From c20df61861b702605046a7b61b1da6143c05fc4d Mon Sep 17 00:00:00 2001 From: Dafna Hirschfeld Date: Sun, 10 Nov 2019 07:25:03 +0100 Subject: media: vimc: upon streaming, check that the pipeline starts with a source entity Userspace can disable links and create pipelines that do not start with a source entity. Trying to stream from such a pipeline should fail with -EPIPE currently this is not handled and cause kernel crash. Reproducing the crash: media-ctl -d0 -l "5:1->21:0[0]" -v v4l2-ctl -z platform:vimc -d "RGB/YUV Capture" -v width=1920,height=1440 v4l2-ctl --stream-mmap --stream-count=100 -d /dev/video2 Panic message: [ 39.078841][ T248] BUG: kernel NULL pointer dereference, address: 0000000000000000 [ 39.079338][ T248] #PF: supervisor read access in kernel mode [ 39.079704][ T248] #PF: error_code(0x0000) - not-present page [ 39.080071][ T248] PGD 0 P4D 0 [ 39.080279][ T248] Oops: 0000 [#1] SMP PTI [ 39.080546][ T248] CPU: 0 PID: 248 Comm: vimc-streamer t Not tainted 5.4.0-rc1+ #17 [ 39.081030][ T248] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.12.0-0-ga698c8995f-prebuilt.qemu.org 04/01/2014 [ 39.081779][ T248] RIP: 0010:vimc_sca_process_frame+0xdb/0x210 [vimc] [ 39.082191][ T248] Code: 44 8d 0c 28 8b 93 a4 01 00 00 48 8b 8b 98 01 00 00 85 d2 74 40 48 8b 74 24 10 8d 7a ff 4c 01 c9 31 d2 4c 01 fe eb 03 4c 89 c2 <44> 0f b6 04 16 44 88 04 11 4c 8d 42 01 48 39 fa 75 eb 8b 93 a4 01 [ 39.083436][ T248] RSP: 0018:ffffb15a005abe90 EFLAGS: 00010246 [ 39.083808][ T248] RAX: 0000000000000000 RBX: ffffa3fdc46d2e00 RCX: ffffb15a02579000 [ 39.084298][ T248] RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000002 [ 39.084792][ T248] RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000 [ 39.085280][ T248] R10: 0000000000000001 R11: 0000000000000000 R12: 0000000000000000 [ 39.085770][ T248] R13: ffffa3fdc46d2ee0 R14: 0000000000000000 R15: 0000000000000000 [ 39.086258][ T248] FS: 0000000000000000(0000) GS:ffffa3fdc7800000(0000) knlGS:0000000000000000 [ 39.086806][ T248] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 39.087217][ T248] CR2: 0000000000000000 CR3: 0000000003c92005 CR4: 0000000000360ef0 [ 39.087706][ T248] Call Trace: [ 39.087909][ T248] ? vimc_streamer_pipeline_terminate+0x90/0x90 [vimc] [ 39.088318][ T248] vimc_streamer_thread+0x7c/0xe0 [vimc] [ 39.088663][ T248] kthread+0x10d/0x130 [ 39.088919][ T248] ? kthread_park+0x80/0x80 [ 39.089205][ T248] ret_from_fork+0x35/0x40 [ 39.089475][ T248] Modules linked in: vimc videobuf2_vmalloc videobuf2_memops v4l2_tpg videobuf2_v4l2 videobuf2_common videodev mc [ 39.090208][ T248] CR2: 0000000000000000 [ 39.090463][ T248] ---[ end trace 697650fefbf78bee ]--- [ 39.090796][ T248] RIP: 0010:vimc_sca_process_frame+0xdb/0x210 [vimc] [ 39.091209][ T248] Code: 44 8d 0c 28 8b 93 a4 01 00 00 48 8b 8b 98 01 00 00 85 d2 74 40 48 8b 74 24 10 8d 7a ff 4c 01 c9 31 d2 4c 01 fe eb 03 4c 89 c2 <44> 0f b6 04 16 44 88 04 11 4c 8d 42 01 48 39 fa 75 eb 8b 93 a4 01 [ 39.092417][ T248] RSP: 0018:ffffb15a005abe90 EFLAGS: 00010246 [ 39.092789][ T248] RAX: 0000000000000000 RBX: ffffa3fdc46d2e00 RCX: ffffb15a02579000 [ 