3fe6c7c refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x113740 head:00000000b3fe6c7c order:3 compound_mapcount:0 subpages_mapcount:0 compound_pincount:0 anon flags: 0x17ffffc0010200(slab|head|node=0|zone=2|lastcpupid=0x1fffff) raw: 0017ffffc0010200 ffff888100042dc0 0000000000000000 dead000000000001 raw: 0000000000000000 0000000000100010 00000001ffffffff 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff888113747880: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff888113747900: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb > ffff888113747980: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff888113747a00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff888113747a80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ================================================================== Disabling lock debugging due to kernel taint Fixes: ac751efa6a0d ("console: rename acquire/release_console_sem() to console_lock/unlock()") Reported-by: syzkaller <syzkaller@googlegroups.com> Suggested-by: Jiri Slaby <jirislaby@kernel.org> Signed-off-by: George Kennedy <george.kennedy@oracle.com> Link: https://lore.kernel.org/r/1674577014-12374-1-git-send-email-george.kennedy@oracle.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-09-08vt: Clear selection before changing the fontHelge Deller1-4/+8
commit 566f9c9f89337792070b5a6062dff448b3e7977f upstream. When changing the console font with ioctl(KDFONTOP) the new font size can be bigger than the previous font. A previous selection may thus now be outside of the new screen size and thus trigger out-of-bounds accesses to graphics memory if the selection is removed in vc_do_resize(). Prevent such out-of-memory accesses by dropping the selection before the various con_font_set() console handlers are called. Reported-by: syzbot+14b0e8f3fd1612e35350@syzkaller.appspotmail.com Cc: stable <stable@kernel.org> Tested-by: Khalid Masum <khalid.masum.92@gmail.com> Signed-off-by: Helge Deller <deller@gmx.de> Link: https://lore.kernel.org/r/YuV9apZGNmGfjcor@p100 Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-08-21tty: vt: initialize unicode screen bufferTetsuo Handa1-1/+1
commit af77c56aa35325daa2bc2bed5c2ebf169be61b86 upstream. syzbot reports kernel infoleak at vcs_read() [1], for buffer can be read immediately after resize operation. Initialize buffer using kzalloc(). ---------- #include <fcntl.h> #include <unistd.h> #include <sys/ioctl.h> #include <linux/fb.h> int main(int argc, char *argv[]) { struct fb_var_screeninfo var = { }; const int fb_fd = open("/dev/fb0", 3); ioctl(fb_fd, FBIOGET_VSCREENINFO, &var); var.yres = 0x21; ioctl(fb_fd, FBIOPUT_VSCREENINFO, &var); return read(open("/dev/vcsu", O_RDONLY), &var, sizeof(var)) == -1; } ---------- Link: https://syzkaller.appspot.com/bug?extid=31a641689d43387f05d3 [1] Cc: stable <stable@vger.kernel.org> Reported-by: syzbot <syzbot+31a641689d43387f05d3@syzkaller.appspotmail.com> Reviewed-by: Jiri Slaby <jirislaby@kernel.org> Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> Link: https://lore.kernel.org/r/4ef053cf-e796-fb5e-58b7-3ae58242a4ad@I-love.SAKURA.ne.jp Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-07-29tty: drivers/tty/, stop using tty_schedule_flip()Jiri Slaby2-4/+4
commit 5f6a85158ccacc3f09744b3aafe8b11ab3b6c6f6 upstream. Since commit a9c3f68f3cd8d (tty: Fix low_latency BUG) in 2014, tty_flip_buffer_push() is only a wrapper to tty_schedule_flip(). We are going to remove the latter (as it is used less), so call the former in drivers/tty/. Cc: Vladimir Zapolskiy <vz@mleia.com> Reviewed-by: Johan Hovold <johan@kernel.org> Signed-off-by: Jiri Slaby <jslaby@suse.cz> Link: https://lore.kernel.org/r/20211122111648.30379-2-jslaby@suse.cz Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-07-21vt: fix memory overlapping when deleting chars in the bufferYangxi Xiang1-1/+1
