LKML Archive on lore.kernel.org
 help / color / Atom feed
From: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To: linux-kernel@vger.kernel.org
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
	stable@vger.kernel.org, Samir Virmani <samir@embedur.com>,
	Tycho Andersen <tycho@tycho.ws>
Subject: [PATCH 4.14 26/68] uart: Fix crash in uart_write and uart_put_char
Date: Tue, 29 Jan 2019 12:35:48 +0100
Message-ID: <20190129113133.819071469@linuxfoundation.org> (raw)
In-Reply-To: <20190129113131.751891514@linuxfoundation.org>

4.14-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Samir Virmani <samir@embedur.com>

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()")
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>

---
 drivers/tty/serial/serial_core.c |   12 ++++++++----
 1 file changed, 8 insertions(+), 4 deletions(-)

--- a/drivers/tty/serial/serial_core.c
+++ b/drivers/tty/serial/serial_core.c
@@ -563,10 +563,12 @@ static int uart_put_char(struct tty_stru
 	int ret = 0;
 
 	circ = &state->xmit;
-	if (!circ->buf)
+	port = uart_port_lock(state, flags);
+	if (!circ->buf) {
+		uart_port_unlock(port, flags);
 		return 0;
+	}
 
-	port = uart_port_lock(state, flags);
 	if (port && uart_circ_chars_free(circ) != 0) {
 		circ->buf[circ->head] = c;
 		circ->head = (circ->head + 1) & (UART_XMIT_SIZE - 1);
@@ -599,11 +601,13 @@ static int uart_write(struct tty_struct
 		return -EL3HLT;
 	}
 
+	port = uart_port_lock(state, flags);
 	circ = &state->xmit;
-	if (!circ->buf)
+	if (!circ->buf) {
+		uart_port_unlock(port, flags);
 		return 0;
+	}
 
-	port = uart_port_lock(state, flags);
 	while (port) {
 		c = CIRC_SPACE_TO_END(circ->head, circ->tail, UART_XMIT_SIZE);
 		if (count < c)



