================================================================== BUG: KASAN: use-after-free in instrument_atomic_read include/linux/instrumented.h:71 [inline] BUG: KASAN: use-after-free in test_bit include/asm-generic/bitops/instrumented-non-atomic.h:134 [inline] BUG: KASAN: use-after-free in tty_port_kopened include/linux/tty.h:616 [inline] BUG: KASAN: use-after-free in check_tty_count+0x1a8/0x330 drivers/tty/tty_io.c:295 Read of size 8 at addr ffff88810dea4910 by task syz.5.18/422 CPU: 1 PID: 422 Comm: syz.5.18 Tainted: G W syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026 Call Trace: __dump_stack+0x21/0x24 lib/dump_stack.c:77 dump_stack_lvl+0x1a7/0x208 lib/dump_stack.c:118 print_address_description+0x7f/0x2c0 mm/kasan/report.c:248 __kasan_report mm/kasan/report.c:435 [inline] kasan_report+0x100/0x140 mm/kasan/report.c:452 check_region_inline mm/kasan/generic.c:-1 [inline] kasan_check_range+0x249/0x2a0 mm/kasan/generic.c:189 __kasan_check_read+0x11/0x20 mm/kasan/shadow.c:31 instrument_atomic_read include/linux/instrumented.h:71 [inline] test_bit include/asm-generic/bitops/instrumented-non-atomic.h:134 [inline] tty_port_kopened include/linux/tty.h:616 [inline] check_tty_count+0x1a8/0x330 drivers/tty/tty_io.c:295 tty_release+0xc9/0x1330 drivers/tty/tty_io.c:1747 __fput+0x2dc/0x730 fs/file_table.c:281 ____fput+0x15/0x20 fs/file_table.c:314 task_work_run+0x127/0x190 kernel/task_work.c:189 ptrace_notify+0x230/0x270 kernel/signal.c:2289 ptrace_report_syscall include/linux/tracehook.h:66 [inline] tracehook_report_syscall_exit include/linux/tracehook.h:129 [inline] arch_syscall_exit_tracehook include/linux/entry-common.h:285 [inline] syscall_exit_work+0x6e/0x140 kernel/entry/common.c:239 syscall_exit_to_user_mode_prepare kernel/entry/common.c:266 [inline] syscall_exit_to_user_mode+0x2f/0x40 kernel/entry/common.c:272 do_syscall_64+0x3d/0x40 arch/x86/entry/common.c:56 entry_SYSCALL_64_after_hwframe+0x61/0xcb RIP: 0033:0x7f8795c0d0d9 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:00007ffc35640e68 EFLAGS: 00000246 ORIG_RAX: 00000000000001b4 RAX: 0000000000000000 RBX: 00007f8795e96da0 RCX: 00007f8795c0d0d9 RDX: 0000000000000000 RSI: 000000000000001e RDI: 0000000000000003 RBP: 00007f8795e96da0 R08: 00007f8795e95038 R09: 0000000000000000 R10: 000000000003fda0 R11: 0000000000000246 R12: 00000000000079dc R13: 00007f8795e94fac R14: 00000000000076d5 R15: 00007ffc35640f70 Allocated by task 425: kasan_save_stack mm/kasan/common.c:38 [inline] kasan_set_track mm/kasan/common.c:45 [inline] set_alloc_info mm/kasan/common.c:430 [inline] ____kasan_kmalloc mm/kasan/common.c:509 [inline] __kasan_kmalloc+0xd4/0x100 mm/kasan/common.c:518 kasan_kmalloc include/linux/kasan.h:254 [inline] kmem_cache_alloc_trace+0x179/0x2e0 mm/slub.c:2979 kmalloc include/linux/slab.h:555 [inline] kzalloc include/linux/slab.h:667 [inline] gs_port_alloc