syzbot


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

Status: moderation: reported on 2024/06/14 08:40
Subsystems: hams
[Documentation on labels]
Reported-by: syzbot+88d130bb1596c1546453@syzkaller.appspotmail.com
First crash: 35d, last: 35d

Sample crash report:
==================================================================
BUG: KASAN: slab-use-after-free in ax25_release+0x877/0x950 net/ax25/af_ax25.c:1062
Read of size 1 at addr ffff888021c6d4cc by task syz-executor.3/9760

CPU: 0 PID: 9760 Comm: syz-executor.3 Not tainted 6.10.0-rc2-syzkaller-00761-g3ec8d7572a69 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/07/2024
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0x241/0x360 lib/dump_stack.c:114
 print_address_description mm/kasan/report.c:377 [inline]
 print_report+0x169/0x550 mm/kasan/report.c:488
 kasan_report+0x143/0x180 mm/kasan/report.c:601
 ax25_release+0x877/0x950 net/ax25/af_ax25.c:1062
 __sock_release net/socket.c:659 [inline]
 sock_close+0xbc/0x240 net/socket.c:1421
 __fput+0x406/0x8b0 fs/file_table.c:422
 task_work_run+0x24f/0x310 kernel/task_work.c:180
 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:328 [inline]
 __syscall_exit_to_user_mode_work kernel/entry/common.c:207 [inline]
 syscall_exit_to_user_mode+0x168/0x370 kernel/entry/common.c:218
 do_syscall_64+0x100/0x230 arch/x86/entry/common.c:89
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fbc5487cea9
Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 e1 20 00 00 90 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 b0 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007ffc8523d5f8 EFLAGS: 00000246 ORIG_RAX: 00000000000001b4
RAX: 0000000000000000 RBX: 00007fbc549b5980 RCX: 00007fbc5487cea9
RDX: 0000000000000000 RSI: 000000000000001e RDI: 0000000000000003
RBP: 00007fbc549b5980 R08: 000000008136572d R09: 0000001e00000000
R10: 0000000080000000 R11: 0000000000000246 R12: 00000000000325b4
R13: 00007fbc549b405c R14: 0000000000000032 R15: 00007fbc549b5980
 </TASK>

Allocated by task 9426:
 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:370 [inline]
 __kasan_kmalloc+0x98/0xb0 mm/kasan/common.c:387
 kasan_kmalloc include/linux/kasan.h:211 [inline]
 kmalloc_trace_noprof+0x19c/0x2c0 mm/slub.c:4152
 kmalloc_noprof include/linux/slab.h:660 [inline]
 kzalloc_noprof include/linux/slab.h:778 [inline]
 ax25_dev_device_up+0x58/0x620 net/ax25/ax25_dev.c:57
 ax25_device_event+0x4ed/0x570 net/ax25/af_ax25.c:143
 notifier_call_chain+0x19f/0x3e0 kernel/notifier.c:93
 __dev_notify_flags+0x207/0x400
 dev_change_flags+0xf0/0x1a0 net/core/dev.c:8858
 dev_ifsioc+0x7c8/0xe70 net/core/dev_ioctl.c:530
 dev_ioctl+0x719/0x1340 net/core/dev_ioctl.c:787
 sock_do_ioctl+0x240/0x460 net/socket.c:1236
 sock_ioctl+0x629/0x8e0 net/socket.c:1341
 vfs_ioctl fs/ioctl.c:51 [inline]
 __do_sys_ioctl fs/ioctl.c:907 [inline]
 __se_sys_ioctl+0xfc/0x170 fs/ioctl.c:893
 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 9767:
 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:579
 poison_slab_object+0xe0/0x150 mm/kasan/common.c:240
 __kasan_slab_free+0x37/0x60 mm/kasan/common.c:256
 kasan_slab_free include/linux/kasan.h:184 [inline]
 slab_free_hook mm/slub.c:2195 [inline]
 slab_free mm/slub.c:4436 [inline]
 kfree+0x149/0x360 mm/slub.c:4557
 ax25_device_event+0x523/0x570 net/ax25/af_ax25.c:148
 notifier_call_chain+0x19f/0x3e0 kernel/notifier.c:93
 __dev_notify_flags+0x207/0x400
 dev_change_flags+0xf0/0x1a0 net/core/dev.c:8858
 dev_ifsioc+0x7c8/0xe70 net/core/dev_ioctl.c:530
 dev_ioctl+0x719/0x1340 net/core/dev_ioctl.c:787
 sock_do_ioctl+0x240/0x460 net/socket.c:1236
 sock_ioctl+0x629/0x8e0 net/socket.c:1341
 vfs_ioctl fs/ioctl.c:51 [inline]
 __do_sys_ioctl fs/ioctl.c:907 [inline]
 __se_sys_ioctl+0xfc/0x170 fs/ioctl.c:893
 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 ffff888021c6d400
 which belongs to the cache kmalloc-256 of size 256
The buggy address is located 204 bytes inside of
 freed 256-byte region [ffff888021c6d400, ffff888021c6d500)