  parent reply index

Thread overview: 78+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-01-29 11:35 [PATCH 4.14 00/68] 4.14.97-stable review Greg Kroah-Hartman
2019-01-29 11:35 ` [PATCH 4.14 01/68] amd-xgbe: Fix mdio access for non-zero ports and clause 45 PHYs Greg Kroah-Hartman
2019-01-29 11:35 ` [PATCH 4.14 02/68] net: bridge: Fix ethernet header pointer before check skb forwardable Greg Kroah-Hartman
2019-01-29 11:35 ` [PATCH 4.14 03/68] net: Fix usage of pskb_trim_rcsum Greg Kroah-Hartman
2019-01-29 11:35 ` [PATCH 4.14 04/68] net: phy: mdio_bus: add missing device_del() in mdiobus_register() error handling Greg Kroah-Hartman
2019-01-29 11:35 ` [PATCH 4.14 05/68] net_sched: refetch skb protocol for each filter Greg Kroah-Hartman
2019-01-29 11:35 ` [PATCH 4.14 06/68] openvswitch: Avoid OOB read when parsing flow nlattrs Greg Kroah-Hartman
2019-01-29 11:35 ` [PATCH 4.14 07/68] vhost: log dirty page correctly Greg Kroah-Hartman
2019-01-29 11:35 ` [PATCH 4.14 08/68] net: ipv4: Fix memory leak in network namespace dismantle Greg Kroah-Hartman
2019-01-29 11:35 ` [PATCH 4.14 09/68] tcp: allow MSG_ZEROCOPY transmission also in CLOSE_WAIT state Greg Kroah-Hartman
2019-01-29 11:35 ` [PATCH 4.14 10/68] ipfrag: really prevent allocation on netns exit Greg Kroah-Hartman
2019-01-29 11:35 ` [PATCH 4.14 11/68] mmc: Kconfig: Enable CONFIG_MMC_SDHCI_IO_ACCESSORS Greg Kroah-Hartman
2019-01-29 11:35 ` [PATCH 4.14 12/68] mei: me: add denverton innovation engine device IDs Greg Kroah-Hartman
2019-01-29 11:35 ` [PATCH 4.14 13/68] USB: serial: simple: add Motorola Tetra TPG2200 device id Greg Kroah-Hartman
2019-01-29 11:35 ` [PATCH 4.14 14/68] USB: serial: pl2303: add new PID to support PL2303TB Greg Kroah-Hartman
2019-01-29 11:35 ` [PATCH 4.14 15/68] ASoC: atom: fix a missing check of snd_pcm_lib_malloc_pages Greg Kroah-Hartman
2019-01-29 11:35 ` [PATCH 4.14 16/68] ASoC: rt5514-spi: Fix potential NULL pointer dereference Greg Kroah-Hartman
2019-01-29 11:35 ` [PATCH 4.14 17/68] ALSA: hda - Add mute LED support for HP ProBook 470 G5 Greg Kroah-Hartman
2019-01-29 11:35 ` [PATCH 4.14 18/68] ARCv2: lib: memeset: fix doing prefetchw outside of buffer Greg Kroah-Hartman
2019-01-29 11:35 ` [PATCH 4.14 19/68] ARC: adjust memblock_reserve of kernel memory Greg Kroah-Hartman
2019-01-29 11:35 ` [PATCH 4.14 20/68] ARC: perf: map generic branches to correct hardware condition Greg Kroah-Hartman
2019-01-29 11:35 ` [PATCH 4.14 21/68] s390/early: improve machine detection Greg Kroah-Hartman
2019-01-29 11:35 ` [PATCH 4.14 22/68] s390/smp: fix CPU hotplug deadlock with CPU rescan Greg Kroah-Hartman
2019-01-29 11:35 ` [PATCH 4.14 23/68] char/mwave: fix potential Spectre v1 vulnerability Greg Kroah-Hartman
2019-01-29 11:35 ` [PATCH 4.14 24/68] staging: rtl8188eu: Add device code for D-Link DWA-121 rev B1 Greg Kroah-Hartman
2019-01-29 11:35 ` [PATCH 4.14 25/68] tty: Handle problem if line discipline does not have receive_buf Greg Kroah-Hartman
2019-01-29 11:35 ` Greg Kroah-Hartman [this message]
2019-01-29 11:35 ` [PATCH 4.14 27/68] tty/n_hdlc: fix __might_sleep warning Greg Kroah-Hartman
2019-01-29 11:35 ` [PATCH 4.14 28/68] hv_balloon: avoid touching uninitialized struct page during tail onlining Greg Kroah-Hartman
2019-01-29 11:35 ` [PATCH 4.14 29/68] Drivers: hv: vmbus: Check for ring when getting debug info Greg Kroah-Hartman
2019-01-29 11:35 ` [PATCH 4.14 30/68] CIFS: Fix possible hang during async MTU reads and writes Greg Kroah-Hartman
2019-01-29 11:35 ` [PATCH 4.14 31/68] CIFS: Fix credits calculations for reads with errors Greg Kroah-Hartman
2019-01-29 11:35 ` [PATCH 4.14 32/68] CIFS: Fix credit calculation for encrypted " Greg Kroah-Hartman
2019-01-29 11:35 ` [PATCH 4.14 33/68] CIFS: Do not reconnect TCP session in add_credits() Greg Kroah-Hartman
2019-01-29 11:35 ` [PATCH 4.14 34/68] Input: xpad - add support for SteelSeries Stratus Duo Greg Kroah-Hartman
2019-01-29 11:35 ` [PATCH 4.14 35/68] compiler.h: enable builtin overflow checkers and add fallback code Greg Kroah-Hartman
2019-01-29 11:35 ` [PATCH 4.14 36/68] Input: uinput - fix undefined behavior in uinput_validate_absinfo() Greg Kroah-Hartman
2019-01-29 11:35 ` [PATCH 4.14 37/68] acpi/nfit: Block function zero DSMs Greg Kroah-Hartman
2019-01-29 11:36 ` [PATCH 4.14 38/68] acpi/nfit: Fix command-supported detection Greg Kroah-Hartman
2019-01-29 11:36 ` [PATCH 4.14 39/68] dm thin: fix passdown_double_checking_shared_status() Greg Kroah-Hartman
2019-01-29 11:36 ` [PATCH 4.14 40/68] dm crypt: fix parsing of extended IV arguments Greg Kroah-Hartman
2019-01-29 11:36 ` [PATCH 4.14 41/68] KVM: x86: Fix single-step debugging Greg Kroah-Hartman
2019-01-29 11:36 ` [PATCH 4.14 42/68] x86/pkeys: Properly copy pkey state at fork() Greg Kroah-Hartman
2019-01-29 11:36 ` [PATCH 4.14 43/68] x86/selftests/pkeys: Fork() to check for state being preserved Greg Kroah-Hartman
2019-01-29 11:36 ` [PATCH 4.14 44/68] x86/kaslr: Fix incorrect i8254 outb() parameters Greg Kroah-Hartman
2019-01-29 11:36 ` [PATCH 4.14 45/68] posix-cpu-timers: Unbreak timer rearming Greg Kroah-Hartman
2019-01-29 11:36 ` [PATCH 4.14 46/68] irqchip/gic-v3-its: Align PCI Multi-MSI allocation on their size Greg Kroah-Hartman
2019-01-29 11:36 ` [PATCH 4.14 47/68] can: dev: __can_get_echo_skb(): fix bogous check for non-existing skb by removing it Greg Kroah-Hartman
2019-01-29 11:36 ` [PATCH 4.14 48/68] can: bcm: check timer values before ktime conversion Greg Kroah-Hartman
2019-01-29 11:36 ` [PATCH 4.14 49/68] vt: invoke notifier on screen size change Greg Kroah-Hartman
2019-01-29 11:36 ` [PATCH 4.14 50/68] perf unwind: Unwind with libdw doesnt take symfs into account Greg Kroah-Hartman
2019-01-29 11:36 ` [PATCH 4.14 51/68] perf unwind: Take pgoff into account when reporting elf to libdwfl Greg Kroah-Hartman
2019-01-29 11:36 ` [PATCH 4.14 52/68] Revert "seccomp: add a selftest for get_metadata" Greg Kroah-Hartman
2019-01-29 11:36 ` [PATCH 4.14 53/68] net: stmmac: Use correct values in TQS/RQS fields Greg Kroah-Hartman
2019-01-29 11:36 ` [PATCH 4.14 54/68] KVM: x86: Fix a 4.14 backport regression related to userspace/guest FPU Greg Kroah-Hartman
2019-01-29 11:36 ` [PATCH 4.14 55/68] s390/smp: Fix calling smp_call_ipl_cpu() from ipl CPU Greg Kroah-Hartman
2019-01-29 11:36 ` [PATCH 4.14 56/68] nvmet-rdma: Add unlikely for response allocated check Greg Kroah-Hartman
2019-01-29 11:36 ` [PATCH 4.14 57/68] nvmet-rdma: fix null dereference under heavy load Greg Kroah-Hartman
2019-01-29 11:36 ` [PATCH 4.14 58/68] usb: dwc3: gadget: Clear req->needs_extra_trb flag on cleanup Greg Kroah-Hartman
2019-01-29 11:36 ` [PATCH 4.14 59/68] xhci: Fix leaking USB3 shared_hcd at xhci removal Greg Kroah-Hartman
2019-01-29 11:36 ` [PATCH 4.14 60/68] ptp_kvm: probe for kvm guest availability Greg Kroah-Hartman
2019-01-29 11:36 ` [PATCH 4.14 61/68] x86/pvclock: add setter for pvclock_pvti_cpu0_va Greg Kroah-Hartman
2019-01-29 11:36 ` [PATCH 4.14 62/68] x86/xen/time: set pvclock flags on xen_time_init() Greg Kroah-Hartman
2019-01-29 11:36 ` [PATCH 4.14 63/68] x86/xen/time: setup vcpu 0 time info page Greg Kroah-Hartman
2019-01-29 11:36 ` [PATCH 4.14 64/68] x86/xen/time: Output xen sched_clock time from 0 Greg Kroah-Hartman
2019-01-29 11:36 ` [PATCH 4.14 65/68] xen: Fix x86 sched_clock() interface for xen Greg Kroah-Hartman
2019-01-29 11:36 ` [PATCH 4.14 66/68] f2fs: read page index before freeing Greg Kroah-Hartman
2019-01-29 11:36 ` [PATCH 4.14 67/68] btrfs: fix error handling in btrfs_dev_replace_start Greg Kroah-Hartman
2019-01-29 11:36 ` [PATCH 4.14 68/68] btrfs: dev-replace: go back to suspended state if target device is missing Greg Kroah-Hartman
2019-01-30  2:06 ` [PATCH 4.14 00/68] 4.14.97-stable review shuah
2019-01-30 12:51 ` Jon Hunter
2019-01-31  7:51   ` Greg Kroah-Hartman
2019-01-30 12:55 ` Naresh Kamboju
2019-01-30 18:49   ` Amir Goldstein
2019-01-30 19:32     ` Greg Kroah-Hartman
2019-02-04 10:12       ` Amir Goldstein
2019-02-04 10:35         ` Greg Kroah-Hartman
2019-01-30 22:13 ` Guenter Roeck

