[PATCH 5.5 169/257] remoteproc: Fix NULL pointer dereference in rproc_virtio_notify

From: Greg Kroah-Hartman
Date: Thu Apr 16 2020 - 11:39:04 EST

From: Nikita Shubin <NShubin@xxxxxxxxxx>

commit 791c13b709dd51eb37330f2a5837434e90c87c27 upstream.

Undefined rproc_ops .kick method in remoteproc driver will result in
"Unable to handle kernel NULL pointer dereference" in rproc_virtio_notify,
after firmware loading if:

1) .kick method wasn't defined in driver
2) resource_table exists in firmware and has "Virtio device entry" defined

Let's refuse to register an rproc-induced virtio device if no kick method was
defined for rproc.

[ 13.180049][ T415] 8<--- cut here ---
[ 13.190558][ T415] Unable to handle kernel NULL pointer dereference at virtual address 00000000
[ 13.212544][ T415] pgd = (ptrval)
[ 13.217052][ T415] [00000000] *pgd=00000000
[ 13.224692][ T415] Internal error: Oops: 80000005 [#1] PREEMPT SMP ARM
[ 13.231318][ T415] Modules linked in: rpmsg_char imx_rproc virtio_rpmsg_bus rpmsg_core [last unloaded: imx_rproc]
[ 13.241687][ T415] CPU: 0 PID: 415 Comm: unload-load.sh Not tainted 5.5.2-00002-g707df13bbbdd #6
[ 13.250561][ T415] Hardware name: Freescale i.MX7 Dual (Device Tree)
[ 13.257009][ T415] PC is at 0x0
[ 13.260249][ T415] LR is at rproc_virtio_notify+0x2c/0x54
[ 13.265738][ T415] pc : [<00000000>] lr : [<8050f6b0>] psr: 60010113
[ 13.272702][ T415] sp : b8d47c48 ip : 00000001 fp : bc04de00
[ 13.278625][ T415] r10: bc04c000 r9 : 00000cc0 r8 : b8d46000
[ 13.284548][ T415] r7 : 00000000 r6 : b898f200 r5 : 00000000 r4 : b8a29800
[ 13.291773][ T415] r3 : 00000000 r2 : 990a3ad4 r1 : 00000000 r0 : b8a29800
[ 13.299000][ T415] Flags: nZCv IRQs on FIQs on Mode SVC_32 ISA ARM Segment none
[ 13.306833][ T415] Control: 10c5387d Table: b8b4806a DAC: 00000051
[ 13.313278][ T415] Process unload-load.sh (pid: 415, stack limit = 0x(ptrval))
[ 13.320591][ T415] Stack: (0xb8d47c48 to 0xb8d48000)
[ 13.325651][ T415] 7c40: b895b680 00000001 b898f200 803c6430 b895bc80 7f00ae18
[ 13.334531][ T415] 7c60: 00000035 00000000 00000000 b9393200 80b3ed80 00004000 b9393268 bbf5a9a2
[ 13.343410][ T415] 7c80: 00000e00 00000200 00000000 7f00aff0 7f00a014 b895b680 b895b800 990a3ad4
[ 13.352290][ T415] 7ca0: 00000001 b898f210 b898f200 00000000 00000000 7f00e000 00000001 00000000
[ 13.361170][ T415] 7cc0: 00000000 803c62e0 80b2169c 802a0924 b898f210 00000000 00000000 b898f210
[ 13.370049][ T415] 7ce0: 80b9ba44 00000000 80b9ba48 00000000 7f00e000 00000008 80b2169c 80400114
[ 13.378929][ T415] 7d00: 80b2169c 8061fd64 b898f210 7f00e000 80400744 b8d46000 80b21634 80b21634
[ 13.387809][ T415] 7d20: 80b2169c 80400614 80b21634 80400718 7f00e000 00000000 b8d47d7c 80400744
