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2020-04-24tty: evh_bytechan: Fix out of bounds accessesStephen Rothwell
commit 3670664b5da555a2a481449b3baafff113b0ac35 upstream. ev_byte_channel_send() assumes that its third argument is a 16 byte array. Some places where it is called it may not be (or we can't easily tell if it is). Newer compilers have started producing warnings about this, so make sure we actually pass a 16 byte array. There may be more elegant solutions to this, but the driver is quite old and hasn't been updated in many years. The warnings (from a powerpc allyesconfig build) are: In file included from include/linux/byteorder/big_endian.h:5, from arch/powerpc/include/uapi/asm/byteorder.h:14, from include/asm-generic/bitops/le.h:6, from arch/powerpc/include/asm/bitops.h:250, from include/linux/bitops.h:29, from include/linux/kernel.h:12, from include/asm-generic/bug.h:19, from arch/powerpc/include/asm/bug.h:109, from include/linux/bug.h:5, from include/linux/mmdebug.h:5, from include/linux/gfp.h:5, from include/linux/slab.h:15, from drivers/tty/ehv_bytechan.c:24: drivers/tty/ehv_bytechan.c: In function ‘ehv_bc_udbg_putc’: arch/powerpc/include/asm/epapr_hcalls.h:298:20: warning: array subscript 1 is outside array bounds of ‘const char[1]’ [-Warray-bounds] 298 | r6 = be32_to_cpu(p[1]); include/uapi/linux/byteorder/big_endian.h:40:51: note: in definition of macro ‘__be32_to_cpu’ 40 | #define __be32_to_cpu(x) ((__force __u32)(__be32)(x)) | ^ arch/powerpc/include/asm/epapr_hcalls.h:298:7: note: in expansion of macro ‘be32_to_cpu’ 298 | r6 = be32_to_cpu(p[1]); | ^~~~~~~~~~~ drivers/tty/ehv_bytechan.c:166:13: note: while referencing ‘data’ 166 | static void ehv_bc_udbg_putc(char c) | ^~~~~~~~~~~~~~~~ Fixes: dcd83aaff1c8 ("tty/powerpc: introduce the ePAPR embedded hypervisor byte channel driver") Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au> Tested-by: Laurentiu Tudor <laurentiu.tudor@nxp.com> [mpe: Trim warnings from change log] Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20200109183912.5fcb52aa@canb.auug.org.au Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-04-02vt: vt_ioctl: fix use-after-free in vt_in_use()Eric Biggers
commit 7cf64b18b0b96e751178b8d0505d8466ff5a448f upstream. vt_in_use() dereferences console_driver->ttys[i] without proper locking. This is broken because the tty can be closed and freed concurrently. We could fix this by using 'READ_ONCE(console_driver->ttys[i]) != NULL' and skipping the check of tty_struct::count. But, looking at console_driver->ttys[i] isn't really appropriate anyway because even if it is NULL the tty can still be in the process of being closed. Instead, fix it by making vt_in_use() require console_lock() and check whether the vt is allocated and has port refcount > 1. This works since following the patch "vt: vt_ioctl: fix VT_DISALLOCATE freeing in-use virtual console" the port refcount is incremented while the vt is open. Reproducer (very unreliable, but it worked for me after a few minutes): #include <fcntl.h> #include <linux/vt.h> int main() { int fd, nproc; struct vt_stat state; char ttyname[16]; fd = open("/dev/tty10", O_RDONLY); for (nproc = 1; nproc < 8; nproc *= 2) fork(); for (;;) { sprintf(ttyname, "/dev/tty%d", rand() % 8); close(open(ttyname, O_RDONLY)); ioctl(fd, VT_GETSTATE, &state); } } KASAN report: BUG: KASAN: use-after-free in vt_in_use drivers/tty/vt/vt_ioctl.c:48 [inline] BUG: KASAN: use-after-free in vt_ioctl+0x1ad3/0x1d70 drivers/tty/vt/vt_ioctl.c:657 Read of size 4 at addr ffff888065722468 by task syz-vt2/132 CPU: 0 PID: 132 Comm: syz-vt2 Not tainted 5.6.0-rc5-00130-g089b6d3654916 #13 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS ?-20191223_100556-anatol 04/01/2014 Call Trace: [...] vt_in_use drivers/tty/vt/vt_ioctl.c:48 [inline] vt_ioctl+0x1ad3/0x1d70 drivers/tty/vt/vt_ioctl.c:657 tty_ioctl+0x9db/0x11b0 drivers/tty/tty_io.c:2660 [...] Allocated by task 136: [...] kzalloc include/linux/slab.h:669 [inline] alloc_tty_struct+0x96/0x8a0 drivers/tty/tty_io.c:2982 tty_init_dev+0x23/0x350 drivers/tty/tty_io.c:1334 tty_open_by_driver drivers/tty/tty_io.c:1987 [inline] tty_open+0x3ca/0xb30 drivers/tty/tty_io.c:2035 [...] Freed by task 41: [...] kfree+0xbf/0x200 mm/slab.c:3757 free_tty_struct+0x8d/0xb0 drivers/tty/tty_io.c:177 release_one_tty+0x22d/0x2f0 drivers/tty/tty_io.c:1468 process_one_work+0x7f1/0x14b0 kernel/workqueue.c:2264 worker_thread+0x8b/0xc80 kernel/workqueue.c:2410 [...] Fixes: 4001d7b7fc27 ("vt: push down the tty lock so we can see what is left to tackle") Cc: <stable@vger.kernel.org> # v3.4+ Acked-by: Jiri Slaby <jslaby@suse.cz> Signed-off-by: Eric Biggers <ebiggers@google.com> Link: https://lore.kernel.org/r/20200322034305.210082-3-ebiggers@kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-04-02vt: vt_ioctl: fix VT_DISALLOCATE freeing in-use virtual consoleEric Biggers
