[syzbot] UBSAN: array-index-out-of-bounds in pvr2_i2c_core_init

[syzbot] UBSAN: array-index-out-of-bounds in pvr2_i2c_core_init

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit:    4ea3c6425269 Merge tag 'powerpc-5.18-2' of git://git.kerne..
git tree:       upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=148cb824f00000
kernel config:  https://syzkaller.appspot.com/x/.config?x=307baecfd5e87ced
dashboard link: https://syzkaller.appspot.com/bug?extid=1a247e36149ffd709a9b
compiler:       gcc (Debian 10.2.1-6) 10.2.1 20210110, GNU ld (GNU Binutils for Debian) 2.35.2
syz repro:      https://syzkaller.appspot.com/x/repro.syz?x=17279a70f00000
C reproducer:   https://syzkaller.appspot.com/x/repro.c?x=121dc124f00000

Bisection is inconclusive: the issue happens on the oldest tested release.

bisection log:  https://syzkaller.appspot.com/x/bisect.txt?x=142753df700000
final oops:     https://syzkaller.appspot.com/x/report.txt?x=162753df700000
console output: https://syzkaller.appspot.com/x/log.txt?x=122753df700000

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+1a247e36149ffd709a9b@syzkaller.appspotmail.com

pvrusb2: You need to resolve the failing condition before this driver can function.  There should be some earlier messages giving more information about the problem.
pvrusb2: Invalid write control endpoint
================================================================================
UBSAN: array-index-out-of-bounds in drivers/media/usb/pvrusb2/pvrusb2-i2c-core.c:602:13
index -1 is out of range for type 'int [20]'
CPU: 0 PID: 1959 Comm: pvrusb2-context Not tainted 5.18.0-rc1-syzkaller-00401-g4ea3c6425269 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0xcd/0x134 lib/dump_stack.c:106
 ubsan_epilogue+0xb/0x50 lib/ubsan.c:151
 __ubsan_handle_out_of_bounds.cold+0x62/0x6c lib/ubsan.c:283
 pvr2_i2c_core_init+0xc7d/0xd30 drivers/media/usb/pvrusb2/pvrusb2-i2c-core.c:602
 pvr2_hdw_setup_low drivers/media/usb/pvrusb2/pvrusb2-hdw.c:2134 [inline]
 pvr2_hdw_setup drivers/media/usb/pvrusb2/pvrusb2-hdw.c:2261 [inline]
 pvr2_hdw_initialize+0x787/0x37d0 drivers/media/usb/pvrusb2/pvrusb2-hdw.c:2338
 pvr2_context_check drivers/media/usb/pvrusb2/pvrusb2-context.c:109 [inline]
 pvr2_context_thread_func+0x250/0x850 drivers/media/usb/pvrusb2/pvrusb2-context.c:158
 kthread+0x2e9/0x3a0 kernel/kthread.c:376
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:298
 </TASK>
================================================================================
Kernel panic - not syncing: panic_on_warn set ...
CPU: 0 PID: 1959 Comm: pvrusb2-context Not tainted 5.18.0-rc1-syzkaller-00401-g4ea3c6425269 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0xcd/0x134 lib/dump_stack.c:106
 panic+0x2d7/0x636 kernel/panic.c:250
 ubsan_epilogue+0x4a/0x50 lib/ubsan.c:158
 __ubsan_handle_out_of_bounds.cold+0x62/0x6c lib/ubsan.c:283
 pvr2_i2c_core_init+0xc7d/0xd30 drivers/media/usb/pvrusb2/pvrusb2-i2c-core.c:602
 pvr2_hdw_setup_low drivers/media/usb/pvrusb2/pvrusb2-hdw.c:2134 [inline]
 pvr2_hdw_setup drivers/media/usb/pvrusb2/pvrusb2-hdw.c:2261 [inline]
 pvr2_hdw_initialize+0x787/0x37d0 drivers/media/usb/pvrusb2/pvrusb2-hdw.c:2338
 pvr2_context_check drivers/media/usb/pvrusb2/pvrusb2-context.c:109 [inline]
 pvr2_context_thread_func+0x250/0x850 drivers/media/usb/pvrusb2/pvrusb2-context.c:158
 kthread+0x2e9/0x3a0 kernel/kthread.c:376
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:298
 </TASK>
Kernel Offset: disabled
Rebooting in 86400 seconds..


