From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-oi1-f208.google.com (mail-oi1-f208.google.com [209.85.167.208]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id EBC4117B50F for ; Sun, 2 Aug 2026 00:53:23 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.167.208 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1785632005; cv=none; b=KqdRtlZpJavunfRWyBx0W2R78K8NXkzycJJ6nuhLCaFnWkZoXqV/GXv0zlDpDh6N+l5IbxNFgYVq+eHY66mLoGTupjTmAtWN8l7YUG4iRRO2UwxvSko9lZlEphDDKwmfDAhw7b1/q21owL+iE+KyEHtVfJsrhJY3aLzOXFXodNU= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1785632005; c=relaxed/simple; bh=9pds59ONWpFSQh3ATJ7E9SbpRpkzkhieq0V1myNMakI=; h=MIME-Version:Date:Message-ID:Subject:From:To:Content-Type; b=QlXeEqmZZatz7Aj/sGNbtYlJNL8HcQNjCC4g7CmO05klgVRe7xHohQSrxk7jmBwXSRf1glQEpuFb906W8ELuTIaJGSBIO9628w0N1QpR5wf0gYlklYpdnqZliKmvexYxB0q6LtzSjJrWXIcyCKMgbZhy0EKiRWP+OBrRYr4mXC0= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=fail (p=none dis=none) header.from=syzkaller.appspotmail.com; spf=pass smtp.mailfrom=M3KW2WVRGUFZ5GODRSRYTGD7.apphosting.bounces.google.com; arc=none smtp.client-ip=209.85.167.208 Authentication-Results: smtp.subspace.kernel.org; dmarc=fail (p=none dis=none) header.from=syzkaller.appspotmail.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=M3KW2WVRGUFZ5GODRSRYTGD7.apphosting.bounces.google.com Received: by mail-oi1-f208.google.com with SMTP id 5614622812f47-4a41f46d629so3288820b6e.3 for ; Sat, 01 Aug 2026 17:53:23 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20251104; t=1785632003; x=1786236803; h=content-type:to:from:subject:message-id:date:mime-version :x-gm-message-state:from:to:cc:subject:date:message-id:reply-to :content-type; bh=JwtvidpVUFBvuJvVNtKIynYdIILypxvFi2OM8WU+Lqk=; b=ALP3/OBx8T2iDBbBdCfnKCE8535E0IqLt8866ebQ0YpvZFnwdLVYKMDvqri8svX6Z3 ZYEWHiPAUTMaOYlgBUn4oUgnHVkZ0ESxkqeJSfUkCPBLZqTwcc2ezf5ljg8IAYvfFTzO GuHol8wbp1evTmhM58r5+fDI9nV0f2VvS5nUQbgWH0CG4i7ZMhZb3tdcqw1W41lL12IT wBtmWe9xv0MqnWL2KDvU+KWADJDM7xJC1OcQzUyL8V7EKRb7g87j8PFIYYfkKiL608r0 WYVXvN58bsADE7sSYgcu2ZSH5kRplZUsj5i/YwUds3ziOyumtPDWfIkTE1sg8UNFH7kZ 8wvw== X-Gm-Message-State: AOJu0YzwMQoe+p4FEHLaDdh2F0Ak9K7nq99ZR/0BjPLQA6lfmAlSjHr2 eBUSIjnN26V8mjZEx+R0n3/dUVXog9K5SD8vF+IHw8sKRJvLKzgallUb1QKdeQxw80v0IqZYaF5 OE2RWr5fMmDM8S94MG7RpE4khoDC5QsupxTtYkWJcbH/fz8pLWR7pw6X/xuttVw== Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-Received: by 2002:a05:6808:1a0c:b0:4a3:ec8e:2052 with SMTP id 5614622812f47-4af5e18ac5amr8574111b6e.8.1785632002843; Sat, 01 Aug 2026 17:53:22 -0700 (PDT) Date: Sat, 01 Aug 2026 17:53:22 -0700 X-Google-Appengine-App-Id: s~syzkaller X-Google-Appengine-App-Id-Alias: syzkaller Message-ID: <6a6e9502.f794c993.27aeb.0018.GAE@google.com> Subject: [syzbot] [media?] KASAN: slab-use-after-free Write in usb_free_urb From: syzbot To: linux-kernel@vger.kernel.org, linux-media@vger.kernel.org, mchehab@kernel.org, syzkaller-bugs@googlegroups.com Content-Type: text/plain; charset="UTF-8" Hello, syzbot found the following issue on: HEAD commit: 62cc90241548 Merge tag 'mm-hotfixes-stable-2026-07-27-14-1.. git