commit ca4463bf8438b403596edd0ec961ca0d4fbe0220 upstream. The VT_DISALLOCATE ioctl can free a virtual console while tty_release() is still running, causing a use-after-free in con_shutdown(). This occurs because VT_DISALLOCATE considers a virtual console's 'struct vc_data' to be unused as soon as the corresponding tty's refcount hits 0. But actually it may be still being closed. Fix this by making vc_data be reference-counted via the embedded 'struct tty_port'. A newly allocated virtual console has refcount 1. Opening it for the first time increments the refcount to 2. Closing it for the last time decrements the refcount (in tty_operations::cleanup() so that it happens late enough), as does VT_DISALLOCATE. Reproducer: #include <fcntl.h> #include <linux/vt.h> #include <sys/ioctl.h> #include <unistd.h> int main() { if (fork()) { for (;;) close(open("/dev/tty5", O_RDWR)); } else { int fd = open("/dev/tty10", O_RDWR); for (;;) ioctl(fd, VT_DISALLOCATE, 5); } } KASAN report: BUG: KASAN: use-after-free in con_shutdown+0x76/0x80 drivers/tty/vt/vt.c:3278 Write of size 8 at addr ffff88806a4ec108 by task syz_vt/129 CPU: 0 PID: 129 Comm: syz_vt Not tainted 5.6.0-rc2 #11 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS ?-20191223_100556-anatol 04/01/2014 Call Trace: [...] con_shutdown+0x76/0x80 drivers/tty/vt/vt.c:3278 release_tty+0xa8/0x410 drivers/tty/tty_io.c:1514 tty_release_struct+0x34/0x50 drivers/tty/tty_io.c:1629 tty_release+0x984/0xed0 drivers/tty/tty_io.c:1789 [...] Allocated by task 129: [...] kzalloc include/linux/slab.h:669 [inline] vc_allocate drivers/tty/vt/vt.c:1085 [inline] vc_allocate+0x1ac/0x680 drivers/tty/vt/vt.c:1066 con_install+0x4d/0x3f0 drivers/tty/vt/vt.c:3229 tty_driver_install_tty drivers/tty/tty_io.c:1228 [inline] tty_init_dev+0x94/0x350 drivers/tty/tty_io.c:1341 tty_open_by_driver drivers/tty/tty_io.c:1987 [inline] tty_open+0x3ca/0xb30 drivers/tty/tty_io.c:2035 [...] Freed by task 130: [...] kfree+0xbf/0x1e0 mm/slab.c:3757 vt_disallocate drivers/tty/vt/vt_ioctl.c:300 [inline] vt_ioctl+0x16dc/0x1e30 drivers/tty/vt/vt_ioctl.c:818 tty_ioctl+0x9db/0x11b0 drivers/tty/tty_io.c:2660 [...] Fixes: 4001d7b7fc27 ("vt: push down the tty lock so we can see what is left to tackle") Cc: <stable@vger.kernel.org> # v3.4+ Reported-by: syzbot+522643ab5729b0421998@syzkaller.appspotmail.com Acked-by: Jiri Slaby <jslaby@suse.cz> Signed-off-by: Eric Biggers <ebiggers@google.com> Link: https://lore.kernel.org/r/20200322034305.210082-2-ebiggers@kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-04-02vt: vt_ioctl: remove unnecessary console allocation checksEric Biggers
commit 1aa6e058dd6cd04471b1f21298270014daf48ac9 upstream. The vc_cons_allocated() checks in vt_ioctl() and vt_compat_ioctl() are unnecessary because they can only be reached by calling ioctl() on an open tty, which implies the corresponding virtual console is allocated. And even if the virtual console *could* be freed concurrently, then these checks would be broken since they aren't done under console_lock, and the vc_data is dereferenced before them anyway. So, remove these unneeded checks to avoid confusion. Signed-off-by: Eric Biggers <ebiggers@google.com> Link: https://lore.kernel.org/r/20200224080326.295046-1-ebiggers@kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-04-02vt: switch vt_dont_switch to boolJiri Slaby
commit f400991bf872debffb01c46da882dc97d7e3248e upstream. vt_dont_switch is pure boolean, no need for whole char. Signed-off-by: Jiri Slaby <jslaby@suse.cz> Link: https://lore.kernel.org/r/20200219073951.16151-6-jslaby@suse.cz Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-04-02vt: ioctl, switch VT_IS_IN_USE and VT_BUSY to inlinesJiri Slaby
commit e587e8f17433ddb26954f0edf5b2f95c42155ae9 upstream. These two were macros. Switch them to static inlines, so that it's more understandable what they are doing. Signed-off-by: Jiri Slaby <jslaby@suse.cz> Link: https://lore.kernel.org/r/20200219073951.16151-2-jslaby@suse.cz Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-04-02vt: selection, introduce vc_is_selJiri Slaby
commit dce05aa6eec977f1472abed95ccd71276b9a3864 upstream. Avoid global variables (namely sel_cons) by introducing vc_is_sel. It checks whether the parameter is the current selection console. This will help putting sel_cons to a struct later. Signed-off-by: Jiri Slaby <jslaby@suse.cz> Link: https://lore.kernel.org/r/20200219073951.16151-1-jslaby@suse.cz Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-03-11vt: selection, push sel_lock upJiri Slaby
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") Cc: stable <stable@vger.kernel.org> Link: https://lore.kernel.org/r/20200228115406.5735-2-jslaby@suse.cz Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-03-11vt: selection, push console lock downJiri Slaby
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") Cc: stable <stable@vger.kernel.org> Link: https://lore.kernel.org/r/20200228115406.5735-1-jslaby@suse.cz Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-03-11vt: selection, close sel_buffer raceJiri Slaby
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 Cc: stable <stable@vger.kernel.org> Link: https://lore.kernel.org/r/20200210081131.23572-2-jslaby@suse.cz Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-03-11tty:serial:mvebu-uart:fix a wrong returntangbin
commit 4a3e208474204e879d22a310b244cb2f39e5b1f8 upstream. in this place, the function should return a negative value and the PTR_ERR already returns a negative,so return -PTR_ERR() is wrong. Signed-off-by: tangbin <tangbin@cmss.chinamobile.com> Cc: stable <stable@vger.kernel.org> Acked-by: Jiri Slaby <jslaby@suse.cz> Link: https://lore.kernel.org/r/20200305013823.20976-1-tangbin@cmss.chinamobile.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-03-11serial: ar933x_uart: set UART_CS_{RX,TX}_READY_ORIDEDaniel Golle
