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KASAN: slab-out-of-bounds Read in geneve_exit_batch_rtnl

Status: closed as invalid on 2025/03/17 11:18
Subsystems: net
[Documentation on labels]
First crash: 74d, last: 60d
▶ ▼ Last patch testing requests (1)
Created Duration User Patch Repo Result
2025/02/18 11:12 16m retest repro upstream report log

Sample crash report:
==================================================================
BUG: KASAN: slab-out-of-bounds in read_pnet include/net/net_namespace.h:395 [inline]
BUG: KASAN: slab-out-of-bounds in dev_net include/linux/netdevice.h:2663 [inline]
BUG: KASAN: slab-out-of-bounds in geneve_destroy_tunnels drivers/net/geneve.c:1917 [inline]
BUG: KASAN: slab-out-of-bounds in geneve_exit_batch_rtnl+0x274/0x300 drivers/net/geneve.c:1928
Read of size 8 at addr ffff88804ada5fa1 by task kworker/u32:4/74

CPU: 1 UID: 0 PID: 74 Comm: kworker/u32:4 Not tainted 6.14.0-rc1-syzkaller-00020-g0de63bb7d919 #0
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2~bpo12+1 04/01/2014
Workqueue: netns cleanup_net
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:94 [inline]
 dump_stack_lvl+0x116/0x1f0 lib/dump_stack.c:120
 print_address_description mm/kasan/report.c:378 [inline]
 print_report+0xc3/0x620 mm/kasan/report.c:489
 kasan_report+0xd9/0x110 mm/kasan/report.c:602
 read_pnet include/net/net_namespace.h:395 [inline]
 dev_net include/linux/netdevice.h:2663 [inline]
 geneve_destroy_tunnels drivers/net/geneve.c:1917 [inline]
 geneve_exit_batch_rtnl+0x274/0x300 drivers/net/geneve.c:1928
 cleanup_net+0x557/0xbf0 net/core/net_namespace.c:645
 process_one_work+0x9c5/0x1ba0 kernel/workqueue.c:3236
 process_scheduled_works kernel/workqueue.c:3317 [inline]
 worker_thread+0x6c8/0xf00 kernel/workqueue.c:3398
 kthread+0x3af/0x750 kernel/kthread.c:464
 ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:148
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244
 </TASK>

Allocated by task 8496:
 kasan_save_stack+0x33/0x60 mm/kasan/common.c:47
 kasan_save_track+0x14/0x30 mm/kasan/common.c:68
 poison_kmalloc_redzone mm/kasan/common.c:377 [inline]
 __kasan_kmalloc+0xaa/0xb0 mm/kasan/common.c:394
 kasan_kmalloc include/linux/kasan.h:260 [inline]
 __do_kmalloc_node mm/slub.c:4294 [inline]
 __kmalloc_noprof+0x21c/0x510 mm/slub.c:4306
 kmalloc_noprof include/linux/slab.h:905 [inline]
 kzalloc_noprof include/linux/slab.h:1037 [inline]
 __register_sysctl_table+0xb4/0x1910 fs/proc/proc_sysctl.c:1376
 ip4_frags_ns_ctl_register net/ipv4/ip_fragment.c:622 [inline]
 ipv4_frags_init_net net/ipv4/ip_fragment.c:697 [inline]
 ipv4_frags_init_net+0x287/0x3d0 net/ipv4/ip_fragment.c:665
 ops_init+0x1df/0x5f0 net/core/net_namespace.c:138
 setup_net+0x21f/0x860 net/core/net_namespace.c:362
 copy_net_ns+0x2b4/0x6c0 net/core/net_namespace.c:516
 create_new_namespaces+0x3ea/0xad0 kernel/nsproxy.c:110
 unshare_nsproxy_namespaces+0xc0/0x1f0 kernel/nsproxy.c:228
 ksys_unshare+0x45d/0xa40 kernel/fork.c:3342
 __do_sys_unshare kernel/fork.c:3413 [inline]
 __se_sys_unshare kernel/fork.c:3411 [inline]
 __x64_sys_unshare+0x31/0x40 kernel/fork.c:3411
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xcd/0x250 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