The buggy address belongs to the physical page:
page: refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x21c6c
head: order:1 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0
ksm flags: 0xfff00000000040(head|node=0|zone=1|lastcpupid=0x7ff)
page_type: 0xffffefff(slab)
raw: 00fff00000000040 ffff888015041b40 ffffea0000a5cc00 dead000000000003
raw: 0000000000000000 0000000000100010 00000001ffffefff 0000000000000000
head: 00fff00000000040 ffff888015041b40 ffffea0000a5cc00 dead000000000003
head: 0000000000000000 0000000000100010 00000001ffffefff 0000000000000000
head: 00fff00000000001 ffffea0000871b01 ffffffffffffffff 0000000000000000
head: ffff888000000002 0000000000000000 00000000ffffffff 0000000000000000
page dumped because: kasan: bad access detected
page_owner tracks the page as allocated
page last allocated via order 1, migratetype Unmovable, gfp_mask 0xd20c0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 5115, tgid 5115 (syz-executor.3), ts 75925089521, free_ts 75915082958
 set_page_owner include/linux/page_owner.h:32 [inline]
 post_alloc_hook+0x1f3/0x230 mm/page_alloc.c:1468
 prep_new_page mm/page_alloc.c:1476 [inline]
 get_page_from_freelist+0x2e2d/0x2ee0 mm/page_alloc.c:3402
 __alloc_pages_noprof+0x256/0x6c0 mm/page_alloc.c:4660
 __alloc_pages_node_noprof include/linux/gfp.h:269 [inline]
 alloc_pages_node_noprof include/linux/gfp.h:296 [inline]
 alloc_slab_page+0x5f/0x120 mm/slub.c:2264
 allocate_slab+0x5a/0x2e0 mm/slub.c:2427
 new_slab mm/slub.c:2480 [inline]
 ___slab_alloc+0xcd1/0x14b0 mm/slub.c:3666
 __slab_alloc+0x58/0xa0 mm/slub.c:3756
 __slab_alloc_node mm/slub.c:3809 [inline]
 slab_alloc_node mm/slub.c:3988 [inline]
 __do_kmalloc_node mm/slub.c:4120 [inline]
 __kmalloc_noprof+0x257/0x400 mm/slub.c:4134
 kmalloc_noprof include/linux/slab.h:664 [inline]
 kzalloc_noprof include/linux/slab.h:778 [inline]
 new_dir fs/proc/proc_sysctl.c:953 [inline]
 get_subdir fs/proc/proc_sysctl.c:997 [inline]
 sysctl_mkdir_p fs/proc/proc_sysctl.c:1292 [inline]
 __register_sysctl_table+0xb53/0x1460 fs/proc/proc_sysctl.c:1373
 neigh_sysctl_register+0x3f8/0x4e0 net/core/neighbour.c:3861
 devinet_sysctl_register+0xaf/0x1f0 net/ipv4/devinet.c:2639
 inetdev_init+0x296/0x4d0 net/ipv4/devinet.c:291
 inetdev_event+0x338/0x15c0 net/ipv4/devinet.c:1565
 notifier_call_chain+0x19f/0x3e0 kernel/notifier.c:93
 call_netdevice_notifiers_extack net/core/dev.c:2030 [inline]
 call_netdevice_notifiers net/core/dev.c:2044 [inline]
 register_netdevice+0x1570/0x19e0 net/core/dev.c:10408
 veth_newlink+0x628/0xcd0 drivers/net/veth.c:1829
page last free pid 5115 tgid 5115 stack trace:
 reset_page_owner include/linux/page_owner.h:25 [inline]
 free_pages_prepare mm/page_alloc.c:1088 [inline]
 free_unref_page+0xd22/0xea0 mm/page_alloc.c:2565
 discard_slab mm/slub.c:2526 [inline]
 __put_partials+0xeb/0x130 mm/slub.c:2994
 put_cpu_partial+0x17c/0x250 mm/slub.c:3069
 __slab_free+0x2ea/0x3d0 mm/slub.c:4306
 qlink_free mm/kasan/quarantine.c:163 [inline]
 qlist_free_all+0x9e/0x140 mm/kasan/quarantine.c:179
 kasan_quarantine_reduce+0x14f/0x170 mm/kasan/quarantine.c:286
 __kasan_slab_alloc+0x23/0x80 mm/kasan/common.c:322
 kasan_slab_alloc include/linux/kasan.h:201 [inline]
 slab_post_alloc_hook mm/slub.c:3940 [inline]
 slab_alloc_node mm/slub.c:4000 [inline]
 kmem_cache_alloc_node_noprof+0x16b/0x320 mm/slub.c:4043
 __alloc_skb+0x1c3/0x440 net/core/skbuff.c:656
 netlink_sendmsg+0x631/0xcb0 net/netlink/af_netlink.c:1876
 sock_sendmsg_nosec net/socket.c:730 [inline]
 __sock_sendmsg+0x221/0x270 net/socket.c:745
 __sys_sendto+0x3a4/0x4f0 net/socket.c:2192
 __do_sys_sendto net/socket.c:2204 [inline]
 __se_sys_sendto net/socket.c:2200 [inline]
 __x64_sys_sendto+0xde/0x100 net/socket.c:2200
 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

Memory state around the buggy address:
 ffff888021c6d380: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
 ffff888021c6d400: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>ffff888021c6d480: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                                              ^
 ffff888021c6d500: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
 ffff888021c6d580: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
==================================================================

Crashes (1):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
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
* Struck through repros no longer work on HEAD.