[ 13.396689][ T415] 7d40: b8d46000 80b21634 80b21634 803fe338 b898f254 b80fe76c b8d32e38 990a3ad4
[ 13.405569][ T415] 7d60: fffffff3 b898f210 b8d46000 00000001 b898f254 803ffe7c 80857a90 b898f210
[ 13.414449][ T415] 7d80: 00000001 990a3ad4 b8d46000 b898f210 b898f210 80b17aec b8a29c20 803ff0a4
[ 13.423328][ T415] 7da0: b898f210 00000000 b8d46000 803fb8e0 b898f200 00000000 80b17aec b898f210
[ 13.432209][ T415] 7dc0: b8a29c20 990a3ad4 b895b900 b898f200 8050fb7c 80b17aec b898f210 b8a29c20
[ 13.441088][ T415] 7de0: b8a29800 b895b900 b8a29a04 803c5ec0 b8a29c00 b898f200 b8a29a20 00000007
[ 13.449968][ T415] 7e00: b8a29c20 8050fd78 b8a29800 00000000 b8a29a20 b8a29c04 b8a29820 b8a299d0
[ 13.458848][ T415] 7e20: b895b900 8050e5a4 b8a29800 b8a299d8 b8d46000 b8a299e0 b8a29820 b8a299d0
[ 13.467728][ T415] 7e40: b895b900 8050e008 000041ed 00000000 b8b8c440 b8a299d8 b8a299e0 b8a299d8
[ 13.476608][ T415] 7e60: b8b8c440 990a3ad4 00000000 b8a29820 b8b8c400 00000006 b8a29800 b895b880
[ 13.485487][ T415] 7e80: b8d47f78 00000000 00000000 8050f4b4 00000006 b895b890 b8b8c400 008fbea0
[ 13.494367][ T415] 7ea0: b895b880 8029f530 00000000 00000000 b8d46000 00000006 b8d46000 008fbea0
[ 13.503246][ T415] 7ec0: 8029f434 00000000 b8d46000 00000000 00000000 8021e2e4 0000000a 8061fd0c
[ 13.512125][ T415] 7ee0: 0000000a b8af0c00 0000000a b8af0c40 00000001 b8af0c40 00000000 8061f910
[ 13.521005][ T415] 7f00: 0000000a 80240af4 00000002 b8d46000 00000000 8061fd0c 00000002 80232d7c
[ 13.529884][ T415] 7f20: 00000000 b8d46000 00000000 990a3ad4 00000000 00000006 b8a62d80 008fbea0
[ 13.538764][ T415] 7f40: b8d47f78 00000000 b8d46000 00000000 00000000 802210c0 b88f2900 00000000
[ 13.547644][ T415] 7f60: b8a62d80 b8a62d80 b8d46000 00000006 008fbea0 80221320 00000000 00000000
[ 13.556524][ T415] 7f80: b8af0c00 990a3ad4 0000006c 008fbea0 76f1cda0 00000004 80101204 00000004
[ 13.565403][ T415] 7fa0: 00000000 80101000 0000006c 008fbea0 00000001 008fbea0 00000006 00000000
[ 13.574283][ T415] 7fc0: 0000006c 008fbea0 76f1cda0 00000004 00000006 00000006 00000000 00000000
[ 13.583162][ T415] 7fe0: 00000004 7ebaf7d0 76eb4c0b 76e3f206 600d0030 00000001 00000000 00000000
[ 13.592056][ T415] [<8050f6b0>] (rproc_virtio_notify) from [<803c6430>] (virtqueue_notify+0x1c/0x34)
[ 13.601298][ T415] [<803c6430>] (virtqueue_notify) from [<7f00ae18>] (rpmsg_probe+0x280/0x380 [virtio_rpmsg_bus])
[ 13.611663][ T415] [<7f00ae18>] (rpmsg_probe [virtio_rpmsg_bus]) from [<803c62e0>] (virtio_dev_probe+0x1f8/0x2c4)
[ 13.622022][ T415] [<803c62e0>] (virtio_dev_probe) from [<80400114>] (really_probe+0x200/0x450)
[ 13.630817][ T415] [<80400114>] (really_probe) from [<80400614>] (driver_probe_device+0x16c/0x1ac)