drivers/usb/gadget/function/u_serial.c:1162 [inline] gserial_alloc_line_no_console+0x238/0x700 drivers/usb/gadget/function/u_serial.c:1242 obex_alloc_inst+0x86/0xe0 drivers/usb/gadget/function/f_obex.c:435 try_get_usb_function_instance drivers/usb/gadget/functions.c:28 [inline] usb_get_function_instance+0xe2/0x2f0 drivers/usb/gadget/functions.c:44 function_make+0x118/0x350 drivers/usb/gadget/configfs.c:636 configfs_mkdir+0x5d2/0xd90 fs/configfs/dir.c:1382 vfs_mkdir+0x42c/0x600 fs/namei.c:3798 do_mkdirat+0x14c/0x340 fs/namei.c:3820 __do_sys_mkdirat fs/namei.c:3831 [inline] __se_sys_mkdirat fs/namei.c:3829 [inline] __x64_sys_mkdirat+0x7b/0x90 fs/namei.c:3829 do_syscall_64+0x31/0x40 arch/x86/entry/common.c:46 entry_SYSCALL_64_after_hwframe+0x61/0xcb Freed by task 425: kasan_save_stack mm/kasan/common.c:38 [inline] kasan_set_track+0x4a/0x70 mm/kasan/common.c:45 kasan_set_free_info+0x23/0x40 mm/kasan/generic.c:370 ____kasan_slab_free+0x125/0x160 mm/kasan/common.c:362 __kasan_slab_free+0x11/0x20 mm/kasan/common.c:370 kasan_slab_free include/linux/kasan.h:220 [inline] slab_free_hook mm/slub.c:1600 [inline] slab_free_freelist_hook+0xc5/0x190 mm/slub.c:1626 slab_free mm/slub.c:3208 [inline] kfree+0xc0/0x270 mm/slub.c:4196 gserial_free_port+0x240/0x2d0 drivers/usb/gadget/function/u_serial.c:1206 gserial_free_line+0x9f/0x1b0 drivers/usb/gadget/function/u_serial.c:1223 obex_free_inst+0x39/0x60 drivers/usb/gadget/function/f_obex.c:421 usb_put_function_instance+0x85/0xa0 drivers/usb/gadget/functions.c:77 obex_attr_release+0x15/0x20 drivers/usb/gadget/function/f_obex.c:391 config_item_cleanup fs/configfs/item.c:130 [inline] config_item_release fs/configfs/item.c:139 [inline] kref_put include/linux/kref.h:65 [inline] config_item_put+0x158/0x210 fs/configfs/item.c:151 configfs_rmdir+0x89f/0x960 fs/configfs/dir.c:1608 vfs_rmdir+0x1ab/0x3c0 fs/namei.c:3860 do_rmdir+0x232/0x630 fs/namei.c:3920 __do_sys_rmdir fs/namei.c:3938 [inline] __se_sys_rmdir fs/namei.c:3936 [inline] __x64_sys_rmdir+0x49/0x50 fs/namei.c:3936 do_syscall_64+0x31/0x40 arch/x86/entry/common.c:46 entry_SYSCALL_64_after_hwframe+0x61/0xcb The buggy address belongs to the object at ffff88810dea4800 which belongs to the cache kmalloc-1k of size 1024 The buggy address is located 272 bytes inside of 1024-byte region [ffff88810dea4800, ffff88810dea4c00) The buggy address belongs to the page: page:ffffea000437a800 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x10dea0 head:ffffea000437a800 order:3 compound_mapcount:0 compound_pincount:0 flags: 0x4000000000010200(slab|head) raw: 4000000000010200 dead000000000100 dead000000000122 ffff888100042f00 raw: 0000000000000000 0000000000100010 00000001ffffffff 0000000000000000 page dumped because: kasan: bad access detected page_owner tracks the page as allocated page last allocated via order 3, migratetype Unmovable, gfp_mask 0xd20c0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 