linux/drivers
Samir Virmani aff9cf5955 uart: Fix crash in uart_write and uart_put_char
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 a5ba1d95e4 ("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: a5ba1d95e4 ("uart: fix race between uart_put_char() and uart_shutdown()")
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Samir Virmani <samir@embedur.com>
Acked-by: Tycho Andersen <tycho@tycho.ws>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-01-18 13:03:47 +01:00
..
accessibility
acpi arm64 fixes for -rc2 2019-01-11 12:25:40 -08:00
amba
android binder: implement binderfs 2018-12-19 09:40:13 +01:00
ata for-linus-20190112 2019-01-12 13:40:51 -08:00
atm cross-tree: phase out dma_zalloc_coherent() 2019-01-08 07:58:37 -05:00
auxdisplay auxdisplay: charlcd: fix x/y command parsing 2018-12-21 21:27:21 +01:00
base Merge branches 'pm-cpuidle', 'pm-cpufreq' and 'pm-sleep' 2019-01-11 10:09:51 +01:00
bcma
block for-linus-20190112 2019-01-12 13:40:51 -08:00
bluetooth Bluetooth: hci_bcm: Handle specific unknown packets after firmware loading 2018-12-19 13:43:42 +01:00
bus ARM: SoC driver updates 2018-12-31 17:32:35 -08:00
cdrom gdrom: fix a memory leak bug 2018-12-29 08:20:44 -07:00
char Remove 'type' argument from access_ok() function 2019-01-03 18:57:57 -08:00
clk Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/dtor/input 2019-01-02 18:56:59 -08:00
clocksource arch/csky patches for 4.21-rc1 2019-01-05 09:50:07 -08:00
connector
cpufreq Merge branches 'pm-cpuidle', 'pm-cpufreq' and 'pm-sleep' 2019-01-11 10:09:51 +01:00
cpuidle powerpc updates for 4.21 2018-12-27 10:43:24 -08:00
crypto cross-tree: phase out dma_zalloc_coherent() 2019-01-08 07:58:37 -05:00
dax mm, devm_memremap_pages: fix shutdown handling 2018-12-28 12:11:47 -08:00
dca
devfreq PM / devfreq: add devfreq_suspend/resume() functions 2018-12-11 11:40:13 +09:00
dio
dma cross-tree: phase out dma_zalloc_coherent() 2019-01-08 07:58:37 -05:00
dma-buf drivers/dma-buf/udmabuf.c: convert to use vm_fault_t 2019-01-04 13:13:46 -08:00
edac EDAC, fsl_ddr: Add LS1021A to the list of supported hardware 2018-12-19 11:57:45 +01:00
eisa
extcon
firewire FireWire (IEEE 1394) subsystem patch: 2019-01-05 18:33:21 -08:00
firmware arm64 fixes for -rc1 2019-01-05 11:28:39 -08:00
fmc
fpga Remove 'type' argument from access_ok() function 2019-01-03 18:57:57 -08:00
fsi
gnss Merge 4.20-rc6 into tty-next 2018-12-10 10:17:45 +01:00
gpio This is the bulk of GPIO changes for the v4.21 kernel series: 2018-12-28 20:00:21 -08:00
gpu remove dma_zalloc_coherent 2019-01-12 10:52:40 -08:00
hid Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/hid/hid 2019-01-05 17:53:40 -08:00
hsi
hv Char/Misc driver patches for 4.21-rc1 2018-12-28 20:54:57 -08:00
hwmon Kconfig updates for v4.21 2018-12-29 13:03:29 -08:00
hwspinlock hwspinlock: fix return value check in stm32_hwspinlock_probe() 2019-01-03 11:42:10 -08:00
hwtracing intel_th: msu: Fix an off-by-one in attribute store 2018-12-19 20:21:06 +01:00
i2c i2c: tegra: Fix Maximum transfer size 2019-01-11 00:15:04 +01:00
i3c i3c: master: cdns: fix I2C transfers in Cadence I3C master driver 2018-12-12 17:08:32 +01:00
ide for-4.21/block-20181221 2018-12-28 13:19:59 -08:00
idle
iio Staging/IIO driver patches for 4.21-rc1 2018-12-28 20:39:58 -08:00
infiniband cross-tree: phase out dma_zalloc_coherent() 2019-01-08 07:58:37 -05:00
input cross-tree: phase out dma_zalloc_coherent() 2019-01-08 07:58:37 -05:00
iommu cross-tree: phase out dma_zalloc_coherent() 2019-01-08 07:58:37 -05:00
ipack
irqchip irqchip/csky: fixup handle_irq_perbit break irq 2019-01-09 00:18:46 +08:00
isdn isdn: fix kernel-infoleak in capi_unlocked_ioctl 2019-01-02 10:31:39 -08:00
leds LEDs for 4.21-rc1 2018-12-25 14:52:50 -08:00
lightnvm lightnvm: pblk: fix use-after-free bug 2018-12-22 14:45:35 -07:00
macintosh Remove 'type' argument from access_ok() function 2019-01-03 18:57:57 -08:00
mailbox mailbox: tegra-hsp: Use device-managed registration API 2018-12-21 22:31:26 -06:00
mcb