[ Upstream commit 87c5cbf71ecbb9e289d60a2df22eb686c70bf196 ] On AR934x this UART is usually not initialized by the bootloader as it is only used as a secondary serial port while the primary UART is a newly introduced NS16550-compatible. In order to make use of the ar933x-uart on AR934x without RTS/CTS hardware flow control, one needs to set the UART_CS_{RX,TX}_READY_ORIDE bits as other than on AR933x where this UART is used as primary/console, the bootloader on AR934x typically doesn't set those bits. Setting them explicitely on AR933x should not do any harm, so just set them unconditionally. Tested-by: Chuanhong Guo <gch981213@gmail.com> Signed-off-by: Daniel Golle <daniel@makrotopia.org> Link: https://lore.kernel.org/r/20200207095335.GA179836@makrotopia.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-03-11serial: 8250: Check UPF_IRQ_SHARED in advanceAndy Shevchenko
commit 7febbcbc48fc92e3f33863b32ed715ba4aff18c4 upstream. The commit 54e53b2e8081 ("tty: serial: 8250: pass IRQ shared flag to UART ports") nicely explained the problem: ---8<---8<--- On some systems IRQ lines between multiple UARTs might be shared. If so, the irqflags have to be configured accordingly. The reason is: The 8250 port startup code performs IRQ tests *before* the IRQ handler for that particular port is registered. This is performed in serial8250_do_startup(). This function checks whether IRQF_SHARED is configured and only then disables the IRQ line while testing. This test is performed upon each open() of the UART device. Imagine two UARTs share the same IRQ line: On is already opened and the IRQ is active. When the second UART is opened, the IRQ line has to be disabled while performing IRQ tests. Otherwise an IRQ might handler might be invoked, but the IRQ itself cannot be handled, because the corresponding handler isn't registered, yet. That's because the 8250 code uses a chain-handler and invokes the corresponding port's IRQ handling routines himself. Unfortunately this IRQF_SHARED flag isn't configured for UARTs probed via device tree even if the IRQs are shared. This way, the actual and shared IRQ line isn't disabled while performing tests and the kernel correctly detects a spurious IRQ. So, adding this flag to the DT probe solves the issue. Note: The UPF_SHARE_IRQ flag is configured unconditionally. Therefore, the IRQF_SHARED flag can be set unconditionally as well. Example stack trace by performing `echo 1 > /dev/ttyS2` on a non-patched system: |irq 85: nobody cared (try booting with the "irqpoll" option) | [...] |handlers: |[<ffff0000080fc628>] irq_default_primary_handler threaded [<ffff00000855fbb8>] serial8250_interrupt |Disabling IRQ #85 ---8<---8<--- But unfortunately didn't fix the root cause. Let's try again here by moving IRQ flag assignment from serial_link_irq_chain() to serial8250_do_startup(). This should fix the similar issue reported for 8250_pnp case. Since this change we don't need to have custom solutions in 8250_aspeed_vuart and 8250_of drivers, thus, drop them. Fixes: 1c2f04937b3e ("serial: 8250: add IRQ trigger support") Reported-by: Li RongQing <lirongqing@baidu.com> Cc: Kurt Kanzenbach <kurt@linutronix.de> Cc: Vikram Pandita <vikram.pandita@ti.com> Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Cc: stable <stable@vger.kernel.org> Acked-by: Kurt Kanzenbach <kurt@linutronix.de> Link: https://lore.kernel.org/r/20200211135559.85960-1-andriy.shevchenko@linux.intel.com [Kurt: Backport to v4.9] Signed-off-by: Kurt Kanzenbach <kurt@linutronix.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-03-11sysrq: Remove duplicated sysrq messagePetr Mladek
commit c3fee60908db4a8594f2e4a2131998384b8fa006 upstream. The commit 97f5f0cd8cd0a0544 ("Input: implement SysRq as a separate input handler") added pr_fmt() definition. It caused a duplicated message prefix in the sysrq header messages, for example: [ 177.053931] sysrq: SysRq : Show backtrace of all active CPUs [ 742.864776] sysrq: SysRq : HELP : loglevel(0-9) reboot(b) crash(c) Fixes: 97f5f0cd8cd0a05 ("Input: implement SysRq as a separate input handler") Signed-off-by: Petr Mladek <pmladek@suse.com> Reviewed-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com> Cc: Tommi Rantala <tommi.t.rantala@nokia.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-03-11sysrq: Restore original console_loglevel when sysrq disabledPetr Mladek
commit 075e1a0c50f59ea210561d0d0fedbd945615df78 upstream. The sysrq header line is printed with an increased loglevel to provide users some positive feedback. The original loglevel is not restored when the sysrq operation is disabled. This bug was introduced in 2.6.12 (pre-git-history) by the commit ("Allow admin to enable only some of the Magic-Sysrq functions"). Signed-off-by: Petr Mladek <pmladek@suse.com> Reviewed-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com> Reviewed-by: Steven Rostedt (VMware) <rostedt@goodmis.org> Cc: Tommi Rantala <tommi.t.rantala@nokia.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-02-28vt: vt_ioctl: fix race in VT_RESIZEXEric Dumazet
