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2020-04-28vt: selection, push sel_lock upJiri Slaby1-9/+7
commit e8c75a30a23c6ba63f4ef6895cbf41fd42f21aa2 upstream. sel_lock cannot nest in the console lock. Thanks to syzkaller, the kernel states firmly: > WARNING: possible circular locking dependency detected > 5.6.0-rc3-syzkaller #0 Not tainted > ------------------------------------------------------ > syz-executor.4/20336 is trying to acquire lock: > ffff8880a2e952a0 (&tty->termios_rwsem){++++}, at: tty_unthrottle+0x22/0x100 drivers/tty/tty_ioctl.c:136 > > but task is already holding lock: > ffffffff89462e70 (sel_lock){+.+.}, at: paste_selection+0x118/0x470 drivers/tty/vt/selection.c:374 > > which lock already depends on the new lock. > > the existing dependency chain (in reverse order) is: > > -> #2 (sel_lock){+.+.}: > mutex_lock_nested+0x1b/0x30 kernel/locking/mutex.c:1118 > set_selection_kernel+0x3b8/0x18a0 drivers/tty/vt/selection.c:217 > set_selection_user+0x63/0x80 drivers/tty/vt/selection.c:181 > tioclinux+0x103/0x530 drivers/tty/vt/vt.c:3050 > vt_ioctl+0x3f1/0x3a30 drivers/tty/vt/vt_ioctl.c:364 This is ioctl(TIOCL_SETSEL). Locks held on the path: console_lock -> sel_lock > -> #1 (console_lock){+.+.}: > console_lock+0x46/0x70 kernel/printk/printk.c:2289 > con_flush_chars+0x50/0x650 drivers/tty/vt/vt.c:3223 > n_tty_write+0xeae/0x1200 drivers/tty/n_tty.c:2350 > do_tty_write drivers/tty/tty_io.c:962 [inline] > tty_write+0x5a1/0x950 drivers/tty/tty_io.c:1046 This is write(). Locks held on the path: termios_rwsem -> console_lock > -> #0 (&tty->termios_rwsem){++++}: > down_write+0x57/0x140 kernel/locking/rwsem.c:1534 > tty_unthrottle+0x22/0x100 drivers/tty/tty_ioctl.c:136 > mkiss_receive_buf+0x12aa/0x1340 drivers/net/hamradio/mkiss.c:902 > tty_ldisc_receive_buf+0x12f/0x170 drivers/tty/tty_buffer.c:465 > paste_selection+0x346/0x470 drivers/tty/vt/selection.c:389 > tioclinux+0x121/0x530 drivers/tty/vt/vt.c:3055 > vt_ioctl+0x3f1/0x3a30 drivers/tty/vt/vt_ioctl.c:364 This is ioctl(TIOCL_PASTESEL). Locks held on the path: sel_lock -> termios_rwsem > other info that might help us debug this: > > Chain exists of: > &tty->termios_rwsem --> console_lock --> sel_lock Clearly. From the above, we have: console_lock -> sel_lock sel_lock -> termios_rwsem termios_rwsem -> console_lock Fix this by reversing the console_lock -> sel_lock dependency in ioctl(TIOCL_SETSEL). First, lock sel_lock, then console_lock. Signed-off-by: Jiri Slaby <jslaby@suse.cz> Reported-by: syzbot+26183d9746e62da329b8@syzkaller.appspotmail.com Fixes: 07e6124a1a46 ("vt: selection, close sel_buffer race") Link: https://lore.kernel.org/r/20200228115406.5735-2-jslaby@suse.cz Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
2020-04-28vt: selection, push console lock downJiri Slaby2-3/+12
commit 4b70dd57a15d2f4685ac6e38056bad93e81e982f upstream. We need to nest the console lock in sel_lock, so we have to push it down a bit. Fortunately, the callers of set_selection_* just lock the console lock around the function call. So moving it down is easy. In the next patch, we switch the order. Signed-off-by: Jiri Slaby <jslaby@suse.cz> Fixes: 07e6124a1a46 ("vt: selection, close sel_buffer race") Link: https://lore.kernel.org/r/20200228115406.5735-1-jslaby@suse.cz Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
2020-04-28vt: selection, close sel_buffer raceJiri Slaby1-6/+17
commit 07e6124a1a46b4b5a9b3cacc0c306b50da87abf5 upstream. syzkaller reported this UAF: BUG: KASAN: use-after-free in n_tty_receive_buf_common+0x2481/0x2940 drivers/tty/n_tty.c:1741 Read of size 1 at addr ffff8880089e40e9 by task syz-executor.1/13184 CPU: 0 PID: 13184 Comm: syz-executor.1 Not tainted 5.4.7 #1 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.12.0-1 04/01/2014 Call Trace: ... kasan_report+0xe/0x20 mm/kasan/common.c:634 n_tty_receive_buf_common+0x2481/0x2940 drivers/tty/n_tty.c:1741 tty_ldisc_receive_buf+0xac/0x190 drivers/tty/tty_buffer.c:461 paste_selection+0x297/0x400 drivers/tty/vt/selection.c:372 tioclinux+0x20d/0x4e0 drivers/tty/vt/vt.c:3044 vt_ioctl+0x1bcf/0x28d0 drivers/tty/vt/vt_ioctl.c:364 tty_ioctl+0x525/0x15a0 drivers/tty/tty_io.c:2657 vfs_ioctl fs/ioctl.c:47 [inline] It is due to a race between parallel paste_selection (TIOCL_PASTESEL) and set_selection_user (TIOCL_SETSEL) invocations. One uses sel_buffer, while the other frees it and reallocates a new one for another selection. Add a mutex to close this race. The mutex takes care properly of sel_buffer and sel_buffer_lth only. The other selection global variables (like sel_start, sel_end, and sel_cons) are protected only in set_selection_user. The other functions need quite some more work to close the races of the variables there. This is going to happen later. This likely fixes (I am unsure as there is no reproducer provided) bug 206361 too. It was marked as CVE-2020-8648. Signed-off-by: Jiri Slaby <jslaby@suse.cz> Reported-by: syzbot+59997e8d5cbdc486e6f6@syzkaller.appspotmail.com References: https://bugzilla.kernel.org/show_bug.cgi?id=206361 Link: https://lore.kernel.org/r/20200210081131.23572-2-jslaby@suse.cz Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> [bwh: Backported to 3.16: adjust context] Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
2020-04-28vt: selection, handle pending signals in paste_selectionJiri Slaby1-1/+6
commit 687bff0cd08f790d540cfb7b2349f0d876cdddec upstream. When pasting a selection to a vt, the task is set as INTERRUPTIBLE while waiting for a tty to unthrottle. But signals are not handled at all. Normally, this is not a problem as tty_ldisc_receive_buf receives all the goods and a user has no reason to interrupt the task. There are two scenarios where this matters: 1) when the tty is throttled and a signal is sent to the process, it spins on a CPU until the tty is unthrottled. schedule() does not really echedule, but returns immediately, of course. 2) when the sel_buffer becomes invalid, KASAN prevents any reads from it and the loop simply does not proceed and spins forever (causing the tty to throttle, but the code never sleeps, the same as above). This sometimes happens as there is a race in the sel_buffer handling code. So add signal handling to this ioctl (TIOCL_PASTESEL) and return -EINTR in case a signal is pending. Signed-off-by: Jiri Slaby <jslaby@suse.cz> Link: https://lore.kernel.org/r/20200210081131.23572-1-jslaby@suse.cz Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> [bwh: Backported to 3.16: - No need to include <linux/sched/signal.h> - Adjust context] Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
2020-04-28tty: vt: Fix !TASK_RUNNING diagnostic warning from paste_selection()Peter Hurley1-0/+1
commit 61e86cc90af49cecef9c54ccea1f572fbcb695ac upstream. Pasting text with gpm on a VC produced warning [1]. Reset task state to TASK_RUNNING in the paste_selection() loop, if the loop did not sleep. [1] WARNING: CPU: 6 PID: 1960 at /home/peter/src/kernels/mainline/kernel/sched/core.c:7286 __might_sleep+0x7f/0x90() do not call blocking ops when !TASK_RUNNING; state=1 set at [<ffffffff8151805e>] paste_selection+0x9e/0x1a0 Modules linked in: btrfs xor raid6_pq ufs qnx4 hfsplus hfs minix ntfs msdos jfs xfs libcrc32c ..... CPU: 6 PID: 1960 Comm: gpm Not tainted 4.1.0-rc7+tty-xeon+debug #rc7+tty Hardware name: Dell Inc. Precision WorkStation T5400 /0RW203, BIOS A11 04/30/2012 ffffffff81c9c0a0 ffff8802b0fd3ac8 ffffffff8185778a 0000000000000001 ffff8802b0fd3b18 ffff8802b0fd3b08 ffffffff8108039a ffffffff82ae8510 ffffffff81c9ce00 0000000000000015 0000000000000000 0000000000000000 Call Trace: [<ffffffff8185778a>] dump_stack+0x4f/0x7b [<ffffffff8108039a>] warn_slowpath_common+0x8a/0xc0 [<ffffffff81080416>] warn_slowpath_fmt+0x46/0x50 [<ffffffff810ddced>] ? __lock_acquire+0xe2d/0x13a0 [<ffffffff8151805e>] ? paste_selection+0x9e/0x1a0 [<ffffffff8151805e>] ? paste_selection+0x9e/0x1a0 [<ffffffff810ad4ff>] __might_sleep+0x7f/0x90 [<ffffffff8185f76a>] down_read+0x2a/0xa0 [<ffffffff810bb1d8>] ? sched_clock_cpu+0xb8/0xe0 [<ffffffff8150d1dc>] n_tty_receive_buf_common+0x4c/0xba0 [<ffffffff810dc875>] ? mark_held_locks+0x75/0xa0 [<ffffffff81861c95>] ? _raw_spin_unlock_irqrestore+0x65/0x80 [<ffffffff810b49a1>] ? get_parent_ip+0x11/0x50 [<ffffffff8150dd44>] n_tty_receive_buf2+0x14/0x20 [<ffffffff81518117>] paste_selection+0x157/0x1a0 [<ffffffff810b77b0>] ? wake_up_state+0x20/0x20 [<ffffffff815203f8>] tioclinux+0xb8/0x2c0 [<ffffffff81515bfe>] vt_ioctl+0xaee/0x11a0 [<ffffffff810baf75>] ? sched_clock_local+0x25/0x90 [<ffffffff810bbe11>] ? vtime_account_user+0x91/0xa0 [<ffffffff8150810c>] tty_ioctl+0x20c/0xe20 [<ffffffff810bbe11>] ? vtime_account_user+0x91/0xa0 [<ffffffff810b49a1>] ? get_parent_ip+0x11/0x50 [<ffffffff810b4a69>] ? preempt_count_sub+0x49/0x50 [<ffffffff811ab71c>] ? context_tracking_exit+0x5c/0x290 [<ffffffff811ab71c>] ? context_tracking_exit+0x5c/0x290 [<ffffffff81248b98>] do_vfs_ioctl+0x318/0x570 [<ffffffff810dca8d>] ? trace_hardirqs_on+0xd/0x10 [<ffffffff810dc9b5>] ? trace_hardirqs_on_caller+0x115/0x1e0 [<ffffffff81254acc>] ? __fget_light+0x6c/0xa0 [<ffffffff81248e71>] SyS_ioctl+0x81/0xa0 [<ffffffff81862832>] system_call_fastpath+0x16/0x7a Signed-off-by: Peter Hurley <peter@hurleysoftware.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
2020-04-28tty: always relink the portSudip Mukherjee1-2/+1
commit 273f632912f1b24b642ba5b7eb5022e43a72f3b5 upstream. If the serial device is disconnected and reconnected, it re-enumerates properly but does not link it. fwiw, linking means just saving the port index, so allow it always as there is no harm in saving the same value again even if it tries to relink with the same port. Fixes: fb2b90014d78 ("tty: link tty and port before configuring it as console") Reported-by: Kenneth R. Crudup <kenny@panix.com> Signed-off-by: Sudip Mukherjee <sudipm.mukherjee@gmail.com> Link: https://lore.kernel.org/r/20191227174434.12057-1-sudipm.mukherjee@gmail.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
2020-04-28tty: link tty and port before configuring it as consoleSudip Mukherjee2-1/+3
commit fb2b90014d782d80d7ebf663e50f96d8c507a73c upstream. There seems to be a race condition in tty drivers and I could see on many boot cycles a NULL pointer dereference as tty_init_dev() tries to do 'tty->port->itty = tty' even though tty->port is NULL. 'tty->port' will be set by the driver and if the driver has not yet done it before we open the tty device we can get to this situation. By adding some extra debug prints, I noticed that: 6.650130: uart_add_one_port 6.663849: register_console 6.664846: tty_open 6.674391: tty_init_dev 6.675456: tty_port_link_device uart_add_one_port() registers the console, as soon as it registers, the userspace tries to use it and that leads to tty_open() but uart_add_one_port() has not yet done tty_port_link_device() and so tty->port is not yet configured when control reaches tty_init_dev(). Further look into the code and tty_port_link_device() is done by uart_add_one_port(). After registering the console uart_add_one_port() will call tty_port_register_device_attr_serdev() and tty_port_link_device() is called from this. Call add tty_port_link_device() before uart_configure_port() is done and add a check in tty_port_link_device() so that it only links the port if it has not been done yet. Suggested-by: Jiri Slaby <jslaby@suse.com> Signed-off-by: Sudip Mukherjee <sudipm.mukherjee@gmail.com> Link: https://lore.kernel.org/r/20191212131602.29504-1-sudipm.mukherjee@gmail.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
2020-04-28tty: serial: msm_serial: Fix lockup for sysrq and oopsLeo Yan1-2/+11
commit 0e4f7f920a5c6bfe5e851e989f27b35a0cc7fb7e upstream. As the commit 677fe555cbfb ("serial: imx: Fix recursive locking bug") has mentioned the uart driver might cause recursive locking between normal printing and the kernel debugging facilities (e.g. sysrq and oops). In the commit it gave out suggestion for fixing recursive locking issue: "The solution is to avoid locking in the sysrq case and trylock in the oops_in_progress case." This patch follows the suggestion (also used the exactly same code with other serial drivers, e.g. amba-pl011.c) to fix the recursive locking issue, this can avoid stuck caused by deadlock and print out log for sysrq and oops. Fixes: 04896a77a97b ("msm_serial: serial driver for MSM7K onboard serial peripheral.") Signed-off-by: Leo Yan <leo.yan@linaro.org> Reviewed-by: Jeffrey Hugo <jeffrey.l.hugo@gmail.com> Link: https://lore.kernel.org/r/20191127141544.4277-2-leo.yan@linaro.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
2020-02-11tty: vt: keyboard: reject invalid keycodesDmitry Torokhov1-1/+1
commit b2b2dd71e0859436d4e05b2f61f86140250ed3f8 upstream. Do not try to handle keycodes that are too big, otherwise we risk doing out-of-bounds writes: BUG: KASAN: global-out-of-bounds in clear_bit include/asm-generic/bitops-instrumented.h:56 [inline] BUG: KASAN: global-out-of-bounds in kbd_keycode drivers/tty/vt/keyboard.c:1411 [inline] BUG: KASAN: global-out-of-bounds in kbd_event+0xe6b/0x3790 drivers/tty/vt/keyboard.c:1495 Write of size 8 at addr ffffffff89a1b2d8 by task syz-executor108/1722 ... kbd_keycode drivers/tty/vt/keyboard.c:1411 [inline] kbd_event+0xe6b/0x3790 drivers/tty/vt/keyboard.c:1495 input_to_handler+0x3b6/0x4c0 drivers/input/input.c:118 input_pass_values.part.0+0x2e3/0x720 drivers/input/input.c:145 input_pass_values drivers/input/input.c:949 [inline] input_set_keycode+0x290/0x320 drivers/input/input.c:954 evdev_handle_set_keycode_v2+0xc4/0x120 drivers/input/evdev.c:882 evdev_do_ioctl drivers/input/evdev.c:1150 [inline] In this case we were dealing with a fuzzed HID device that declared over 12K buttons, and while HID layer should not be reporting to us such big keycodes, we should also be defensive and reject invalid data ourselves as well. Reported-by: syzbot+19340dff067c2d3835c0@syzkaller.appspotmail.com Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com> Link: https://lore.kernel.org/r/20191122204220.GA129459@dtor-ws Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
2020-02-11serial: serial_core: Perform NULL checks for break_ctl opsJiangfeng Xiao1-1/+1
commit 7d73170e1c282576419f8b50a771f1fcd2b81a94 upstream. Doing fuzz test on sbsa uart device, causes a kernel crash due to NULL pointer dereference: ------------[ cut here ]------------ Unable to handle kernel paging request at virtual address fffffffffffffffc pgd = ffffffe331723000 [fffffffffffffffc] *pgd=0000002333595003, *pud=0000002333595003, *pmd=00000 Internal error: Oops: 96000005 [#1] PREEMPT SMP Modules linked in: ping(O) jffs2 rtos_snapshot(O) pramdisk(O) hisi_sfc(O) Drv_Nandc_K(O) Drv_SysCtl_K(O) Drv_SysClk_K(O) bsp_reg(O) hns3(O) hns3_uio_enet(O) hclgevf(O) hclge(O) hnae3(O) mdio_factory(O) mdio_registry(O) mdio_dev(O) mdio(O) hns3_info(O) rtos_kbox_panic(O) uart_suspend(O) rsm(O) stp llc tunnel4 xt_tcpudp ipt_REJECT nf_reject_ipv4 iptable_filter ip_tables x_tables sd_mod xhci_plat_hcd xhci_pci xhci_hcd usbmon usbhid usb_storage ohci_platform ohci_pci ohci_hcd hid_generic hid ehci_platform ehci_pci ehci_hcd vfat fat usbcore usb_common scsi_mod yaffs2multi(O) ext4 jbd2 ext2 mbcache ofpart i2c_dev i2c_core uio ubi nand nand_ecc nand_ids cfi_cmdset_0002 cfi_cmdset_0001 cfi_probe gen_probe cmdlinepart chipreg mtdblock mtd_blkdevs mtd nfsd auth_rpcgss oid_registry nfsv3 nfs nfs_acl lockd sunrpc grace autofs4 CPU: 2 PID: 2385 Comm: tty_fuzz_test Tainted: G O 4.4.193 #1 task: ffffffe32b23f110 task.stack: ffffffe32bda4000 PC is at uart_break_ctl+0x44/0x84 LR is at uart_break_ctl+0x34/0x84 pc : [<ffffff8393196098>] lr : [<ffffff8393196088>] pstate: 80000005 sp : ffffffe32bda7cc0 x29: ffffffe32bda7cc0 x28: ffffffe32b23f110 x27: ffffff8393402000 x26: 0000000000000000 x25: ffffffe32b233f40 x24: ffffffc07a8ec680 x23: 0000000000005425 x22: 00000000ffffffff x21: ffffffe33ed73c98 