commit 39cdb68c64d84e71a4a717000b6e5de208ee60cc upstream. A memory overlapping copy occurs when deleting a long line. This memory overlapping copy can cause data corruption when scr_memcpyw is optimized to memcpy because memcpy does not ensure its behavior if the destination buffer overlaps with the source buffer. The line buffer is not always broken, because the memcpy utilizes the hardware acceleration, whose result is not deterministic. Fix this problem by using replacing the scr_memcpyw with scr_memmovew. Fixes: 81732c3b2fed ("tty vt: Fix line garbage in virtual console on command line edition") Cc: stable <stable@kernel.org> Signed-off-by: Yangxi Xiang <xyangxi5@gmail.com> Link: https://lore.kernel.org/r/20220628093322.5688-1-xyangxi5@gmail.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-06-29vt: drop old FONT ioctlsJiri Slaby2-187/+3
commit ff2047fb755d4415ec3c70ac799889371151796d upstream. Drop support for these ioctls: * PIO_FONT, PIO_FONTX * GIO_FONT, GIO_FONTX * PIO_FONTRESET As was demonstrated by commit 90bfdeef83f1 (tty: make FONTX ioctl use the tty pointer they were actually passed), these ioctls are not used from userspace, as: 1) they used to be broken (set up font on current console, not the open one) and racy (before the commit above) 2) KDFONTOP ioctl is used for years instead Note that PIO_FONTRESET is defunct on most systems as VGA_CONSOLE is set on them for ages. That turns on BROKEN_GRAPHICS_PROGRAMS which makes PIO_FONTRESET just return an error. We are removing KD_FONT_FLAG_OLD here as it was used only by these removed ioctls. kd.h header exists both in kernel and uapi headers, so we can remove the kernel one completely. Everyone includeing kd.h will now automatically get the uapi one. There are now unused definitions of the ioctl numbers and "struct consolefontdesc" in kd.h, but as it is a uapi header, I am not touching these. Signed-off-by: Jiri Slaby <jslaby@suse.cz> Link: https://lore.kernel.org/r/20210105120239.28031-8-jslaby@suse.cz Cc: guodaxing <guodaxing@huawei.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-02-16vt_ioctl: add array_index_nospec to VT_ACTIVATEJakob Koschel1-0/+1
commit 28cb138f559f8c1a1395f5564f86b8bbee83631b upstream. in vt_setactivate an almost identical code path has been patched with array_index_nospec. In the VT_ACTIVATE path the user input is from a system call argument instead of a usercopy. For consistency both code paths should have the same mitigations applied. Kasper Acknowledgements: Jakob Koschel, Brian Johannesmeyer, Kaveh Razavi, Herbert Bos, Cristiano Giuffrida from the VUSec group at VU Amsterdam. Co-developed-by: Brian Johannesmeyer <bjohannesmeyer@gmail.com> Signed-off-by: Brian Johannesmeyer <bjohannesmeyer@gmail.com> Signed-off-by: Jakob Koschel <jakobkoschel@gmail.com> Link: https://lore.kernel.org/r/20220127144406.3589293-2-jakobkoschel@gmail.com Cc: stable <stable@vger.kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-02-16vt_ioctl: fix array_index_nospec in vt_setactivateJakob Koschel1-1/+1
commit 61cc70d9e8ef5b042d4ed87994d20100ec8896d9 upstream. array_index_nospec ensures that an out-of-bounds value is set to zero on the transient path. Decreasing the value by one afterwards causes a transient integer underflow. vsa.console should be decreased first and then sanitized with array_index_nospec. Kasper Acknowledgements: Jakob Koschel, Brian Johannesmeyer, Kaveh Razavi, Herbert Bos, Cristiano Giuffrida from the VUSec group at VU Amsterdam. Co-developed-by: Brian Johannesmeyer <bjohannesmeyer@gmail.com> Signed-off-by: Brian Johannesmeyer <bjohannesmeyer@gmail.com> Signed-off-by: Jakob Koschel <jakobkoschel@gmail.com> Link: https://lore.kernel.org/r/20220127144406.3589293-1-jakobkoschel@gmail.com Cc: stable <stable@vger.kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-10-06tty: Fix out-of-bound vmalloc access in imageblitIgor Matheus Andrade Torrente1-2/+19
