3.16.60-rc1 review patch. If anyone has any objections, please let me know.
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From: Mauro Carvalho Chehab mchehab@s-opensource.com
commit 85ea29f19eab56ec16ec6b92bc67305998706afa upstream.
At put_v4l2_window32(), it tries to access kp->clips. However, kp points to an userspace pointer. So, it should be obtained via get_user(), otherwise it can OOPS:
vivid-000: ================== END STATUS ================== BUG: unable to handle kernel paging request at 00000000fffb18e0 IP: [<ffffffffc05468d9>] __put_v4l2_format32+0x169/0x220 [videodev] PGD 3f5776067 PUD 3f576f067 PMD 3f5769067 PTE 800000042548f067 Oops: 0001 [#1] SMP Modules linked in: vivid videobuf2_vmalloc videobuf2_memops v4l2_dv_timings videobuf2_core v4l2_common videodev media xt_CHECKSUM iptable_mangle ipt_MASQUERADE nf_nat_masquerade_ipv4 iptable_nat nf_nat_ipv4 nf_nat nf_conntrack_ipv4 nf_defrag_ipv4 xt_conntrack nf_conntrack tun bridge stp llc ebtable_filter ebtables ip6table_filter ip6_tables bluetooth rfkill binfmt_misc snd_hda_codec_hdmi i915 snd_hda_intel snd_hda_controller snd_hda_codec intel_rapl x86_pkg_temp_thermal snd_hwdep intel_powerclamp snd_pcm coretemp snd_seq_midi kvm_intel kvm snd_seq_midi_event snd_rawmidi i2c_algo_bit drm_kms_helper snd_seq drm crct10dif_pclmul e1000e snd_seq_device crc32_pclmul snd_timer ghash_clmulni_intel snd mei_me mei ptp pps_core soundcore lpc_ich video crc32c_intel [last unloaded: media] CPU: 2 PID: 28332 Comm: v4l2-compliance Not tainted 3.18.102+ #107 Hardware name: /NUC5i7RYB, BIOS RYBDWi35.86A.0364.2017.0511.0949 05/11/2017 task: ffff8804293f8000 ti: ffff8803f5640000 task.ti: ffff8803f5640000 RIP: 0010:[<ffffffffc05468d9>] [<ffffffffc05468d9>] __put_v4l2_format32+0x169/0x220 [videodev] RSP: 0018:ffff8803f5643e28 EFLAGS: 00010246 RAX: 0000000000000000 RBX: 0000000000000000 RCX: 00000000fffb1ab4 RDX: 00000000fffb1a68 RSI: 00000000fffb18d8 RDI: 00000000fffb1aa8 RBP: ffff8803f5643e48 R08: 0000000000000001 R09: ffff8803f54b0378 R10: 0000000000000000 R11: 0000000000000168 R12: 00000000fffb18c0 R13: 00000000fffb1a94 R14: 00000000fffb18c8 R15: 0000000000000000 FS: 0000000000000000(0000) GS:ffff880456d00000(0063) knlGS:00000000f7100980 CS: 0010 DS: 002b ES: 002b CR0: 0000000080050033 CR2: 00000000fffb18e0 CR3: 00000003f552b000 CR4: 00000000003407e0 Stack: 00000000fffb1a94 00000000c0cc5640 0000000000000056 ffff8804274f3600 ffff8803f5643ed0 ffffffffc0547e16 0000000000000003 ffff8803f5643eb0 ffffffff81301460 ffff88009db44b01 ffff880441942520 ffff8800c0d05640 Call Trace: [<ffffffffc0547e16>] v4l2_compat_ioctl32+0x12d6/0x1b1d [videodev] [<ffffffff81301460>] ? file_has_perm+0x70/0xc0 [<ffffffff81252a2c>] compat_SyS_ioctl+0xec/0x1200 [<ffffffff8173241a>] sysenter_dispatch+0x7/0x21 Code: 00 00 48 8b 80 48 c0 ff ff 48 83 e8 38 49 39 c6 0f 87 2b ff ff ff 49 8d 45 1c e8 a3 ce e3 c0 85 c0 0f 85 1a ff ff ff 41 8d 40 ff <4d> 8b 64 24 20 41 89 d5 48 8d 44 40 03 4d 8d 34 c4 eb 15 0f 1f RIP [<ffffffffc05468d9>] __put_v4l2_format32+0x169/0x220 [videodev] RSP <ffff8803f5643e28> CR2: 00000000fffb18e0
Tested with vivid driver on Kernel v3.18.102.
