linux/drivers/tty
Rob Herring d0f4bce2bc tty: serial_core: fix NULL struct tty pointer access in uart_write_wakeup
Since commit 761ed4a945 ("tty: serial_core: convert uart_close to
use tty_port_close"), the serial console is broken on various systems
and typing "reboot" splats the following on the serial console:

INIT: Sending p[  427.863916] BUG: unable to handle kernel NULL pointer dereference at 00000000000001e0
[  427.885156] IP: [] tty_wakeup+0xc/0x70
[  427.898337] PGD 0 [  427.902051]
[  427.907498] Oops: 0000 [#1] PREEMPT SMP
[  427.917635] Modules linked in: nfsv3 nfs_acl nfs fscache lockd
sunrpc grace edd af_packet cpufreq_conservative cpufreq_userspace
cpufreq_powersave fuse loop md_mod dm_mod joydev hid_generic usbhid
ipmi_ssif ohci_pci ohci_hcd ehci_pci ehci_hcd e1000e ptp firewire_ohci
edac_core pps_core tpm_infineon sp5100_tco firewire_core acpi_cpufreq
serio_raw pcspkr fjes usbcore shpchp edac_mce_amd tpm_tis ipmi_si
tpm_tis_core i2c_piix4 k10temp sg ipmi_msghandler tpm sr_mod button
cdrom kvm_amd kvm irqbypass crc_itu_t ast ttm drm_kms_helper drm
fb_sys_fops sysimgblt sysfillrect syscopyarea i2c_algo_bit scsi_dh_rdac
scsi_dh_alua scsi_dh_emc scsi_dh_hp_sw ata_generic pata_atiixp
[  428.054179] CPU: 0 PID: 0 Comm: swapper/0 Not tainted 4.9.0-rc1-1.g73e3f23-default #1
[  428.072868] Hardware name: System manufacturer System Product Name/KGP(M)E-D16, BIOS 0902    12/03/2010
[  428.094755] task: ffffffffa2c0d500 task.stack: ffffffffa2c00000
[  428.109717] RIP: 0010:[]  [] tty_wakeup+0xc/0x70
[  428.128407] RSP: 0018:ffff9a1a5fc03df8  EFLAGS: 00010086
[  428.142184] RAX: ffff9a1857258000 RBX: ffffffffa3050ea0 RCX: 0000000000000000
[  428.159649] RDX: 000000000000001b RSI: 0000000000000000 RDI: 0000000000000000
[  428.177109] RBP: ffff9a1a5fc03e08 R08: 0000000000000000 R09: 0000000000000000
[  428.194547] R10: 0000000000021c77 R11: 0000000000000000 R12: ffff9a1857258000
[  428.212002] R13: 0000000000000000 R14: 0000000000000020 R15: 0000000000000020
[  428.229481] FS:  0000000000000000(0000) GS:ffff9a1a5fc00000(0000) knlGS:0000000000000000
[  428.248938] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[  428.263726] CR2: 00000000000001e0 CR3: 0000000390c06000 CR4: 00000000000006f0
[  428.281331] Stack:
[  428.288696]  ffffffffa3050ea0 ffff9a1857258000 ffff9a1a5fc03e18 ffffffffa24e0ab1
[  428.307064]  ffff9a1a5fc03e40 ffffffffa24e8865 ffffffffa3050ea0 00000000000000c2
[  428.325456]  0000000000000046 ffff9a1a5fc03e78 ffffffffa24e8a5f ffffffffa3050ea0
[  428.343905] Call Trace:
[  428.352319]   [  428.356216]  [] uart_write_wakeup+0x21/0x30

The problem is for console ports, the serial port is not shutdown and
interrupts may fire after the struct tty is gone. Simply calling the
tty_port helper tty_port_tty_wakeup instead of tty_wakeup directly will
ensure there is a valid struct tty.