[ Upstream commit 3b0c406124719b625b1aba431659f5cdc24a982c ] This issue happens when a userspace program does an ioctl FBIOPUT_VSCREENINFO passing the fb_var_screeninfo struct containing only the fields xres, yres, and bits_per_pixel with values. If this struct is the same as the previous ioctl, the vc_resize() detects it and doesn't call the resize_screen(), leaving the fb_var_screeninfo incomplete. And this leads to the updatescrollmode() calculates a wrong value to fbcon_display->vrows, which makes the real_y() return a wrong value of y, and that value, eventually, causes the imageblit to access an out-of-bound address value. To solve this issue I made the resize_screen() be called even if the screen does not need any resizing, so it will "fix and fill" the fb_var_screeninfo independently. Cc: stable <stable@vger.kernel.org> # after 5.15-rc2 is out, give it time to bake Reported-and-tested-by: syzbot+858dc7a2f7ef07c2c219@syzkaller.appspotmail.com Signed-off-by: Igor Matheus Andrade Torrente <igormtorrente@gmail.com> Link: https://lore.kernel.org/r/20210628134509.15895-1-igormtorrente@gmail.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-09-26console: consume APC, DM, DCSnick black1-4/+27
commit 3a2b2eb55681158d3e3ef464fbf47574cf0c517c upstream. The Linux console's VT102 implementation already consumes OSC ("Operating System Command") sequences, probably because that's how palette changes are transmitted. In addition to OSC, there are three other major clases of ANSI control strings: APC ("Application Program Command"), PM ("Privacy Message"), and DCS ("Device Control String"). They are handled similarly to OSC in terms of termination. Source: vt100.net Add three new enumerated states, one for each of these types. All three are handled the same way right now--they simply consume input until terminated. I hope to expand upon this firmament in the future. Add new predicate ansi_control_string(), returning true for any of these states. Replace explicit checks against ESosc with calls to this function. Transition to these states appropriately from the escape initiation (ESesc) state. This was motivated by the following Notcurses bugs: https://github.com/dankamongmen/notcurses/issues/2050 https://github.com/dankamongmen/notcurses/issues/1828 https://github.com/dankamongmen/notcurses/issues/2069 where standard VT sequences are not consumed by the Linux console. It's not necessary that the Linux console *support* these sequences, but it ought *consume* these well-specified classes of sequences. Tested by sending a variety of escape sequences to the console, and verifying that they still worked, or were now properly consumed. Verified that the escapes were properly terminated at a generic level. Verified that the Notcurses tools continued to show expected output on the Linux console, except now without escape bleedthrough. Link: https://lore.kernel.org/lkml/YSydL0q8iaUfkphg@schwarzgerat.orthanc/ Signed-off-by: nick black <dankamongmen@gmail.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Jiri Slaby <jirislaby@kernel.org> Cc: Tetsuo Handa <penguin-kernel@i-love.sakura.ne.jp> Cc: Daniel Vetter <daniel.vetter@ffwll.ch> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-09-03vt_kdsetmode: extend console lockingLinus Torvalds1-4/+6
commit 2287a51ba822384834dafc1c798453375d1107c7 upstream. As per the long-suffering comment. Reported-by: Minh Yuan <yuanmingbuaa@gmail.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Jiri Slaby <jirislaby@kernel.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-05-26tty: vt: always invoke vc->vc_sw->con_resize callbackTetsuo Handa1-1/+1
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>
2021-05-26vt: Fix character height handling with VT_RESIZEXMaciej W. Rozycki1-3/+3
commit 860dafa902595fb5f1d23bbcce1215188c3341e6 upstream. 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> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-05-26vt_ioctl: Revert VT_RESIZEX parameter handling removalMaciej W. Rozycki1-10/+47