39.093278][ T248] RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000002 [ 39.093766][ T248] RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000 [ 39.094254][ T248] R10: 0000000000000001 R11: 0000000000000000 R12: 0000000000000000 [ 39.094742][ T248] R13: ffffa3fdc46d2ee0 R14: 0000000000000000 R15: 0000000000000000 [ 39.095309][ T248] FS: 0000000000000000(0000) GS:ffffa3fdc7800000(0000) knlGS:0000000000000000 [ 39.095974][ T248] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 39.096372][ T248] CR2: 0000000000000000 CR3: 0000000003c92005 CR4: 0000000000360ef0 Signed-off-by: Dafna Hirschfeld Acked-by: Helen Koike Signed-off-by: Hans Verkuil Signed-off-by: Mauro Carvalho Chehab --- drivers/media/platform/vimc/vimc-common.c | 10 ++++++++++ drivers/media/platform/vimc/vimc-common.h | 8 ++++++++ drivers/media/platform/vimc/vimc-streamer.c | 13 +++++++++++-- 3 files changed, 29 insertions(+), 2 deletions(-) (limited to 'drivers/media') diff --git a/drivers/media/platform/vimc/vimc-common.c b/drivers/media/platform/vimc/vimc-common.c index 43e6fa5886da..16ce9f3b7c75 100644 --- a/drivers/media/platform/vimc/vimc-common.c +++ b/drivers/media/platform/vimc/vimc-common.c @@ -164,6 +164,16 @@ static const struct vimc_pix_map vimc_pix_map_list[] = { }, }; +bool vimc_is_source(struct media_entity *ent) +{ + unsigned int i; + + for (i = 0; i < ent->num_pads; i++) + if (ent->pads[i].flags & MEDIA_PAD_FL_SINK) + return false; + return true; +} + const struct vimc_pix_map *vimc_pix_map_by_index(unsigned int i) { if (i >= ARRAY_SIZE(vimc_pix_map_list)) diff --git a/drivers/media/platform/vimc/vimc-common.h b/drivers/media/platform/vimc/vimc-common.h index bf729fcde6a9..87eb8259c2a8 100644 --- a/drivers/media/platform/vimc/vimc-common.h +++ b/drivers/media/platform/vimc/vimc-common.h @@ -139,6 +139,14 @@ struct vimc_ent_config { void (*rm)(struct vimc_device *vimc, struct vimc_ent_device *ved); }; +/** + * vimc_is_source - returns true if the entity has only source pads + * + * @ent: pointer to &struct media_entity + * + */ +bool vimc_is_source(struct media_entity *ent); + /* prototypes for vimc_ent_config add and rm hooks */ struct vimc_ent_device *vimc_cap_add(struct vimc_device *vimc, const char *vcfg_name); diff --git a/drivers/media/platform/vimc/vimc-streamer.c b/drivers/media/platform/vimc/vimc-streamer.c index 1349be188a5b..cd6b55433c9e 100644 --- a/drivers/media/platform/vimc/vimc-streamer.c +++ b/drivers/media/platform/vimc/vimc-streamer.c @@ -104,9 +104,18 @@ static int vimc_streamer_pipeline_init(struct vimc_stream *stream, } entity = vimc_get_source_entity(ved->ent); - /* Check if the end of the pipeline was reached*/ - if (!entity) + /* Check if the end of the pipeline was reached */ + if (!entity) { + /* the first entity of the pipe should be source only */ + if (!vimc_is_source(ved->ent)) { + dev_err(ved->dev, + "first entity in the pipe '%s' is not a source\n", + ved->ent->name); + vimc_streamer_pipeline_terminate(stream); + return -EPIPE; + } return 0; + } /* Get the next device in the pipeline */ if (is_media_entity_v4l2_subdev(entity)) { -- cgit v1.2.3