tree: upstream console output: https://syzkaller.appspot.com/x/log.txt?x=11e4249e580000 kernel config: https://syzkaller.appspot.com/x/.config?x=c05be6c9b0d36cb9 dashboard link: https://syzkaller.appspot.com/bug?extid=832ce9fa3face1b7d44d compiler: Debian clang version 22.1.8 (++20260613092233+e80beda6e255-1~exp1~20260613092250.77), Debian LLD 22.1.8 Unfortunately, I don't have any reproducer for this issue yet. Downloadable assets: disk image (non-bootable): https://storage.googleapis.com/syzbot-assets/d900f083ada3/non_bootable_disk-62cc9024.raw.xz vmlinux: https://storage.googleapis.com/syzbot-assets/4f85523029b9/vmlinux-62cc9024.xz kernel image: https://storage.googleapis.com/syzbot-assets/d37f4266b11c/bzImage-62cc9024.xz IMPORTANT: if you fix the issue, please add the following tag to the commit: Reported-by: syzbot+832ce9fa3face1b7d44d@syzkaller.appspotmail.com FAULT_INJECTION: forcing a failure. name failslab, interval 1, probability 0, space 0, times 1 CPU: 0 UID: 0 PID: 5337 Comm: syz.0.0 Not tainted syzkaller #0 PREEMPT(full) Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2 04/01/2014 Call Trace: dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120 fail_dump lib/fault-inject.c:73 [inline] should_fail_ex+0x40c/0x560 lib/fault-inject.c:174 should_failslab+0xa8/0x100 mm/failslab.c:46 slab_pre_alloc_hook mm/slub.c:4539 [inline] slab_alloc_node mm/slub.c:4897 [inline] __do_kmalloc_node mm/slub.c:5333 [inline] __kmalloc_noprof+0xfe/0x720 mm/slub.c:5359 _kmalloc_noprof include/linux/slab.h:992 [inline] usb_alloc_urb+0x46/0x150 drivers/usb/core/urb.c:75 hackrf_alloc_urbs drivers/media/usb/hackrf/hackrf.c:683 [inline] hackrf_start_streaming+0x722/0x1350 drivers/media/usb/hackrf/hackrf.c:827 vb2_start_streaming+0x11e/0x450 drivers/media/common/videobuf2/videobuf2-core.c:1783 vb2_core_streamon+0x2c0/0x4d0 drivers/media/common/videobuf2/videobuf2-core.c:2336 __video_do_ioctl+0x8af/0xc70 drivers/media/v4l2-core/v4l2-ioctl.c:3133 video_usercopy+0x860/0x1430 drivers/media/v4l2-core/v4l2-ioctl.c:3475 v4l2_ioctl+0x18d/0x1e0 drivers/media/v4l2-core/v4l2-dev.c:366 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:597 [inline] __se_sys_ioctl+0xfc/0x170 fs/ioctl.c:583 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x174/0x580 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f1b1359de99 Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 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 e8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f1b1450bfe8 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00007f1b13826180 RCX: 00007f1b1359de99 RDX: 0000200000000600 RSI: 0000000040045612 RDI: 0000000000000005 RBP: 00007f1b1450c050 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000002 R13: 00007f1b13826218 R14: 00007f1b13826180 R15: 00007fffe6212058 ================================================================== BUG: KASAN: slab-use-after-free in instrument_atomic_read_write include/linux/instrumented.h:112 [inline] BUG: KASAN: slab-use-after-free in atomic_fetch_sub_release