commit a90c275eb144c1b755f04769e1f29d832d6daeaf upstream. Revert the removal of code handling extra VT_RESIZEX ioctl's parameters beyond those that VT_RESIZE supports, fixing a functional regression causing `svgatextmode' not to resize the VT anymore. As a consequence of the reverted change when the video adapter is 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), the VT geometry does not get updated and only upper two thirds of the screen are used for the VT, and the lower part remains blank. The proportions change according to text mode geometries chosen. Revert the change verbatim then, bringing back previous VT resizing. Signed-off-by: Maciej W. Rozycki <macro@orcam.me.uk> Fixes: 988d0763361b ("vt_ioctl: make VT_RESIZEX behave like VT_RESIZE") Cc: stable@vger.kernel.org # v5.10+ Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-05-11tty: fix memory leak in vc_deallocatePavel Skripkin1-0/+1
commit 211b4d42b70f1c1660feaa968dac0efc2a96ac4d upstream. syzbot reported memory leak in tty/vt. The problem was in VT_DISALLOCATE ioctl cmd. After allocating unimap with PIO_UNIMAP it wasn't freed via VT_DISALLOCATE, but vc_cons[currcons].d was zeroed. Reported-by: syzbot+bcc922b19ccc64240b42@syzkaller.appspotmail.com Signed-off-by: Pavel Skripkin <paskripkin@gmail.com> Cc: stable <stable@vger.kernel.org> Link: https://lore.kernel.org/r/20210327214443.21548-1-paskripkin@gmail.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-03-07vt/consolemap: do font sum unsignedJiri Slaby1-1/+1
[ Upstream commit 9777f8e60e718f7b022a94f2524f967d8def1931 ] The constant 20 makes the font sum computation signed which can lead to sign extensions and signed wraps. It's not much of a problem as we build with -fno-strict-overflow. But if we ever decide not to, be ready, so switch the constant to unsigned. Signed-off-by: Jiri Slaby <jslaby@suse.cz> Link: https://lore.kernel.org/r/20210105120239.28031-7-jslaby@suse.cz Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-11-08Merge tag 'tty-5.10-rc3' of ↵Linus Torvalds1-22/+2
git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty Pull tty/serial fixes from Greg KH: "Here are a small number of small tty and serial fixes for some reported problems for the tty core, vt code, and some serial drivers. They include fixes for: - a buggy and obsolete vt font ioctl removal - 8250_mtk serial baudrate runtime warnings - imx serial earlycon build configuration fix - txx9 serial driver error path cleanup issues - tty core fix in release_tty that can be triggered by trying to bind an invalid serial port name to a speakup console device Almost all of these have been in linux-next without any problems, the only one that hasn't, just deletes code :)" * tag 'tty-5.10-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty: vt: Disable KD_FONT_OP_COPY tty: fix crash in release_tty if tty->port is not set serial: txx9: add missing platform_driver_unregister() on error in serial_txx9_init tty: serial: imx: enable earlycon by default if IMX_SERIAL_CONSOLE is enabled serial: 8250_mtk: Fix uart_get_baud_rate warning
2020-11-08vt: Disable KD_FONT_OP_COPYDaniel Vetter1-22/+2
It's buggy: On Fri, Nov 06, 2020 at 10:30:08PM +0800, Minh Yuan wrote: > We recently discovered a slab-out-of-bounds read in fbcon in the latest > kernel ( v5.10-rc2 for now ). The root cause of this vulnerability is that > "fbcon_do_set_font" did not handle "vc->vc_font.data" and > "vc->vc_font.height" correctly, and the patch > <https://lkml.org/lkml/2020/9/27/223> for VT_RESIZEX can't handle this > issue. > > Specifically, we use KD_FONT_OP_SET to set a small font.data for tty6, and > use KD_FONT_OP_SET again to set a large font.height for tty1. After that, > we use KD_FONT_OP_COPY to assign tty6's vc_font.data to tty1's vc_font.data > in "fbcon_do_set_font", while tty1 retains the original larger > height. Obviously, this will cause an out-of-bounds read, because we can > access a smaller vc_font.data with a larger vc_font.height. Further there was only one user ever. - Android's loadfont, busybox and console-tools only ever use OP_GET and OP_SET - fbset documentation only mentions the kernel cmdline font: option, not anything else. - systemd used