Reply instructions:

You may reply publically to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20190129113133.819071469@linuxfoundation.org \
    --to=gregkh@linuxfoundation.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=samir@embedur.com \
    --cc=stable@vger.kernel.org \
    --cc=tycho@tycho.ws \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link

LKML Archive on lore.kernel.org

Archives are clonable:
	git clone --mirror https://lore.kernel.org/lkml/0 lkml/git/0.git
	git clone --mirror https://lore.kernel.org/lkml/1 lkml/git/1.git
	git clone --mirror https://lore.kernel.org/lkml/2 lkml/git/2.git
	git clone --mirror https://lore.kernel.org/lkml/3 lkml/git/3.git
	git clone --mirror https://lore.kernel.org/lkml/4 lkml/git/4.git
	git clone --mirror https://lore.kernel.org/lkml/5 lkml/git/5.git
	git clone --mirror https://lore.kernel.org/lkml/6 lkml/git/6.git
	git clone --mirror https://lore.kernel.org/lkml/7 lkml/git/7.git

	# If you have public-inbox 1.1+ installed, you may
	# initialize and index your mirror using the following commands:
	public-inbox-init -V2 lkml lkml/ https://lore.kernel.org/lkml \
		linux-kernel@vger.kernel.org linux-kernel@archiver.kernel.org
	public-inbox-index lkml

Example config snippet for mirrors

Newsgroup available over NNTP:
	nntp://nntp.lore.kernel.org/org.kernel.vger.linux-kernel


AGPL code for this site: git clone https://public-inbox.org/ public-inbox