[syzbot] [media?] KASAN: use-after-free Read in em28xx_close_extension (2)

[syzbot] [media?] KASAN: use-after-free Read in em28xx_close_extension (2)

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit:    68d4209158f4 sub: cdns3: Use predefined PCI vendor ID cons..
git tree:       https://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb.git usb-testing
console output: https://syzkaller.appspot.com/x/log.txt?x=139b97c7980000
kernel config:  https://syzkaller.appspot.com/x/.config?x=cb61872d4d8c5df9
dashboard link: https://syzkaller.appspot.com/bug?extid=a11c46f37ee083a73deb
compiler:       gcc (Debian 12.2.0-14) 12.2.0, GNU ld (GNU Binutils for Debian) 2.40
syz repro:      https://syzkaller.appspot.com/x/repro.syz?x=1571e797980000
C reproducer:   https://syzkaller.appspot.com/x/repro.c?x=11166200580000

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/c69290425359/disk-68d42091.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/caf4f26a3e85/vmlinux-68d42091.xz
kernel image: https://storage.googleapis.com/syzbot-assets/3acdec4b62e6/bzImage-68d42091.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+a11c46f37ee083a73deb@syzkaller.appspotmail.com

list_del corruption. next->prev should be ffff888112424250, but was 0000000000000000. (next=ffff888112acc250)
------------[ cut here ]------------
kernel BUG at lib/list_debug.c:65!
Oops: invalid opcode: 0000 [#1] PREEMPT SMP KASAN PTI
CPU: 0 UID: 0 PID: 42 Comm: kworker/0:2 Not tainted 6.11.0-rc7-syzkaller-00152-g68d4209158f4 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/06/2024
Workqueue: usb_hub_wq hub_event
RIP: 0010:__list_del_entry_valid_or_report+0x141/0x1c0 lib/list_debug.c:65
Code: e1 fe 90 0f 0b 48 89 c2 48 c7 c7 a0 9e 46 87 e8 05 b1 e1 fe 90 0f 0b 48 89 d1 48 c7 c7 20 9f 46 87 48 89 c2 e8 f0 b0 e1 fe 90 <0f> 0b 48 89 34 24 e8 d4 2e 57 ff 48 8b 34 24 e9 d5 fe ff ff 48 89
RSP: 0018:ffffc900004d76f0 EFLAGS: 00010282
RAX: 000000000000006d RBX: ffffffff89df37a0 RCX: ffffffff813560b9
RDX: 0000000000000000 RSI: ffffffff8135f4f6 RDI: 0000000000000005
RBP: ffff888112424250 R08: 0000000000000005 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000001 R12: dffffc0000000000
R13: ffff888112424000 R14: ffffffff89e0d908 R15: ffff888121f0c000
FS:  0000000000000000(0000) GS:ffff8881f5800000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000055853d6842e0 CR3: 0000000111614000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 __list_del_entry_valid include/linux/list.h:124 [inline]
 __list_del_entry include/linux/list.h:215 [inline]
 list_del include/linux/list.h:229 [inline]
 em28xx_close_extension+0x10e/0x2b0 drivers/media/usb/em28xx/em28xx-core.c:1137
 em28xx_usb_disconnect+0x19d/0x610 drivers/media/usb/em28xx/em28xx-cards.c:4197
 usb_unbind_interface+0x1e8/0x970 drivers/usb/core/driver.c:461
 device_remove drivers/base/dd.c:568 [inline]
 device_remove+0x122/0x170 drivers/base/dd.c:560
 __device_release_driver drivers/base/dd.c:1272 [inline]
 device_release_driver_internal+0x44a/0x610 drivers/base/dd.c:1295
 bus_remove_device+0x22f/0x420 drivers/base/bus.c:574
 device_del+0x396/0x9f0 drivers/base/core.c:3871
 usb_disable_device+0x36c/0x7f0 drivers/usb/core/message.c:1418
 usb_disconnect+0x2e1/0x920 drivers/usb/core/hub.c:2304
 hub_port_connect drivers/usb/core/hub.c:5361 [inline]
 hub_port_connect_change drivers/usb/core/hub.c:5661 [inline]
 port_event drivers/usb/core/hub.c:5821 [inline]
 hub_event+0x1bed/0x4f40 drivers/usb/core/hub.c:5903
 process_one_work+0x9c5/0x1b40 kernel/workqueue.c:3231
 process_scheduled_works kernel/workqueue.c:3312 [inline]
 worker_thread+0x6c8/0xed0 kernel/workqueue.c:3389
 kthread+0x2c1/0x3a0 kernel/kthread.c:389
 ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:147
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244
 </TASK>
Modules linked in:
---[ end trace 0000000000000000 ]---
RIP: 0010:__list_del_entry_valid_or_report+0x141/0x1c0 lib/list_debug.c:65
Code: e1 fe 90 0f 0b 48 89 c2 48 c7 c7 a0 9e 46 87 e8 05 b1 e1 fe 90 0f 0b 48 89 d1 48 c7 c7 20 9f 46 87 48 89 c2 e8 f0 b0 e1 fe 90 <0f> 0b 48 89 34 24 e8 d4 2e 57 ff 48 8b 34 24 e9 d5 fe ff ff 48 89
RSP: 0018:ffffc900004d76f0 EFLAGS: 00010282
RAX: 000000000000006d RBX: ffffffff89df37a0 RCX: ffffffff813560b9
RDX: 0000000000000000 RSI: ffffffff8135f4f6 RDI: 0000000000000005
RBP: ffff888112424250 R08: 0000000000000005 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000001 R12: dffffc0000000000
R13: ffff888112424000 R14: ffffffff89e0d908 R15: ffff888121f0c000
FS:  0000000000000000(0000) GS:ffff8881f5800000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000055853d6842e0 CR3: 0000000111614000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400