OP_COPY before release 232 published in Nov 2016 Now unfortunately the crucial report seems to have gone down with gmane, and the commit message doesn't say much. But the pull request hints at OP_COPY being broken https://github.com/systemd/systemd/pull/3651 So in other words, this never worked, and the only project which foolishly every tried to use it, realized that rather quickly too. Instead of trying to fix security issues here on dead code by adding missing checks, fix the entire thing by removing the functionality. Note that systemd code using the OP_COPY function ignored the return value, so it doesn't matter what we're doing here really - just in case a lone server somewhere happens to be extremely unlucky and running an affected old version of systemd. The relevant code from font_copy_to_all_vcs() in systemd was: /* copy font from active VT, where the font was uploaded to */ cfo.op = KD_FONT_OP_COPY; cfo.height = vcs.v_active-1; /* tty1 == index 0 */ (void) ioctl(vcfd, KDFONTOP, &cfo); Note this just disables the ioctl, garbage collecting the now unused callbacks is left for -next. v2: Tetsuo found the old mail, which allowed me to find it on another archive. Add the link too. Acked-by: Peilin Ye <yepeilin.cs@gmail.com> Reported-by: Minh Yuan <yuanmingbuaa@gmail.com> References: https://lists.freedesktop.org/archives/systemd-devel/2016-June/036935.html References: https://github.com/systemd/systemd/pull/3651 Cc: Greg KH <greg@kroah.com> Cc: Peilin Ye <yepeilin.cs@gmail.com> Cc: Tetsuo Handa <penguin-kernel@i-love.sakura.ne.jp> Signed-off-by: Daniel Vetter <daniel.vetter@intel.com> Link: https://lore.kernel.org/r/20201108153806.3140315-1-daniel.vetter@ffwll.ch Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-11-03tty: make FONTX ioctl use the tty pointer they were actually passedLinus Torvalds1-17/+19
Some of the font tty ioctl's always used the current foreground VC for their operations. Don't do that then. This fixes a data race on fg_console. Side note: both Michael Ellerman and Jiri Slaby point out that all these ioctls are deprecated, and should probably have been removed long ago, and everything seems to be using the KDFONTOP ioctl instead. In fact, Michael points out that it looks like busybox's loadfont program seems to have switched over to using KDFONTOP exactly _because_ of this bug (ahem.. 12 years ago ;-). Reported-by: Minh Yuan <yuanmingbuaa@gmail.com> Acked-by: Michael Ellerman <mpe@ellerman.id.au> Acked-by: Jiri Slaby <jirislaby@kernel.org> Cc: Greg KH <greg@kroah.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-10-28vt_ioctl: fix GIO_UNIMAP regressionJiri Slaby1-6/+5
In commit 5ba127878722, we shuffled with the check of 'perm'. But my brain somehow inverted the condition in 'do_unimap_ioctl' (I thought it is ||, not &&), so GIO_UNIMAP stopped working completely. Move the 'perm' checks back to do_unimap_ioctl and do them right again. In fact, this reverts this part of code to the pre-5ba127878722 state. Except 'perm' is now a bool. Fixes: 5ba127878722 ("vt_ioctl: move perm checks level up") Cc: stable@vger.kernel.org Reported-by: Fabian Vogt <fvogt@suse.com> Signed-off-by: Jiri Slaby <jslaby@suse.cz> Link: https://lore.kernel.org/r/20201026055419.30518-1-jslaby@suse.cz Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-10-28vt: keyboard, extend func_buf_lock to readersJiri Slaby1-4/+13
Both read-side users of func_table/func_buf need locking. Without that, one can easily confuse the code by repeatedly setting altering strings like: while (1) for (a = 0; a < 2; a++) { struct kbsentry kbs = {}; strcpy((char *)kbs.kb_string, a ? ".\n" : "88888\n"); ioctl(fd, KDSKBSENT, &kbs); } When that program runs, one can get unexpected output by holding F1 (note the unxpected period on the last line): . 