x20: 0000000000000000 x19: ffffffe33ed94168 x18: 0000000000000004 x17: 0000007f92ae9d30 x16: ffffff8392fa6064 x15: 0000000000000010 x14: 0000000000000000 x13: 0000000000000000 x12: 0000000000000000 x11: 0000000000000020 x10: 0000007ffdac1708 x9 : 0000000000000078 x8 : 000000000000001d x7 : 0000000052a64887 x6 : ffffffe32bda7e08 x5 : ffffffe32b23c000 x4 : 0000005fbc5b0000 x3 : ffffff83938d5018 x2 : 0000000000000080 x1 : ffffffe32b23c040 x0 : ffffff83934428f8 virtual start addr offset is 38ac00000 module base offset is 2cd4cf1000 linear region base offset is : 0 Process tty_fuzz_test (pid: 2385, stack limit = 0xffffffe32bda4000) Stack: (0xffffffe32bda7cc0 to 0xffffffe32bda8000) 7cc0: ffffffe32bda7cf0 ffffff8393177718 ffffffc07a8ec680 ffffff8393196054 7ce0: 000000001739f2e0 0000007ffdac1978 ffffffe32bda7d20 ffffff8393179a1c 7d00: 0000000000000000 ffffff8393c0a000 ffffffc07a8ec680 cb88537fdc8ba600 7d20: ffffffe32bda7df0 ffffff8392fa5a40 ffffff8393c0a000 0000000000005425 7d40: 0000007ffdac1978 ffffffe32b233f40 ffffff8393178dcc 0000000000000003 7d60: 000000000000011d 000000000000001d ffffffe32b23f110 000000000000029e 7d80: ffffffe34fe8d5d0 0000000000000000 ffffffe32bda7e14 cb88537fdc8ba600 7da0: ffffffe32bda7e30 ffffff8393042cfc ffffff8393c41720 ffffff8393c46410 7dc0: ffffff839304fa68 ffffffe32b233f40 0000000000005425 0000007ffdac1978 7de0: 000000000000011d cb88537fdc8ba600 ffffffe32bda7e70 ffffff8392fa60cc 7e00: 0000000000000000 ffffffe32b233f40 ffffffe32b233f40 0000000000000003 7e20: 0000000000005425 0000007ffdac1978 ffffffe32bda7e70 ffffff8392fa60b0 7e40: 0000000000000280 ffffffe32b233f40 ffffffe32b233f40 0000000000000003 7e60: 0000000000005425 cb88537fdc8ba600 0000000000000000 ffffff8392e02e78 7e80: 0000000000000280 0000005fbc5b0000 ffffffffffffffff 0000007f92ae9d3c 7ea0: 0000000060000000 0000000000000015 0000000000000003 0000000000005425 7ec0: 0000007ffdac1978 0000000000000000 00000000a54c910e 0000007f92b95014 7ee0: 0000007f92b95090 0000000052a64887 000000000000001d 0000000000000078 7f00: 0000007ffdac1708 0000000000000020 0000000000000000 0000000000000000 7f20: 0000000000000000 0000000000000010 000000556acf0090 0000007f92ae9d30 7f40: 0000000000000004 000000556acdef10 0000000000000000 000000556acdebd0 7f60: 0000000000000000 0000000000000000 0000000000000000 0000000000000000 7f80: 0000000000000000 0000000000000000 0000000000000000 0000007ffdac1840 7fa0: 000000556acdedcc 0000007ffdac1840 0000007f92ae9d3c 0000000060000000 7fc0: 0000000000000000 0000000000000000 0000000000000003 000000000000001d 7fe0: 0000000000000000 0000000000000000 0000000000000000 0000000000000000 Call trace: Exception stack(0xffffffe32bda7ab0 to 0xffffffe32bda7bf0) 7aa0: 0000000000001000 0000007fffffffff 7ac0: ffffffe32bda7cc0 ffffff8393196098 0000000080000005 0000000000000025 7ae0: ffffffe32b233f40 ffffff83930d777c ffffffe32bda7b30 ffffff83930d777c 7b00: ffffffe32bda7be0 ffffff83938d5000 ffffffe32bda7be0 ffffffe32bda7c20 7b20: ffffffe32bda7b60 ffffff83930d777c ffffffe32bda7c10 ffffff83938d5000 7b40: ffffffe32bda7c10 ffffffe32bda7c50 ffffff8393c0a000 ffffffe32b23f110 7b60: ffffffe32bda7b70 ffffff8392e09df4 ffffffe32bda7bb0 cb88537fdc8ba600 7b80: ffffff83934428f8 ffffffe32b23c040 0000000000000080 ffffff83938d5018 7ba0: 0000005fbc5b0000 ffffffe32b23c000 ffffffe32bda7e08 0000000052a64887 7bc0: 000000000000001d 0000000000000078 0000007ffdac1708 0000000000000020 7be0: 0000000000000000 0000000000000000 [<ffffff8393196098>] uart_break_ctl+0x44/0x84 [<ffffff8393177718>] send_break+0xa0/0x114 [<ffffff8393179a1c>] tty_ioctl+0xc50/0xe84 [<ffffff8392fa5a40>] do_vfs_ioctl+0xc4/0x6e8 [<ffffff8392fa60cc>] SyS_ioctl+0x68/0x9c [<ffffff8392e02e78>] __sys_trace_return+0x0/0x4 Code: b9410ea0 34000160 f9408aa0 f9402814 (b85fc280) ---[ end trace 8606094f1960c5e0 ]--- Kernel panic - not syncing: Fatal exception Fix this problem by adding NULL checks prior to calling break_ctl ops. Signed-off-by: Jiangfeng Xiao <xiaojiangfeng@huawei.com> Link: https://lore.kernel.org/r/1574263133-28259-1-git-send-email-xiaojiangfeng@huawei.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
2020-02-11serial: ifx6x60: add missed pm_runtime_disableChuhong Yuan1-0/+3
commit 50b2b571c5f3df721fc81bf9a12c521dfbe019ba upstream. The driver forgets to call pm_runtime_disable in remove. Add the missed calls to fix it. Signed-off-by: Chuhong Yuan <hslester96@gmail.com> Link: https://lore.kernel.org/r/20191118024833.21587-1-hslester96@gmail.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
2020-02-11tty: serial: pch_uart: correct usage of dma_unmap_sgPeng Fan1-1/+4
commit 74887542fdcc92ad06a48c0cca17cdf09fc8aa00 upstream. Per Documentation/DMA-API-HOWTO.txt, To unmap a scatterlist, just call: dma_unmap_sg(dev, sglist, nents, direction); .. note:: The 'nents' argument to the dma_unmap_sg call must be the _same_ one you passed into the dma_map_sg call, it should _NOT_ be the 'count' value _returned_ from the dma_map_sg call. However in the driver, priv->nent is directly assigned with value returned from dma_map_sg, and dma_unmap_sg use priv->nent for unmap, this breaks the API usage. So introduce a new entry orig_nent to remember 'nents'. Fixes: da3564ee027e ("pch_uart: add multi-scatter processing") Signed-off-by: Peng Fan <peng.fan@nxp.com> Link: https://lore.kernel.org/r/1573623259-6339-1-git-send-email-peng.fan@nxp.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
2020-02-11tty: serial: imx: use the sg count from dma_map_sgPeng Fan1-1/+1
commit 596fd8dffb745afcebc0ec6968e17fe29f02044c upstream. The dmaengine_prep_slave_sg needs to use sg count returned by dma_map_sg, not use sport->dma_tx_nents, because the return value of dma_map_sg is not always same with "nents". Fixes: b4cdc8f61beb ("serial: imx: add DMA support for imx6q") Signed-off-by: Peng Fan <peng.fan@nxp.com> Link: https://lore.kernel.org/r/1573108875-26530-1-git-send-email-peng.fan@nxp.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
2020-02-11tty: serial: msm_serial: Fix flow controlJeffrey Hugo1-1/+5
commit b027ce258369cbfa88401a691c23dad01deb9f9b upstream. hci_qca interfaces to the wcn3990 via a uart_dm on the msm8998 mtp and Lenovo Miix 630 laptop. As part of initializing the wcn3990, hci_qca disables flow, configures the uart baudrate, and then reenables flow - at which point an event is expected to be received over the uart from the wcn3990. It is observed that this event comes after the baudrate change but before hci_qca re-enables flow. This is unexpected, and is a result of msm_reset() being broken. According to the uart_dm hardware documentation, it is recommended that automatic hardware flow control be enabled by setting RX_RDY_CTL. Auto hw flow control will manage RFR based on the configured watermark. When there is space to receive data, the hw will assert RFR. When the watermark is hit, the hw will de-assert RFR. The hardware documentation indicates that RFR can me manually managed via CR when RX_RDY_CTL is not set. SET_RFR asserts RFR, and RESET_RFR de-asserts RFR. msm_reset() is broken because after resetting the hardware, it unconditionally asserts RFR via SET_RFR. This enables flow regardless of the current configuration, and would undo a previous flow disable operation. It should instead de-assert RFR via RESET_RFR to block flow until the hardware is reconfigured. msm_serial should rely on the client to specify that flow should be enabled, either via mctrl() or the termios structure, and only assert RFR in response to those triggers. Fixes: 04896a77a97b ("msm_serial: serial driver for MSM7K onboard serial peripheral.") Signed-off-by: Jeffrey Hugo <jeffrey.l.hugo@gmail.com> Reviewed-by: Bjorn Andersson <bjorn.andersson@linaro.org> Reviewed-by: Andy Gross <agross@kernel.org> Link: https://lore.kernel.org/r/20191021154616.25457-1-jeffrey.l.hugo@gmail.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
2019-12-19serial: uartlite: fix exit path null pointerRandy Dunlap1-1/+2