---
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See https://goo.gl/tpsmEJ for more information about syzbot.
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syzbot will keep track of this issue. See:
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If the report is already addressed, let syzbot know by replying with:
#syz fix: exact-commit-title

If you want syzbot to run the reproducer, reply with:
#syz test: git://repo/address.git branch-or-commit-hash
If you attach or paste a git patch, syzbot will apply it before testing.

If you want to overwrite report's subsystems, reply with:
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(See the list of subsystem names on the web dashboard)

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#syz dup: exact-subject-of-another-report

If you want to undo deduplication, reply with:
#syz undup

Re: [syzbot] [media?] KASAN: use-after-free Read in em28xx_close_extension (2)

[Hillf Danton]

On Thu, 19 Sep 2024 08:00:19 -0700
> syzbot found the following issue on:
> 
> HEAD commit:    68d4209158f4 sub: cdns3: Use predefined PCI vendor ID cons..
> git tree:       https://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb.git usb-testing
> C reproducer:   https://syzkaller.appspot.com/x/repro.c?x=11166200580000

#syz test

--- x/drivers/media/usb/em28xx/em28xx-core.c
+++ y/drivers/media/usb/em28xx/em28xx-core.c
@@ -1134,7 +1134,7 @@ void em28xx_close_extension(struct em28x
 			ops->fini(dev);
 		}
 	}
-	list_del(&dev->devlist);
+	list_del_init(&dev->devlist);
 	mutex_unlock(&em28xx_devlist_mutex);
 }
 
--- x/drivers/media/usb/em28xx/em28xx-cards.c
+++ y/drivers/media/usb/em28xx/em28xx-cards.c
@@ -3910,6 +3910,7 @@ static int em28xx_usb_probe(struct usb_i
 		retval = -ENOMEM;
 		goto err;
 	}
+	INIT_LIST_HEAD(&dev->devlist);
 
 	/* compute alternate max packet sizes */
 	dev->alt_max_pkt_size_isoc = kcalloc(intf->num_altsetting,
@@ -4156,6 +4157,8 @@ static int em28xx_usb_probe(struct usb_i
 	return 0;
 
 err_free:
+	if (!list_empty(&dev->devlist))
+		em28xx_close_extension(dev);
 	kfree(dev->alt_max_pkt_size_isoc);
 	kfree(dev);
 
