KASAN: use-after-free Read in ax25_find

Kernel	Title	Rank 🛈	Repro	Cause bisect	Fix bisect	Count	Last	Reported	Patched	Status
linux-6.1	KASAN: use-after-free Read in ax25_find_cb origin:upstream	19	syz		error	1	79d	79d	0/3	upstream: reported syz repro on 2025/11/09 13:50
upstream	KASAN: slab-use-after-free Read in ax25_find_cb hams	19	C	error		8	1d00h	96d	0/29	upstream: reported C repro on 2025/10/23 12:13
linux-6.6	KASAN: slab-use-after-free Read in ax25_find_cb origin:upstream	19	C			1	16d	51d	0/2	upstream: reported C repro on 2025/12/08 04:33

================================================================== BUG: KASAN: use-after-free in ax25_find_cb+0x175/0x3a0 net/ax25/af_ax25.c:232 Read of size 8 at addr ffff88801b3b7b08 by task syz.2.694/6721 CPU: 0 PID: 6721 Comm: syz.2.694 Not tainted 5.15.189-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025 Call Trace: <TASK> dump_stack_lvl+0x168/0x230 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_find_cb+0x175/0x3a0 net/ax25/af_ax25.c:232 rose_link_up net/rose/rose_link.c:129 [inline] rose_transmit_link+0x169/0x730 net/rose/rose_link.c:271 rose_write_internal+0x673/0x1e80 net/rose/rose_subr.c:198 rose_release+0x22a/0x4e0 net/rose/af_rose.c:670 __sock_release net/socket.c:649 [inline] sock_close+0xd5/0x240 net/socket.c:1336 __fput+0x234/0x930 fs/file_table.c:311 task_work_run+0x125/0x1a0 kernel/task_work.c:188 get_signal+0x1222/0x12c0 kernel/signal.c:2672 arch_do_signal_or_restart+0xc1/0x1300 arch/x86/kernel/signal.c:867 handle_signal_work kernel/entry/common.c:154 [inline] exit_to_user_mode_loop+0x9e/0x130 kernel/entry/common.c:178 exit_to_user_mode_prepare+0xb1/0x140 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 RIP: 0033:0x7fe2095cabe9 Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 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 a8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007fe207832038 EFLAGS: 00000246 ORIG_RAX: 000000000000002a RAX: fffffffffffffe00 RBX: 00007fe2097f1fa0 RCX: 00007fe2095cabe9 RDX: 0000000000000040 RSI: 0000200000000100 RDI: 0000000000000010 RBP: 00007fe20964de19 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007fe2097f2038 R14: 00007fe2097f1fa0 R15: 00007fff3ba91918 </TASK> Allocated by task 4458: 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:604 [inline] kzalloc include/linux/slab.h:735 [inline] ax25_dev_device_up+0x50/0x580 net/ax25/ax25_dev.c:55 ax25_device_event+0x483/0x4f0 net/ax25/af_ax25.c:139 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:2061 [inline] call_netdevice_notifiers net/core/dev.c:2075 [inline] __dev_notify_flags+0x178/0x2d0 net/core/dev.c:-1 dev_change_flags+0xe3/0x1a0 net/core/dev.c:8929 dev_ifsioc+0x147/0xe70 net/core/dev_ioctl.c:324 dev_ioctl+0x55f/0xe50 net/core/dev_ioctl.c:587 sock_do_ioctl+0x222/0x2f0 net/socket.c:1154 sock_ioctl+0x4ed/0x6e0 net/socket.c:1257 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:874 [inline] __se_sys_ioctl+0xfa/0x170 fs/ioctl.c:860 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 6738: 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:1705 [inline] slab_free_freelist_hook+0xea/0x170 mm/slub.c:1731 slab_free mm/slub.c:3499 [inline] kfree+0xef/0x2a0 mm/slub.c:4559 ax25_dev_put include/net/ax25.h:302 [inline] ax25_release+0x661/0x870 net/ax25/af_ax25.c:1062 __sock_release net/socket.c:649 [inline] sock_close+0xd5/0x240 net/socket.c:1336 __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+0xb1/0x140 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+0x11d/0x1d0 