================================================================== BUG: KASAN: use-after-free in ax25_fillin_cb_from_dev net/ax25/af_ax25.c:468 [inline] BUG: KASAN: use-after-free in ax25_fillin_cb+0x459/0x640 net/ax25/af_ax25.c:495 Read of size 4 at addr ffff888020916938 by task syz.0.707/7085 CPU: 1 PID: 7085 Comm: syz.0.707 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026 Call Trace: dump_stack_lvl+0x188/0x250 lib/dump_stack.c:106 print_address_description+0x60/0x2d0 mm/kasan/report.c:248 __kasan_report mm/kasan/report.c:434 [inline] kasan_report+0xdf/0x130 mm/kasan/report.c:451 ax25_fillin_cb_from_dev net/ax25/af_ax25.c:468 [inline] ax25_fillin_cb+0x459/0x640 net/ax25/af_ax25.c:495 ax25_setsockopt+0x8c9/0xa60 net/ax25/af_ax25.c:690 __sys_setsockopt+0x2bf/0x3d0 net/socket.c:2212 __do_sys_setsockopt net/socket.c:2223 [inline] __se_sys_setsockopt net/socket.c:2220 [inline] __x64_sys_setsockopt+0xb1/0xc0 net/socket.c:2220 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: 0033:0x7fba8fd3d799 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:00007fba8df76028 EFLAGS: 00000246 ORIG_RAX: 0000000000000036 RAX: ffffffffffffffda RBX: 00007fba8ffb7090 RCX: 00007fba8fd3d799 RDX: 0000000000000019 RSI: 0000000000000101 RDI: 0000000000000009 RBP: 00007fba8fdd3bd9 R08: 0000000000000010 R09: 0000000000000000 R10: 0000200000000240 R11: 0000000000000246 R12: 0000000000000000 R13: 00007fba8ffb7128 R14: 00007fba8ffb7090 R15: 00007ffc83f4cc18 Allocated by task 7030: kasan_save_stack mm/kasan/common.c:38 [inline] kasan_set_track mm/kasan/common.c:46 [inline] set_alloc_info mm/kasan/common.c:434 [inline] ____kasan_kmalloc mm/kasan/common.c:513 [inline] __kasan_kmalloc+0xb5/0xf0 mm/kasan/common.c:522 kmalloc include/linux/slab.h:607 [inline] kzalloc include/linux/slab.h:738 [inline] loopback_open+0x11d/0xa20 sound/drivers/aloop.c:1193 snd_pcm_open_substream+0x10e3/0x23a0 sound/core/pcm_native.c:2759 snd_pcm_oss_open_file sound/core/oss/pcm_oss.c:2453 [inline] snd_pcm_oss_open+0x1075/0x1e60 sound/core/oss/pcm_oss.c:2534 chrdev_open+0x5c5/0x6a0 fs/char_dev.c:414 do_dentry_open+0x7ff/0xf80 fs/open.c:826 do_open fs/namei.c:3616 [inline] path_openat+0x26f5/0x2fa0 fs/namei.c:3750 do_filp_open+0x1e2/0x410 fs/namei.c:3777 do_sys_openat2+0x150/0x4b0 fs/open.c:1255 do_sys_open fs/open.c:1271 [inline] __do_sys_openat fs/open.c:1287 [inline] __se_sys_openat fs/open.c:1282 [inline] __x64_sys_openat+0x135/0x160 fs/open.c:1282 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 7027: kasan_save_stack mm/kasan/common.c:38 [inline] kasan_set_track+0x4b/0x70 mm/kasan/common.c:46 kasan_set_free_info+0x1f/0x40 mm/kasan/generic.c:360 ____kasan_slab_free+0xd5/0x110 mm/kasan/common.c:366 kasan_slab_free include/linux/kasan.h:230 [inline] slab_free_hook mm/slub.c:1710 [inline] slab_free_freelist_hook+0xea/0x170 mm/slub.c:1736 slab_free mm/slub.c:3504 [inline] kfree+0xef/0x2a0 mm/slub.c:4564 snd_pcm_detach_substream+0x81/0x270 sound/core/pcm.c:994 snd_pcm_oss_release_file sound/core/oss/pcm_oss.c:2412 [inline] snd_pcm_oss_release+0x180/0x240 sound/core/oss/pcm_oss.c:2591 __fput+0x234/0x930 fs/file_table.c:311 task_work_run+0x125/0x1a0 kernel/task_work.c:188 