--

Re: [syzbot] [media?] KASAN: use-after-free Read in em28xx_close_extension (2)

[syzbot]

Hello,

syzbot has tested the proposed patch but the reproducer is still triggering an issue:
KASAN: use-after-free Read in em28xx_init_extension

em28xx 1-1:0.0: No AC97 audio processor
==================================================================
BUG: KASAN: use-after-free in __list_add_valid_or_report+0xe4/0x100 lib/list_debug.c:32
Read of size 8 at addr ffff88811ec98250 by task kworker/0:2/42

CPU: 0 UID: 0 PID: 42 Comm: kworker/0:2 Not tainted 6.11.0-rc7-syzkaller-00152-g68d4209158f4-dirty #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/06/2024
Workqueue: usb_hub_wq hub_event

Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:93 [inline]
 dump_stack_lvl+0x116/0x1f0 lib/dump_stack.c:119
 print_address_description mm/kasan/report.c:377 [inline]
 print_report+0xc3/0x620 mm/kasan/report.c:488
 kasan_report+0xd9/0x110 mm/kasan/report.c:601
 __list_add_valid_or_report+0xe4/0x100 lib/list_debug.c:32
 __list_add_valid include/linux/list.h:88 [inline]
 __list_add include/linux/list.h:150 [inline]
 list_add_tail include/linux/list.h:183 [inline]
 em28xx_init_extension+0x48/0x200 drivers/media/usb/em28xx/em28xx-core.c:1114
 em28xx_init_dev.constprop.0+0x197b/0x3090 drivers/media/usb/em28xx/em28xx-cards.c:3679
 em28xx_usb_probe+0x1151/0x3770 drivers/media/usb/em28xx/em28xx-cards.c:4035
 usb_probe_interface+0x309/0x9d0 drivers/usb/core/driver.c:399
 call_driver_probe drivers/base/dd.c:578 [inline]
 really_probe+0x23e/0xa90 drivers/base/dd.c:657
 __driver_probe_device+0x1de/0x440 drivers/base/dd.c:799
 driver_probe_device+0x4c/0x1b0 drivers/base/dd.c:829
 __device_attach_driver+0x1df/0x310 drivers/base/dd.c:957
 bus_for_each_drv+0x157/0x1e0 drivers/base/bus.c:457
 __device_attach+0x1e8/0x4b0 drivers/base/dd.c:1029
 bus_probe_device+0x17f/0x1c0 drivers/base/bus.c:532
 device_add+0x114b/0x1a70 drivers/base/core.c:3682
 usb_set_configuration+0x10cb/0x1c50 drivers/usb/core/message.c:2210
 usb_generic_driver_probe+0xb1/0x110 drivers/usb/core/generic.c:254
 usb_probe_device+0xec/0x3e0 drivers/usb/core/driver.c:294
 call_driver_probe drivers/base/dd.c:578 [inline]
 really_probe+0x23e/0xa90 drivers/base/dd.c:657
 __driver_probe_device+0x1de/0x440 drivers/base/dd.c:799
 driver_probe_device+0x4c/0x1b0 drivers/base/dd.c:829
 __device_attach_driver+0x1df/0x310 drivers/base/dd.c:957
 bus_for_each_drv+0x157/0x1e0 drivers/base/bus.c:457
 __device_attach+0x1e8/0x4b0 drivers/base/dd.c:1029
 bus_probe_device+0x17f/0x1c0 drivers/base/bus.c:532
 device_add+0x114b/0x1a70 drivers/base/core.c:3682
 usb_new_device+0xd90/0x1a10 drivers/usb/core/hub.c:2651
 hub_port_connect drivers/usb/core/hub.c:5521 [inline]
 hub_port_connect_change drivers/usb/core/hub.c:5661 [inline]
 port_event drivers/usb/core/hub.c:5821 [inline]
 hub_event+0x2e58/0x4f40 drivers/usb/core/hub.c:5903
 process_one_work+0x9c5/0x1b40 kernel/workqueue.c:3231
 process_scheduled_works kernel/workqueue.c:3312 [inline]
 worker_thread+0x6c8/0xed0 kernel/workqueue.c:3389
 kthread+0x2c1/0x3a0 kernel/kthread.c:389
 ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:147
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244
 </TASK>

