syzbot


KASAN: slab-use-after-free Read in ax25_release

Status: upstream: reported on 2024/12/30 01:55
Subsystems: hams
[Documentation on labels]
Reported-by: syzbot+a5716c7fb89dcd7205d8@syzkaller.appspotmail.com
First crash: 242d, last: 21d
Discussions (2)
Title Replies (including bot) Last reply
[syzbot] Monthly hams report (Jan 2025) 0 (1) 2025/01/16 10:12
[syzbot] [hams?] KASAN: slab-use-after-free Read in ax25_release 0 (1) 2024/12/30 01:55

Sample crash report:
==================================================================
BUG: KASAN: slab-use-after-free in ax25_release+0x87d/0x950 net/ax25/af_ax25.c:1062
Read of size 1 at addr ffff88803eeae8cc by task syz.0.0/5313

CPU: 0 UID: 0 PID: 5313 Comm: syz.0.0 Not tainted 6.13.0-rc7-syzkaller-00209-g9528d418de4d #0
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2~bpo12+1 04/01/2014
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:94 [inline]
 dump_stack_lvl+0x241/0x360 lib/dump_stack.c:120
 print_address_description mm/kasan/report.c:378 [inline]
 print_report+0x169/0x550 mm/kasan/report.c:489
 kasan_report+0x143/0x180 mm/kasan/report.c:602
 ax25_release+0x87d/0x950 net/ax25/af_ax25.c:1062
 __sock_release net/socket.c:640 [inline]
 sock_close+0xbc/0x240 net/socket.c:1408
 __fput+0x23c/0xa50 fs/file_table.c:450
 task_work_run+0x24f/0x310 kernel/task_work.c:239
 resume_user_mode_work include/linux/resume_user_mode.h:50 [inline]
 exit_to_user_mode_loop kernel/entry/common.c:114 [inline]
 exit_to_user_mode_prepare include/linux/entry-common.h:329 [inline]
 __syscall_exit_to_user_mode_work kernel/entry/common.c:207 [inline]
 syscall_exit_to_user_mode+0x13f/0x340 kernel/entry/common.c:218
 do_syscall_64+0x100/0x230 arch/x86/entry/common.c:89
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7efca3385d29
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:00007ffd2b6616c8 EFLAGS: 00000246 ORIG_RAX: 00000000000001b4
RAX: 0000000000000000 RBX: 00007efca3577ba0 RCX: 00007efca3385d29
RDX: 0000000000000000 RSI: 000000000000001e RDI: 0000000000000003
RBP: 00007efca3577ba0 R08: 0000000000000000 R09: 00007ffd2b6619bf
R10: 00007efca3577ac0 R11: 0000000000000246 R12: 00000000000119fa
R13: 00007efca3575fa0 R14: 0000000000000032 R15: ffffffffffffffff
 </TASK>

Allocated by task 5315:
 kasan_save_stack mm/kasan/common.c:47 [inline]
 kasan_save_track+0x3f/0x80 mm/kasan/common.c:68
 poison_kmalloc_redzone mm/kasan/common.c:377 [inline]
 __kasan_kmalloc+0x98/0xb0 mm/kasan/common.c:394
 kasan_kmalloc include/linux/kasan.h:260 [inline]
 __kmalloc_cache_noprof+0x243/0x390 mm/slub.c:4329
 kmalloc_noprof include/linux/slab.h:901 [inline]
 kzalloc_noprof include/linux/slab.h:1037 [inline]
 ax25_dev_device_up+0x58/0x620 net/ax25/ax25_dev.c:57
 ax25_device_event+0x4f3/0x580 net/ax25/af_ax25.c:143
 notifier_call_chain+0x1a5/0x3f0 kernel/notifier.c:85
 __dev_notify_flags+0x207/0x400
 dev_change_flags+0xf0/0x1a0 net/core/dev.c:9045
 dev_ifsioc+0x7c8/0xe70 net/core/dev_ioctl.c:526
 dev_ioctl+0x719/0x1340 net/core/dev_ioctl.c:783
 sock_do_ioctl+0x240/0x460 net/socket.c:1223
 sock_ioctl+0x626/0x8e0 net/socket.c:1328
 vfs_ioctl fs/ioctl.c:51 [inline]
 __do_sys_ioctl fs/ioctl.c:906 [inline]
 __se_sys_ioctl+0xf5/0x170 fs/ioctl.c:892
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