88888 .8888 So protect all accesses to 'func_table' (and func_buf) by preexisting 'func_buf_lock'. It is easy in 'k_fn' handler as 'puts_queue' is expected not to sleep. On the other hand, KDGKBSENT needs a local (atomic) copy of the string because copy_to_user can sleep. Use already allocated, but unused 'kbs->kb_string' for that purpose. Note that the program above needs at least CAP_SYS_TTY_CONFIG. This depends on the previous patch and on the func_buf_lock lock added in commit 46ca3f735f34 (tty/vt: fix write/write race in ioctl(KDSKBSENT) handler) in 5.2. Likely fixes CVE-2020-25656. Cc: <stable@vger.kernel.org> Reported-by: Minh Yuan <yuanmingbuaa@gmail.com> Signed-off-by: Jiri Slaby <jslaby@suse.cz> Link: https://lore.kernel.org/r/20201019085517.10176-2-jslaby@suse.cz Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-10-28vt: keyboard, simplify vt_kdgkbsentJiri Slaby1-19/+9
Use 'strlen' of the string, add one for NUL terminator and simply do 'copy_to_user' instead of the explicit 'for' loop. This makes the KDGKBSENT case more compact. The only thing we need to take care about is NULL 'func_table[i]'. Use an empty string in that case. The original check for overflow could never trigger as the func_buf strings are always shorter or equal to 'struct kbsentry's. Cc: <stable@vger.kernel.org> Signed-off-by: Jiri Slaby <jslaby@suse.cz> Link: https://lore.kernel.org/r/20201019085517.10176-1-jslaby@suse.cz Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-09-27vt_ioctl: make VT_RESIZEX behave like VT_RESIZETetsuo Handa1-47/+10
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. VT_RESIZEX was introduced in Linux 1.3.3, but it is unclear that what comes to the "+ more" part, and I couldn't find a user of VT_RESIZEX. #define VT_RESIZE 0x5609 /* set kernel's idea of screensize */ #define VT_RESIZEX 0x560A /* set kernel's idea of screensize + more */ So far we are not aware of syzbot reports caused by setting non-zero value to v_vlin parameter. But given that it is possible that nobody is using VT_RESIZEX, we can try removing support for v_clin and v_vlin parameters. Therefore, this patch effectively makes VT_RESIZEX behave like VT_RESIZE, with emitting a message if somebody is still using v_clin and/or v_vlin parameters. [1] https://syzkaller.appspot.com/bug?id=32577e96d88447ded2d3b76d71254fb855245837 [2] https://syzkaller.appspot.com/bug?id=6b8355d27b2b94fb5cedf4655e3a59162d9e48e3 Reported-by: syzbot <syzbot+b308f5fd049fbbc6e74f@syzkaller.appspotmail.com> Reported-by: syzbot <syzbot+16469b5e8e5a72e9131e@syzkaller.appspotmail.com> Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> Cc: stable <stable@vger.kernel.org> Link: https://lore.kernel.org/r/4933b81b-9b1a-355b-df0e-9b31e8280ab9@i-love.sakura.ne.jp Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-08-31Merge 5.9-rc3 into tty-nextGreg Kroah-Hartman2-6/+17
We need the tty/serial fixes in here as well. Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-08-26Merge tag 'tty-5.9-rc3' of ↵Linus Torvalds2-3/+14
git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty Pull tty/serial fixes from Greg KH: "Here are a few small TTY/Serial/vt fixes for 5.9-rc3 Included in here are: - qcom serial fixes - vt ioctl and core bugfixes - pl011 serial driver fixes - 8250 serial driver fixes - other misc serial driver fixes and for good measure: - fbcon fix for syzbot found problem. All of these have been in linux-next for a while with no reported issues" * tag 'tty-5.9-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty: tty: serial: imx: add dependence and build for earlycon serial: samsung: Removes the IRQ not found warning serial: 8250: change lock order in serial8250_do_startup() serial: stm32: avoid kernel warning on absence of optional IRQ serial: pl011: Fix oops on -EPROBE_DEFER serial: pl011: Don't leak amba_ports entry on driver register error serial: 8250_exar: Fix number of ports for Commtech PCIe cards tty: serial: qcom_geni_serial: Drop __init from qcom_geni_console_setup serial: qcom_geni_serial: Fix recent kdb hang vt_ioctl: change VT_RESIZEX ioctl to check for error return from vc_resize() fbcon: prevent user font height or width change from causing potential out-of-bounds access vt: defer kfree() of vc_screenbuf in vc_do_resize()
