================================================================== BUG: KASAN: use-after-free in __list_del_entry_valid_or_report+0x1b1/0x1d0 lib/list_debug.c:62 Read of size 8 at addr ffff88802c510978 by task syz.7.20857/23213 CPU: 1 UID: 0 PID: 23213 Comm: syz.7.20857 Tainted: G L syzkaller #0 PREEMPT(full) Tainted: [L]=SOFTLOCKUP Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026 Call Trace: __dump_stack lib/dump_stack.c:94 [inline] dump_stack_lvl+0x100/0x190 lib/dump_stack.c:120 print_address_description mm/kasan/report.c:378 [inline] print_report+0x156/0x4c9 mm/kasan/report.c:482 kasan_report+0xdf/0x1e0 mm/kasan/report.c:595 __list_del_entry_valid_or_report+0x1b1/0x1d0 lib/list_debug.c:62 __list_del_entry_valid include/linux/list.h:132 [inline] __list_del_entry include/linux/list.h:223 [inline] list_del_init include/linux/list.h:295 [inline] trace_transfers fs/pnode.c:132 [inline] bulk_make_private+0xd8/0x720 fs/pnode.c:168 umount_tree+0x3fb/0xec0 fs/namespace.c:1786 put_mnt_ns+0x267/0x300 fs/namespace.c:6230 nsproxy_free kernel/nsproxy.c:65 [inline] deactivate_nsproxy kernel/nsproxy.c:79 [inline] put_nsproxy include/linux/nsproxy.h:110 [inline] put_nsproxy include/linux/nsproxy.h:107 [inline] switch_task_namespaces+0x133/0x2c0 kernel/nsproxy.c:252 do_exit+0x824/0x2aa0 kernel/exit.c:970 do_group_exit+0xd5/0x2a0 kernel/exit.c:1112 get_signal+0x1ec7/0x21e0 kernel/signal.c:3034 arch_do_signal_or_restart+0x91/0x7a0 arch/x86/kernel/signal.c:337 __exit_to_user_mode_loop kernel/entry/common.c:64 [inline] exit_to_user_mode_loop+0x86/0x4a0 kernel/entry/common.c:98 __exit_to_user_mode_prepare include/linux/irq-entry-common.h:226 [inline] syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:256 [inline] syscall_exit_to_user_mode include/linux/entry-common.h:325 [inline] do_syscall_64+0x67c/0xf80 arch/x86/entry/syscall_64.c:100 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f2b7879c629 Code: Unable to access opcode bytes at 0x7f2b7879c5ff. RSP: 002b:00007f2b79656028 EFLAGS: 00000246 ORIG_RAX: 000000000000012b RAX: 0000000000010106 RBX: 00007f2b78a15fa0 RCX: 00007f2b7879c629 RDX: 0000000000010106 RSI: 00002000000000c0 RDI: 0000000000000003 RBP: 00007f2b78832b39 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000002 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f2b78a16038 R14: 00007f2b78a15fa0 R15: 00007fff9beed748 The buggy address belongs to the physical page: page: refcount:0 mapcount:0 mapping:0000000000000000 index:0xffff88802c510c00 pfn:0x2c510 flags: 0xfff00000000000(node=0|zone=1|lastcpupid=0x7ff) raw: 00fff00000000000 ffffea00017b6a88 ffffea0000ce3488 0000000000000000 raw: ffff88802c510c00 0000000000000000 00000000ffffffff 0000000000000000 page dumped because: kasan: bad access detected page_owner tracks the page as freed page last allocated via order 1, migratetype Unmovable, gfp_mask 0xd20c0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 22685, tgid 22680 (syz.2.20696), ts 1620019747937, free_ts 1653349109832 set_page_owner include/linux/page_owner.h:32 [inline] post_alloc_hook+0x153/0x170 mm/page_alloc.c:1889 prep_new_page mm/page_alloc.c:1897 [inline] get_page_from_freelist+0x111d/0x3140 mm/page_alloc.c:3962 __alloc_frozen_pages_noprof+0x27c/0x2ba0 mm/page_alloc.c:5250 alloc_slab_page mm/slub.c:3255 [inline] allocate_slab mm/slub.c:3444 [inline] new_slab+0xa6/0x6d0 mm/slub.c:3502 refill_objects+0x26b/0x400 mm/slub.c:7134 refill_sheaf mm/slub.c:2804 [inline] alloc_full_sheaf mm/slub.c:2825 [inline] __pcs_replace_empty_main+0x19f/0x600 mm/slub.c:4588 alloc_from_pcs mm/slub.c:4681 [inline] slab_alloc_node mm/slub.c:4815 [inline] __do_kmalloc_node mm/slub.c:5218 [inline] __kmalloc_noprof+0x688/0x850 mm/slub.c:5231 kmalloc_noprof include/linux/slab.h:966 [inline] kmalloc_array_noprof include/linux/slab.h:1113 [inline] iter_file_splice_write+0x1d3/0x10a0 fs/splice.c:679 do_splice_from fs/splice.c:938 [inline] direct_splice_actor+0x192/0x6c0 fs/splice.c:1161 splice_direct_to_actor+0x345/0xa30 fs/splice.c:1105 do_splice_direct_actor fs/splice.c:1204 [inline] do_splice_direct+0x174/0x240 fs/splice.c:1230 do_sendfile+0xadc/0xe20 fs/read_write.c:1372 __do_sys_sendfile64 fs/read_write.c:1433 [inline] __se_sys_sendfile64 fs/read_write.c:1419 [inline] __x64_sys_sendfile64+0x1d8/0x220 fs/read_write.c:1419 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x106/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f page last free pid 42 tgid 42 stack trace: reset_page_owner include/linux/page_owner.h:25 [inline] __free_pages_prepare mm/page_alloc.c:1433 [inline] __free_frozen_pages+0x7e1/0x10d0 mm/page_alloc.c:2978 qlink_free mm/kasan/quarantine.c:163 [inline] qlist_free_all+0x47/0xe0 mm/kasan/quarantine.c:179 kasan_quarantine_reduce+0x1a0/0x1f0 mm/kasan/quarantine.c:286 __kasan_slab_alloc+0x69/0x90 mm/kasan/common.c:350 kasan_slab_alloc include/linux/kasan.h:253 [inline] slab_post_alloc_hook mm/slub.c:4501 [inline] slab_alloc_node mm/slub.c:4830 [inline] __kmalloc_cache_noprof+0x243/0x6f0 mm/slub.c:5334 kmalloc_noprof include/linux/slab.h:962 [inline] m920x_rc_core_query+0x4d/0x500 drivers/media/usb/dvb-usb/m920x.c:222 dvb_usb_read_remote_control+0xdd/0x1b0 drivers/media/usb/dvb-usb/dvb-usb-remote.c:261 process_one_work+0x9d7/0x1920 kernel/workqueue.c:3275 process_scheduled_works kernel/workqueue.c:3358 [inline] worker_thread+0x5da/0xe40 kernel/workqueue.c:3439 kthread+0x370/0x450 kernel/kthread.c:467 ret_from_fork+0x754/0xd80 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: ffff88802c510800: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ffff88802c510880: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff >ffff88802c510900: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ^ ffff88802c510980: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ffff88802c510a00: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ==================================================================