Same bug happens upstream too:
BUG: KASAN: user-memory-access in __put_v4l2_format32+0x98/0x4d0 [videodev] Read of size 8 at addr 00000000ffe48400 by task v4l2-compliance/8713
CPU: 0 PID: 8713 Comm: v4l2-compliance Not tainted 4.16.0-rc4+ #108 Hardware name: /NUC5i7RYB, BIOS RYBDWi35.86A.0364.2017.0511.0949 05/11/2017 Call Trace: dump_stack+0x5c/0x7c kasan_report+0x164/0x380 ? __put_v4l2_format32+0x98/0x4d0 [videodev] __put_v4l2_format32+0x98/0x4d0 [videodev] v4l2_compat_ioctl32+0x1aec/0x27a0 [videodev] ? __fsnotify_inode_delete+0x20/0x20 ? __put_v4l2_format32+0x4d0/0x4d0 [videodev] compat_SyS_ioctl+0x646/0x14d0 ? do_ioctl+0x30/0x30 do_fast_syscall_32+0x191/0x3f4 entry_SYSENTER_compat+0x6b/0x7a ================================================================== Disabling lock debugging due to kernel taint BUG: unable to handle kernel paging request at 00000000ffe48400 IP: __put_v4l2_format32+0x98/0x4d0 [videodev] PGD 3a22fb067 P4D 3a22fb067 PUD 39b6f0067 PMD 39b6f1067 PTE 80000003256af067 Oops: 0001 [#1] SMP KASAN Modules linked in: vivid videobuf2_vmalloc videobuf2_dma_contig videobuf2_memops v4l2_tpg v4l2_dv_timings videobuf2_v4l2 videobuf2_common v4l2_common videodev xt_CHECKSUM iptable_mangle ipt_MASQUERADE nf_nat_masquerade_ipv4 iptable_nat nf_nat_ipv4 nf_nat nf_conntrack_ipv4 nf_defrag_ipv4 xt_conntrack nf_conntrack libcrc32c tun bridge stp llc ebtable_filter ebtables ip6table_filter ip6_tables bluetooth rfkill ecdh_generic binfmt_misc snd_hda_codec_hdmi intel_rapl x86_pkg_temp_thermal intel_powerclamp i915 coretemp snd_hda_intel snd_hda_codec kvm_intel snd_hwdep snd_hda_core kvm snd_pcm irqbypass crct10dif_pclmul crc32_pclmul snd_seq_midi ghash_clmulni_intel snd_seq_midi_event i2c_algo_bit intel_cstate snd_rawmidi intel_uncore snd_seq drm_kms_helper e1000e snd_seq_device snd_timer intel_rapl_perf drm ptp snd mei_me mei lpc_ich pps_core soundcore video crc32c_intel CPU: 0 PID: 8713 Comm: v4l2-compliance Tainted: G B 4.16.0-rc4+ #108 Hardware name: /NUC5i7RYB, BIOS RYBDWi35.86A.0364.2017.0511.0949 05/11/2017 RIP: 0010:__put_v4l2_format32+0x98/0x4d0 [videodev] RSP: 0018:ffff8803b9be7d30 EFLAGS: 00010282 RAX: 0000000000000000 RBX: ffff8803ac983e80 RCX: ffffffff8cd929f2 RDX: 1ffffffff1d0a149 RSI: 0000000000000297 RDI: 0000000000000297 RBP: 00000000ffe485c0 R08: fffffbfff1cf5123 R09: ffffffff8e7a8948 R10: 0000000000000001 R11: fffffbfff1cf5122 R12: 00000000ffe483e0 R13: 00000000ffe485c4 R14: ffff8803ac985918 R15: 00000000ffe483e8 FS: 0000000000000000(0000) GS:ffff880407400000(0063) knlGS:00000000f7a46980 CS: 0010 DS: 002b ES: 002b CR0: 0000000080050033 CR2: 00000000ffe48400 CR3: 00000003a83f2003 CR4: 00000000003606f0 Call Trace: v4l2_compat_ioctl32+0x1aec/0x27a0 [videodev] ? __fsnotify_inode_delete+0x20/0x20 ? __put_v4l2_format32+0x4d0/0x4d0 [videodev] compat_SyS_ioctl+0x646/0x14d0 ? do_ioctl+0x30/0x30 do_fast_syscall_32+0x191/0x3f4 entry_SYSENTER_compat+0x6b/0x7a Code: 4c 89 f7 4d 8d 7c 24 08 e8 e6 a4 69 cb 48 8b 83 98 1a 00 00 48 83 e8 10 49 39 c7 0f 87 9d 01 00 00 49 8d 7c 24 20 e8 c8 a4 69 cb <4d> 8b 74 24 20 4c 89 ef 4c 89 fe ba 10 00 00 00 e8 23 d9 08 cc RIP: __put_v4l2_format32+0x98/0x4d0 [videodev] RSP: ffff8803b9be7d30 CR2: 00000000ffe48400
Signed-off-by: Mauro Carvalho Chehab mchehab@s-opensource.com Reviewed-by: Sakari Ailus sakari.ailus@linux.intel.com Reviewed-by: Hans Verkuil hans.verkuil@cisco.com Signed-off-by: Mauro Carvalho Chehab mchehab@s-opensource.com Signed-off-by: Ben Hutchings ben@decadent.org.uk --- drivers/media/v4l2-core/v4l2-compat-ioctl32.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-)
--- a/drivers/media/v4l2-core/v4l2-compat-ioctl32.c +++ b/drivers/media/v4l2-core/v4l2-compat-ioctl32.c @@ -101,7 +101,7 @@ static int get_v4l2_window32(struct v4l2 static int put_v4l2_window32(struct v4l2_window __user *kp, struct v4l2_window32 __user *up) { - struct v4l2_clip __user *kclips = kp->clips; + struct v4l2_clip __user *kclips; struct v4l2_clip32 __user *uclips; compat_caddr_t p; u32 clipcount; @@ -116,6 +116,8 @@ static int put_v4l2_window32(struct v4l2 if (!clipcount) return 0;
+ if (get_user(kclips, &kp->clips)) + return -EFAULT; if (get_user(p, &up->clips)) return -EFAULT; uclips = compat_ptr(p);