From dcc7fdbec53a960588f2c40232db2c6466c09917 Mon Sep 17 00:00:00 2001 From: Antonio Ospite Date: Fri, 2 Oct 2015 17:33:13 -0300 Subject: [PATCH] [media] gspca: ov534/topro: prevent a division by 0 v4l2-compliance sends a zeroed struct v4l2_streamparm in v4l2-test-formats.cpp::testParmType(), and this results in a division by 0 in some gspca subdrivers: divide error: 0000 [#1] SMP Modules linked in: gspca_ov534 gspca_main ... CPU: 0 PID: 17201 Comm: v4l2-compliance Not tainted 4.3.0-rc2-ao2 #1 Hardware name: System manufacturer System Product Name/M2N-E SLI, BIOS ASUS M2N-E SLI ACPI BIOS Revision 1301 09/16/2010 task: ffff8800818306c0 ti: ffff880095c4c000 task.ti: ffff880095c4c000 RIP: 0010:[] [] sd_set_streamparm+0x12/0x60 [gspca_ov534] RSP: 0018:ffff880095c4fce8 EFLAGS: 00010296 RAX: 0000000000000000 RBX: ffff8800c9522000 RCX: ffffffffa077a140 RDX: 0000000000000000 RSI: ffff880095e0c100 RDI: ffff8800c9522000 RBP: ffff880095e0c100 R08: ffffffffa077a100 R09: 00000000000000cc R10: ffff880067ec7740 R11: 0000000000000016 R12: ffffffffa07bb400 R13: 0000000000000000 R14: ffff880081b6a800 R15: 0000000000000000 FS: 00007fda0de78740(0000) GS:ffff88012fc00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00000000014630f8 CR3: 00000000cf349000 CR4: 00000000000006f0 Stack: ffffffffa07a6431 ffff8800c9522000 ffffffffa077656e 00000000c0cc5616 ffff8800c9522000 ffffffffa07a5e20 ffff880095e0c100 0000000000000000 ffff880067ec7740 ffffffffa077a140 ffff880067ec7740 0000000000000016 Call Trace: [] ? v4l_s_parm+0x21/0x50 [videodev] [] ? vidioc_s_parm+0x4e/0x60 [gspca_main] [] ? __video_do_ioctl+0x280/0x2f0 [videodev] [] ? video_ioctl2+0x20/0x20 [videodev] [] ? video_usercopy+0x319/0x4e0 [videodev] [] ? page_add_new_anon_rmap+0x71/0xa0 [] ? mem_cgroup_commit_charge+0x52/0x90 [] ? handle_mm_fault+0xc18/0x1680 [] ? v4l2_ioctl+0xac/0xd0 [videodev] [] ? do_vfs_ioctl+0x28f/0x480 [] ? SyS_ioctl+0x74/0x80 [] ? entry_SYSCALL_64_fastpath+0x16/0x75 Code: c7 93 d9 79 a0 5b 5d e9 f1 f3 9a e0 0f 1f 00 66 2e 0f 1f 84 00 00 00 00 00 66 66 66 66 90 53 31 d2 48 89 fb 48 83 ec 08 8b 46 10 76 0c 80 bf ac 0c 00 00 00 88 87 4e 0e 00 00 74 09 80 bf 4f RIP [] sd_set_streamparm+0x12/0x60 [gspca_ov534] RSP ---[ end trace 279710c2c6c72080 ]--- Following what the doc says about a zeroed timeperframe (see http://www.linuxtv.org/downloads/v4l-dvb-apis/vidioc-g-parm.html): ... To reset manually applications can just set this field to zero. fix the issue by resetting the frame rate to a default value in case of an unusable timeperframe. The fix is done in the subdrivers instead of gspca.c because only the subdrivers have notion of a default frame rate to reset the camera to. Signed-off-by: Antonio Ospite Cc: stable@vger.kernel.org Reviewed-by: Hans de Goede Signed-off-by: Hans Verkuil Signed-off-by: Mauro Carvalho Chehab --- drivers/media/usb/gspca/ov534.c | 9 +++++++-- drivers/media/usb/gspca/topro.c | 6 +++++- 2 files changed, 12 insertions(+), 3 deletions(-) diff --git a/drivers/media/usb/gspca/ov534.c b/drivers/media/usb/gspca/ov534.c index 146071b8e116..bfff1d1c70ab 100644 --- a/drivers/media/usb/gspca/ov534.c +++ b/drivers/media/usb/gspca/ov534.c @@ -1491,8 +1491,13 @@ static void sd_set_streamparm(struct gspca_dev *gspca_dev, struct v4l2_fract *tpf = &cp->timeperframe; struct sd *sd = (struct sd *) gspca_dev; - /* Set requested framerate */ - sd->frame_rate = tpf->denominator / tpf->numerator; + if (tpf->numerator == 0 || tpf->denominator == 0) + /* Set default framerate */ + sd->frame_rate = 30; + else + /* Set requested framerate */ + sd->frame_rate = tpf->denominator / tpf->numerator; + if (gspca_dev->streaming) set_frame_rate(gspca_dev); diff --git a/drivers/media/usb/gspca/topro.c b/drivers/media/usb/gspca/topro.c index c70ff406b07a..c028a5c2438e 100644 --- a/drivers/media/usb/gspca/topro.c +++ b/drivers/media/usb/gspca/topro.c @@ -4802,7 +4802,11 @@ static void sd_set_streamparm(struct gspca_dev *gspca_dev, struct v4l2_fract *tpf = &cp->timeperframe; int fr, i; - sd->framerate = tpf->denominator / tpf->numerator; + if (tpf->numerator == 0 || tpf->denominator == 0) + sd->framerate = 30; + else + sd->framerate = tpf->denominator / tpf->numerator; + if (gspca_dev->streaming) setframerate(gspca_dev, v4l2_ctrl_g_ctrl(gspca_dev->exposure)); -- 2.39.5