---
This report is generated by a bot. It may contain errors.
See https://goo.gl/tpsmEJ for more information about syzbot.
syzbot engineers can be reached at syzkaller@googlegroups.com.

syzbot will keep track of this issue. See:
https://goo.gl/tpsmEJ#status for how to communicate with syzbot.
For information about bisection process see: https://goo.gl/tpsmEJ#bisection
syzbot can test patches for this issue, for details see:
https://goo.gl/tpsmEJ#testing-patches

Re: [syzbot] UBSAN: array-index-out-of-bounds in pvr2_i2c_core_init

[Pavel Skripkin]

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Hi Syzbot,

On 4/14/22 21:47, syzbot wrote:
> Hello,
> 
> syzbot found the following issue on:
> 
> HEAD commit:    4ea3c6425269 Merge tag 'powerpc-5.18-2' of git://git.kerne..
> git tree:       upstream
> console output: https://syzkaller.appspot.com/x/log.txt?x=148cb824f00000
> kernel config:  https://syzkaller.appspot.com/x/.config?x=307baecfd5e87ced
> dashboard link: https://syzkaller.appspot.com/bug?extid=1a247e36149ffd709a9b
> compiler:       gcc (Debian 10.2.1-6) 10.2.1 20210110, GNU ld (GNU Binutils for Debian) 2.35.2
> syz repro:      https://syzkaller.appspot.com/x/repro.syz?x=17279a70f00000
> C reproducer:   https://syzkaller.appspot.com/x/repro.c?x=121dc124f00000
> 
> Bisection is inconclusive: the issue happens on the oldest tested release.
> 
> bisection log:  https://syzkaller.appspot.com/x/bisect.txt?x=142753df700000
> final oops:     https://syzkaller.appspot.com/x/report.txt?x=162753df700000
> console output: https://syzkaller.appspot.com/x/log.txt?x=122753df700000
> 
> IMPORTANT: if you fix the issue, please add the following tag to the commit:


just guessing


#syz test:
git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git master




With regards,
Pavel Skripkin

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diff --git a/drivers/media/usb/pvrusb2/pvrusb2-hdw.c b/drivers/media/usb/pvrusb2/pvrusb2-hdw.c
index cd7b118d5929..2a1a0a0ca225 100644
--- a/drivers/media/usb/pvrusb2/pvrusb2-hdw.c
+++ b/drivers/media/usb/pvrusb2/pvrusb2-hdw.c
@@ -2569,6 +2569,9 @@ struct pvr2_hdw *pvr2_hdw_create(struct usb_interface *intf,
 	} while (0);
 	mutex_unlock(&pvr2_unit_mtx);
 
+	if (hdw->unit_number == -1)
+	  	goto fail;
+
 	cnt1 = 0;
 	cnt2 = scnprintf(hdw->name+cnt1,sizeof(hdw->name)-cnt1,"pvrusb2");
 	cnt1 += cnt2;

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Re: [syzbot] UBSAN: array-index-out-of-bounds in pvr2_i2c_core_init

[syzbot]

Hello,

syzbot has tested the proposed patch but the reproducer is still triggering an issue:
WARNING in pvr2_hdw_create

pvrusb2: Hardware description: OnAir USB2 Hybrid USB tuner
------------[ cut here ]------------
WARNING: CPU: 1 PID: 3607 at kernel/workqueue.c:3066 __flush_work+0x926/0xb10 kernel/workqueue.c:3066
Modules linked in:
CPU: 1 PID: 3607 Comm: kworker/1:4 Not tainted 5.18.0-rc2-syzkaller-00187-g115acbb56978-dirty #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Workqueue: usb_hub_wq hub_event
RIP: 0010:__flush_work+0x926/0xb10 kernel/workqueue.c:3066
Code: ff 41 89 c4 89 8d 88 fe ff ff e8 d5 2b 77 00 48 0f ba 2b 03 e9 6a fa ff ff e8 c6 8f 2b 00 0f 0b e9 5a fc ff ff e8 ba 8f 2b 00 <0f> 0b 45 31 f6 e9 4b fc ff ff e8 eb 28 77 00 e9 3a fb ff ff e8 a1
RSP: 0018:ffffc90003d1ee00 EFLAGS: 00010293

