================================================================== 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_port.h:180 [inline] BUG: KASAN: use-after-free in tty_open_by_driver drivers/tty/tty_io.c:2079 [inline] BUG: KASAN: use-after-free in tty_open+0x823/0x1040 drivers/tty/tty_io.c:2148 Read of size 8 at addr ffff8881138f0110 by task syz.5.17/401 CPU: 1 PID: 401 Comm: syz.5.17 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026 Call Trace: __dump_stack+0x21/0x30 lib/dump_stack.c:88 dump_stack_lvl+0x110/0x170 lib/dump_stack.c:106 print_address_description+0x7f/0x2c0 mm/kasan/report.c:248 __kasan_report mm/kasan/report.c:427 [inline] kasan_report+0x10f/0x150 mm/kasan/report.c:444 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_port.h:180 [inline] tty_open_by_driver drivers/tty/tty_io.c:2079 [inline] tty_open+0x823/0x1040 drivers/tty/tty_io.c:2148 chrdev_open+0x585/0x5f0 fs/char_dev.c:414 do_dentry_open+0x82a/0x1010 fs/open.c:828 vfs_open+0x73/0x80 fs/open.c:960 do_open fs/namei.c:3616 [inline] path_openat+0x26e6/0x2f80 fs/namei.c:3750 do_filp_open+0x1df/0x400 fs/namei.c:3777 do_sys_openat2+0x15e/0x7f0 fs/open.c:1236 do_sys_open fs/open.c:1252 [inline] __do_sys_openat fs/open.c:1268 [inline] __se_sys_openat fs/open.c:1263 [inline] __x64_sys_openat+0x136/0x160 fs/open.c:1263 x64_sys_call+0x219/0x9a0 arch/x86/include/generated/asm/syscalls_64.h:258 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x66/0xd0 RIP: 0033:0x7fa9cab840d9 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:00007fa9ca9e5028 EFLAGS: 00000246 ORIG_RAX: 0000000000000101 RAX: ffffffffffffffda RBX: 00007fa9cae0bfa0 RCX: 00007fa9cab840d9 RDX: 0000000000000002 RSI: 0000200000000800 RDI: ffffffffffffff9c RBP: 00007fa9cac1b024 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007fa9cae0c038 R14: 00007fa9cae0bfa0 R15: 00007ffe67d253d8 Allocated by task 395: 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:433 [inline] ____kasan_kmalloc mm/kasan/common.c:512 [inline] __kasan_kmalloc+0xd4/0x100 mm/kasan/common.c:521 kasan_kmalloc include/linux/kasan.h:227 [inline] kmem_cache_alloc_trace+0x119/0x270 mm/slub.c:3274 kmalloc include/linux/slab.h:619 [inline] kzalloc include/linux/slab.h:750 [inline] gs_port_alloc drivers/usb/gadget/function/u_serial.c:1158 [inline] gserial_alloc_line_no_console+0x238/0x700 drivers/usb/gadget/function/u_serial.c:1238 gserial_alloc_line+0x15/0x20 drivers/usb/gadget/function/u_serial.c:1272 acm_alloc_instance+0x86/0xe0 drivers/usb/gadget/function/f_acm.c:845 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:642 configfs_mkdir+0x50a/0x9c0 fs/configfs/dir.c:1329 vfs_mkdir+0x38b/0x590 fs/namei.c:4073 do_mkdirat+0x174/0x4d0 fs/namei.c:4098 __do_sys_mkdirat fs/namei.c:4113 [inline] __se_sys_mkdirat fs/namei.c:4111 [inline] __x64_sys_mkdirat+0x89/0xa0 fs/namei.c:4111 x64_sys_call+0x37e/0x9a0 arch/x86/include/generated/asm/syscalls_64.h:259 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x66/0xd0 Freed by task 395: 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:365 __kasan_slab_free+0x11/0x20 mm/kasan/common.c:373 kasan_slab_free include/linux/kasan.h:193 [inline] slab_free_hook mm/slub.c:1728 [inline] slab_free_freelist_hook+0xc2/0x190 mm/slub.c:1754 slab_free mm/slub.c:3526 [inline] kfree+0xc4/0x270 mm/slub.c:4588 