The buggy address belongs to the physical page:
page: refcount:0 mapcount:0 mapping:0000000000000000 index:0xffff88811ec9aa00 pfn:0x11ec98
flags: 0x200000000000000(node=0|zone=2)
page_type: 0xbfffffff(buddy)
raw: 0200000000000000 ffffea000446c508 ffffea0004668f08 0000000000000000
raw: ffff88811ec9aa00 0000000000000002 00000000bfffffff 0000000000000000
page dumped because: kasan: bad access detected
page_owner tracks the page as freed
page last allocated via order 2, migratetype Unmovable, gfp_mask 0x140cc0(GFP_USER|__GFP_COMP), pid 8, tgid 8 (kworker/0:0), ts 189962545246, free_ts 190359765080
 set_page_owner include/linux/page_owner.h:32 [inline]
 post_alloc_hook+0x2d1/0x350 mm/page_alloc.c:1500
 prep_new_page mm/page_alloc.c:1508 [inline]
 get_page_from_freelist+0x1311/0x25f0 mm/page_alloc.c:3446
 __alloc_pages_noprof+0x21e/0x2290 mm/page_alloc.c:4702
 __alloc_pages_node_noprof include/linux/gfp.h:269 [inline]
 alloc_pages_node_noprof include/linux/gfp.h:296 [inline]
 ___kmalloc_large_node+0x7f/0x1a0 mm/slub.c:4107
 __kmalloc_large_node_noprof+0x1c/0x70 mm/slub.c:4134
 __do_kmalloc_node mm/slub.c:4150 [inline]
 __kmalloc_node_track_caller_noprof.cold+0x5/0x5e mm/slub.c:4181
 kmemdup_noprof+0x29/0x60 mm/util.c:133
 kmemdup_noprof include/linux/fortify-string.h:753 [inline]
 em28xx_duplicate_dev drivers/media/usb/em28xx/em28xx-cards.c:3732 [inline]
 em28xx_usb_probe+0x1f2e/0x3770 drivers/media/usb/em28xx/em28xx-cards.c:4083
 usb_probe_interface+0x309/0x9d0 drivers/usb/core/driver.c:399
 call_driver_probe drivers/base/dd.c:578 [inline]
 really_probe+0x23e/0xa90 drivers/base/dd.c:657
 __driver_probe_device+0x1de/0x440 drivers/base/dd.c:799
 driver_probe_device+0x4c/0x1b0 drivers/base/dd.c:829
 __device_attach_driver+0x1df/0x310 drivers/base/dd.c:957
 bus_for_each_drv+0x157/0x1e0 drivers/base/bus.c:457
 __device_attach+0x1e8/0x4b0 drivers/base/dd.c:1029
 bus_probe_device+0x17f/0x1c0 drivers/base/bus.c:532
page last free pid 8 tgid 8 stack trace:
 reset_page_owner include/linux/page_owner.h:25 [inline]
 free_pages_prepare mm/page_alloc.c:1101 [inline]
 free_unref_page+0x698/0xce0 mm/page_alloc.c:2619
 __folio_put+0x1dc/0x260 mm/swap.c:128
 em28xx_free_device drivers/media/usb/em28xx/em28xx-cards.c:3566 [inline]
 kref_put include/linux/kref.h:65 [inline]
 em28xx_usb_disconnect+0x4e0/0x610 drivers/media/usb/em28xx/em28xx-cards.c:4207
 usb_unbind_interface+0x1e8/0x970 drivers/usb/core/driver.c:461
 device_remove drivers/base/dd.c:568 [inline]
 device_remove+0x122/0x170 drivers/base/dd.c:560
 __device_release_driver drivers/base/dd.c:1272 [inline]
 device_release_driver_internal+0x44a/0x610 drivers/base/dd.c:1295
 bus_remove_device+0x22f/0x420 drivers/base/bus.c:574
 device_del+0x396/0x9f0 drivers/base/core.c:3871
 usb_disable_device+0x36c/0x7f0 drivers/usb/core/message.c:1418
 usb_disconnect+0x2e1/0x920 drivers/usb/core/hub.c:2304
 hub_port_connect drivers/usb/core/hub.c:5361 [inline]
 hub_port_connect_change drivers/usb/core/hub.c:5661 [inline]
 port_event drivers/usb/core/hub.c:5821 [inline]
 hub_event+0x1bed/0x4f40 drivers/usb/core/hub.c:5903
 process_one_work+0x9c5/0x1b40 kernel/workqueue.c:3231
 process_scheduled_works kernel/workqueue.c:3312 [inline]
 worker_thread+0x6c8/0xed0 kernel/workqueue.c:3389
 kthread+0x2c1/0x3a0 kernel/kthread.c:389
 ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:147
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244