2020-08-24Revert "vc_screen: extract vcs_read_buf_header"Jiri Slaby1-18/+13
This reverts commit b1c32fcfadf5593ab7a63261cc8a5747c36e627e, because Syzkaller reports a use-after-free, a write in vcs_read: BUG: KASAN: use-after-free in vcs_read_buf drivers/tty/vt/vc_screen.c:357 [inline] BUG: KASAN: use-after-free in vcs_read+0xaa7/0xb40 drivers/tty/vt/vc_screen.c:449 Write of size 2 at addr ffff8880a8014000 by task syz-executor.5/16936 CPU: 1 PID: 16936 Comm: syz-executor.5 Not tainted 5.9.0-rc1-next-20200820-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: ... kasan_report.cold+0x1f/0x37 mm/kasan/report.c:530 vcs_read_buf drivers/tty/vt/vc_screen.c:357 [inline] vcs_read+0xaa7/0xb40 drivers/tty/vt/vc_screen.c:449 There are two issues with the patch: 1) vcs_read rounds the 'count' *up* to an even number. So if we read odd bytes from the header (3 bytes in the reproducer), the second byte of a (2-byte/ushort) write to temporary con_buf won't fit. It is because with the patch applied, we only subtract the real number read (3 bytes) and not the whole header (4 bytes). 2) in this scenario, we perform unaligned accesses now: there are 2-byte/ushort writes to odd addresses. Due to the same reason as above. Revert this for now, re-think and retry later. Signed-off-by: Jiri Slaby <jslaby@suse.cz> Reported-by: syzbot+ad1f53726c3bd11180cb@syzkaller.appspotmail.com Fixes: b1c32fcfadf5 ("vc_screen: extract vcs_read_buf_header") Cc: akpm@linux-foundation.org Cc: nico@fluxnic.net Link: https://lore.kernel.org/r/20200824095425.4376-1-jslaby@suse.cz Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-08-24treewide: Use fallthrough pseudo-keywordGustavo A. R. Silva1-3/+3
Replace the existing /* fall through */ comments and its variants with the new pseudo-keyword macro fallthrough[1]. Also, remove unnecessary fall-through markings when it is the case. [1] https://www.kernel.org/doc/html/v5.7/process/deprecated.html?highlight=fallthrough#implicit-switch-case-fall-through Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>
2020-08-18tty: vt, fix kernel-docJiri Slaby3-6/+6
As in the previous patches, fix kernel-doc in vt. Signed-off-by: Jiri Slaby <jslaby@suse.cz> Link: https://lore.kernel.org/r/20200818085655.12071-6-jslaby@suse.cz Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-08-18vc_screen: prune macrosJiri Slaby1-4/+0
Do not undefine random words. I guess this was here as there were macros with such generic names somewhere. I very doubt they still exist. So drop these. And remove a spare blank line. Signed-off-by: Jiri Slaby <jslaby@suse.cz> Link: https://lore.kernel.org/r/20200818085706.12163-16-jslaby@suse.cz Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-08-18vc_screen: extract vcs_read_buf_headerJiri Slaby1-13/+18
The attribute header handling is terrible in vcs_read_buf. Separate it to a new function and simply do memmove (of up to 4 bytes) to the start of the con_buf -- if user seeked. Signed-off-by: Jiri Slaby <jslaby@suse.cz> Link: https://lore.kernel.org/r/20200818085706.12163-15-jslaby@suse.cz Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-08-18vc_screen: extract vcs_read_bufJiri Slaby1-68/+78
And finally, move the attributes buffer handling to a separate function. Leaving vcs_read quite compact. Signed-off-by: Jiri Slaby <jslaby@suse.cz> Link: https://lore.kernel.org/r/20200818085706.12163-14-jslaby@suse.cz Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-08-18vc_screen: extract vcs_read_buf_noattrJiri Slaby1-11/+22
Now, move the code for no-attributes handling to a separate function. Signed-off-by: Jiri Slaby <jslaby@suse.cz> Link: https://lore.kernel.org/r/20200818085706.12163-13-jslaby@suse.cz Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-08-18vc_screen: extract vcs_read_buf_uniJiri Slaby1-19/+30
