This is a note to let you know that I've just added the patch titled

usb: typec: tcpm: Add NULL check before dereferencing config

to my usb git tree which can be found at git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb.git in the usb-linus branch.

The patch will show up in the next release of the linux-next tree (usually sometime within the next 24 hours during the week.)

The patch will hopefully also be merged in Linus's tree for the next -rc kernel release.

If you have any questions about this process, please let me know.

From 1957de95d425d1c06560069dc7277a73a8b28683 Mon Sep 17 00:00:00 2001

From: Guenter Roeck linux@roeck-us.net Date: Wed, 24 Jul 2019 07:38:32 -0700 Subject: usb: typec: tcpm: Add NULL check before dereferencing config

When instantiating tcpm on an NXP OM 13588 board with NXP PTN5110, the following crash is seen when writing into the 'preferred_role' sysfs attribute.

Unable to handle kernel NULL pointer dereference at virtual address 00000028 pgd = f69149ad [00000028] *pgd=00000000 Internal error: Oops: 5 [#1] THUMB2 Modules linked in: tcpci tcpm CPU: 0 PID: 1882 Comm: bash Not tainted 5.1.18-sama5-armv7-r2 #4 Hardware name: Atmel SAMA5 PC is at tcpm_try_role+0x3a/0x4c [tcpm] LR is at tcpm_try_role+0x15/0x4c [tcpm] pc : [<bf8000e2>] lr : [<bf8000bd>] psr: 60030033 sp : dc1a1e88 ip : c03fb47d fp : 00000000 r10: dc216190 r9 : dc1a1f78 r8 : 00000001 r7 : df4ae044 r6 : dd032e90 r5 : dd1ce340 r4 : df4ae054 r3 : 00000000 r2 : 00000000 r1 : 00000000 r0 : df4ae044 Flags: nZCv IRQs on FIQs on Mode SVC_32 ISA Thumb Segment none Control: 50c53c7d Table: 3efec059 DAC: 00000051 Process bash (pid: 1882, stack limit = 0x6a6d4aa5) Stack: (0xdc1a1e88 to 0xdc1a2000) 1e80: dd05d808 dd1ce340 00000001 00000007 dd1ce340 c03fb4a7 1ea0: 00000007 00000007 dc216180 00000000 00000000 c01e1e03 00000000 00000000 1ec0: c0907008 dee98b40 c01e1d5d c06106c4 00000000 00000000 00000007 c0194e8b 1ee0: 0000000a 00000400 00000000 c01a97db dc22bf00 ffffe000 df4b6a00 df745900 1f00: 00000001 00000001 000000dd c01a9c2f 7aeab3be c0907008 00000000 dc22bf00 1f20: c0907008 00000000 00000000 00000000 00000000 7aeab3be 00000007 dee98b40 1f40: 005dc318 dc1a1f78 00000000 00000000 00000007 c01969f7 0000000a c01a20cb 1f60: dee98b40 c0907008 dee98b40 005dc318 00000000 c0196b9b 00000000 00000000 1f80: dee98b40 7aeab3be 00000074 005dc318 b6f3bdb0 00000004 c0101224 dc1a0000 1fa0: 00000004 c0101001 00000074 005dc318 00000001 005dc318 00000007 00000000 1fc0: 00000074 005dc318 b6f3bdb0 00000004 00000007 00000007 00000000 00000000 1fe0: 00000004 be800880 b6ed35b3 b6e5c746 60030030 00000001 00000000 00000000 [<bf8000e2>] (tcpm_try_role [tcpm]) from [<c03fb4a7>] (preferred_role_store+0x2b/0x5c) [<c03fb4a7>] (preferred_role_store) from [<c01e1e03>] (kernfs_fop_write+0xa7/0x150) [<c01e1e03>] (kernfs_fop_write) from [<c0194e8b>] (__vfs_write+0x1f/0x104) [<c0194e8b>] (__vfs_write) from [<c01969f7>] (vfs_write+0x6b/0x104) [<c01969f7>] (vfs_write) from [<c0196b9b>] (ksys_write+0x43/0x94) [<c0196b9b>] (ksys_write) from [<c0101001>] (ret_fast_syscall+0x1/0x62)

Since commit 96232cbc6c994 ("usb: typec: tcpm: support get typec and pd config from device properties"), the 'config' pointer in struct tcpc_dev is optional when registering a Type-C port. Since it is optional, we have to check if it is NULL before dereferencing it.

Reported-by: Douglas Gilbert dgilbert@interlog.com Cc: Douglas Gilbert dgilbert@interlog.com Fixes: 96232cbc6c994 ("usb: typec: tcpm: support get typec and pd config from device properties") Signed-off-by: Guenter Roeck linux@roeck-us.net Cc: stable stable@vger.kernel.org Reviewed-by: Jun Li jun.li@nxp.com Reviewed-by: Heikki Krogerus heikki.krogerus@linux.intel.com Link: https://lore.kernel.org/r/1563979112-22483-1-git-send-email-linux@roeck-us.n... Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- drivers/usb/typec/tcpm/tcpm.c | 7 ++++--- 1 file changed, 4 insertions(+), 3 deletions(-)

diff --git a/drivers/usb/typec/tcpm/tcpm.c b/drivers/usb/typec/tcpm/tcpm.c index fba32d84e578..77f71f602f73 100644 --- a/drivers/usb/typec/tcpm/tcpm.c +++ b/drivers/usb/typec/tcpm/tcpm.c @@ -379,7 +379,8 @@ static enum tcpm_state tcpm_default_state(struct tcpm_port *port) return SNK_UNATTACHED; else if (port->try_role == TYPEC_SOURCE) return SRC_UNATTACHED; - else if (port->tcpc->config->default_role == TYPEC_SINK) + else if (port->tcpc->config && + port->tcpc->config->default_role == TYPEC_SINK) return SNK_UNATTACHED; /* Fall through to return SRC_UNATTACHED */ } else if (port->port_type == TYPEC_PORT_SNK) { @@ -4114,7 +4115,7 @@ static int tcpm_try_role(const struct typec_capability *cap, int role) mutex_lock(&port->lock); if (tcpc->try_role) ret = tcpc->try_role(tcpc, role); - if (!ret && !tcpc->config->try_role_hw) + if (!ret && (!tcpc->config || !tcpc->config->try_role_hw)) port->try_role = role; port->try_src_count = 0; port->try_snk_count = 0; @@ -4701,7 +4702,7 @@ static int tcpm_copy_caps(struct tcpm_port *port, port->typec_caps.prefer_role = tcfg->default_role; port->typec_caps.type = tcfg->type; port->typec_caps.data = tcfg->data; - port->self_powered = port->tcpc->config->self_powered; + port->self_powered = tcfg->self_powered;

return 0; }