[ 13.639873][ T415] [<80400614>] (driver_probe_device) from [<803fe338>] (bus_for_each_drv+0x84/0xc8)
[ 13.649102][ T415] [<803fe338>] (bus_for_each_drv) from [<803ffe7c>] (__device_attach+0xd4/0x164)
[ 13.658069][ T415] [<803ffe7c>] (__device_attach) from [<803ff0a4>] (bus_probe_device+0x84/0x8c)
[ 13.666950][ T415] [<803ff0a4>] (bus_probe_device) from [<803fb8e0>] (device_add+0x444/0x768)
[ 13.675572][ T415] [<803fb8e0>] (device_add) from [<803c5ec0>] (register_virtio_device+0xa4/0xfc)
[ 13.684541][ T415] [<803c5ec0>] (register_virtio_device) from [<8050fd78>] (rproc_add_virtio_dev+0xcc/0x1b8)
[ 13.694466][ T415] [<8050fd78>] (rproc_add_virtio_dev) from [<8050e5a4>] (rproc_start+0x148/0x200)
[ 13.703521][ T415] [<8050e5a4>] (rproc_start) from [<8050e008>] (rproc_boot+0x384/0x5c0)
[ 13.711708][ T415] [<8050e008>] (rproc_boot) from [<8050f4b4>] (state_store+0x3c/0xc8)
[ 13.719723][ T415] [<8050f4b4>] (state_store) from [<8029f530>] (kernfs_fop_write+0xfc/0x214)
[ 13.728348][ T415] [<8029f530>] (kernfs_fop_write) from [<8021e2e4>] (__vfs_write+0x30/0x1cc)
[ 13.736971][ T415] [<8021e2e4>] (__vfs_write) from [<802210c0>] (vfs_write+0xac/0x17c)
[ 13.744985][ T415] [<802210c0>] (vfs_write) from [<80221320>] (ksys_write+0x64/0xe4)
[ 13.752825][ T415] [<80221320>] (ksys_write) from [<80101000>] (ret_fast_syscall+0x0/0x54)
[ 13.761178][ T415] Exception stack(0xb8d47fa8 to 0xb8d47ff0)
[ 13.766932][ T415] 7fa0: 0000006c 008fbea0 00000001 008fbea0 00000006 00000000
[ 13.775811][ T415] 7fc0: 0000006c 008fbea0 76f1cda0 00000004 00000006 00000006 00000000 00000000
[ 13.784687][ T415] 7fe0: 00000004 7ebaf7d0 76eb4c0b 76e3f206
[ 13.790442][ T415] Code: bad PC value
[ 13.839214][ T415] ---[ end trace 1fe21ecfc9f28852 ]---

Reviewed-by: Mathieu Poirier <mathieu.poirier@xxxxxxxxxx>
Signed-off-by: Nikita Shubin <NShubin@xxxxxxxxxx>
Fixes: 7a186941626d ("remoteproc: remove the single rpmsg vdev limitation")
Cc: stable@xxxxxxxxxxxxxxx
Link: https://lore.kernel.org/r/20200306072452.24743-1-NShubin@xxxxxxxxxx
Signed-off-by: Bjorn Andersson <bjorn.andersson@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
drivers/remoteproc/remoteproc_virtio.c | 7 +++++++
1 file changed, 7 insertions(+)

--- a/drivers/remoteproc/remoteproc_virtio.c
+++ b/drivers/remoteproc/remoteproc_virtio.c
@@ -334,6 +334,13 @@ int rproc_add_virtio_dev(struct rproc_vd
struct rproc_mem_entry *mem;
int ret;

+ if (rproc->ops->kick == NULL) {
+ ret = -EINVAL;
+ dev_err(dev, ".kick method not defined for %s",
+ rproc->name);
+ goto out;
+ }
+
/* Try to find dedicated vdev buffer carveout */
mem = rproc_find_carveout_by_name(rproc, "vdev%dbuffer", rvdev->index);
if (mem) {