RAX: 0000000000000000 RBX: ffff88806e4040d0 RCX: 0000000000000000
RDX: ffff88801e1eba00 RSI: ffffffff814d8be6 RDI: 0000000000000003
RBP: ffffc90003d1ef98 R08: 0000000000000000 R09: 0000000000000001
R10: ffffffff814d8365 R11: 0000000000000000 R12: dffffc0000000000
R13: ffff88806e405678 R14: 0000000000000001 R15: ffff88806e4040e8
FS:  0000000000000000(0000) GS:ffff8880b9d00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007ffd4ad80638 CR3: 000000002067b000 CR4: 00000000003506e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 pvr2_hdw_create+0x11da/0x2630 drivers/media/usb/pvrusb2/pvrusb2-hdw.c:2612
 pvr2_context_create+0x1ae/0x280 drivers/media/usb/pvrusb2/pvrusb2-context.c:222
 pvr_probe+0x21/0xc0 drivers/media/usb/pvrusb2/pvrusb2-main.c:62
 usb_probe_interface+0x315/0x7f0 drivers/usb/core/driver.c:396
 call_driver_probe drivers/base/dd.c:542 [inline]
 really_probe+0x23e/0xb20 drivers/base/dd.c:621
 __driver_probe_device+0x338/0x4d0 drivers/base/dd.c:752
 driver_probe_device+0x4c/0x1a0 drivers/base/dd.c:782
 __device_attach_driver+0x20b/0x2f0 drivers/base/dd.c:899
 bus_for_each_drv+0x15f/0x1e0 drivers/base/bus.c:427
 __device_attach+0x228/0x4a0 drivers/base/dd.c:970
 bus_probe_device+0x1e4/0x290 drivers/base/bus.c:487
 device_add+0xb83/0x1e20 drivers/base/core.c:3405
 usb_set_configuration+0x101e/0x1900 drivers/usb/core/message.c:2170
 usb_generic_driver_probe+0xba/0x100 drivers/usb/core/generic.c:238
 usb_probe_device+0xd9/0x2c0 drivers/usb/core/driver.c:293
 call_driver_probe drivers/base/dd.c:542 [inline]
 really_probe+0x23e/0xb20 drivers/base/dd.c:621
 __driver_probe_device+0x338/0x4d0 drivers/base/dd.c:752
 driver_probe_device+0x4c/0x1a0 drivers/base/dd.c:782
 __device_attach_driver+0x20b/0x2f0 drivers/base/dd.c:899
 bus_for_each_drv+0x15f/0x1e0 drivers/base/bus.c:427
 __device_attach+0x228/0x4a0 drivers/base/dd.c:970
 bus_probe_device+0x1e4/0x290 drivers/base/bus.c:487
 device_add+0xb83/0x1e20 drivers/base/core.c:3405
 usb_new_device.cold+0x641/0x1091 drivers/usb/core/hub.c:2566
 hub_port_connect drivers/usb/core/hub.c:5363 [inline]
 hub_port_connect_change drivers/usb/core/hub.c:5507 [inline]
 port_event drivers/usb/core/hub.c:5665 [inline]
 hub_event+0x25c6/0x4680 drivers/usb/core/hub.c:5747
 process_one_work+0x996/0x1610 kernel/workqueue.c:2289
 process_scheduled_works kernel/workqueue.c:2352 [inline]
 worker_thread+0x854/0x1080 kernel/workqueue.c:2438
 kthread+0x2e9/0x3a0 kernel/kthread.c:376
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:298
 </TASK>


Tested on:

commit:         115acbb5 Merge tag 's390-5.18-3' of git://git.kernel.o..
git tree:       upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=12ef7197700000
kernel config:  https://syzkaller.appspot.com/x/.config?x=eb177500e563582f
dashboard link: https://syzkaller.appspot.com/bug?extid=1a247e36149ffd709a9b
compiler:       gcc (Debian 10.2.1-6) 10.2.1 20210110, GNU ld (GNU Binutils for Debian) 2.35.2
patch:          https://syzkaller.appspot.com/x/patch.diff?x=14838637700000

Re: [syzbot] UBSAN: array-index-out-of-bounds in pvr2_i2c_core_init

[Pavel Skripkin]

[-- Attachment #1.1.1: Type: text/plain, Size: 1167 bytes --]