[ Upstream commit 6cd1ed50efd88261298577cd92a14f2768eddeeb ] We need to make sure vc_cons[i].d is not NULL after grabbing console_lock(), or risk a crash. general protection fault, probably for non-canonical address 0xdffffc0000000068: 0000 [#1] PREEMPT SMP KASAN KASAN: null-ptr-deref in range [0x0000000000000340-0x0000000000000347] CPU: 1 PID: 19462 Comm: syz-executor.5 Not tainted 5.5.0-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:vt_ioctl+0x1f96/0x26d0 drivers/tty/vt/vt_ioctl.c:883 Code: 74 41 e8 bd a6 84 fd 48 89 d8 48 c1 e8 03 42 80 3c 28 00 0f 85 e4 04 00 00 48 8b 03 48 8d b8 40 03 00 00 48 89 fa 48 c1 ea 03 <42> 0f b6 14 2a 84 d2 74 09 80 fa 03 0f 8e b1 05 00 00 44 89 b8 40 RSP: 0018:ffffc900086d7bb0 EFLAGS: 00010202 RAX: 0000000000000000 RBX: ffffffff8c34ee88 RCX: ffffc9001415c000 RDX: 0000000000000068 RSI: ffffffff83f0e6e3 RDI: 0000000000000340 RBP: ffffc900086d7cd0 R08: ffff888054ce0100 R09: fffffbfff16a2f6d R10: ffff888054ce0998 R11: ffff888054ce0100 R12: 000000000000001d R13: dffffc0000000000 R14: 1ffff920010daf79 R15: 000000000000ff7f FS: 00007f7d13c12700(0000) GS:ffff8880ae900000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007ffd477e3c38 CR3: 0000000095d0a000 CR4: 00000000001406e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: tty_ioctl+0xa37/0x14f0 drivers/tty/tty_io.c:2660 vfs_ioctl fs/ioctl.c:47 [inline] ksys_ioctl+0x123/0x180 fs/ioctl.c:763 __do_sys_ioctl fs/ioctl.c:772 [inline] __se_sys_ioctl fs/ioctl.c:770 [inline] __x64_sys_ioctl+0x73/0xb0 fs/ioctl.c:770 do_syscall_64+0xfa/0x790 arch/x86/entry/common.c:294 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x45b399 Code: ad b6 fb ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 0f 83 7b b6 fb ff c3 66 2e 0f 1f 84 00 00 00 00 RSP: 002b:00007f7d13c11c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00007f7d13c126d4 RCX: 000000000045b399 RDX: 0000000020000080 RSI: 000000000000560a RDI: 0000000000000003 RBP: 000000000075bf20 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff R13: 0000000000000666 R14: 00000000004c7f04 R15: 000000000075bf2c Modules linked in: ---[ end trace 80970faf7a67eb77 ]--- RIP: 0010:vt_ioctl+0x1f96/0x26d0 drivers/tty/vt/vt_ioctl.c:883 Code: 74 41 e8 bd a6 84 fd 48 89 d8 48 c1 e8 03 42 80 3c 28 00 0f 85 e4 04 00 00 48 8b 03 48 8d b8 40 03 00 00 48 89 fa 48 c1 ea 03 <42> 0f b6 14 2a 84 d2 74 09 80 fa 03 0f 8e b1 05 00 00 44 89 b8 40 RSP: 0018:ffffc900086d7bb0 EFLAGS: 00010202 RAX: 0000000000000000 RBX: ffffffff8c34ee88 RCX: ffffc9001415c000 RDX: 0000000000000068 RSI: ffffffff83f0e6e3 RDI: 0000000000000340 RBP: ffffc900086d7cd0 R08: ffff888054ce0100 R09: fffffbfff16a2f6d R10: ffff888054ce0998 R11: ffff888054ce0100 R12: 000000000000001d R13: dffffc0000000000 R14: 1ffff920010daf79 R15: 000000000000ff7f FS: 00007f7d13c12700(0000) GS:ffff8880ae900000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007ffd477e3c38 CR3: 0000000095d0a000 CR4: 00000000001406e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Signed-off-by: Eric Dumazet <edumazet@google.com> Cc: stable <stable@vger.kernel.org> Reported-by: syzbot <syzkaller@googlegroups.com> Link: https://lore.kernel.org/r/20200210190721.200418-1-edumazet@google.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-02-28VT_RESIZEX: get rid of field-by-field copyinAl Viro
[ Upstream commit 1b3bce4d6bf839304a90951b4b25a5863533bf2a ] Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-02-28tty: serial: imx: setup the correct sg entry for tx dmaFugang Duan
commit f76707831829530ffdd3888bebc108aecefccaa0 upstream. There has oops as below happen on i.MX8MP EVK platform that has 6G bytes DDR memory. when (xmit->tail < xmit->head) && (xmit->head == 0), it setups one sg entry with sg->length is zero: sg_set_buf(sgl + 1, xmit->buf, xmit->head); if xmit->buf is allocated from >4G address space, and SDMA only support <4G address space, then dma_map_sg() will call swiotlb_map() to do bounce buffer copying and mapping. But swiotlb_map() don't allow sg entry's length is zero, otherwise report BUG_ON(). So the patch is to correct the tx DMA scatter list. Oops: [ 287.675715] kernel BUG at kernel/dma/swiotlb.c:497! [ 287.680592] Internal error: Oops - BUG: 0 [#1] PREEMPT SMP [ 287.686075] Modules linked in: [ 287.689133] CPU: 0 PID: 0 Comm: swapper/0 Not tainted 5.4.3-00016-g3fdc4e0-dirty #10 [ 287.696872] Hardware name: FSL i.MX8MP EVK (DT) [ 287.701402] pstate: 80000085 (Nzcv daIf -PAN -UAO) [ 287.706199] pc : swiotlb_tbl_map_single+0x1fc/0x310 [ 287.711076] lr : swiotlb_map+0x60/0x148 [ 287.714909] sp : ffff800010003c00 [ 287.718221] x29: ffff800010003c00 x28: 0000000000000000 [ 287.723533] x27: 0000000000000040 x26: ffff800011ae0000 [ 287.728844] x25: ffff800011ae09f8 x24: 0000000000000000 [ 287.734155] x23: 00000001b7af9000 x22: 0000000000000000 [ 287.739465] x21: ffff000176409c10 x20: 00000000001f7ffe [ 287.744776] x19: ffff000176409c10 x18: 000000000000002e [ 287.750087] x17: 0000000000000000 x16: 0000000000000000 [ 287.755397] x15: 0000000000000000 x14: 0000000000000000 [ 287.760707] x13: ffff00017f334000 x12: 0000000000000001 [ 287.766018] x11: 00000000001fffff x10: 0000000000000000 [ 287.771328] x9 : 0000000000000003 x8 : 0000000000000000 [ 287.776638] x7 : 0000000000000000 x6 : 0000000000000000 [ 287.781949] x5 : 0000000000200000 x4 : 0000000000000000 [ 287.787259] x3 : 0000000000000001 x2 : 00000001b7af9000 [ 287.792570] x1 : 00000000fbfff000 x0 : 0000000000000000 [ 287.797881] Call trace: [ 287.800328] swiotlb_tbl_map_single+0x1fc/0x310 [ 287.804859] swiotlb_map+0x60/0x148 [ 287.808347] dma_direct_map_page+0xf0/0x130 [ 287.812530] dma_direct_map_sg+0x78/0xe0 [ 287.816453] imx_uart_dma_tx+0x134/0x2f8 [ 287.820374] imx_uart_dma_tx_callback+0xd8/0x168 [ 287.824992] vchan_complete+0x194/0x200 [ 287.828828] tasklet_action_common.isra.0+0x154/0x1a0 [ 287.833879] tasklet_action+0x24/0x30 [ 287.837540] __do_softirq+0x120/0x23c [ 287.841202] irq_exit+0xb8/0xd8 [ 287.844343] __handle_domain_irq+0x64/0xb8 [ 287.848438] gic_handle_irq+0x5c/0x148 [ 287.852185] el1_irq+0xb8/0x180 [ 287.855327] cpuidle_enter_state+0x84/0x360 [ 287.859508] cpuidle_enter+0x34/0x48 [ 287.863083] call_cpuidle+0x18/0x38 [ 287.866571] do_idle+0x1e0/0x280 [ 287.869798] cpu_startup_entry+0x20/0x40 [ 287.873721] rest_init+0xd4/0xe0 [ 287.876949] arch_call_rest_init+0xc/0x14 [ 287.880958] start_kernel+0x420/0x44c [ 287.884622] Code: 9124c021 9417aff8 a94363f7 17ffffd5 (d4210000) [ 287.890718] ---[ end trace 5bc44c4ab6b009ce ]--- [ 287.895334] Kernel panic - not syncing: Fatal exception in interrupt [ 287.901686] SMP: stopping secondary CPUs [ 288.905607] SMP: failed to stop secondary CPUs 0-1 [ 288.910395] Kernel Offset: disabled [ 288.913882] CPU features: 0x0002,2000200c [ 288.917888] Memory Limit: none [ 288.920944] ---[ end Kernel panic - not syncing: Fatal exception in interrupt ]--- Reported-by: Eagle Zhou <eagle.zhou@nxp.com> Tested-by: Eagle Zhou <eagle.zhou@nxp.com> Signed-off-by: Fugang Duan <fugang.duan@nxp.com> Cc: stable <stable@vger.kernel.org> Fixes: 7942f8577f2a ("serial: imx: TX DMA: clean up sg initialization") Reviewed-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> Link: https://lore.kernel.org/r/1581401761-6378-1-git-send-email-fugang.duan@nxp.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-02-28tty/serial: atmel: manage shutdown in case of RS485 or ISO7816 modeNicolas Ferre
commit 04b5bfe3dc94e64d0590c54045815cb5183fb095 upstream. In atmel_shutdown() we call atmel_stop_rx() and atmel_stop_tx() functions. Prevent the rx restart that is implemented in RS485 or ISO7816 modes when calling atmel_stop_tx() by using the atomic information tasklet_shutdown that is already in place for this purpose. Fixes: 98f2082c3ac4 ("tty/serial: atmel: enforce tasklet init and termination sequences") Signed-off-by: Nicolas Ferre <nicolas.ferre@microchip.com> Cc: stable <stable@vger.kernel.org> Link: https://lore.kernel.org/r/20200210152053.8289-1-nicolas.ferre@microchip.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-02-28vt: selection, handle pending signals in paste_selectionJiri Slaby
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> Cc: stable <stable@vger.kernel.org> Link: https://lore.kernel.org/r/20200210081131.23572-1-jslaby@suse.cz Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-02-28tty: synclink_gt: Adjust indentation in several functionsNathan Chancellor
[ Upstream commit 446e76873b5e4e70bdee5db2f2a894d5b4a7d081 ] Clang warns: ../drivers/tty/synclink_gt.c:1337:3: warning: misleading indentation; statement is not part of the previous 'if' [-Wmisleading-indentation] if (C_CRTSCTS(tty)) { ^ ../drivers/tty/synclink_gt.c:1335:2: note: previous statement is here if (I_IXOFF(tty)) ^ ../drivers/tty/synclink_gt.c:2563:3: warning: misleading indentation; statement is not part of the previous 'if' [-Wmisleading-indentation] if (I_BRKINT(info->port.tty) || I_PARMRK(info->port.tty)) ^ ../drivers/tty/synclink_gt.c:2561:2: note: previous statement is here if (I_INPCK(info->port.tty)) ^ ../drivers/tty/synclink_gt.c:3221:3: warning: misleading indentation; statement is not part of the previous 'else' [-Wmisleading-indentation] set_signals(info); ^ ../drivers/tty/synclink_gt.c:3219:2: note: previous statement is here else ^ 3 warnings generated. The indentation on these lines is not at all consistent, tabs and spaces are mixed together. Convert to just using tabs to be consistent with the Linux kernel coding style and eliminate these warnings from clang. Link: https://github.com/ClangBuiltLinux/linux/issues/822 Signed-off-by: Nathan Chancellor <natechancellor@gmail.com> Link: https://lore.kernel.org/r/20191218023912.13827-1-natechancellor@gmail.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-02-28tty: synclinkmp: Adjust indentation in several functionsNathan Chancellor
[ Upstream commit 1feedf61e7265128244f6993f23421f33dd93dbc ] Clang warns: ../drivers/tty/synclinkmp.c:1456:3: warning: misleading indentation; statement is not part of the previous 'if' [-Wmisleading-indentation] if (C_CRTSCTS(tty)) { ^ ../drivers/tty/synclinkmp.c:1453:2: note: previous statement is here if (I_IXOFF(tty)) ^ ../drivers/tty/synclinkmp.c:2473:8: warning: misleading indentation; statement is not part of the previous 'if' [-Wmisleading-indentation] info->port.tty->hw_stopped = 0; ^ ../drivers/tty/synclinkmp.c:2471:7: note: previous statement is here if ( debug_level >= DEBUG_LEVEL_ISR ) ^ ../drivers/tty/synclinkmp.c:2482:8: warning: misleading indentation; statement is not part of the previous 'if' [-Wmisleading-indentation] info->port.tty->hw_stopped = 1; ^ ../drivers/tty/synclinkmp.c:2480:7: note: previous statement is here if ( debug_level >= DEBUG_LEVEL_ISR ) ^ ../drivers/tty/synclinkmp.c:2809:3: warning: misleading indentation; statement is not part of the previous 'if' [-Wmisleading-indentation] if (I_BRKINT(info->port.tty) || I_PARMRK(info->port.tty)) ^ ../drivers/tty/synclinkmp.c:2807:2: note: previous statement is here if (I_INPCK(info->port.tty)) ^ ../drivers/tty/synclinkmp.c:3246:3: warning: misleading indentation; statement is not part of the previous 'else' [-Wmisleading-indentation] set_signals(info); ^ ../drivers/tty/synclinkmp.c:3244:2: note: previous statement is here else ^ 5 warnings generated. The indentation on these lines is not at all consistent, tabs and spaces are mixed together. Convert to just using tabs to be consistent with the Linux kernel coding style and eliminate these warnings from clang. Link: https://github.com/ClangBuiltLinux/linux/issues/823 Signed-off-by: Nathan Chancellor <natechancellor@gmail.com> Link: https://lore.kernel.org/r/20191218024720.3528-1-natechancellor@gmail.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-02-05serial: 8250_bcm2835aux: Fix line mismatch on driver unbindLukas Wunner