commit a553add0846f355a28ed4e81134012e4a1e280c2 upstream. Call uart_unregister_driver() conditionally instead of unconditionally, only if it has been previously registered. This uses driver.state, just as the sh-sci.c driver does. Fixes this null pointer dereference in tty_unregister_driver(), since the 'driver' argument is null: general protection fault: 0000 [#1] PREEMPT SMP KASAN PTI RIP: 0010:tty_unregister_driver+0x25/0x1d0 Fixes: 238b8721a554 ("[PATCH] serial uartlite driver") Signed-off-by: Randy Dunlap <rdunlap@infradead.org> Cc: Peter Korsgaard <jacmet@sunsite.dk> Link: https://lore.kernel.org/r/9c8e6581-6fcc-a595-0897-4d90f5d710df@infradead.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
2019-11-22tty/ldsem, locking/rwsem: Add missing ACQUIRE to read_failed sleep loopPeter Zijlstra1-3/+2
commit 952041a8639a7a3a73a2b6573cb8aa8518bc39f8 upstream. While reviewing rwsem down_slowpath, Will noticed ldsem had a copy of a bug we just found for rwsem. X = 0; CPU0 CPU1 rwsem_down_read() for (;;) { set_current_state(TASK_UNINTERRUPTIBLE); X = 1; rwsem_up_write(); rwsem_mark_wake() atomic_long_add(adjustment, &sem->count); smp_store_release(&waiter->task, NULL); if (!waiter.task) break; ... } r = X; Allows 'r == 0'. Reported-by: Will Deacon <will@kernel.org> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Acked-by: Will Deacon <will@kernel.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Hurley <peter@hurleysoftware.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Fixes: 4898e640caf0 ("tty: Add timed, writer-prioritized rw semaphore") Signed-off-by: Ingo Molnar <mingo@kernel.org> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
2019-11-01tty: serial: cpm_uart - fix init when SMC is relocatedChristophe Leroy1-6/+11
commit 06aaa3d066db87e8478522d910285141d44b1e58 upstream. SMC relocation can also be activated earlier by the bootloader, so the driver's behaviour cannot rely on selected kernel config. When the SMC is relocated, CPM_CR_INIT_TRX cannot be used. But the only thing CPM_CR_INIT_TRX does is to clear the rstate and tstate registers, so this can be done manually, even when SMC is not relocated. Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr> Fixes: 9ab921201444 ("cpm_uart: fix non-console port startup bug") Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
2019-10-05tty: max310x: Fix external crystal register setupJoe Burmeister1-1/+1
commit 5d24f455c182d5116dd5db8e1dc501115ecc9c2c upstream. The datasheet states: Bit 4: ClockEnSet the ClockEn bit high to enable an external clocking (crystal or clock generator at XIN). Set the ClockEn bit to 0 to disable clocking Bit 1: CrystalEnSet the CrystalEn bit high to enable the crystal oscillator. When using an external clock source at XIN, CrystalEn must be set low. The bit 4, MAX310X_CLKSRC_EXTCLK_BIT, should be set and was not. This was required to make the MAX3107 with an external crystal on our board able to send or receive data. Signed-off-by: Joe Burmeister <joe.burmeister@devtank.co.uk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
2019-10-05serial: sh-sci: disable DMA for uart_consoleGeorge G. Davis1-0/+7
commit 099506cbbc79c0bd52b19cb6b930f256dabc3950 upstream. As noted in commit 84b40e3b57ee ("serial: 8250: omap: Disable DMA for console UART"), UART console lines use low-level PIO only access functions which will conflict with use of the line when DMA is enabled, e.g. when the console line is also used for systemd messages. So disable DMA support for UART console lines. Reported-by: Michael Rodin <mrodin@de.adit-jv.com> Link: https://patchwork.kernel.org/patch/10929511/ Tested-by: Eugeniu Rosca <erosca@de.adit-jv.com> Reviewed-by: Simon Horman <horms+renesas@verge.net.au> Reviewed-by: Wolfram Sang <wsa+renesas@sang-engineering.com> Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be> Signed-off-by: George G. Davis <george_davis@mentor.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> [bwh: Backported to 3.16: adjust context] Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
2019-09-23TTY: serial_core, add ->installJiri Slaby1-3/+12
commit 4cdd17ba1dff20ffc99fdbd2e6f0201fc7fe67df upstream. We need to compute the uart state only on the first open. This is usually what is done in the ->install hook. serial_core used to do this in ->open on every open. So move it to ->install. As a side effect, it ensures the state is set properly in the window after tty_init_dev is called, but before uart_open. This fixes a bunch of races between tty_open and flush_to_ldisc we were dealing with recently. One of such bugs was attempted to fix in commit fedb5760648a (serial: fix race between flush_to_ldisc and tty_open), but it only took care of a couple of functions (uart_start and uart_unthrottle). I was able to reproduce the crash on a SLE system, but in uart_write_room which is also called from flush_to_ldisc via process_echoes. I was *unable* to reproduce the bug locally. It is due to having this patch in my queue since 2012! general protection fault: 0000 [#1] SMP KASAN PTI CPU: 1 PID: 5 Comm: kworker/u4:0 Tainted: G L 4.12.14-396-default #1 SLE15-SP1 (unreleased) Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.12.0-0-ga698c89-prebuilt.qemu.org 04/01/2014 Workqueue: events_unbound flush_to_ldisc task: ffff8800427d8040 task.stack: ffff8800427f0000 RIP: 0010:uart_write_room+0xc4/0x590 RSP: 0018:ffff8800427f7088 EFLAGS: 00010202 RAX: dffffc0000000000 RBX: 0000000000000000 RCX: 0000000000000000 RDX: 000000000000002f RSI: 00000000000000ee RDI: ffff88003888bd90 RBP: ffffffffb9545850 R08: 0000000000000001 R09: 0000000000000400 R10: ffff8800427d825c R11: 000000000000006e R12: 1ffff100084fee12 R13: ffffc900004c5000 R14: ffff88003888bb28 R15: 0000000000000178 FS: 0000000000000000(0000) GS:ffff880043300000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000561da0794148 CR3: 000000000ebf4000 CR4: 00000000000006e0 Call Trace: tty_write_room+0x6d/0xc0 __process_echoes+0x55/0x870 n_tty_receive_buf_common+0x105e/0x26d0 tty_ldisc_receive_buf+0xb7/0x1c0 tty_port_default_receive_buf+0x107/0x180 flush_to_ldisc+0x35d/0x5c0 ... 0 in rbx means tty->driver_data is NULL in uart_write_room. 0x178 is tried to be dereferenced (0x178 >> 3 is 0x2f in rdx) at uart_write_room+0xc4. 0x178 is exactly (struct uart_state *)NULL->refcount used in uart_port_lock from uart_write_room. So revert the upstream commit here as my local patch should fix the whole family. Signed-off-by: Jiri Slaby <jslaby@suse.cz> Cc: Li RongQing <lirongqing@baidu.com> Cc: Wang Li <wangli39@baidu.com> Cc: Zhang Yu <zhangyu31@baidu.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> [bwh: Backported to 3.16: The previous fix didn't apply, so we don't need to revert it here.] Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
2019-09-23tty/vt: fix write/write race in ioctl(KDSKBSENT) handlerSergei Trofimovich1-6/+27