Memory state around the buggy address:
 ffff88811ec98100: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
 ffff88811ec98180: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
>ffff88811ec98200: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
                                                 ^
 ffff88811ec98280: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
 ffff88811ec98300: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
==================================================================


Tested on:

commit:         68d42091 sub: cdns3: Use predefined PCI vendor ID cons..
git tree:       https://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb.git usb-testing
console output: https://syzkaller.appspot.com/x/log.txt?x=130b2e9f980000
kernel config:  https://syzkaller.appspot.com/x/.config?x=cb61872d4d8c5df9
dashboard link: https://syzkaller.appspot.com/bug?extid=a11c46f37ee083a73deb
compiler:       gcc (Debian 12.2.0-14) 12.2.0, GNU ld (GNU Binutils for Debian) 2.40
patch:          https://syzkaller.appspot.com/x/patch.diff?x=15aa1607980000

Re: [syzbot] [media?] KASAN: use-after-free Read in em28xx_close_extension (2)

[Hillf Danton]

On Thu, 19 Sep 2024 08:00:19 -0700
> syzbot found the following issue on:
> 
> HEAD commit:    68d4209158f4 sub: cdns3: Use predefined PCI vendor ID cons..
> git tree:       https://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb.git usb-testing
> C reproducer:   https://syzkaller.appspot.com/x/repro.c?x=11166200580000

#syz test

--- x/drivers/media/usb/em28xx/em28xx-core.c
+++ y/drivers/media/usb/em28xx/em28xx-core.c
@@ -1134,7 +1134,7 @@ void em28xx_close_extension(struct em28x
 			ops->fini(dev);
 		}
 	}
-	list_del(&dev->devlist);
+	list_del_init(&dev->devlist);
 	mutex_unlock(&em28xx_devlist_mutex);
 }
 
--- x/drivers/media/usb/em28xx/em28xx-cards.c
+++ y/drivers/media/usb/em28xx/em28xx-cards.c
@@ -3735,6 +3735,7 @@ static int em28xx_duplicate_dev(struct e
 		dev->dev_next = NULL;
 		return -ENOMEM;
 	}
+	INIT_LIST_HEAD(&sec_dev->devlist);
 	/* Check to see next free device and mark as used */
 	do {
 		nr = find_first_zero_bit(em28xx_devused, EM28XX_MAXBOARDS);
@@ -3910,6 +3911,7 @@ static int em28xx_usb_probe(struct usb_i
 		retval = -ENOMEM;
 		goto err;
 	}
+	INIT_LIST_HEAD(&dev->devlist);
 
 	/* compute alternate max packet sizes */
 	dev->alt_max_pkt_size_isoc = kcalloc(intf->num_altsetting,
@@ -4156,6 +4158,8 @@ static int em28xx_usb_probe(struct usb_i
 	return 0;
 
 err_free:
+	if (!list_empty(&dev->devlist))
+		em28xx_close_extension(dev);
 	kfree(dev->alt_max_pkt_size_isoc);
 	kfree(dev);
 