commit dc76697d7e933d5e299116f219c890568785ea15 upstream. Unbinding the bcm2835aux UART driver raises the following error if the maximum number of 8250 UARTs is set to 1 (via the 8250.nr_uarts module parameter or CONFIG_SERIAL_8250_RUNTIME_UARTS): (NULL device *): Removing wrong port: a6f80333 != fa20408b That's because bcm2835aux_serial_probe() retrieves UART line number 1 from the devicetree and stores it in data->uart.port.line, while serial8250_register_8250_port() instead uses UART line number 0, which is stored in data->line. On driver unbind, bcm2835aux_serial_remove() uses data->uart.port.line, which contains the wrong number. Fix it. The issue does not occur if the maximum number of 8250 UARTs is >= 2. Fixes: bdc5f3009580 ("serial: bcm2835: add driver for bcm2835-aux-uart") Signed-off-by: Lukas Wunner <lukas@wunner.de> Cc: stable@vger.kernel.org # v4.6+ Cc: Martin Sperl <kernel@martin.sperl.org> Reviewed-by: Nicolas Saenz Julienne <nsaenzjulienne@suse.de> Tested-by: Nicolas Saenz Julienne <nsaenzjulienne@suse.de> Link: https://lore.kernel.org/r/912ccf553c5258135c6d7e8f404a101ef320f0f4.1579175223.git.lukas@wunner.de Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-01-29serial: stm32: fix transmit_chars when tx is stoppedErwan Le Ray
[ Upstream commit b83b957c91f68e53f0dc596e129e8305761f2a32 ] Disables the tx irq when the transmission is ended and updates stop_tx conditions for code cleanup. Fixes: 48a6092fb41f ("serial: stm32-usart: Add STM32 USART Driver") Signed-off-by: Erwan Le Ray <erwan.leray@st.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-01-29tty: ipwireless: Fix potential NULL pointer dereferenceYueHaibing
[ Upstream commit 7dd50e205b3348dc7784efbdf85723551de64a25 ] 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: Sasha Levin <sashal@kernel.org>
2020-01-23tty: serial: pch_uart: correct usage of dma_unmap_sgPeng Fan
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>
2020-01-23tty: serial: imx: use the sg count from dma_map_sgPeng Fan
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>
2020-01-14tty: always relink the portSudip Mukherjee
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> Cc: stable <stable@vger.kernel.org> Link: https://lore.kernel.org/r/20191227174434.12057-1-sudipm.mukherjee@gmail.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-01-14tty: link tty and port before configuring it as consoleSudip Mukherjee
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> Cc: stable <stable@vger.kernel.org> Link: https://lore.kernel.org/r/20191212131602.29504-1-sudipm.mukherjee@gmail.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-01-12powerpc/pseries/hvconsole: Fix stack overread via udbgDaniel Axtens
[ Upstream commit 934bda59f286d0221f1a3ebab7f5156a996cc37d ] While developing KASAN for 64-bit book3s, I hit the following stack over-read. It occurs because the hypercall to put characters onto the terminal takes 2 longs (128 bits/16 bytes) of characters at a time, and so hvc_put_chars() would unconditionally copy 16 bytes from the argument buffer, regardless of supplied length. However, udbg_hvc_putc() can call hvc_put_chars() with a single-byte buffer, leading to the error. ================================================================== BUG: KASAN: stack-out-of-bounds in hvc_put_chars+0xdc/0x110 Read of size 8 at addr c0000000023e7a90 by task swapper/0 CPU: 0 PID: 0 Comm: swapper Not tainted 5.2.0-rc2-next-20190528-02824-g048a6ab4835b #113 Call Trace: dump_stack+0x104/0x154 (unreliable) print_address_description+0xa0/0x30c __kasan_report+0x20c/0x224 kasan_report+0x18/0x30 __asan_report_load8_noabort+0x24/0x40 hvc_put_chars+0xdc/0x110 hvterm_raw_put_chars+0x9c/0x110 udbg_hvc_putc+0x154/0x200 udbg_write+0xf0/0x240 console_unlock+0x868/0xd30 register_console+0x970/0xe90 register_early_udbg_console+0xf8/0x114 setup_arch+0x108/0x790 start_kernel+0x104/0x784 start_here_common+0x1c/0x534 Memory state around the buggy address: c0000000023e7980: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 c0000000023e7a00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 f1 f1 >c0000000023e7a80: f1 f1 01 f2 f2 f2 00 00 00 00 00 00 00 00 00 00 ^ c0000000023e7b00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 c0000000023e7b80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ================================================================== Document that a 16-byte buffer is requred, and provide it in udbg. Signed-off-by: Daniel Axtens <dja@axtens.net> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-01-12tty: serial: msm_serial: Fix lockup for sysrq and oopsLeo Yan
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: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-01-04tty/serial: atmel: fix out of range clock divider handlingDavid Engraf