The same as making write more readable, extract unicode handling from vcs_read. The other two cases (w/ and w/o attributes) will follow. Signed-off-by: Jiri Slaby <jslaby@suse.cz> Link: https://lore.kernel.org/r/20200818085706.12163-12-jslaby@suse.cz Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-08-18vs_screen: kill tmp_count from vcs_readJiri Slaby1-8/+2
Both tmp_count computations and the single use can be eliminated using min(). Do so. Side note: we need HEADER_SIZE to be unsigned for min() not to complain. Fix that too as all its other uses do not mind. Signed-off-by: Jiri Slaby <jslaby@suse.cz> Link: https://lore.kernel.org/r/20200818085706.12163-11-jslaby@suse.cz Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-08-18vc_screen: sanitize types in vcs_readJiri Slaby1-8/+7
* pos is derived from the passed ppos, so make it long enough, i.e. loff_t * attr and uni_mode are booleans, so... * size is limited by vcs_size() which returns an int * read, p, orig_count and this_round are always ">= 0" and "< size", so uint is enough * row, col, and max_col are derived from vc->vc_cols (uint) and p, so make them uint too * tmp_count is derived from this_round, so make it an uint too. * use u16 * for org (instead of unsigned short *). No need to initialize org too. Signed-off-by: Jiri Slaby <jslaby@suse.cz> Link: https://lore.kernel.org/r/20200818085706.12163-10-jslaby@suse.cz Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-08-18vc_screen: eliminate ifdefs from vcs_write_bufJiri Slaby1-12/+17
Introduce a new inline function called vc_compile_le16 and do the shifts and ORs there. Depending on LE x BE. I tried cpu_to_le16, but it ends up with worse assembly on BE for whatever reason -- the compiler seems to be unable to optimize the swap. Signed-off-by: Jiri Slaby <jslaby@suse.cz> Link: https://lore.kernel.org/r/20200818085706.12163-9-jslaby@suse.cz Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-08-18vc_screen: extract vcs_write_bufJiri Slaby1-76/+92
This is the counterpart of the previous patch: here, we extract buffer writing with attributes from vcs_write. Now, there is no need for org to be initialized to NULL. The org0 check before update_region() confuses compilers, so check org instead. It provides the same semantics. And it also eliminates the need for initialization of org0. We switch the branches of the attr 'if' too, as the inversion brings only confusion now. Signed-off-by: Jiri Slaby <jslaby@suse.cz> Link: https://lore.kernel.org/r/20200818085706.12163-8-jslaby@suse.cz Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-08-18vc_screen: extract vcs_write_buf_noattrJiri Slaby1-21/+34
vcs_write is too long to be readable. Extract buffer handling w/o attributes from there to a separate function. Signed-off-by: Jiri Slaby <jslaby@suse.cz> Link: https://lore.kernel.org/r/20200818085706.12163-7-jslaby@suse.cz Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-08-18vc_screen: sanitize types in vcs_writeJiri Slaby1-10/+7
* ret can carry error codes, so make it signed, i.e. ssize_t * pos is derived from the passed ppos, so make it long enough, i.e. loff_t * attr is a boolean, so... * size is limited by vcs_size() which returns an int * written, p, orig_count and this_round are always ">= 0" and "< size", so uint is enough * col and max_col are derived from vc->vc_cols (uint) and p, so make them uint too * place con_buf0 and con_buf declaration to a single line Signed-off-by: Jiri Slaby <jslaby@suse.cz> Link: https://lore.kernel.org/r/20200818085706.12163-6-jslaby@suse.cz Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-08-18vc_screen: rewrite vcs_size to accept vc, not inodeJiri Slaby1-17/+29
It is weird to fetch the information from the inode over and over. Read and write already have the needed information, so rewrite vcs_size to accept a vc, attr and unicode and adapt vcs_lseek to that. Also make sure all sites check the return value of vcs_size for errors. And document it using kernel-doc. Signed-off-by: Jiri Slaby <jslaby@suse.cz> Link: https://lore.kernel.org/r/20200818085706.12163-5-jslaby@suse.cz Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>