commit 46ca3f735f345c9d87383dd3a09fa5d43870770e upstream. The bug manifests as an attempt to access deallocated memory: BUG: unable to handle kernel paging request at ffff9c8735448000 #PF error: [PROT] [WRITE] PGD 288a05067 P4D 288a05067 PUD 288a07067 PMD 7f60c2063 PTE 80000007f5448161 Oops: 0003 [#1] PREEMPT SMP CPU: 6 PID: 388 Comm: loadkeys Tainted: G C 5.0.0-rc6-00153-g5ded5871030e #91 Hardware name: Gigabyte Technology Co., Ltd. To be filled by O.E.M./H77M-D3H, BIOS F12 11/14/2013 RIP: 0010:__memmove+0x81/0x1a0 Code: 4c 89 4f 10 4c 89 47 18 48 8d 7f 20 73 d4 48 83 c2 20 e9 a2 00 00 00 66 90 48 89 d1 4c 8b 5c 16 f8 4c 8d 54 17 f8 48 c1 e9 03 <f3> 48 a5 4d 89 1a e9 0c 01 00 00 0f 1f 40 00 48 89 d1 4c 8b 1e 49 RSP: 0018:ffffa1b9002d7d08 EFLAGS: 00010203 RAX: ffff9c873541af43 RBX: ffff9c873541af43 RCX: 00000c6f105cd6bf RDX: 0000637882e986b6 RSI: ffff9c8735447ffb RDI: ffff9c8735447ffb RBP: ffff9c8739cd3800 R08: ffff9c873b802f00 R09: 00000000fffff73b R10: ffffffffb82b35f1 R11: 00505b1b004d5b1b R12: 0000000000000000 R13: ffff9c873541af3d R14: 000000000000000b R15: 000000000000000c FS: 00007f450c390580(0000) GS:ffff9c873f180000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: ffff9c8735448000 CR3: 00000007e213c002 CR4: 00000000000606e0 Call Trace: vt_do_kdgkb_ioctl+0x34d/0x440 vt_ioctl+0xba3/0x1190 ? __bpf_prog_run32+0x39/0x60 ? mem_cgroup_commit_charge+0x7b/0x4e0 tty_ioctl+0x23f/0x920 ? preempt_count_sub+0x98/0xe0 ? __seccomp_filter+0x67/0x600 do_vfs_ioctl+0xa2/0x6a0 ? syscall_trace_enter+0x192/0x2d0 ksys_ioctl+0x3a/0x70 __x64_sys_ioctl+0x16/0x20 do_syscall_64+0x54/0xe0 entry_SYSCALL_64_after_hwframe+0x49/0xbe The bug manifests on systemd systems with multiple vtcon devices: # cat /sys/devices/virtual/vtconsole/vtcon0/name (S) dummy device # cat /sys/devices/virtual/vtconsole/vtcon1/name (M) frame buffer device There systemd runs 'loadkeys' tool in tapallel for each vtcon instance. This causes two parallel ioctl(KDSKBSENT) calls to race into adding the same entry into 'func_table' array at: drivers/tty/vt/keyboard.c:vt_do_kdgkb_ioctl() The function has no locking around writes to 'func_table'. The simplest reproducer is to have initrams with the following init on a 8-CPU machine x86_64: #!/bin/sh loadkeys -q windowkeys ru4 & loadkeys -q windowkeys ru4 & loadkeys -q windowkeys ru4 & loadkeys -q windowkeys ru4 & loadkeys -q windowkeys ru4 & loadkeys -q windowkeys ru4 & loadkeys -q windowkeys ru4 & loadkeys -q windowkeys ru4 & wait The change adds lock on write path only. Reads are still racy. CC: Greg Kroah-Hartman <gregkh@linuxfoundation.org> CC: Jiri Slaby <jslaby@suse.com> Link: https://lkml.org/lkml/2019/2/17/256 Signed-off-by: Sergei Trofimovich <slyfox@gentoo.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
2019-08-13serial: sh-sci: Fix setting SCSCR_TIE while transferring dataHoan Nguyen An1-11/+1
commit 93bcefd4c6bad4c69dbc4edcd3fbf774b24d930d upstream. We disable transmission interrupt (clear SCSCR_TIE) after all data has been transmitted (if uart_circ_empty(xmit)). While transmitting, if the data is still in the tty buffer, re-enable the SCSCR_TIE bit, which was done at sci_start_tx(). This is unnecessary processing, wasting CPU operation if the data transmission length is large. And further, transmit end, FIFO empty bits disabling have also been performed in the step above. Signed-off-by: Hoan Nguyen An <na-hoan@jinso.co.jp> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> [bwh: Backported to 3.16: adjust context] Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
2019-08-13tty: mxs-auart: fix a potential NULL pointer dereferenceKangjie Lu1-0/+4
commit 6734330654dac550f12e932996b868c6d0dcb421 upstream. In case ioremap fails, the fix returns -ENOMEM to avoid NULL pointer dereferences. Multiple places use port.membase. Signed-off-by: Kangjie Lu <kjlu@umn.edu> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> [bwh: Backported to 3.16: There is no out_disable_clks label, so goto out_free_clk on error] Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
2019-08-13tty: atmel_serial: fix a potential NULL pointer dereferenceKangjie Lu1-0/+4
commit c85be041065c0be8bc48eda4c45e0319caf1d0e5 upstream. In case dmaengine_prep_dma_cyclic fails, the fix returns a proper error code to avoid NULL pointer dereference. Signed-off-by: Kangjie Lu <kjlu@umn.edu> Fixes: 34df42f59a60 ("serial: at91: add rx dma support") Acked-by: Richard Genoud <richard.genoud@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> [bwh: Backported to 3.16: adjust context] Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
2019-08-13serial: max310x: Fix to avoid potential NULL pointer dereferenceAditya Pakki1-0/+2
commit 3a10e3dd52e80b9a97a3346020024d17b2c272d6 upstream. of_match_device can return a NULL pointer when matching device is not found. This patch avoids a scenario causing NULL pointer derefernce. Signed-off-by: Aditya Pakki <pakki001@umn.edu> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
2019-07-10serial: 8250_of: assume reg-shift of 2 for mrvl,mmp-uartLubomir Rintel1-0/+4
commit f4817843e39ce78aace0195a57d4e8500a65a898 upstream. There are two other drivers that bind to mrvl,mmp-uart and both of them assume register shift of 2 bits. There are device trees that lack the property and rely on that assumption. If this driver wins the race to bind to those devices, it should behave the same as the older deprecated driver. Signed-off-by: Lubomir Rintel <lkundrak@v3.sk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> [bwh: Backported to 3.16: adjust filename] Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
2019-07-10serial: 8250_pci: Have ACCES cards that use the four port Pericom PI7C9X7954 ↵Jay Dolan1-0/+105
chip use the pci_pericom_setup() commit 78d3820b9bd39028727c6aab7297b63c093db343 upstream. The four port Pericom chips have the fourth port at the wrong address. Make use of quirk to fix it. Fixes: c8d192428f52 ("serial: 8250: added acces i/o products quad and octal serial cards") Signed-off-by: Jay Dolan <jay.dolan@accesio.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
2019-07-10serial: 8250_pci: Fix number of ports for ACCES serial cardsJay Dolan1-18/+18
commit b896b03bc7fce43a07012cc6bf5e2ab2fddf3364 upstream. Have the correct number of ports created for ACCES serial cards. Two port cards show up as four ports, and four port cards show up as eight. Fixes: c8d192428f52 ("serial: 8250: added acces i/o products quad and octal serial cards") Signed-off-by: Jay Dolan <jay.dolan@accesio.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
2019-07-10tty: ipwireless: Fix potential NULL pointer dereferenceYueHaibing1-0/+2
commit 7dd50e205b3348dc7784efbdf85723551de64a25 upstream. There is a potential NULL pointer dereference in case alloc_ctrl_packet() fails and returns NULL. Fixes: 099dc4fb6265 ("ipwireless: driver for PC Card 3G/UMTS modem") Signed-off-by: YueHaibing <yuehaibing@huawei.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
2019-05-02tty: Handle problem if line discipline does not have receive_bufGreg Kroah-Hartman1-1/+2
commit 27cfb3a53be46a54ec5e0bd04e51995b74c90343 upstream. Some tty line disciplines do not have a receive buf callback, so properly check for that before calling it. If they do not have this callback, just eat the character quietly, as we can't fail this call. Reported-by: Jann Horn <jannh@google.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> [bwh: Backported to 3.16: adjust context] Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
2019-05-02vt: invoke notifier on screen size changeNicolas Pitre1-0/+1
commit 0c9b1965faddad7534b6974b5b36c4ad37998f8e upstream. User space using poll() on /dev/vcs devices are not awaken when a screen size change occurs. Let's fix that. Signed-off-by: Nicolas Pitre <nico@linaro.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
2019-05-02vt: always call notifier with the console lock heldNicolas Pitre1-1/+1
commit 7e1d226345f89ad5d0216a9092c81386c89b4983 upstream. Every invocation of notify_write() and notify_update() is performed under the console lock, except for one case. Let's fix that. Signed-off-by: Nicolas Pitre <nico@linaro.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
2019-05-02tty/n_hdlc: fix __might_sleep warningPaul Fulghum1-0/+1
commit fc01d8c61ce02c034e67378cd3e645734bc18c8c upstream. Fix __might_sleep warning[1] in tty/n_hdlc.c read due to copy_to_user call while current is TASK_INTERRUPTIBLE. This is a false positive since the code path does not depend on current state remaining TASK_INTERRUPTIBLE. The loop breaks out and sets TASK_RUNNING after calling copy_to_user. This patch supresses the warning by setting TASK_RUNNING before calling copy_to_user. [1] https://syzkaller.appspot.com/bug?id=17d5de7f1fcab794cb8c40032f893f52de899324 Signed-off-by: Paul Fulghum <paulkf@microgate.com> Reported-by: syzbot <syzbot+c244af085a0159d22879@syzkaller.appspotmail.com> Cc: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> Cc: Alan Cox <alan@lxorguk.ukuu.org.uk> Acked-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