gserial_free_port+0x245/0x2e0 drivers/usb/gadget/function/u_serial.c:1202 gserial_free_line+0x9b/0x1a0 drivers/usb/gadget/function/u_serial.c:1219 acm_free_instance+0x39/0x60 drivers/usb/gadget/function/f_acm.c:832 usb_put_function_instance+0x85/0xa0 drivers/usb/gadget/functions.c:77 acm_attr_release+0x15/0x20 drivers/usb/gadget/function/f_acm.c:781 config_item_cleanup fs/configfs/item.c:128 [inline] config_item_release fs/configfs/item.c:137 [inline] kref_put include/linux/kref.h:65 [inline] config_item_put+0x158/0x210 fs/configfs/item.c:149 configfs_rmdir+0x89f/0x960 fs/configfs/dir.c:1540 vfs_rmdir+0x1ae/0x450 fs/namei.c:4157 do_rmdir+0x261/0x6b0 fs/namei.c:4218 __do_sys_rmdir fs/namei.c:4237 [inline] __se_sys_rmdir fs/namei.c:4235 [inline] __x64_sys_rmdir+0x49/0x50 fs/namei.c:4235 x64_sys_call+0x25f/0x9a0 arch/x86/include/generated/asm/syscalls_64.h:85 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x66/0xd0 The buggy address belongs to the object at ffff8881138f0000 which belongs to the cache kmalloc-1k of size 1024 The buggy address is located 272 bytes inside of 1024-byte region [ffff8881138f0000, ffff8881138f0400) The buggy address belongs to the page: page:ffffea00044e3c00 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x1138f0 head:ffffea00044e3c00 order:3 compound_mapcount:0 compound_pincount:0 flags: 0x4000000000010200(slab|head|zone=1) raw: 4000000000010200 0000000000000000 0000000100000001 ffff888100043080 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 101, ts 4924100586, free_ts 0 set_page_owner include/linux/page_owner.h:33 [inline] post_alloc_hook+0x192/0x1b0 mm/page_alloc.c:2607 prep_new_page+0x1c/0x110 mm/page_alloc.c:2613 get_page_from_freelist+0x2c3a/0x2cd0 mm/page_alloc.c:4487 __alloc_pages+0x1a2/0x460 mm/page_alloc.c:5824 alloc_slab_page mm/slub.c:-1 [inline] allocate_slab mm/slub.c:1937 [inline] new_slab+0xa0/0x4d0 mm/slub.c:2000 ___slab_alloc+0x3ac/0x840 mm/slub.c:3033 __slab_alloc+0x49/0x90 mm/slub.c:3120 slab_alloc_node mm/slub.c:3211 [inline] slab_alloc mm/slub.c:3255 [inline] __kmalloc_track_caller+0x169/0x2c0 mm/slub.c:4954 kmalloc_reserve net/core/skbuff.c:357 [inline] __alloc_skb+0x210/0x730 net/core/skbuff.c:428 alloc_skb include/linux/skbuff.h:1183 [inline] netlink_alloc_large_skb net/netlink/af_netlink.c:1186 [inline] netlink_sendmsg+0x611/0xb80 net/netlink/af_netlink.c:1902 sock_sendmsg_nosec net/socket.c:704 [inline] __sock_sendmsg net/socket.c:716 [inline] ____sys_sendmsg+0x5be/0x8f0 net/socket.c:2436 ___sys_sendmsg+0x236/0x2e0 net/socket.c:2490 __sys_sendmsg net/socket.c:2519 [inline] __do_sys_sendmsg net/socket.c:2528 [inline] __se_sys_sendmsg net/socket.c:2526 [inline] __x64_sys_sendmsg+0x201/0x2d0 net/socket.c:2526 x64_sys_call+0x4b/0x9a0 arch/x86/include/generated/asm/syscalls_64.h:47 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x66/0xd0 page_owner free stack trace missing Memory state around the buggy address: ffff8881138f0000: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff8881138f0080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff8881138f0100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff8881138f0180: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff8881138f0200: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ==================================================================