@@ -4201,6 +4205,8 @@ static void em28xx_usb_disconnect(struct
 	em28xx_release_resources(dev);
 
 	if (dev->dev_next) {
+		if (!list_empty(&dev->dev_next->devlist))
+			em28xx_close_extension(dev->dev_next);
 		kref_put(&dev->dev_next->ref, em28xx_free_device);
 		dev->dev_next = NULL;
 	}
--

Re: [syzbot] [media?] KASAN: use-after-free Read in em28xx_close_extension (2)

[syzbot]

Hello,

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

Reported-by: syzbot+a11c46f37ee083a73deb@syzkaller.appspotmail.com
Tested-by: syzbot+a11c46f37ee083a73deb@syzkaller.appspotmail.com

Tested on:

commit:         68d42091 sub: cdns3: Use predefined PCI vendor ID cons..
git tree:       https://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb.git usb-testing
console output: https://syzkaller.appspot.com/x/log.txt?x=13fdcca9980000
kernel config:  https://syzkaller.appspot.com/x/.config?x=cb61872d4d8c5df9
dashboard link: https://syzkaller.appspot.com/bug?extid=a11c46f37ee083a73deb
compiler:       gcc (Debian 12.2.0-14) 12.2.0, GNU ld (GNU Binutils for Debian) 2.40
patch:          https://syzkaller.appspot.com/x/patch.diff?x=17219607980000

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

Re: [syzbot] [media?] KASAN: use-after-free Read in em28xx_close_extension (2)

[Fedor Pchelkin]

#syz test

--- a/drivers/media/usb/em28xx/em28xx-cards.c
+++ b/drivers/media/usb/em28xx/em28xx-cards.c
@@ -3445,17 +3445,16 @@ static void request_module_async(struct work_struct *work)
 
        /*
         * Devices with an audio-only intf also have a V4L/DVB/RC
-        * intf. Don't register extensions twice on those devices.
+        * intf.
         */
        if (dev->is_audio_only) {
 #if defined(CONFIG_MODULES) && defined(MODULE)
                request_module("em28xx-alsa");
 #endif
+               em28xx_init_extension(dev);
                return;
        }
 
-       em28xx_init_extension(dev);
-
 #if defined(CONFIG_MODULES) && defined(MODULE)
        if (dev->has_video)
                request_module("em28xx-v4l");
@@ -3469,6 +3468,8 @@ static void request_module_async(struct work_struct *work)
            ((dev->board.ir_codes || dev->board.has_ir_i2c) && !disable_ir))
                request_module("em28xx-rc");
 #endif /* CONFIG_MODULES */
+
+       em28xx_init_extension(dev);
 }
 
 static void request_modules(struct em28xx *dev)
@@ -3676,8 +3677,6 @@ static int em28xx_init_dev(struct em28xx *dev, struct usb_device *udev,
                        retval = -ENODEV;
                        goto err_deinit_media;
                }
-               em28xx_init_extension(dev);
-
                return 0;
        }

Re: [syzbot] [usb?] [media?] KASAN: use-after-free Read in em28xx_close_extension (2)

[syzbot]

Hello,

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

Reported-by: syzbot+a11c46f37ee083a73deb@syzkaller.appspotmail.com
Tested-by: syzbot+a11c46f37ee083a73deb@syzkaller.appspotmail.com

Tested on:

commit:         e9a6fb0b Linux 6.18-rc5
git tree:       upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=1600b412580000
kernel config:  https://syzkaller.appspot.com/x/.config?x=cec18221b2e23baa
dashboard link: https://syzkaller.appspot.com/bug?extid=a11c46f37ee083a73deb
compiler:       gcc (Debian 12.2.0-14+deb12u1) 12.2.0, GNU ld (GNU Binutils for Debian) 2.40
patch:          https://syzkaller.appspot.com/x/patch.diff?x=17cc1a92580000

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