[ Upstream commit cb47b9f8630ae3fa3f5fbd0c7003faba7abdf711 ] Use MCK_DIV8 when the clock divider is > 65535. Unfortunately the mode register was already written thus the clock selection is ignored. Fix by doing the baud rate calulation before setting the mode. Fixes: 5bf5635ac170 ("tty/serial: atmel: add fractional baud rate support") Signed-off-by: David Engraf <david.engraf@sysgo.com> Acked-by: Ludovic Desroches <ludovic.desroches@microchip.com> Acked-by: Richard Genoud <richard.genoud@gmail.com> Cc: stable <stable@vger.kernel.org> Link: https://lore.kernel.org/r/20191216085403.17050-1-david.engraf@sysgo.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2019-12-21tty: vt: keyboard: reject invalid keycodesDmitry Torokhov
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> Cc: stable <stable@vger.kernel.org> Link: https://lore.kernel.org/r/20191122204220.GA129459@dtor-ws Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-12-21tty: Don't block on IO when ldisc change is pendingDmitry Safonov
[ Upstream commit c96cf923a98d1b094df9f0cf97a83e118817e31b ] There might be situations where tty_ldisc_lock() has blocked, but there is already IO on tty and it prevents line discipline changes. It might theoretically turn into dead-lock. Basically, provide more priority to pending tty_ldisc_lock() than to servicing reads/writes over tty. User-visible issue was reported by Mikulas where on pa-risc with Debian 5 reboot took either 80 seconds, 3 minutes or 3:25 after proper locking in tty_reopen(). Cc: Jiri Slaby <jslaby@suse.com> Reported-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Dmitry Safonov <dima@arista.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2019-12-21serial: imx: fix error handling in console_setupStefan Agner
[ Upstream commit 63fd4b94b948c14eeb27a3bbf50ea0f7f0593bad ] 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: Sasha Levin <sashal@kernel.org>
2019-12-21serial: ifx6x60: add missed pm_runtime_disableChuhong Yuan
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> Cc: stable <stable@vger.kernel.org> Link: https://lore.kernel.org/r/20191118024833.21587-1-hslester96@gmail.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-12-21serial: serial_core: Perform NULL checks for break_ctl opsJiangfeng Xiao
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> Cc: stable <stable@vger.kernel.org> Link: https://lore.kernel.org/r/1574263133-28259-1-git-send-email-xiaojiangfeng@huawei.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-12-21serial: pl011: Fix DMA ->flush_buffer()Vincent Whitchurch
commit f6a196477184b99a31d16366a8e826558aa11f6d upstream. PL011's ->flush_buffer() implementation releases and reacquires the port lock. Due to a race condition here, data can end up being added to the circular buffer but neither being discarded nor being sent out. This leads to, for example, tcdrain(2) waiting indefinitely. Process A Process B uart_flush_buffer() - acquire lock - circ_clear - pl011_flush_buffer() -- release lock -- dmaengine_terminate_all() uart_write() - acquire lock - add chars to circ buffer - start_tx() -- start DMA - release lock -- acquire lock -- turn off DMA -- release lock // Data in circ buffer but DMA is off According to the comment in the code, the releasing of the lock around dmaengine_terminate_all() is to avoid a deadlock with the DMA engine callback. However, since the time this code was written, the DMA engine API documentation seems to have been clarified to say that dmaengine_terminate_all() (in the identically implemented but differently named dmaengine_terminate_async() variant) does not wait for any running complete callback to be completed and can even be called from a complete callback. So there is no possibility of deadlock if the DMA engine driver implements this API correctly. So we should be able to just remove this release and reacquire of the lock to prevent the aforementioned race condition. Signed-off-by: Vincent Whitchurch <vincent.whitchurch@axis.com> Cc: stable <stable@vger.kernel.org> Link: https://lore.kernel.org/r/20191118092547.32135-1-vincent.whitchurch@axis.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-12-21tty: serial: msm_serial: Fix flow controlJeffrey Hugo
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> Cc: stable <stable@vger.kernel.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>
2019-12-21tty: serial: fsl_lpuart: use the sg count from dma_map_sgPeng Fan
commit 487ee861de176090b055eba5b252b56a3b9973d6 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". When enabling iommu for lpuart + edma, iommu framework may concatenate two sgs into one. Fixes: 6250cc30c4c4e ("tty: serial: fsl_lpuart: Use scatter/gather DMA for Tx") Cc: <stable@vger.kernel.org> Signed-off-by: Peng Fan <peng.fan@nxp.com> Link: https://lore.kernel.org/r/1572932977-17866-1-git-send-email-peng.fan@nxp.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-12-05serial: max310x: Fix tx_empty() callbackAlexander Shiyan
[ Upstream commit a8da3c7873ea57acb8f9cea58c0af477522965aa ] Function max310x_tx_empty() accesses the IRQSTS register, which is cleared by IC when reading, so if there is an interrupt status, we will lose it. This patch implement the transmitter check only by the current FIFO level. Signed-off-by: Alexander Shiyan <shc_work@mail.ru> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2019-11-28synclink_gt(): fix compat_ioctl()Al Viro
[ Upstream commit 27230e51349fde075598c1b59d15e1ff802f3f6e ] compat_ptr() for pointer-taking ones... Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Sasha Levin <sashal@kernel.org>
2019-11-25serial: mxs-auart: Fix potential infinite loopAnton Vasilyev