Last potentially related work creation:
 kasan_save_stack+0x33/0x60 mm/kasan/common.c:47
 kasan_record_aux_stack+0xb8/0xd0 mm/kasan/generic.c:548
 kvfree_call_rcu+0x76/0x470 mm/slab_common.c:1947
 drop_sysctl_table+0x356/0x5f0 fs/proc/proc_sysctl.c:1518
 unregister_sysctl_table fs/proc/proc_sysctl.c:1539 [inline]
 unregister_sysctl_table+0x41/0x60 fs/proc/proc_sysctl.c:1531
 ip4_frags_ns_ctl_unregister net/ipv4/ip_fragment.c:642 [inline]
 ipv4_frags_exit_net+0x5c/0xb0 net/ipv4/ip_fragment.c:710
 ops_exit_list+0xb0/0x180 net/core/net_namespace.c:172
 cleanup_net+0x5c6/0xbf0 net/core/net_namespace.c:652
 process_one_work+0x9c5/0x1ba0 kernel/workqueue.c:3236
 process_scheduled_works kernel/workqueue.c:3317 [inline]
 worker_thread+0x6c8/0xf00 kernel/workqueue.c:3398
 kthread+0x3af/0x750 kernel/kthread.c:464
 ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:148
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244

The buggy address belongs to the object at ffff88804ada5e00
 which belongs to the cache kmalloc-cg-256 of size 256
The buggy address is located 201 bytes to the right of
 allocated 216-byte region [ffff88804ada5e00, ffff88804ada5ed8)

The buggy address belongs to the physical page:
page: refcount:0 mapcount:0 mapping:0000000000000000 index:0xffff88804ada4800 pfn:0x4ada4
head: order:1 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0
memcg:ffff888028f7ff01
anon flags: 0xfff00000000040(head|node=0|zone=1|lastcpupid=0x7ff)
page_type: f5(slab)
raw: 00fff00000000040 ffff88801b04dcc0 0000000000000000 dead000000000001
raw: ffff88804ada4800 000000000010000e 00000000f5000000 ffff888028f7ff01
head: 00fff00000000040 ffff88801b04dcc0 0000000000000000 dead000000000001
head: ffff88804ada4800 000000000010000e 00000000f5000000 ffff888028f7ff01
head: 00fff00000000001 ffffea00012b6901 ffffffffffffffff 0000000000000000
head: 0000000000000002 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 5985, tgid 5985 (syz-executor), ts 165914528257, free_ts 0
 set_page_owner include/linux/page_owner.h:32 [inline]
 post_alloc_hook+0x181/0x1b0 mm/page_alloc.c:1551
 prep_new_page mm/page_alloc.c:1559 [inline]
 get_page_from_freelist+0xfce/0x2f80 mm/page_alloc.c:3477
 __alloc_frozen_pages_noprof+0x221/0x2470 mm/page_alloc.c:4739
 alloc_pages_mpol+0x1fc/0x540 mm/mempolicy.c:2270
 alloc_slab_page mm/slub.c:2423 [inline]
 allocate_slab mm/slub.c:2587 [inline]
 new_slab+0x23d/0x330 mm/slub.c:2640
 ___slab_alloc+0xc5d/0x1720 mm/slub.c:3826
 __slab_alloc.constprop.0+0x56/0xb0 mm/slub.c:3916
 __slab_alloc_node mm/slub.c:3991 [inline]
 slab_alloc_node mm/slub.c:4152 [inline]
 __kmalloc_cache_noprof+0xfa/0x410 mm/slub.c:4320
 kmalloc_noprof include/linux/slab.h:901 [inline]
 kzalloc_noprof include/linux/slab.h:1037 [inline]
 alloc_netdev_mqs+0xf25/0x15d0 net/core/dev.c:11523
 __ip_tunnel_create+0x31f/0x690 net/ipv4/ip_tunnel.c:254
 ip_tunnel_init_net+0x22a/0x790 net/ipv4/ip_tunnel.c:1160
 ops_init+0x1df/0x5f0 net/core/net_namespace.c:138
 setup_net+0x21f/0x860 net/core/net_namespace.c:362
 copy_net_ns+0x2b4/0x6c0 net/core/net_namespace.c:516
 create_new_namespaces+0x3ea/0xad0 kernel/nsproxy.c:110
 unshare_nsproxy_namespaces+0xc0/0x1f0 kernel/nsproxy.c:228
page_owner free stack trace missing

Memory state around the buggy address:
 ffff88804ada5e80: 00 00 00 00 00 00 00 00 00 00 00 fc fc fc fc fc
 ffff88804ada5f00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
>ffff88804ada5f80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
                               ^
 ffff88804ada6000: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
 ffff88804ada6080: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
==================================================================

Crashes (1):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2025/02/04 10:49 upstream 0de63bb7d919 8f267cef .config console log report syz / log [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream KASAN: slab-out-of-bounds Read in geneve_exit_batch_rtnl
* Struck through repros no longer work on HEAD.