Freed by task 5314:
 kasan_save_stack mm/kasan/common.c:47 [inline]
 kasan_save_track+0x3f/0x80 mm/kasan/common.c:68
 kasan_save_free_info+0x40/0x50 mm/kasan/generic.c:582
 poison_slab_object mm/kasan/common.c:247 [inline]
 __kasan_slab_free+0x59/0x70 mm/kasan/common.c:264
 kasan_slab_free include/linux/kasan.h:233 [inline]
 slab_free_hook mm/slub.c:2353 [inline]
 slab_free mm/slub.c:4613 [inline]
 kfree+0x196/0x430 mm/slub.c:4761
 ax25_device_event+0x529/0x580 net/ax25/af_ax25.c:148
 notifier_call_chain+0x1a5/0x3f0 kernel/notifier.c:85
 call_netdevice_notifiers_extack net/core/dev.c:2064 [inline]
 call_netdevice_notifiers net/core/dev.c:2078 [inline]
 dev_close_many+0x33c/0x4c0 net/core/dev.c:1619
 dev_close+0x1c0/0x2c0 net/core/dev.c:1641
 bpq_device_event+0x372/0x8b0 drivers/net/hamradio/bpqether.c:547
 notifier_call_chain+0x1a5/0x3f0 kernel/notifier.c:85
 call_netdevice_notifiers_extack net/core/dev.c:2064 [inline]
 call_netdevice_notifiers net/core/dev.c:2078 [inline]
 dev_close_many+0x33c/0x4c0 net/core/dev.c:1619
 dev_close+0x1c0/0x2c0 net/core/dev.c:1641
 bond_setup_by_slave+0x66/0x390 drivers/net/bonding/bond_main.c:1631
 bond_enslave+0x7b4/0x3ac0 drivers/net/bonding/bond_main.c:2043
 bond_do_ioctl+0x749/0xb50 drivers/net/bonding/bond_main.c:4685
 dev_ifsioc+0xb73/0xe70
 dev_ioctl+0x719/0x1340 net/core/dev_ioctl.c:783
 sock_do_ioctl+0x240/0x460 net/socket.c:1223
 sock_ioctl+0x626/0x8e0 net/socket.c:1328
 vfs_ioctl fs/ioctl.c:51 [inline]
 __do_sys_ioctl fs/ioctl.c:906 [inline]
 __se_sys_ioctl+0xf5/0x170 fs/ioctl.c:892
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

The buggy address belongs to the object at ffff88803eeae800
 which belongs to the cache kmalloc-256 of size 256
The buggy address is located 204 bytes inside of
 freed 256-byte region [ffff88803eeae800, ffff88803eeae900)

The buggy address belongs to the physical page:
page: refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x3eeae
flags: 0x4fff00000000000(node=1|zone=1|lastcpupid=0x7ff)
page_type: f5(slab)
raw: 04fff00000000000 ffff88801ac41b40 ffffea0000fbaa00 dead000000000004
raw: 0000000000000000 0000000000080008 00000001f5000000 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 0x52cc0(GFP_KERNEL|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP), pid 1, tgid 1 (swapper/0), ts 19591470250, free_ts 0
 set_page_owner include/linux/page_owner.h:32 [inline]
 post_alloc_hook+0x1f3/0x230 mm/page_alloc.c:1558
 prep_new_page mm/page_alloc.c:1566 [inline]
 get_page_from_freelist+0x365c/0x37a0 mm/page_alloc.c:3476
 __alloc_pages_noprof+0x292/0x710 mm/page_alloc.c:4753
 alloc_pages_mpol_noprof+0x3e1/0x780 mm/mempolicy.c:2269
 alloc_slab_page+0x6a/0x110 mm/slub.c:2423
 allocate_slab+0x5a/0x2b0 mm/slub.c:2589
 new_slab mm/slub.c:2642 [inline]
 ___slab_alloc+0xc27/0x14a0 mm/slub.c:3830
 __slab_alloc+0x58/0xa0 mm/slub.c:3920
 __slab_alloc_node mm/slub.c:3995 [inline]
 slab_alloc_node mm/slub.c:4156 [inline]
 __do_kmalloc_node mm/slub.c:4297 [inline]
 __kmalloc_node_track_caller_noprof+0x2e9/0x4c0 mm/slub.c:4317
 kmemdup_noprof+0x2a/0x60 mm/util.c:135
 ip6_route_net_init+0xe4/0x7c0 net/ipv6/route.c:6503
 ops_init+0x31e/0x590 net/core/net_namespace.c:138
 __register_pernet_operations net/core/net_namespace.c:1267 [inline]
 register_pernet_operations+0x30d/0x630 net/core/net_namespace.c:1343
 register_pernet_subsys+0x28/0x40 net/core/net_namespace.c:1384
 ip6_route_init+0x120/0x410 net/ipv6/route.c:6727
 inet6_init+0x335/0x6a0 net/ipv6/af_inet6.c:1163
page_owner free stack trace missing

Memory state around the buggy address:
 ffff88803eeae780: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
 ffff88803eeae800: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>ffff88803eeae880: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                                              ^
 ffff88803eeae900: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
 ffff88803eeae980: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
==================================================================

Crashes (8):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2025/01/20 05:49 upstream 9528d418de4d f2cb035c .config console log report [disk image (non-bootable)] [vmlinux] [kernel image] ci-snapshot-upstream-root KASAN: slab-use-after-free Read in ax25_release
2024/12/30 02:24 upstream 4099a71718b0 d3ccff63 .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream KASAN: slab-use-after-free Read in ax25_release
2024/12/30 01:54 upstream 4099a71718b0 d3ccff63 .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream KASAN: slab-use-after-free Read in ax25_release
2025/01/09 20:00 net d1bf27c4e176 40f46913 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-net-this-kasan-gce KASAN: slab-use-after-free Read in ax25_release
2024/11/17 19:03 net-next 38f83a57aa8e cfe3a04a .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-net-kasan-gce KASAN: slab-use-after-free Read in ax25_release
2024/06/13 14:04 net-next 3ec8d7572a69 2aa5052f .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-net-kasan-gce KASAN: slab-use-after-free Read in ax25_release
2024/08/20 14:56 upstream 6e4436539ae1 9f0ab3fb .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kmsan-gce-root KMSAN: uninit-value in ax25_release
2024/07/27 02:26 upstream 2f8c4f506285 46eb10b7 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kmsan-gce-root KMSAN: uninit-value in ax25_release
* Struck through repros no longer work on HEAD.