[ Upstream commit 5963e8a3122471cadfe0eba41c4ceaeaa5c8bb4d ] On the error path of mxs_auart_request_gpio_irq() is performed backward iterating with index i of enum type. Underline enum type may be unsigned char. In this case check (--i >= 0) will be always true and error handling goes into infinite loop. The patch changes the check so that it is valid for signed and unsigned types. Found by Linux Driver Verification project (linuxtesting.org). Signed-off-by: Anton Vasilyev <vasilyev@ispras.ru> Acked-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2019-11-06serial: mctrl_gpio: Check for NULL pointerAdam Ford
[ Upstream commit 37e3ab00e4734acc15d96b2926aab55c894f4d9c ] When using mctrl_gpio_to_gpiod, it dereferences gpios into a single requested GPIO. This dereferencing can break if gpios is NULL, so this patch adds a NULL check before dereferencing it. If gpios is NULL, this function will also return NULL. Signed-off-by: Adam Ford <aford173@gmail.com> Reviewed-by: Yegor Yefremov <yegorslists@googlemail.com> Link: https://lore.kernel.org/r/20191006163314.23191-1-aford173@gmail.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2019-11-06sc16is7xx: Fix for "Unexpected interrupt: 8"Phil Elwell
[ Upstream commit 30ec514d440cf2c472c8e4b0079af2c731f71a3e ] The SC16IS752 has an Enhanced Feature Register which is aliased at the same address as the Interrupt Identification Register; accessing it requires that a magic value is written to the Line Configuration Register. If an interrupt is raised while the EFR is mapped in then the ISR won't be able to access the IIR, leading to the "Unexpected interrupt" error messages. Avoid the problem by claiming a mutex around accesses to the EFR register, also claiming the mutex in the interrupt handler work item (this is equivalent to disabling interrupts to interlock against a non-threaded interrupt handler). See: https://github.com/raspberrypi/linux/issues/2529 Signed-off-by: Phil Elwell <phil@raspberrypi.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2019-10-17serial: uartlite: fix exit path null pointerRandy Dunlap
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: stable <stable@vger.kernel.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>
2019-09-21tty/serial: atmel: reschedule TX after RX was startedRazvan Stefanescu
commit d2ace81bf902a9f11d52e59e5d232d2255a0e353 upstream. When half-duplex RS485 communication is used, after RX is started, TX tasklet still needs to be scheduled tasklet. This avoids console freezing when more data is to be transmitted, if the serial communication is not closed. Fixes: 69646d7a3689 ("tty/serial: atmel: RS485 HD w/DMA: enable RX after TX is stopped") Signed-off-by: Razvan Stefanescu <razvan.stefanescu@microchip.com> Cc: stable <stable@vger.kernel.org> Link: https://lore.kernel.org/r/20190813074025.16218-1-razvan.stefanescu@microchip.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-09-21serial: sprd: correct the wrong sequence of argumentsChunyan Zhang
commit 9c801e313195addaf11c16e155f50789d6ebfd19 upstream. The sequence of arguments which was passed to handle_lsr_errors() didn't match the parameters defined in that function, &lsr was passed to flag and &flag was passed to lsr, this patch fixed that. Fixes: b7396a38fb28 ("tty/serial: Add Spreadtrum sc9836-uart driver support") Signed-off-by: Chunyan Zhang <chunyan.zhang@unisoc.com> Signed-off-by: Chunyan Zhang <zhang.lyra@gmail.com> Cc: stable <stable@vger.kernel.org> Link: https://lore.kernel.org/r/20190905074151.5268-1-zhang.lyra@gmail.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-08-25tty/ldsem, locking/rwsem: Add missing ACQUIRE to read_failed sleep loopPeter Zijlstra
[ Upstream commit 952041a8639a7a3a73a2b6573cb8aa8518bc39f8 ] 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: Sasha Levin <sashal@kernel.org>
2019-08-04serial: sh-sci: Fix TX DMA buffer flushing and workqueue racesGeert Uytterhoeven
[ Upstream commit 8493eab02608b0e82f67b892aa72882e510c31d0 ] When uart_flush_buffer() is called, the .flush_buffer() callback zeroes the tx_dma_len field. This may race with the work queue function handling transmit DMA requests: 1. If the buffer is flushed before the first DMA API call, dmaengine_prep_slave_single() may be called with a zero length, causing the DMA request to never complete, leading to messages like: rcar-dmac e7300000.dma-controller: Channel Address Error happen and, with debug enabled: sh-sci e6e88000.serial: sci_dma_tx_work_fn: ffff800639b55000: 0...0, cookie 126 and DMA timeouts. 2. If the buffer is flushed after the first DMA API call, but before the second, dma_sync_single_for_device() may be called with a zero length, causing the transmit data not to be flushed to RAM, and leading to stale data being output. Fix this by: 1. Letting sci_dma_tx_work_fn() return immediately if the transmit buffer is empty, 2. Extending the critical section to cover all DMA preparational work, so tx_dma_len stays consistent for all of it, 3. Using local copies of circ_buf.head and circ_buf.tail, to make sure they match the actual operation above. Reported-by: Eugeniu Rosca <erosca@de.adit-jv.com> Suggested-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com> Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be> Reviewed-by: Eugeniu Rosca <erosca@de.adit-jv.com> Tested-by: Eugeniu Rosca <erosca@de.adit-jv.com> Link: https://lore.kernel.org/r/20190624123540.20629-2-geert+renesas@glider.be Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Sasha Levin <sashal@kernel.org>