================================================================== BUG: KASAN: use-after-free in dvb_device_open+0xc6/0x370 drivers/media/dvb-core/dvbdev.c:99 Read of size 8 at addr ffff8881401aea18 by task syz.1.512/6328 CPU: 0 PID: 6328 Comm: syz.1.512 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026 Call Trace: dump_stack_lvl+0x188/0x24e lib/dump_stack.c:106 print_address_description mm/kasan/report.c:316 [inline] print_report+0xa8/0x210 mm/kasan/report.c:420 kasan_report+0x10b/0x140 mm/kasan/report.c:524 dvb_device_open+0xc6/0x370 drivers/media/dvb-core/dvbdev.c:99 chrdev_open+0x5c5/0x6a0 fs/char_dev.c:414 do_dentry_open+0x7e9/0x10d0 fs/open.c:882 do_open fs/namei.c:3634 [inline] path_openat+0x2635/0x2ee0 fs/namei.c:3791 do_filp_open+0x1f1/0x430 fs/namei.c:3818 do_sys_openat2+0x150/0x4b0 fs/open.c:1320 do_sys_open fs/open.c:1336 [inline] __do_sys_openat fs/open.c:1352 [inline] __se_sys_openat fs/open.c:1347 [inline] __x64_sys_openat+0x135/0x160 fs/open.c:1347 do_syscall_x64 arch/x86/entry/common.c:46 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:76 entry_SYSCALL_64_after_hwframe+0x68/0xd2 RIP: 0033:0x7f07be75c84e Code: 08 0f 85 a5 a8 ff ff 49 89 fb 48 89 f0 48 89 d7 48 89 ce 4c 89 c2 4d 89 ca 4c 8b 44 24 08 4c 8b 4c 24 10 4c 89 5c 24 08 0f 05 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 80 00 00 00 00 48 83 ec 08 RSP: 002b:00007f07bf5b4b28 EFLAGS: 00000246 ORIG_RAX: 0000000000000101 RAX: ffffffffffffffda RBX: 00007f07bf5b56c0 RCX: 00007f07be75c84e RDX: 0000000000040002 RSI: 00007f07bf5b4c00 RDI: ffffffffffffff9c RBP: 00007f07bf5b4c00 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: cccccccccccccccd R13: 00007f07bea16128 R14: 00007f07bea16090 R15: 00007fff56bb4528 Allocated by task 5056: kasan_save_stack mm/kasan/common.c:46 [inline] kasan_set_track+0x4b/0x70 mm/kasan/common.c:53 ____kasan_kmalloc mm/kasan/common.c:375 [inline] __kasan_kmalloc+0x8e/0xa0 mm/kasan/common.c:384 kmalloc include/linux/slab.h:563 [inline] usb_string+0x10d/0x760 drivers/usb/core/message.c:979 usb_cache_string+0x7c/0x130 drivers/usb/core/message.c:1029 usb_enumerate_device drivers/usb/core/hub.c:2502 [inline] usb_new_device+0x2fa/0x1650 drivers/usb/core/hub.c:2629 hub_port_connect drivers/usb/core/hub.c:5517 [inline] hub_port_connect_change drivers/usb/core/hub.c:5657 [inline] port_event drivers/usb/core/hub.c:5817 [inline] hub_event+0x2dcf/0x5560 drivers/usb/core/hub.c:5899 process_one_work+0x8a2/0x1160 kernel/workqueue.c:2292 worker_thread+0xaa2/0x1270 kernel/workqueue.c:2439 kthread+0x29d/0x330 kernel/kthread.c:376 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295 Last potentially related work creation: kasan_save_stack+0x3a/0x60 mm/kasan/common.c:46 __kasan_record_aux_stack+0xb2/0xc0 mm/kasan/generic.c:486 kvfree_call_rcu+0x103/0x870 kernel/rcu/tree.c:3405 drop_sysctl_table+0x359/0x4e0 fs/proc/proc_sysctl.c:1731 drop_sysctl_table+0x348/0x4e0 fs/proc/proc_sysctl.c:1734 unregister_sysctl_table+0x85/0x130 fs/proc/proc_sysctl.c:1769 retire_ipc_sysctls+0x5a/0x80 ipc/ipc_sysctl.c:310 free_ipc_ns ipc/namespace.c:144 [inline] free_ipc+0x91/0x1d0 ipc/namespace.c:159 process_one_work+0x8a2/0x1160 kernel/workqueue.c:2292 worker_thread+0xaa2/0x1270 kernel/workqueue.c:2439 kthread+0x29d/0x330 kernel/kthread.c:376 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295 The buggy address belongs to the object at ffff8881401aea00 which belongs to the cache kmalloc-256 of size 256 The buggy address is located 24 bytes inside of 256-byte region [ffff8881401aea00, ffff8881401aeb00) The buggy address belongs to the physical page: page:ffffea0005006b80 refcount:1 mapcount:0 mapping:0000000000000000 index:0xffff8881401aea00 pfn:0x1401ae head:ffffea0005006b80 order:1 compound_mapcount:0 compound_pincount:0 flags: 0x57ff00000010200(slab|head|node=1|zone=2|lastcpupid=0x7ff) raw: 057ff00000010200 ffff888140000708 ffffea0005324488 ffff888017441b40 raw: ffff8881401aea00 000000000010000f 00000001ffffffff 0000000000000000 page dumped because: kasan: bad access detected page_owner tracks the page as allocated page last allocated via order 1, migratetype Unmovable, gfp_mask 0xd20c0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 1, tgid 1 (swapper/0), ts 16352326930, free_ts 0 set_page_owner include/linux/page_owner.h:31 [inline] post_alloc_hook+0x173/0x1a0 mm/page_alloc.c:2559 prep_new_page mm/page_alloc.c:2566 [inline] get_page_from_freelist+0x1a1e/0x1ab0 mm/page_alloc.c:4357 __alloc_pages+0x1ec/0x4f0 mm/page_alloc.c:5643 alloc_page_interleave+0x24/0x1e0 mm/mempolicy.c:2115 alloc_slab_page+0x5d/0x160 mm/slub.c:1799 allocate_slab mm/slub.c:1944 [inline] new_slab+0x87/0x2c0 mm/slub.c:1997 ___slab_alloc+0xbc6/0x1240 mm/slub.c:3154 __slab_alloc mm/slub.c:3240 [inline] slab_alloc_node mm/slub.c:3325 [inline] __kmem_cache_alloc_node+0x1a0/0x260 mm/slub.c:3398 kmalloc_trace+0x26/0xe0 mm/slab_common.c:1026 kmalloc include/linux/slab.h:563 [inline] kzalloc include/linux/slab.h:699 [inline] bus_add_driver+0xda/0x5a0 drivers/base/bus.c:604 driver_register+0x32d/0x430 drivers/base/driver.c:246 usb_register_driver+0x202/0x3d0 drivers/usb/core/driver.c:1062 do_one_initcall+0x26a/0x840 init/main.c:1310 do_initcall_level+0x137/0x1e4 init/main.c:1383 do_initcalls+0x4b/0x8a init/main.c:1399 kernel_init_freeable+0x415/0x5be init/main.c:1638 page_owner free stack trace missing Memory state around the buggy address: ffff8881401ae900: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff8881401ae980: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc >ffff8881401aea00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff8881401aea80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff8881401aeb00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ==================================================================