On 4/14/22 23:14, syzbot wrote:
> Hello,
> 
> syzbot has tested the proposed patch but the reproducer is still triggering an issue:
> WARNING in pvr2_hdw_create
> 
> pvrusb2: Hardware description: OnAir USB2 Hybrid USB tuner
> ------------[ cut here ]------------
> WARNING: CPU: 1 PID: 3607 at kernel/workqueue.c:3066 __flush_work+0x926/0xb10 kernel/workqueue.c:3066
> Modules linked in:
> CPU: 1 PID: 3607 Comm: kworker/1:4 Not tainted 5.18.0-rc2-syzkaller-00187-g115acbb56978-dirty #0
> Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
> Workqueue: usb_hub_wq hub_event
> RIP: 0010:__flush_work+0x926/0xb10 kernel/workqueue.c:3066
> Code: ff 41 89 c4 89 8d 88 fe ff ff e8 d5 2b 77 00 48 0f ba 2b 03 e9 6a fa ff ff e8 c6 8f 2b 00 0f 0b e9 5a fc ff ff e8 ba 8f 2b 00 <0f> 0b 45 31 f6 e9 4b fc ff ff e8 eb 28 77 00 e9 3a fb ff ff e8 a1
> RSP: 0018:ffffc90003d1ee00 EFLAGS: 00010293
> 

Not bad guess.

Moving work initialization upper, since rewriting error handling is boring


#syz test:
git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git master




With regards,
Pavel Skripkin

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diff --git a/drivers/media/usb/pvrusb2/pvrusb2-hdw.c b/drivers/media/usb/pvrusb2/pvrusb2-hdw.c
index cd7b118d5929..f3a38f106212 100644
--- a/drivers/media/usb/pvrusb2/pvrusb2-hdw.c
+++ b/drivers/media/usb/pvrusb2/pvrusb2-hdw.c
@@ -2569,6 +2569,11 @@ struct pvr2_hdw *pvr2_hdw_create(struct usb_interface *intf,
 	} while (0);
 	mutex_unlock(&pvr2_unit_mtx);
 
+	INIT_WORK(&hdw->workpoll,pvr2_hdw_worker_poll);
+
+	if (hdw->unit_number == -1)
+		goto fail;
+
 	cnt1 = 0;
 	cnt2 = scnprintf(hdw->name+cnt1,sizeof(hdw->name)-cnt1,"pvrusb2");
 	cnt1 += cnt2;
@@ -2580,8 +2585,6 @@ struct pvr2_hdw *pvr2_hdw_create(struct usb_interface *intf,
 	if (cnt1 >= sizeof(hdw->name)) cnt1 = sizeof(hdw->name)-1;
 	hdw->name[cnt1] = 0;
 
-	INIT_WORK(&hdw->workpoll,pvr2_hdw_worker_poll);
-
 	pvr2_trace(PVR2_TRACE_INIT,"Driver unit number is %d, name is %s",
 		   hdw->unit_number,hdw->name);
 
@@ -2600,7 +2603,7 @@ struct pvr2_hdw *pvr2_hdw_create(struct usb_interface *intf,
 	mutex_init(&hdw->big_lock_mutex);
 
 	return hdw;
- fail:
+fail:
 	if (hdw) {
 		del_timer_sync(&hdw->quiescent_timer);
 		del_timer_sync(&hdw->decoder_stabilization_timer);

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Re: [syzbot] UBSAN: array-index-out-of-bounds in pvr2_i2c_core_init

[syzbot]

Hello,

syzbot has tested the proposed patch and the reproducer did not trigger any issue:

Reported-and-tested-by: syzbot+1a247e36149ffd709a9b@syzkaller.appspotmail.com

Tested on:

commit:         115acbb5 Merge tag 's390-5.18-3' of git://git.kernel.o..
git tree:       upstream
kernel config:  https://syzkaller.appspot.com/x/.config?x=eb177500e563582f
dashboard link: https://syzkaller.appspot.com/bug?extid=1a247e36149ffd709a9b
compiler:       gcc (Debian 10.2.1-6) 10.2.1 20210110, GNU ld (GNU Binutils for Debian) 2.35.2
patch:          https://syzkaller.appspot.com/x/patch.diff?x=113c24e0f00000

Note: testing is done by a robot and is best-effort only.