| From 076736fd2e74b00a9f072c5cff04186b4735c151 Mon Sep 17 00:00:00 2001 |
| From: Sasha Levin <sashal@kernel.org> |
| Date: Wed, 12 May 2021 17:18:36 +0200 |
| Subject: media: bt8xx: Fix a missing check bug in bt878_probe |
| |
| From: Zheyu Ma <zheyuma97@gmail.com> |
| |
| [ Upstream commit 1a4520090681853e6b850cbe54b27247a013e0e5 ] |
| |
| In 'bt878_irq', the driver calls 'tasklet_schedule', but this tasklet is |
| set in 'dvb_bt8xx_load_card' of another driver 'dvb-bt8xx'. |
| However, this two drivers are separate. The user may not load the |
| 'dvb-bt8xx' driver when loading the 'bt8xx' driver, that is, the tasklet |
| has not been initialized when 'tasklet_schedule' is called, so it is |
| necessary to check whether the tasklet is initialized in 'bt878_probe'. |
| |
| Fix this by adding a check at the end of bt878_probe. |
| |
| The KASAN's report reveals it: |
| |
| BUG: unable to handle kernel NULL pointer dereference at 0000000000000000 |
| PGD 800000006aab2067 P4D 800000006aab2067 PUD 6b2ea067 PMD 0 |
| Oops: 0010 [#1] PREEMPT SMP KASAN PTI |
| CPU: 2 PID: 8724 Comm: syz-executor.0 Not tainted 4.19.177- |
| gdba4159c14ef-dirty #40 |
| Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.12.0-59- |
| gc9ba5276e321-prebuilt.qemu.org 04/01/2014 |
| RIP: 0010: (null) |
| Code: Bad RIP value. |
| RSP: 0018:ffff88806c287ea0 EFLAGS: 00010246 |
| RAX: fffffbfff1b01774 RBX: dffffc0000000000 RCX: 0000000000000000 |
| RDX: 0000000000000000 RSI: 1ffffffff1b01775 RDI: 0000000000000000 |
| RBP: ffff88806c287f00 R08: fffffbfff1b01774 R09: fffffbfff1b01774 |
| R10: 0000000000000001 R11: fffffbfff1b01773 R12: 0000000000000000 |
| R13: ffff88806c29f530 R14: ffffffff8d80bb88 R15: ffffffff8d80bb90 |
| FS: 00007f6b550e6700(0000) GS:ffff88806c280000(0000) knlGS: |
| 0000000000000000 |
| CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 |
| CR2: ffffffffffffffd6 CR3: 000000005ec98000 CR4: 00000000000006e0 |
| DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 |
| DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 |
| Call Trace: |
| <IRQ> |
| tasklet_action_common.isra.17+0x141/0x420 kernel/softirq.c:522 |
| tasklet_action+0x50/0x70 kernel/softirq.c:540 |
| __do_softirq+0x224/0x92c kernel/softirq.c:292 |
| invoke_softirq kernel/softirq.c:372 [inline] |
| irq_exit+0x15a/0x180 kernel/softirq.c:412 |
| exiting_irq arch/x86/include/asm/apic.h:535 [inline] |
| do_IRQ+0x123/0x1e0 arch/x86/kernel/irq.c:260 |
| common_interrupt+0xf/0xf arch/x86/entry/entry_64.S:670 |
| </IRQ> |
| RIP: 0010:__do_sys_interrupt kernel/sys.c:2593 [inline] |
| RIP: 0010:__se_sys_interrupt kernel/sys.c:2584 [inline] |
| RIP: 0010:__x64_sys_interrupt+0x5b/0x80 kernel/sys.c:2584 |
| Code: ba 00 04 00 00 48 c7 c7 c0 99 31 8c e8 ae 76 5e 01 48 85 c0 75 21 e8 |
| 14 ae 24 00 48 c7 c3 c0 99 31 8c b8 0c 00 00 00 0f 01 c1 <31> db e8 fe ad |
| 24 00 48 89 d8 5b 5d c3 48 c7 c3 ea ff ff ff eb ec |