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:2061 [inline] call_netdevice_notifiers net/core/dev.c:2075 [inline] register_netdevice+0x1275/0x16b0 net/core/dev.c:10428 __ip_tunnel_create+0x2bf/0x380 net/ipv4/ip_tunnel.c:267 ip_tunnel_init_net+0x232/0x6b0 net/ipv4/ip_tunnel.c:1098 ops_init+0x357/0x600 net/core/net_namespace.c:138 setup_net+0x38d/0x9f0 net/core/net_namespace.c:333 copy_net_ns+0x348/0x5b0 net/core/net_namespace.c:503 create_new_namespaces+0x3d3/0x6f0 kernel/nsproxy.c:110 unshare_nsproxy_namespaces+0x116/0x160 kernel/nsproxy.c:226 ksys_unshare+0x4bc/0x890 kernel/fork.c:3175 __do_sys_unshare kernel/fork.c:3249 [inline] __se_sys_unshare kernel/fork.c:3247 [inline] __x64_sys_unshare+0x34/0x40 kernel/fork.c:3247 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 ffff88801b3b7b00 which belongs to the cache kmalloc-192 of size 192 The buggy address is located 8 bytes inside of 192-byte region [ffff88801b3b7b00, ffff88801b3b7bc0) The buggy address belongs to the page: page:ffffea00006cedc0 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x1b3b7 flags: 0xfff00000000200(slab|node=0|zone=1|lastcpupid=0x7ff) raw: 00fff00000000200 ffffea00008f9bc0 0000000400000004 ffff888016841a00 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 2596020273, free_ts 0 prep_new_page mm/page_alloc.c:2426 [inline] get_page_from_freelist+0x1b77/0x1c60 mm/page_alloc.c:4192 __alloc_pages+0x1e1/0x470 mm/page_alloc.c:5474 alloc_page_interleave+0x24/0x1e0 mm/mempolicy.c:2031 alloc_slab_page mm/slub.c:1775 [inline] allocate_slab mm/slub.c:1912 [inline] new_slab+0xc0/0x4b0 mm/slub.c:1975 ___slab_alloc+0x81e/0xdf0 mm/slub.c:3008 __slab_alloc mm/slub.c:3095 [inline] slab_alloc_node mm/slub.c:3186 [inline] slab_alloc mm/slub.c:3228 [inline] kmem_cache_alloc_trace+0x1a5/0x2a0 mm/slub.c:3245 kmalloc include/linux/slab.h:604 [inline] kzalloc include/linux/slab.h:735 [inline] kset_create lib/kobject.c:982 [inline] kset_create_and_add+0x56/0x160 lib/kobject.c:1025 bus_register+0x363/0x6c0 drivers/base/bus.c:816 subsys_register+0x20/0x1c0 drivers/base/bus.c:1089 container_dev_init+0x14/0x50 drivers/base/container.c:38 do_basic_setup+0x14/0x80 init/main.c:1407 kernel_init_freeable+0x3ce/0x560 init/main.c:1615 kernel_init+0x19/0x1b0 init/main.c:1506 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287 page_owner free stack trace missing Memory state around the buggy address: ffff88801b3b7a00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ffff88801b3b7a80: 00 00 00 fc fc fc fc fc fc fc fc fc fc fc fc fc >ffff88801b3b7b00: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff88801b3b7b80: fb fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc ffff88801b3b7c00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ==================================================================

Crashes (3):
Time	Kernel	Commit	Syzkaller	Config	Log	Report	VM info	Assets (help?)	Manager	Title
2025/08/22 02:07	linux-5.15.y	c79648372d02	3e79b825	.config	console log	report	info	[disk image] [vmlinux] [kernel image]	ci2-linux-5-15-kasan	KASAN: use-after-free Read in ax25_find_cb
2025/07/23 00:58	linux-5.15.y	c79648372d02	8e9d1dc1	.config	console log	report	info	[disk image] [vmlinux] [kernel image]	ci2-linux-5-15-kasan-arm64	KASAN: use-after-free Read in ax25_find_cb
2025/07/23 00:34	linux-5.15.y	c79648372d02	8e9d1dc1	.config	console log	report	info	[disk image] [vmlinux] [kernel image]	ci2-linux-5-15-kasan-arm64	KASAN: use-after-free Read in ax25_find_cb

Crashes (3):

Assets (help?)