include/linux/atomic/atomic-instrumented.h:400 [inline] BUG: KASAN: slab-use-after-free in __refcount_sub_and_test include/linux/refcount.h:389 [inline] BUG: KASAN: slab-use-after-free in __refcount_dec_and_test include/linux/refcount.h:432 [inline] BUG: KASAN: slab-use-after-free in refcount_dec_and_test include/linux/refcount.h:450 [inline] BUG: KASAN: slab-use-after-free in kref_put include/linux/kref.h:64 [inline] BUG: KASAN: slab-use-after-free in usb_free_urb+0x24/0x120 drivers/usb/core/urb.c:96 Write of size 4 at addr ffff88801d3b6800 by task syz.0.0/5337 CPU: 0 UID: 0 PID: 5337 Comm: syz.0.0 Not tainted syzkaller #0 PREEMPT(full) Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2 04/01/2014 Call Trace: dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120 print_address_description+0x55/0x1e0 mm/kasan/report.c:378 print_report+0x58/0x70 mm/kasan/report.c:482 kasan_report+0x117/0x150 mm/kasan/report.c:595 check_region_inline mm/kasan/generic.c:-1 [inline] kasan_check_range+0x264/0x2c0 mm/kasan/generic.c:200 instrument_atomic_read_write include/linux/instrumented.h:112 [inline] atomic_fetch_sub_release include/linux/atomic/atomic-instrumented.h:400 [inline] __refcount_sub_and_test include/linux/refcount.h:389 [inline] __refcount_dec_and_test include/linux/refcount.h:432 [inline] refcount_dec_and_test include/linux/refcount.h:450 [inline] kref_put include/linux/kref.h:64 [inline] usb_free_urb+0x24/0x120 drivers/usb/core/urb.c:96 hackrf_free_urbs+0x22b/0x3b0 drivers/media/usb/hackrf/hackrf.c:658 hackrf_start_streaming+0xe12/0x1350 drivers/media/usb/hackrf/hackrf.c:849 vb2_start_streaming+0x11e/0x450 drivers/media/common/videobuf2/videobuf2-core.c:1783 vb2_core_streamon+0x2c0/0x4d0 drivers/media/common/videobuf2/videobuf2-core.c:2336 __video_do_ioctl+0x8af/0xc70 drivers/media/v4l2-core/v4l2-ioctl.c:3133 video_usercopy+0x860/0x1430 drivers/media/v4l2-core/v4l2-ioctl.c:3475 v4l2_ioctl+0x18d/0x1e0 drivers/media/v4l2-core/v4l2-dev.c:366 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:597 [inline] __se_sys_ioctl+0xfc/0x170 fs/ioctl.c:583 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x174/0x580 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f1b1359de99 Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 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 e8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f1b1450bfe8 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00007f1b13826180 RCX: 00007f1b1359de99 RDX: 0000200000000600 RSI: 0000000040045612 RDI: 0000000000000005 RBP: 00007f1b1450c050 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000002 R13: 00007f1b13826218 R14: 00007f1b13826180 R15: 00007fffe6212058 Allocated by task 5337: kasan_save_stack mm/kasan/common.c:57 [inline] kasan_save_track+0x3e/0x80 mm/kasan/common.c:78 poison_kmalloc_redzone mm/kasan/common.c:398 [inline] __kasan_kmalloc+0x93/0xb0 mm/kasan/common.c:415 kasan_kmalloc include/linux/kasan.h:263 [inline] __do_kmalloc_node mm/slub.c:5334 [inline] __kmalloc_noprof+0x375/0x720 mm/slub.c:5359 _kmalloc_noprof