Fixes: 761ed4a945 ("tty: serial_core: convert uart_close to use tty_port_close")
Reported-by: Borislav Petkov <bp@alien8.de>
Reported-by: Mike Galbraith <mgalbraith@suse.de>
Cc: Jiri Slaby <jslaby@suse.cz>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: linux-serial@vger.kernel.org
Signed-off-by: Rob Herring <robh@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-10-28 08:13:07 -04:00
..
hvc tty/hvc: Use opal irqchip interface if available 2016-07-27 12:38:20 +10:00
ipwireless tty: ipwireless, cleanup TIOCGSERIAL 2016-06-25 08:56:30 -07:00
serial tty: serial_core: fix NULL struct tty pointer access in uart_write_wakeup 2016-10-28 08:13:07 -04:00
vt vt: clear selection before resizing 2016-10-27 17:19:35 +02:00
Kconfig devpts: Make each mount of devpts an independent filesystem. 2016-06-05 10:36:01 -07:00
Makefile TTY: Add MIPS EJTAG Fast Debug Channel TTY driver 2015-03-31 12:04:12 +02:00
amiserial.c tty: Replace ASYNC_INITIALIZED bit and update atomically 2016-04-30 09:26:55 -07:00
bfin_jtag_comm.c TTY: bfin_jtag_comm: remove incorrect wait_until_sent operation 2015-03-07 03:44:14 +01:00
cyclades.c tty: stop defining STD_COM_FLAGS in drivers 2016-06-25 08:56:30 -07:00
ehv_bytechan.c drivers/tty: make ehv_bytechan.c explicitly non-modular 2016-02-06 23:26:43 -08:00
goldfish.c tty: goldfish: support platform_device with id -1 2016-03-07 16:11:14 -08:00
isicom.c tty: Replace ASYNC_INITIALIZED bit and update atomically 2016-04-30 09:26:55 -07:00
metag_da.c timers, drivers/tty/metag_da: Initialize the poll timer as pinned 2016-07-07 10:25:14 +02:00
mips_ejtag_fdc.c timers, drivers/tty/mips_ejtag: Initialize the poll timer as pinned 2016-07-07 10:34:59 +02:00
moxa.c tty: Replace ASYNC_INITIALIZED bit and update atomically 2016-04-30 09:26:55 -07:00
moxa.h
mxser.c tty: cyclades+mxser, do not initialize to zero 2016-06-25 08:56:30 -07:00
mxser.h
n_gsm.c TTY and Serial driver update for 4.7-rc1 2016-05-20 20:57:27 -07:00
n_hdlc.c Fix OpenSSH pty regression on close 2016-05-01 13:22:54 -07:00
n_r3964.c tty: r3964: Replace/remove bogus tty lock use 2015-10-17 21:11:29 -07:00
n_tracerouter.c n_tracerouter: stop including <asm-generic/bug> 2015-10-15 00:21:10 +02:00
n_tracesink.c n_tracesink: stop including <asm-generic/bug> 2015-10-15 00:21:11 +02:00
n_tracesink.h
n_tty.c Fix OpenSSH pty regression on close 2016-05-01 13:22:54 -07:00
nozomi.c tty: Replace TTY_THROTTLED bit tests with tty_throttled() 2016-04-30 09:26:55 -07:00
pty.c pty: make ptmx file ops read-only after init 2016-09-15 12:47:03 +02:00
rocket.c TTY: add __init attribute 2016-04-30 09:26:55 -07:00
rocket.h tty: rocket: fix comment of ROCKET_SPD_HI 2015-05-24 12:49:16 -07:00
rocket_int.h tty: rocket: Remove private close_wait 2016-01-28 14:13:44 -08:00
synclink.c TTY and Serial driver update for 4.7-rc1 2016-05-20 20:57:27 -07:00
synclink_gt.c TTY and Serial driver update for 4.7-rc1 2016-05-20 20:57:27 -07:00
synclinkmp.c TTY and Serial driver update for 4.7-rc1 2016-05-20 20:57:27 -07:00
sysrq.c Revert "drivers/tty: Explicitly pass current to show_stack" 2016-09-28 08:12:27 +02:00
tty_audit.c tty: audit: remove unused variable 2016-03-07 16:11:14 -08:00
tty_buffer.c Fix OpenSSH pty regression on close 2016-05-01 13:22:54 -07:00
tty_io.c Merge 4.6-rc7 into tty-next 2016-05-09 09:39:13 +02:00
tty_ioctl.c tty: Replace TTY_THROTTLED bit tests with tty_throttled() 2016-04-30 09:26:55 -07:00
tty_ldisc.c tty: Eliminate global symbol tty_ldisc_N_TTY 2016-01-27 15:13:28 -08:00
tty_ldsem.c tty: Deinline __ldsem_down_write_nested, save 128 bytes 2015-12-13 19:59:48 -08:00
tty_mutex.c Merge 4.5-rc4 into tty-next 2016-02-14 14:36:04 -08:00
tty_port.c tty: Replace ASYNC_INITIALIZED bit and update atomically 2016-04-30 09:26:55 -07:00