2019-05-02uart: Fix crash in uart_write and uart_put_charSamir Virmani1-4/+8
commit aff9cf5955185d1f183227e46c5f8673fa483813 upstream. We were experiencing a crash similar to the one reported as part of commit:a5ba1d95e46e ("uart: fix race between uart_put_char() and uart_shutdown()") in our testbed as well. We continue to observe the same crash after integrating the commit a5ba1d95e46e ("uart: fix race between uart_put_char() and uart_shutdown()") On reviewing the change, the port lock should be taken prior to checking for if (!circ->buf) in fn. __uart_put_char and other fns. that update the buffer uart_state->xmit. Traceback: [11/27/2018 06:24:32.4870] Unable to handle kernel NULL pointer dereference at virtual address 0000003b [11/27/2018 06:24:32.4950] PC is at memcpy+0x48/0x180 [11/27/2018 06:24:32.4950] LR is at uart_write+0x74/0x120 [11/27/2018 06:24:32.4950] pc : [<ffffffc0002e6808>] lr : [<ffffffc0003747cc>] pstate: 000001c5 [11/27/2018 06:24:32.4950] sp : ffffffc076433d30 [11/27/2018 06:24:32.4950] x29: ffffffc076433d30 x28: 0000000000000140 [11/27/2018 06:24:32.4950] x27: ffffffc0009b9d5e x26: ffffffc07ce36580 [11/27/2018 06:24:32.4950] x25: 0000000000000000 x24: 0000000000000140 [11/27/2018 06:24:32.4950] x23: ffffffc000891200 x22: ffffffc01fc34000 [11/27/2018 06:24:32.4950] x21: 0000000000000fff x20: 0000000000000076 [11/27/2018 06:24:32.4950] x19: 0000000000000076 x18: 0000000000000000 [11/27/2018 06:24:32.4950] x17: 000000000047cf08 x16: ffffffc000099e68 [11/27/2018 06:24:32.4950] x15: 0000000000000018 x14: 776d726966205948 [11/27/2018 06:24:32.4950] x13: 50203a6c6974755f x12: 74647075205d3333 [11/27/2018 06:24:32.4950] x11: 3a35323a36203831 x10: 30322f37322f3131 [11/27/2018 06:24:32.4950] x9 : 5b205d303638342e x8 : 746164206f742070 [11/27/2018 06:24:32.4950] x7 : 7520736920657261 x6 : 000000000000003b [11/27/2018 06:24:32.4950] x5 : 000000000000817a x4 : 0000000000000008 [11/27/2018 06:24:32.4950] x3 : 2f37322f31312a5b x2 : 000000000000006e [11/27/2018 06:24:32.4950] x1 : ffffffc0009b9cf0 x0 : 000000000000003b [11/27/2018 06:24:32.4950] CPU2: stopping [11/27/2018 06:24:32.4950] CPU: 2 PID: 0 Comm: swapper/2 Tainted: P D O 4.1.51 #3 [11/27/2018 06:24:32.4950] Hardware name: Broadcom-v8A (DT) [11/27/2018 06:24:32.4950] Call trace: [11/27/2018 06:24:32.4950] [<ffffffc0000883b8>] dump_backtrace+0x0/0x150 [11/27/2018 06:24:32.4950] [<ffffffc00008851c>] show_stack+0x14/0x20 [11/27/2018 06:24:32.4950] [<ffffffc0005ee810>] dump_stack+0x90/0xb0 [11/27/2018 06:24:32.4950] [<ffffffc00008e844>] handle_IPI+0x18c/0x1a0 [11/27/2018 06:24:32.4950] [<ffffffc000080c68>] gic_handle_irq+0x88/0x90 Fixes: a5ba1d95e46e ("uart: fix race between uart_put_char() and uart_shutdown()") Signed-off-by: Samir Virmani <samir@embedur.com> Acked-by: Tycho Andersen <tycho@tycho.ws> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> [bwh: Backported to 3.16: - Keep open-coding uart_port_lock() - Adjust context] Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
2019-04-04tty/ldsem: Wake up readers after timed out down_write()Dmitry Safonov1-0/+10
commit 231f8fd0cca078bd4396dd7e380db813ac5736e2 upstream. ldsem_down_read() will sleep if there is pending writer in the queue. If the writer times out, readers in the queue should be woken up, otherwise they may miss a chance to acquire the semaphore until the last active reader will do ldsem_up_read(). There was a couple of reports where there was one active reader and other readers soft locked up: Showing all locks held in the system: 2 locks held by khungtaskd/17: #0: (rcu_read_lock){......}, at: watchdog+0x124/0x6d1 #1: (tasklist_lock){.+.+..}, at: debug_show_all_locks+0x72/0x2d3 2 locks held by askfirst/123: #0: (&tty->ldisc_sem){.+.+.+}, at: ldsem_down_read+0x46/0x58 #1: (&ldata->atomic_read_lock){+.+...}, at: n_tty_read+0x115/0xbe4 Prevent readers wait for active readers to release ldisc semaphore. Link: lkml.kernel.org/r/20171121132855.ajdv4k6swzhvktl6@wfg-t540p.sh.intel.com Link: lkml.kernel.org/r/20180907045041.GF1110@shao2-debian Cc: Jiri Slaby <jslaby@suse.com> Cc: Peter Zijlstra <peterz@infradead.org> Reported-by: kernel test robot <rong.a.chen@intel.com> Signed-off-by: Dmitry Safonov <dima@arista.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
2019-04-04serial: imx: fix error handling in console_setupStefan Agner1-1/+1
commit 63fd4b94b948c14eeb27a3bbf50ea0f7f0593bad upstream. The ipg clock only needs to be unprepared in case preparing per clock fails. The ipg clock has already disabled at the point. Fixes: 1cf93e0d5488 ("serial: imx: remove the uart_console() check") Signed-off-by: Stefan Agner <stefan@agner.ch> Reviewed-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
2019-02-11kgdboc: fix KASAN global-out-of-bounds bug in param_set_kgdboc_var()Macpaul Lin1-2/+2
commit dada6a43b0402eba438a17ac86fdc64ac56a4607 upstream. This patch is trying to fix KE issue due to "BUG: KASAN: global-out-of-bounds in param_set_kgdboc_var+0x194/0x198" reported by Syzkaller scan." [26364:syz-executor0][name:report8t]BUG: KASAN: global-out-of-bounds in param_set_kgdboc_var+0x194/0x198 [26364:syz-executor0][name:report&]Read of size 1 at addr ffffff900e44f95f by task syz-executor0/26364 [26364:syz-executor0][name:report&] [26364:syz-executor0]CPU: 7 PID: 26364 Comm: syz-executor0 Tainted: G W 0 [26364:syz-executor0]Call trace: [26364:syz-executor0][<ffffff9008095cf8>] dump_bacIctrace+Ox0/0x470 [26364:syz-executor0][<ffffff9008096de0>] show_stack+0x20/0x30 [26364:syz-executor0][<ffffff90089cc9c8>] dump_stack+Oxd8/0x128 [26364:syz-executor0][<ffffff90084edb38>] print_address_description +0x80/0x4a8 [26364:syz-executor0][<ffffff90084ee270>] kasan_report+Ox178/0x390 [26364:syz-executor0][<ffffff90084ee4a0>] _asan_report_loadi_noabort+Ox18/0x20 [26364:syz-executor0][<ffffff9008b092ac>] param_set_kgdboc_var+Ox194/0x198 [26364:syz-executor0][<ffffff900813af64>] param_attr_store+Ox14c/0x270 [26364:syz-executor0][<ffffff90081394c8>] module_attr_store+0x60/0x90 [26364:syz-executor0][<ffffff90086690c0>] sysfs_kl_write+Ox100/0x158 [26364:syz-executor0][<ffffff9008666d84>] kernfs_fop_write+0x27c/0x3a8 [26364:syz-executor0][<ffffff9008508264>] do_loop_readv_writev+0x114/0x1b0 [26364:syz-executor0][<ffffff9008509ac8>] do_readv_writev+0x4f8/0x5e0 [26364:syz-executor0][<ffffff9008509ce4>] vfs_writev+0x7c/Oxb8 [26364:syz-executor0][<ffffff900850ba64>] SyS_writev+Oxcc/0x208 [26364:syz-executor0][<ffffff90080883f0>] elO_svc_naked +0x24/0x28 [26364:syz-executor0][name:report&] [26364:syz-executor0][name:report&]The buggy address belongs to the variable: [26364:syz-executor0][name:report&] kgdb_tty_line+Ox3f/0x40 [26364:syz-executor0][name:report&] [26364:syz-executor0][name:report&]Memory state around the buggy address: [26364:syz-executor0] ffffff900e44f800: 00 00 00 00 00 04 fa fa fa fa fa fa 00 fa fa fa [26364:syz-executor0] ffffff900e44f880: fa fa fa fa 00 fa fa fa fa fa fa fa 00 fa fa fa [26364:syz-executor0]> ffffff900e44f900: fa fa fa fa 04 fa fa fa fa fa fa fa 00 00 00 00 [26364:syz-executor0][name:report&] ^ [26364:syz-executor0] ffffff900e44f980: 00 fa fa fa fa fa fa fa 04 fa fa fa fa fa fa fa [26364:syz-executor0] ffffff900e44fa00: 04 fa fa fa fa fa fa fa 00 fa fa fa fa fa fa fa [26364:syz-executor0][name:report&] [26364:syz-executor0][name:panic&]Disabling lock debugging due to kernel taint [26364:syz-executor0]------------[cut here]------------ After checking the source code, we've found there might be an out-of-bounds access to "config[len - 1]" array when the variable "len" is zero. Signed-off-by: Macpaul Lin <macpaul@gmail.com> Acked-by: Daniel Thompson <daniel.thompson@linaro.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
2019-02-11termios, tty/tty_baudrate.c: fix buffer overrunH. Peter Anvin1-2/+2