| RSP: 0018:ffff888054167f10 EFLAGS: 00000212 ORIG_RAX: ffffffffffffffde |
| RAX: 000000000000000c RBX: ffffffff8c3199c0 RCX: ffffc90001ca6000 |
| RDX: 000000000000001a RSI: ffffffff813478fc RDI: ffffffff8c319dc0 |
| RBP: ffff888054167f18 R08: 0000000000000000 R09: 0000000000000000 |
| R10: 0000000000000080 R11: fffffbfff18633b7 R12: ffff888054167f58 |
| R13: ffff88805f638000 R14: 0000000000000000 R15: 0000000000000000 |
| do_syscall_64+0xb0/0x4e0 arch/x86/entry/common.c:293 |
| entry_SYSCALL_64_after_hwframe+0x49/0xbe |
| RIP: 0033:0x4692a9 |
| Code: f7 d8 64 89 02 b8 ff ff ff ff c3 66 0f 1f 44 00 00 48 89 f8 48 89 f7 |
| 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff |
| ff 73 01 c3 48 c7 c1 bc ff ff ff f7 d8 64 89 01 48 |
| RSP: 002b:00007f6b550e5c48 EFLAGS: 00000246 ORIG_RAX: 000000000000014f |
| RAX: ffffffffffffffda RBX: 000000000077bf60 RCX: 00000000004692a9 |
| RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000020000140 |
| RBP: 00000000004cf7eb R08: 0000000000000000 R09: 0000000000000000 |
| R10: 0000000000000000 R11: 0000000000000246 R12: 000000000077bf60 |
| R13: 0000000000000000 R14: 000000000077bf60 R15: 00007fff55a1dca0 |
| Modules linked in: |
| Dumping ftrace buffer: |
| (ftrace buffer empty) |
| CR2: 0000000000000000 |
| ---[ end trace 68e5849c3f77cbb6 ]--- |
| RIP: 0010: (null) |
| Code: Bad RIP value. |
| RSP: 0018:ffff88806c287ea0 EFLAGS: 00010246 |
| RAX: fffffbfff1b01774 RBX: dffffc0000000000 RCX: 0000000000000000 |
| RDX: 0000000000000000 RSI: 1ffffffff1b01775 RDI: 0000000000000000 |
| RBP: ffff88806c287f00 R08: fffffbfff1b01774 R09: fffffbfff1b01774 |
| R10: 0000000000000001 R11: fffffbfff1b01773 R12: 0000000000000000 |
| R13: ffff88806c29f530 R14: ffffffff8d80bb88 R15: ffffffff8d80bb90 |
| FS: 00007f6b550e6700(0000) GS:ffff88806c280000(0000) knlGS: |
| 0000000000000000 |
| CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 |
| CR2: ffffffffffffffd6 CR3: 000000005ec98000 CR4: 00000000000006e0 |
| DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 |
| DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 |
| |
| Reported-by: Zheyu Ma <zheyuma97@gmail.com> |
| Signed-off-by: Zheyu Ma <zheyuma97@gmail.com> |
| Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl> |
| Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org> |
| Signed-off-by: Sasha Levin <sashal@kernel.org> |
| --- |
| drivers/media/pci/bt8xx/bt878.c | 3 +++ |
| 1 file changed, 3 insertions(+) |
| |
| diff --git a/drivers/media/pci/bt8xx/bt878.c b/drivers/media/pci/bt8xx/bt878.c |
| index 69a304e0db11..0705913972c6 100644 |
| --- a/drivers/media/pci/bt8xx/bt878.c |
| +++ b/drivers/media/pci/bt8xx/bt878.c |
| @@ -478,6 +478,9 @@ static int bt878_probe(struct pci_dev *dev, const struct pci_device_id *pci_id) |
| btwrite(0, BT878_AINT_MASK); |
| bt878_num++; |
| |
| + if (!bt->tasklet.func) |
| + tasklet_disable(&bt->tasklet); |
| + |
| return 0; |
| |
| fail2: |
| -- |
| 2.30.2 |
| |