tracehook_notify_resume include/linux/tracehook.h:189 [inline] exit_to_user_mode_loop+0x10f/0x130 kernel/entry/common.c:181 exit_to_user_mode_prepare+0xee/0x180 kernel/entry/common.c:214 __syscall_exit_to_user_mode_work kernel/entry/common.c:296 [inline] syscall_exit_to_user_mode+0x16/0x40 kernel/entry/common.c:307 do_syscall_64+0x58/0xa0 arch/x86/entry/common.c:86 entry_SYSCALL_64_after_hwframe+0x66/0xd0 Last potentially related work creation: kasan_save_stack+0x35/0x60 mm/kasan/common.c:38 kasan_record_aux_stack+0xb8/0x100 mm/kasan/generic.c:348 insert_work+0x54/0x3d0 kernel/workqueue.c:1366 __queue_work+0x9c5/0xd50 kernel/workqueue.c:1532 queue_work_on+0x124/0x1f0 kernel/workqueue.c:1559 queue_work include/linux/workqueue.h:512 [inline] netdevice_queue_work drivers/infiniband/core/roce_gid_mgmt.c:659 [inline] netdevice_event+0x803/0x900 drivers/infiniband/core/roce_gid_mgmt.c:802 notifier_call_chain kernel/notifier.c:83 [inline] raw_notifier_call_chain+0xcb/0x160 kernel/notifier.c:391 call_netdevice_notifiers_extack net/core/dev.c:2074 [inline] call_netdevice_notifiers net/core/dev.c:2088 [inline] register_netdevice+0x12a6/0x1710 net/core/dev.c:10441 macsec_newlink+0x686/0x10f0 drivers/net/macsec.c:4093 __rtnl_newlink net/core/rtnetlink.c:3526 [inline] rtnl_newlink+0x1359/0x1a50 net/core/rtnetlink.c:3574 rtnetlink_rcv_msg+0x844/0xf30 net/core/rtnetlink.c:5684 netlink_rcv_skb+0x1f5/0x440 net/netlink/af_netlink.c:2507 netlink_unicast_kernel net/netlink/af_netlink.c:1318 [inline] netlink_unicast+0x774/0x920 net/netlink/af_netlink.c:1344 netlink_sendmsg+0x8ba/0xbe0 net/netlink/af_netlink.c:1918 sock_sendmsg_nosec net/socket.c:706 [inline] __sock_sendmsg net/socket.c:718 [inline] __sys_sendto+0x46d/0x620 net/socket.c:2072 __do_sys_sendto net/socket.c:2084 [inline] __se_sys_sendto net/socket.c:2080 [inline] __x64_sys_sendto+0xda/0xf0 net/socket.c:2080 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 Second to last potentially related work creation: kasan_save_stack+0x35/0x60 mm/kasan/common.c:38 kasan_record_aux_stack+0xb8/0x100 mm/kasan/generic.c:348 insert_work+0x54/0x3d0 kernel/workqueue.c:1366 __queue_work+0x9c5/0xd50 kernel/workqueue.c:1532 queue_work_on+0x124/0x1f0 kernel/workqueue.c:1559 queue_work include/linux/workqueue.h:512 [inline] netdevice_queue_work drivers/infiniband/core/roce_gid_mgmt.c:659 [inline] netdevice_event+0x803/0x900 drivers/infiniband/core/roce_gid_mgmt.c:802 notifier_call_chain kernel/notifier.c:83 [inline] raw_notifier_call_chain+0xcb/0x160 kernel/notifier.c:391 __netdev_upper_dev_link+0x41e/0x590 net/core/dev.c:8212 netdev_master_upper_dev_link+0xb9/0x100 net/core/dev.c:8282 team_upper_dev_link drivers/net/team/team.c:1116 [inline] team_port_add drivers/net/team/team.c:1254 [inline] team_add_slave+0xa3f/0x2780 drivers/net/team/team.c:1997 do_set_master net/core/rtnetlink.c:2577 [inline] do_setlink+0xe90/0x3d60 net/core/rtnetlink.c:2788 __rtnl_newlink net/core/rtnetlink.c:3452 [inline] rtnl_newlink+0x1658/0x1a50 net/core/rtnetlink.c:3574 rtnetlink_rcv_msg+0x844/0xf30 net/core/rtnetlink.c:5684 netlink_rcv_skb+0x1f5/0x440 net/netlink/af_netlink.c:2507 netlink_unicast_kernel net/netlink/af_netlink.c:1318 [inline] netlink_unicast+0x774/0x920 net/netlink/af_netlink.c:1344 netlink_sendmsg+0x8ba/0xbe0 net/netlink/af_netlink.c:1918 sock_sendmsg_nosec net/socket.c:706 [inline] __sock_sendmsg net/socket.c:718 [inline] __sys_sendto+0x46d/0x620 net/socket.c:2072 __do_sys_sendto net/socket.c:2084 [inline] __se_sys_sendto net/socket.c:2080 [inline] __x64_sys_sendto+0xda/0xf0 net/socket.c:2080 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 ffff888020916900 which belongs to the cache kmalloc-192 of size 192 The buggy address is located 56 bytes inside of 192-byte region [ffff888020916900, ffff8880209169c0) The buggy address belongs to the page: page:ffffea0000824580 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x20916 flags: 0xfff00000000200(slab|node=0|zone=1|lastcpupid=0x7ff) raw: 00fff00000000200 ffffea00007e2ac0 0000000200000002 ffff888016c41a00 raw: 0000000000000000 0000000000100010 00000001ffffffff 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 0x12cc0(GFP_KERNEL|__GFP_NOWARN|__GFP_NORETRY), pid 1, ts 6974921730, free_ts 6055226744 prep_new_page mm/page_alloc.c:2426 [inline] get_page_from_freelist+0x1bbd/0x1ca0 mm/page_alloc.c:4192 __alloc_pages+0x1ee/0x480 mm/page_alloc.c:5487 alloc_page_interleave+0x24/0x1e0 mm/mempolicy.c:2031 alloc_slab_page mm/slub.c:1780 [inline] allocate_slab mm/slub.c:1917 [inline] new_slab+0xc0/0x4b0 mm/slub.c:1980 ___slab_alloc+0x80a/0xdd0 mm/slub.c:3013 __slab_alloc mm/slub.c:3100 [inline] slab_alloc_node mm/slub.c:3191 [inline] slab_alloc mm/slub.c:3233 [inline] kmem_cache_alloc_trace+0x1a5/0x2a0 mm/slub.c:3250 kmalloc include/linux/slab.h:607 [inline] kzalloc include/linux/slab.h:738 [inline] call_usermodehelper_setup+0x8a/0x260 kernel/umh.c:365 kobject_uevent_env+0x65e/0x890 lib/kobject_uevent.c:629 driver_register+0x3e2/0x430 drivers/base/driver.c:248 usb_register_driver+0x202/0x3d0 drivers/usb/core/driver.c:1061 do_one_initcall+0x272/0x730 init/main.c:1316 do_initcall_level+0x137/0x1f0 init/main.c:1389 do_initcalls+0x4b/0x90 init/main.c:1405 kernel_init_freeable+0x3e9/0x570 init/main.c:1629 kernel_init+0x19/0x1b0 init/main.c:1520 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287 page last free stack trace: reset_page_owner include/linux/page_owner.h:24 [inline] free_pages_prepare mm/page_alloc.c:1340 [inline] free_pcp_prepare mm/page_alloc.c:1391 [inline] free_unref_page_prepare+0x637/0x6c0 mm/page_alloc.c:3317 free_unref_page+0x8f/0x2a0 mm/page_alloc.c:3396 mm_free_pgd kernel/fork.c:653 [inline] __mmdrop+0xaa/0x3e0 kernel/fork.c:704 free_bprm+0x141/0x300 fs/exec.c:1494 kernel_execve+0x380/0x900 fs/exec.c:2015 call_usermodehelper_exec_async+0x207/0x350 kernel/umh.c:112 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287 Memory state around the buggy address: ffff888020916800: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ffff888020916880: 00 00 00 fc fc fc fc fc fc fc fc fc fc fc fc fc >ffff888020916900: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff888020916980: fb fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc ffff888020916a00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ==================================================================