commit 991a25194097006ec1e0d2e0814ff920e59e3465 upstream. On architectures with CBAUDEX == 0 (Alpha and PowerPC), the code in tty_baudrate.c does not do any limit checking on the tty_baudrate[] array, and in fact a buffer overrun is possible on both architectures. Add a limit check to prevent that situation. This will be followed by a much bigger cleanup/simplification patch. Signed-off-by: H. Peter Anvin (Intel) <hpa@zytor.com> Requested-by: Cc: Johan Hovold <johan@kernel.org> Cc: Jiri Slaby <jslaby@suse.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Richard Henderson <rth@twiddle.net> Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru> Cc: Matt Turner <mattst88@gmail.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Kate Stewart <kstewart@linuxfoundation.org> Cc: Philippe Ombredanne <pombredanne@nexb.com> Cc: Eugene Syromiatnikov <esyr@redhat.com> Cc: Alan Cox <alan@lxorguk.ukuu.org.uk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> [bwh: Backported to 3.16: adjust filename, context] Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
2019-02-11kgdboc: Passing ekgdboc to command line causes panicHe Zhe1-0/+5
commit 1bd54d851f50dea6af30c3e6ff4f3e9aab5558f9 upstream. kgdboc_option_setup does not check input argument before passing it to strlen. The argument would be a NULL pointer if "ekgdboc", without its value, is set in command line and thus cause the following panic. PANIC: early exception 0xe3 IP 10:ffffffff8fbbb620 error 0 cr2 0x0 [ 0.000000] CPU: 0 PID: 0 Comm: swapper Not tainted 4.18-rc8+ #1 [ 0.000000] RIP: 0010:strlen+0x0/0x20 ... [ 0.000000] Call Trace [ 0.000000] ? kgdboc_option_setup+0x9/0xa0 [ 0.000000] ? kgdboc_early_init+0x6/0x1b [ 0.000000] ? do_early_param+0x4d/0x82 [ 0.000000] ? parse_args+0x212/0x330 [ 0.000000] ? rdinit_setup+0x26/0x26 [ 0.000000] ? parse_early_options+0x20/0x23 [ 0.000000] ? rdinit_setup+0x26/0x26 [ 0.000000] ? parse_early_param+0x2d/0x39 [ 0.000000] ? setup_arch+0x2f7/0xbf4 [ 0.000000] ? start_kernel+0x5e/0x4c2 [ 0.000000] ? load_ucode_bsp+0x113/0x12f [ 0.000000] ? secondary_startup_64+0xa5/0xb0 This patch adds a check to prevent the panic. Cc: jason.wessel@windriver.com Cc: gregkh@linuxfoundation.org Cc: jslaby@suse.com Signed-off-by: He Zhe <zhe.he@windriver.com> Reviewed-by: Daniel Thompson <daniel.thompson@linaro.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
2018-12-17tty: vt_ioctl: fix potential Spectre v1Gustavo A. R. Silva1-0/+4
commit e97267cb4d1ee01ca0929638ec0fcbb0904f903d upstream. vsa.console is indirectly controlled by user-space, hence leading to a potential exploitation of the Spectre variant 1 vulnerability. This issue was detected with the help of Smatch: drivers/tty/vt/vt_ioctl.c:711 vt_ioctl() warn: potential spectre issue 'vc_cons' [r] Fix this by sanitizing vsa.console before using it to index vc_cons Notice that given that speculation windows are large, the policy is to kill the speculation on the first load and not worry if it can be completed with a dependent load/store [1]. [1] https://marc.info/?l=linux-kernel&m=152449131114778&w=2 Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com> Reviewed-by: Alan Cox <alan@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
2018-12-17serial: cpm_uart: return immediately from console pollChristophe Leroy1-3/+7
commit be28c1e3ca29887e207f0cbcd294cefe5074bab6 upstream. kgdb expects poll function to return immediately and returning NO_POLL_CHAR when no character is available. Fixes: f5316b4aea024 ("kgdb,8250,pl011: Return immediately from console poll") Cc: Jason Wessel <jason.wessel@windriver.com> Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
2018-12-17tty: fix termios input-speed encoding when using BOTHERJohan Hovold1-3/+7
commit 1cee38f0363a88db374e50b232ca17b9a4c12fa0 upstream. When the termios CIBAUD bits are left unset (i.e. B0), we use the same output and input speed and should leave CIBAUD unchanged. When the user requests a rate using BOTHER and c_ospeed which the driver cannot set exactly, the driver can report back the actual baud rate using tty_termios_encode_baud_rate(). If this rate is close enough to a standard rate however, we could end up setting CIBAUD to a Bfoo value despite the user having left it unset. This in turn could lead to an unexpected input rate being set on subsequent termios updates. Fix this by using a zero tolerance value also for the input rate when CIBAUD is clear so that the matching logic works as expected. Fixes: 78137e3b34e1 ("[PATCH] tty: improve encode_baud_rate logic") Signed-off-by: Johan Hovold <johan@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> [bwh: Backported to 3.16: adjust filename] Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
2018-12-17tty: fix termios input-speed encodingJohan Hovold1-0/+3
commit fada18c48d774b9e837928ecdce6a5d5fdd11ee7 upstream. Make sure to clear the CIBAUD bits before OR-ing the new mask when encoding the termios input baud rate. This could otherwise lead to an incorrect input rate being reported back and incidentally set on subsequent termios updates. Fixes: edc6afc54968 ("[PATCH] tty: switch to ktermios and new framework") Signed-off-by: Johan Hovold <johan@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> [bwh: Backported to 3.16: adjust filename] Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
2018-12-17tty: fix typo in comment of tty_termios_encode_baud_rateMatthias Brugger1-1/+1
commit a1d51aa2214cea3f91611893610a2f769cada0e7 upstream. Signed-off-by: Matthias Brugger <matthias.bgg@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
2018-12-17uart: fix race between uart_put_char() and uart_shutdown()Tycho Andersen1-5/+12
commit a5ba1d95e46ecaea638ddd7cd144107c783acb5d upstream. We have reports of the following crash: PID: 7 TASK: ffff88085c6d61c0 CPU: 1 COMMAND: "kworker/u25:0" #0 [ffff88085c6db710] machine_kexec at ffffffff81046239 #1 [ffff88085c6db760] crash_kexec at ffffffff810fc248 #2 [ffff88085c6db830] oops_end at ffffffff81008ae7 #3 [ffff88085c6db860] no_context at ffffffff81050b8f #4 [ffff88085c6db8b0] __bad_area_nosemaphore at ffffffff81050d75 #5 [ffff88085c6db900] bad_area_nosemaphore at ffffffff81050e83 #6 [ffff88085c6db910] __do_page_fault at ffffffff8105132e #7 [ffff88085c6db9b0] do_page_fault at ffffffff8105152c #8 [ffff88085c6db9c0] page_fault at ffffffff81a3f122 [exception RIP: uart_put_char+149] RIP: ffffffff814b67b5 RSP: ffff88085c6dba78 RFLAGS: 00010006 RAX: 0000000000000292 RBX: ffffffff827c5120 RCX: 0000000000000081 RDX: 0000000000000000 RSI: 000000000000005f RDI: ffffffff827c5120 RBP: ffff88085c6dba98 R8: 000000000000012c R9: ffffffff822ea320 R10: ffff88085fe4db04 R11: 0000000000000001 R12: ffff881059f9c000 R13: 0000000000000001 R14: 000000000000005f R15: 0000000000000fba ORIG_RAX: ffffffffffffffff CS: 0010 SS: 0018 #9 [ffff88085c6dbaa0] tty_put_char at ffffffff81497544 #10 [ffff88085c6dbac0] do_output_char at ffffffff8149c91c #11 [ffff88085c6dbae0] __process_echoes at ffffffff8149cb8b #12 [ffff88085c6dbb30] commit_echoes at ffffffff8149cdc2 #13 [ffff88085c6dbb60] n_tty_receive_buf_fast at ffffffff8149e49b #14 [ffff88085c6dbbc0] __receive_buf at ffffffff8149ef5a #15 [ffff88085c6dbc20] n_tty_receive_buf_common at ffffffff8149f016 #16 [ffff88085c6dbca0] n_tty_receive_buf2 at ffffffff8149f194 #17 [ffff88085c6dbcb0] flush_to_ldisc at ffffffff814a238a #18 [ffff88085c6dbd50] process_one_work at ffffffff81090be2 #19 [ffff88085c6dbe20] worker_thread at ffffffff81091b4d #20 [ffff88085c6dbeb0] kthread at ffffffff81096384 #21 [ffff88085c6dbf50] ret_from_fork at ffffffff81a3d69f​ after slogging through some dissasembly: ffffffff814b6720 <uart_put_char>: ffffffff814b6720: 55 push %rbp ffffffff814b6721: 48 89 e5 mov %rsp,%rbp ffffffff814b6724: 48 83 ec 20 sub $0x20,%rsp ffffffff814b6728: 48 89 1c 24 mov %rbx,(%rsp) ffffffff814b672c: 4c 89 64 24 08 mov %r12,0x8(%rsp) ffffffff814b6731: 4c 89 6c 24 10 mov %r13,0x10(%rsp) ffffffff814b6736: 4c 89 74 24 18 mov %r14,0x18(%rsp) ffffffff814b673b: e8 b0 