md Merge branch 'for-next' of git://git.kernel.org/pub/scm/linux/kernel/git/shli/md into for-linus 2019-01-03 08:21:02 -07:00
media cross-tree: phase out dma_zalloc_coherent() 2019-01-08 07:58:37 -05:00
memory ARM: SoC: late updates 2019-01-05 11:30:37 -08:00
memstick MMC core: 2018-12-28 16:52:18 -08:00
message scsi: flip the default on use_clustering 2018-12-18 23:13:12 -05:00
mfd mfd: axp20x: use explicit bit defines 2018-12-13 16:40:03 +00:00
misc cross-tree: phase out dma_zalloc_coherent() 2019-01-08 07:58:37 -05:00
mmc cross-tree: phase out dma_zalloc_coherent() 2019-01-08 07:58:37 -05:00
mtd mtd: rawnand: qcom: fix memory corruption that causes panic 2019-01-08 12:33:24 +01:00
mux
net cross-tree: phase out dma_zalloc_coherent() on headers 2019-01-08 07:58:49 -05:00
nfc
ntb cross-tree: phase out dma_zalloc_coherent() 2019-01-08 07:58:37 -05:00
nubus
nvdimm Merge branch 'akpm' (patches from Andrew) 2018-12-28 16:55:46 -08:00
nvme for-linus-20190112 2019-01-12 13:40:51 -08:00
nvmem
of Merge tag 'devicetree-for-4.21' of git://git.kernel.org/pub/scm/linux/kernel/git/robh/linux 2018-12-28 20:08:34 -08:00
opp cpufreq: scpi/scmi: Fix freeing of dynamic OPPs 2019-01-04 12:19:40 +01:00
oprofile
parisc Kconfig file consolidation for v4.21 2018-12-29 13:40:29 -08:00
parport
pci remove dma_zalloc_coherent 2019-01-12 10:52:40 -08:00
pcmcia Included in this update: 2019-01-05 11:23:17 -08:00
perf drivers/perf: hisi: Fixup one DDRC PMU register offset 2019-01-04 10:13:27 +00:00
phy phy: fix build breakage: add PHY_MODE_SATA 2019-01-12 21:07:14 -08:00
pinctrl Pin control bulk changes for the v4.21 kernel cycle: 2019-01-01 13:19:16 -08:00
platform chrome platform changes for v4.21 2019-01-06 11:40:06 -08:00
pnp Remove 'type' argument from access_ok() function 2019-01-03 18:57:57 -08:00
power power supply and reset changes for the v4.21 series 2018-12-28 20:22:45 -08:00
powercap
pps Kconfig updates for v4.21 2018-12-29 13:03:29 -08:00
ps3
ptp Char/Misc driver patches for 4.21-rc1 2018-12-28 20:54:57 -08:00
pwm pwm: imx: Add ipg clock operation 2018-12-24 12:06:56 +01:00
rapidio cross-tree: phase out dma_zalloc_coherent() 2019-01-08 07:58:37 -05:00
ras treewide: surround Kconfig file paths with double quotes 2018-12-22 00:25:54 +09:00
regulator Merge remote-tracking branch 'regulator/topic/coupled' into regulator-next 2018-12-21 13:43:35 +00:00
remoteproc
reset reset: uniphier-glue: Add AHCI reset control support in glue layer 2019-01-07 16:38:51 +01:00
rpmsg
rtc RTC for 4.21 2019-01-01 13:24:31 -08:00
s390 cross-tree: phase out dma_zalloc_coherent() 2019-01-08 07:58:37 -05:00
sbus Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/sparc-next 2018-12-26 10:32:18 -08:00
scsi cross-tree: phase out dma_zalloc_coherent() 2019-01-08 07:58:37 -05:00
sfi
sh
siox
slimbus
sn
soc ARM: SoC fixes 2019-01-14 10:34:14 +12:00
soundwire
spi cross-tree: phase out dma_zalloc_coherent() 2019-01-08 07:58:37 -05:00
spmi
ssb
staging Staging driver fixes for 5.0-rc2 2019-01-14 05:49:35 +12:00
target SCSI misc on 20181224 2018-12-28 14:48:06 -08:00
tc
tee OP-TEE dynamic shm log message 2018-12-31 13:06:30 -08:00
thermal Merge branch 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/rzhang/linux 2019-01-05 16:07:28 -08:00
thunderbolt
tty uart: Fix crash in uart_write and uart_put_char 2019-01-18 13:03:47 +01:00
uio Char/Misc driver patches for 4.21-rc1 2018-12-28 20:54:57 -08:00
usb USB fixes for 5.0-rc2 2019-01-14 05:45:28 +12:00
uwb
vfio vfio/type1: Fix unmap overflow off-by-one 2019-01-08 09:31:28 -07:00
vhost Remove 'type' argument from access_ok() function 2019-01-03 18:57:57 -08:00
video cross-tree: phase out dma_zalloc_coherent() 2019-01-08 07:58:37 -05:00
virt
virtio virtio, vhost: features, fixes, cleanups 2019-01-02 18:54:45 -08:00
visorbus
vlynq
vme
w1 treewide: surround Kconfig file paths with double quotes 2018-12-22 00:25:54 +09:00
watchdog linux-watchdog 4.21-rc1 tag 2019-01-01 13:16:45 -08:00
xen Remove 'type' argument from access_ok() function 2019-01-03 18:57:57 -08:00
zorro
Kconfig Kconfig file consolidation for v4.21 2018-12-29 13:40:29 -08:00
Makefile