include/linux/slab.h:992 [inline] usb_alloc_urb+0x46/0x150 drivers/usb/core/urb.c:75 hackrf_alloc_urbs drivers/media/usb/hackrf/hackrf.c:683 [inline] hackrf_start_streaming+0x722/0x1350 drivers/media/usb/hackrf/hackrf.c:827 vb2_start_streaming+0x11e/0x450 drivers/media/common/videobuf2/videobuf2-core.c:1783 vb2_core_streamon+0x2c0/0x4d0 drivers/media/common/videobuf2/videobuf2-core.c:2336 __video_do_ioctl+0x8af/0xc70 drivers/media/v4l2-core/v4l2-ioctl.c:3133 video_usercopy+0x860/0x1430 drivers/media/v4l2-core/v4l2-ioctl.c:3475 v4l2_ioctl+0x18d/0x1e0 drivers/media/v4l2-core/v4l2-dev.c:366 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:597 [inline] __se_sys_ioctl+0xfc/0x170 fs/ioctl.c:583 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x174/0x580 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f Freed by task 5337: kasan_save_stack mm/kasan/common.c:57 [inline] kasan_save_track+0x3e/0x80 mm/kasan/common.c:78 kasan_save_free_info+0x40/0x50 mm/kasan/generic.c:584 poison_slab_object mm/kasan/common.c:253 [inline] __kasan_slab_free+0x5c/0x80 mm/kasan/common.c:285 kasan_slab_free include/linux/kasan.h:235 [inline] slab_free_hook mm/slub.c:2677 [inline] slab_free mm/slub.c:6377 [inline] kfree+0x1c5/0x640 mm/slub.c:6692 hackrf_alloc_urbs drivers/media/usb/hackrf/hackrf.c:686 [inline] hackrf_start_streaming+0xa55/0x1350 drivers/media/usb/hackrf/hackrf.c:827 vb2_start_streaming+0x11e/0x450 drivers/media/common/videobuf2/videobuf2-core.c:1783 vb2_core_streamon+0x2c0/0x4d0 drivers/media/common/videobuf2/videobuf2-core.c:2336 __video_do_ioctl+0x8af/0xc70 drivers/media/v4l2-core/v4l2-ioctl.c:3133 video_usercopy+0x860/0x1430 drivers/media/v4l2-core/v4l2-ioctl.c:3475 v4l2_ioctl+0x18d/0x1e0 drivers/media/v4l2-core/v4l2-dev.c:366 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:597 [inline] __se_sys_ioctl+0xfc/0x170 fs/ioctl.c:583 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x174/0x580 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f The buggy address belongs to the object at ffff88801d3b6800 which belongs to the cache kmalloc-192 of size 192 The buggy address is located 0 bytes inside of freed 192-byte region [ffff88801d3b6800, ffff88801d3b68c0) The buggy address belongs to the physical page: page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x1d3b6 flags: 0xfff00000000000(node=0|zone=1|lastcpupid=0x7ff) page_type: f5(slab) raw: 00fff00000000000 ffff88801b0413c0 dead000000000100 dead000000000122 raw: 0000000000000000 0000000800100010 00000000f5000000 0000000000000000 page dumped because: kasan: bad access detected page_owner tracks the page as allocated page last allocated via order 0, migratetype Unmovable, gfp_mask 0x252800(GFP_NOWAIT|__GFP_NORETRY|__GFP_COMP|__GFP_THISNODE), pid 1, tgid 1 (swapper/0), ts 12217348821, free_ts 11554810146 set_page_owner include/linux/page_owner.h:32 [inline] post_alloc_hook+0x1f9/0x250 mm/page_alloc.c:1859 prep_new_page mm/page_alloc.c:1867 [inline] get_page_from_freelist+0x21fa/0x2270 mm/page_alloc.c:3946 __alloc_pages_slowpath+0x383/0xcc0 mm/page_alloc.c:4821 __alloc_frozen_pages_noprof+0x31f/0x380 mm/page_alloc.c:5317 alloc_slab_page mm/slub.c:3266 [inline] allocate_slab+0x79/0x5e0 mm/slub.c:3380 new_slab mm/slub.c:3426 [inline] ___slab_alloc+0x16a/0x950 mm/slub.c:4463 slab_alloc_node mm/slub.c:4908 [inline] __do_kmalloc_node mm/slub.c:5333 [inline] __kvmalloc_node_noprof+0x341/0x860 mm/slub.c:6905 sbitmap_init_node+0x2bc/0x630 lib/sbitmap.c:132 blk_mq_alloc_hctx block/blk-mq.c:4055 [inline] blk_mq_alloc_and_init_hctx+0x4f3/0xc50 block/blk-mq.c:4524 __blk_mq_realloc_hw_ctxs+0x2b2/0x660 block/blk-mq.c:4575 blk_mq_realloc_hw_ctxs block/blk-mq.c:4612 [inline] blk_mq_init_allocated_queue+0x357/0x13c0 block/blk-mq.c:4642 blk_mq_alloc_queue block/blk-mq.c:4424 [inline] __blk_mq_alloc_disk+0x1d2/0x390 block/blk-mq.c:4467 nbd_dev_add+0x494/0xb60 drivers/block/nbd.c:1991 nbd_init+0x15f/0x1e0 drivers/block/nbd.c:2729 do_one_initcall+0x250/0x870 init/main.c:1347 do_initcall_level+0x10a/0x1a0 init/main.c:1409 page last free pid 41 tgid 41 stack trace: reset_page_owner include/linux/page_owner.h:25 [inline] __free_pages_prepare mm/page_alloc.c:1406 [inline] __free_frozen_pages+0xc1e/0xd10 mm/page_alloc.c:2950 __slab_free+0x274/0x2c0 mm/slub.c:5741 qlink_free mm/kasan/quarantine.c:163 [inline] qlist_free_all+0x99/0x100 mm/kasan/quarantine.c:179 kasan_quarantine_reduce+0x148/0x160 mm/kasan/quarantine.c:286 __kasan_slab_alloc+0x22/0x80 mm/kasan/common.c:350 kasan_slab_alloc include/linux/kasan.h:253 [inline] slab_post_alloc_hook mm/slub.c:4584 [inline] slab_alloc_node mm/slub.c:4917 [inline] kmem_cache_alloc_node_noprof+0x355/0x610 mm/slub.c:4989 alloc_task_struct_node kernel/fork.c:188 [inline] dup_task_struct+0x52/0x8e0 kernel/fork.c:921 copy_process+0x820/0x4390 kernel/fork.c:2115 kernel_clone+0x2d7/0x940 kernel/fork.c:2748 user_mode_thread+0x110/0x180 kernel/fork.c:2824 call_usermodehelper_exec_work+0x5c/0x230 kernel/umh.c:171 process_one_work kernel/workqueue.c:3322 [inline] process_scheduled_works+0xa8e/0x14e0 kernel/workqueue.c:3405 worker_thread+0xa47/0xfb0 kernel/workqueue.c:3486 kthread+0x388/0x470 kernel/kthread.c:436 ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 Memory state around the buggy address: ffff88801d3b6700: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ffff88801d3b6780: 00 00 00 fc fc fc fc fc fc fc fc fc fc fc fc fc >ffff88801d3b6800: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff88801d3b6880: fb fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc ffff88801d3b6900: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ================================================================== --- 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. If the report is already addressed, let syzbot know by replying with: #syz fix: exact-commit-title If you want to overwrite report's subsystems, reply with: #syz set subsystems: new-subsystem (See the list of subsystem names on the web dashboard) If the report is a duplicate of another one, reply with: #syz dup: exact-subject-of-another-report If you want to undo deduplication, reply with: #syz undup