8e 58 00 callq ffffffff81a3f5f0 <mcount> ffffffff814b6740: 4c 8b a7 88 02 00 00 mov 0x288(%rdi),%r12 ffffffff814b6747: 45 31 ed xor %r13d,%r13d ffffffff814b674a: 41 89 f6 mov %esi,%r14d ffffffff814b674d: 49 83 bc 24 70 01 00 cmpq $0x0,0x170(%r12) ffffffff814b6754: 00 00 ffffffff814b6756: 49 8b 9c 24 80 01 00 mov 0x180(%r12),%rbx ffffffff814b675d: 00 ffffffff814b675e: 74 2f je ffffffff814b678f <uart_put_char+0x6f> ffffffff814b6760: 48 89 df mov %rbx,%rdi ffffffff814b6763: e8 a8 67 58 00 callq ffffffff81a3cf10 <_raw_spin_lock_irqsave> ffffffff814b6768: 41 8b 8c 24 78 01 00 mov 0x178(%r12),%ecx ffffffff814b676f: 00 ffffffff814b6770: 89 ca mov %ecx,%edx ffffffff814b6772: f7 d2 not %edx ffffffff814b6774: 41 03 94 24 7c 01 00 add 0x17c(%r12),%edx ffffffff814b677b: 00 ffffffff814b677c: 81 e2 ff 0f 00 00 and $0xfff,%edx ffffffff814b6782: 75 23 jne ffffffff814b67a7 <uart_put_char+0x87> ffffffff814b6784: 48 89 c6 mov %rax,%rsi ffffffff814b6787: 48 89 df mov %rbx,%rdi ffffffff814b678a: e8 e1 64 58 00 callq ffffffff81a3cc70 <_raw_spin_unlock_irqrestore> ffffffff814b678f: 44 89 e8 mov %r13d,%eax ffffffff814b6792: 48 8b 1c 24 mov (%rsp),%rbx ffffffff814b6796: 4c 8b 64 24 08 mov 0x8(%rsp),%r12 ffffffff814b679b: 4c 8b 6c 24 10 mov 0x10(%rsp),%r13 ffffffff814b67a0: 4c 8b 74 24 18 mov 0x18(%rsp),%r14 ffffffff814b67a5: c9 leaveq ffffffff814b67a6: c3 retq ffffffff814b67a7: 49 8b 94 24 70 01 00 mov 0x170(%r12),%rdx ffffffff814b67ae: 00 ffffffff814b67af: 48 63 c9 movslq %ecx,%rcx ffffffff814b67b2: 41 b5 01 mov $0x1,%r13b ffffffff814b67b5: 44 88 34 0a mov %r14b,(%rdx,%rcx,1) ffffffff814b67b9: 41 8b 94 24 78 01 00 mov 0x178(%r12),%edx ffffffff814b67c0: 00 ffffffff814b67c1: 83 c2 01 add $0x1,%edx ffffffff814b67c4: 81 e2 ff 0f 00 00 and $0xfff,%edx ffffffff814b67ca: 41 89 94 24 78 01 00 mov %edx,0x178(%r12) ffffffff814b67d1: 00 ffffffff814b67d2: eb b0 jmp ffffffff814b6784 <uart_put_char+0x64> ffffffff814b67d4: 66 66 66 2e 0f 1f 84 data32 data32 nopw %cs:0x0(%rax,%rax,1) ffffffff814b67db: 00 00 00 00 00 for our build, this is crashing at: circ->buf[circ->head] = c; Looking in uart_port_startup(), it seems that circ->buf (state->xmit.buf) protected by the "per-port mutex", which based on uart_port_check() is state->port.mutex. Indeed, the lock acquired in uart_put_char() is uport->lock, i.e. not the same lock. Anyway, since the lock is not acquired, if uart_shutdown() is called, the last chunk of that function may release state->xmit.buf before its assigned to null, and cause the race above. To fix it, let's lock uport->lock when allocating/deallocating state->xmit.buf in addition to the per-port mutex. v2: switch to locking uport->lock on allocation/deallocation instead of locking the per-port mutex in uart_put_char. Note that since uport->lock is a spin lock, we have to switch the allocation to GFP_ATOMIC. v3: move the allocation outside the lock, so we can switch back to GFP_KERNEL Signed-off-by: Tycho Andersen <tycho@tycho.ws> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> [bwh: Backported to 3.16: Use uport->lock directly rather than through uart_port_{,un}lock()] Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
2018-12-17serial: pxa: Fix an error handling path in 'serial_pxa_probe()'Christophe JAILLET1-1/+2
commit 95a0e656580fab3128c7bee5f660c50784f53651 upstream. If port.line is out of range, we still need to release some resources, or we will leak them. Fixes: afc7851fab83 ("serial: pxa: Fix out-of-bounds access through serial port index") Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
2018-11-20vt: prevent leaking uninitialized data to userspace via /dev/vcs*Alexander Potapenko1-2/+2
commit 21eff69aaaa0e766ca0ce445b477698dc6a9f55a upstream. KMSAN reported an infoleak when reading from /dev/vcs*: BUG: KMSAN: kernel-infoleak in vcs_read+0x18ba/0x1cc0 Call Trace: ... kmsan_copy_to_user+0x7a/0x160 mm/kmsan/kmsan.c:1253 copy_to_user ./include/linux/uaccess.h:184 vcs_read+0x18ba/0x1cc0 drivers/tty/vt/vc_screen.c:352 __vfs_read+0x1b2/0x9d0 fs/read_write.c:416 vfs_read+0x36c/0x6b0 fs/read_write.c:452 ... Uninit was created at: kmsan_save_stack_with_flags mm/kmsan/kmsan.c:279 kmsan_internal_poison_shadow+0xb8/0x1b0 mm/kmsan/kmsan.c:189 kmsan_kmalloc+0x94/0x100 mm/kmsan/kmsan.c:315 __kmalloc+0x13a/0x350 mm/slub.c:3818 kmalloc ./include/linux/slab.h:517 vc_allocate+0x438/0x800 drivers/tty/vt/vt.c:787 con_install+0x8c/0x640 drivers/tty/vt/vt.c:2880 tty_driver_install_tty drivers/tty/tty_io.c:1224 tty_init_dev+0x1b5/0x1020 drivers/tty/tty_io.c:1324 tty_open_by_driver drivers/tty/tty_io.c:1959 tty_open+0x17b4/0x2ed0 drivers/tty/tty_io.c:2007 chrdev_open+0xc25/0xd90 fs/char_dev.c:417 do_dentry_open+0xccc/0x1440 fs/open.c:794 vfs_open+0x1b6/0x2f0 fs/open.c:908 ... Bytes 0-79 of 240 are uninitialized Consistently allocating |vc_screenbuf| with kzalloc() fixes the problem Reported-by: syzbot+17a8efdf800000@syzkaller.appspotmail.com Signed-off-by: Alexander Potapenko <glider@google.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
2018-11-20tty: vt, get rid of weird source code flowJiri Slaby1-31/+39
commit 34902b7f2754e6d890feb0cee34187f1bc75c930 upstream. Some code in vc_allocate is indented by 4 spaces. It is inside a condition. Invert the condition and move the code to the first indentation level (using \tab). And insert some empty lines to have logical code blocks separated. Then, instead of freeing in an 'if' false branch, use goto-error label as fail path. Maybe better to look at this patch with diff -w -b. Signed-off-by: Jiri Slaby <jslaby@suse.cz> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
2018-11-20tty: vt, remove reduntant checkJiri Slaby1-4/+0
commit 182846a00f489849c55d113954f0c4a8a286ca39 upstream. MAX_NR_CONSOLES and MAX_NR_USER_CONSOLES are both 63 since they were introduced in 1.1.54. And since vc_allocate does: if (currcons >= MAX_NR_CONSOLES) return -ENXIO; if (!vc_cons[currcons].d) { if (currcons >= MAX_NR_USER_CONSOLES && !capable(CAP_SYS_RESOURCE)) return -EPERM; } the second check is pointless. Remove both the check and the macro MAX_NR_USER_CONSOLES. Signed-off-by: Jiri Slaby <jslaby@suse.cz> Reported-by: Fugang Duan <fugang.duan@nxp.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
2018-11-20n_tty: Access echo_* variables carefully.Tetsuo Handa1-18/+24
commit ebec3f8f5271139df618ebdf8427e24ba102ba94 upstream. syzbot is reporting stalls at __process_echoes() [1]. This is because since ldata->echo_commit < ldata->echo_tail becomes true for some reason, the discard loop is serving as almost infinite loop. This patch tries to avoid falling into ldata->echo_commit < ldata->echo_tail situation by making access to echo_* variables more carefully. Since reset_buffer_flags() is called without output_lock held, it should not touch echo_* variables. And omit a call to reset_buffer_flags() from n_tty_open() by using vzalloc(). Since add_echo_byte() is called without output_lock held, it needs memory barrier between storing into echo_buf[] and incrementing echo_head counter. echo_buf() needs corresponding memory barrier before reading echo_buf[]. Lack of handling the possibility of not-yet-stored multi-byte operation might be the reason of falling into ldata->echo_commit < ldata->echo_tail situation, for if I do WARN_ON(ldata->echo_commit == tail + 1) prior to echo_buf(ldata, tail + 1), the WARN_ON() fires. Also, explicitly masking with buffer for the former "while" loop, and use ldata->echo_commit > tail for the latter "while" loop. [1] https://syzkaller.appspot.com/bug?id=17f23b094cd80df750e5b0f8982c521ee6bcbf40 Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> Reported-by: syzbot <syzbot+108696293d7a21ab688f@syzkaller.appspotmail.com> Cc: Peter Hurley <peter@hurleysoftware.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> [bwh: Backported to 3.16: adjust context] Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
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