294, ts 23990358534, free_ts 23636176411 set_page_owner include/linux/page_owner.h:35 [inline] post_alloc_hook mm/page_alloc.c:2456 [inline] prep_new_page+0x176/0x190 mm/page_alloc.c:2462 get_page_from_freelist+0x225f/0x23f0 mm/page_alloc.c:4254 __alloc_pages_nodemask+0x29a/0x640 mm/page_alloc.c:5384 alloc_slab_page mm/slub.c:-1 [inline] allocate_slab mm/slub.c:1813 [inline] new_slab+0x84/0x3f0 mm/slub.c:1874 new_slab_objects mm/slub.c:2632 [inline] ___slab_alloc+0x2f8/0x4c0 mm/slub.c:2796 __slab_alloc+0x63/0xa0 mm/slub.c:2836 slab_alloc_node mm/slub.c:2918 [inline] slab_alloc mm/slub.c:2960 [inline] __kmalloc_track_caller+0x1e4/0x310 mm/slub.c:4541 __kmalloc_reserve net/core/skbuff.c:144 [inline] __alloc_skb+0xdc/0x520 net/core/skbuff.c:212 alloc_skb_fclone include/linux/skbuff.h:1176 [inline] sk_stream_alloc_skb+0x216/0xb70 net/ipv4/tcp.c:887 tcp_sendmsg_locked+0xc92/0x34e0 net/ipv4/tcp.c:1295 tcp_sendmsg+0x2f/0x50 net/ipv4/tcp.c:1447 inet_sendmsg+0xa5/0xc0 net/ipv4/af_inet.c:830 sock_sendmsg_nosec net/socket.c:652 [inline] __sock_sendmsg net/socket.c:664 [inline] sock_write_iter+0x2a6/0x3a0 net/socket.c:1019 call_write_iter include/linux/fs.h:2066 [inline] new_sync_write fs/read_write.c:518 [inline] vfs_write+0x770/0xd70 fs/read_write.c:605 ksys_write+0x14a/0x260 fs/read_write.c:658 __do_sys_write fs/read_write.c:670 [inline] __se_sys_write fs/read_write.c:667 [inline] __x64_sys_write+0x7b/0x90 fs/read_write.c:667 page last free stack trace: reset_page_owner include/linux/page_owner.h:28 [inline] free_pages_prepare mm/page_alloc.c:1349 [inline] __free_pages_ok+0x80b/0x830 mm/page_alloc.c:1629 free_compound_page+0x73/0x90 mm/page_alloc.c:710 destroy_compound_page include/linux/mm.h:970 [inline] __put_compound_page+0x77/0xb0 mm/swap.c:117 __put_page+0xbd/0xe0 mm/swap.c:133 put_page include/linux/mm.h:1268 [inline] __skb_frag_unref include/linux/skbuff.h:3124 [inline] skb_release_data+0x221/0x690 net/core/skbuff.c:620 skb_release_all net/core/skbuff.c:680 [inline] __kfree_skb+0x50/0x70 net/core/skbuff.c:694 sk_wmem_free_skb include/net/sock.h:1623 [inline] tcp_rtx_queue_unlink_and_free+0x205/0x740 include/net/tcp.h:1890 tcp_clean_rtx_queue net/ipv4/tcp_input.c:3367 [inline] tcp_ack+0x2198/0x5ec0 net/ipv4/tcp_input.c:3924 tcp_rcv_established+0xd35/0x19c0 net/ipv4/tcp_input.c:5921 tcp_v4_do_rcv+0x3e4/0x7c0 net/ipv4/tcp_ipv4.c:1699 tcp_v4_rcv+0x2295/0x2810 net/ipv4/tcp_ipv4.c:2095 ip_protocol_deliver_rcu+0x302/0x650 net/ipv4/ip_input.c:204 ip_local_deliver_finish net/ipv4/ip_input.c:231 [inline] NF_HOOK include/linux/netfilter.h:299 [inline] ip_local_deliver+0x2dd/0x530 net/ipv4/ip_input.c:252 dst_input include/net/dst.h:461 [inline] ip_rcv_finish net/ipv4/ip_input.c:436 [inline] NF_HOOK include/linux/netfilter.h:299 [inline] ip_rcv+0x156/0x290 net/ipv4/ip_input.c:547 __netif_receive_skb_one_core net/core/dev.c:5413 [inline] __netif_receive_skb+0xc8/0x280 net/core/dev.c:5527 process_backlog+0x351/0x600 net/core/dev.c:6434 Memory state around the buggy address: ffff88810dea4800: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88810dea4880: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff88810dea4900: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff88810dea4980: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88810dea4a00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ================================================================== ------------[ cut here ]------------ WARNING: CPU: 1 PID: 422 at drivers/usb/gadget/function/u_serial.c:690 gs_close+0x17d/0x9a0 drivers/usb/gadget/function/u_serial.c:690 Modules linked in: CPU: 1 PID: 422 Comm: syz.5.18 Tainted: G B W syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026 RIP: 0010:gs_close+0x17d/0x9a0 drivers/usb/gadget/function/u_serial.c:690 Code: 7d 56 fe 41 ff cc 42 0f b6 04 2b 84 c0 0f 85 c1 06 00 00 48 8b 44 24 20 44 89 20 48 8b 5c 24 38 e9 bd 02 00 00 e8 33 7d 56 fe <0f> 0b 48 8b 5c 24 38 e9 ac 02 00 00 e8 22 7d 56 fe 49 8d bf 90 02 RSP: 0018:ffffc90000c57b40 EFLAGS: 00010093 RAX: ffffffff830e348d RBX: 1ffff11021bd491a RCX: ffff88812d4da780 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000 RBP: ffffc90000c57c58 R08: 0000000000000003 R09: 0000000000000004 R10: dffffc0000000000 R11: fffff5200018af58 R12: 0000000000000000 R13: dffffc0000000000 R14: 1ffff9200018af70 R15: ffff88810dea4800 FS: 000055555b8a0500(0000) GS:ffff8881f7100000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000031a861b8 CR3: 000000010d70c000 CR4: 00000000003506a0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: tty_release+0x3c8/0x1330 drivers/tty/tty_io.c:1764 __fput+0x2dc/0x730 fs/file_table.c:281 ____fput+0x15/0x20 fs/file_table.c:314 task_work_run+0x127/0x190 kernel/task_work.c:189 ptrace_notify+0x230/0x270 kernel/signal.c:2289 ptrace_report_syscall include/linux/tracehook.h:66 [inline] tracehook_report_syscall_exit include/linux/tracehook.h:129 [inline] arch_syscall_exit_tracehook include/linux/entry-common.h:285 [inline] syscall_exit_work+0x6e/0x140 kernel/entry/common.c:239 syscall_exit_to_user_mode_prepare kernel/entry/common.c:266 [inline] syscall_exit_to_user_mode+0x2f/0x40 kernel/entry/common.c:272 do_syscall_64+0x3d/0x40 arch/x86/entry/common.c:56 entry_SYSCALL_64_after_hwframe+0x61/0xcb RIP: 0033:0x7f8795c0d0d9 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:00007ffc35640e68 EFLAGS: 00000246 ORIG_RAX: 00000000000001b4 RAX: 0000000000000000 RBX: 00007f8795e96da0 RCX: 00007f8795c0d0d9 RDX: 0000000000000000 RSI: 000000000000001e RDI: 0000000000000003 RBP: 00007f8795e96da0 R08: 00007f8795e95038 R09: 0000000000000000 R10: 000000000003fda0 R11: 0000000000000246 R12: 00000000000079dc R13: 00007f8795e94fac R14: 00000000000076d5 R15: 00007ffc35640f70 ---[ end trace 00411192d99abdaf ]---