[syzbot] KASAN: use-after-free Read in nf_tables_dump_sets

syzbot
2021-08-09T15:38:33Z

Hello,

syzbot found the following issue on:

HEAD commit: f9be84db09d2 net: bonding: bond_alb: Remove the dependency..
git tree: net-next
console output: https://syzkaller.appspot.com/x/log.txt?x=1070243a300000
kernel config: https://syzkaller.appspot.com/x/.config?x=8075b2614f3db143
dashboard link: https://syzkaller.appspot.com/bug?extid=8cc940a9689599e10587
compiler: gcc (Debian 10.2.1-6) 10.2.1 20210110, GNU ld (GNU Binutils for Debian) 2.35.1
syz repro: https://syzkaller.appspot.com/x/repro.syz?x=15fbb98e300000

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+8cc940a9689599e10587@syzkaller.appspotmail.com

==================================================================
BUG: KASAN: use-after-free in nf_tables_dump_sets+0xadf/0xaf0 net/netfilter/nf_tables_api.c:4001
Read of size 8 at addr ffff8880166ab580 by task syz-executor.0/26444

CPU: 0 PID: 26444 Comm: syz-executor.0 Not tainted 5.14.0-rc4-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
__dump_stack lib/dump_stack.c:88 [inline]
dump_stack_lvl+0xcd/0x134 lib/dump_stack.c:105
print_address_description.constprop.0.cold+0x6c/0x309 mm/kasan/report.c:233
__kasan_report mm/kasan/report.c:419 [inline]
kasan_report.cold+0x83/0xdf mm/kasan/report.c:436
nf_tables_dump_sets+0xadf/0xaf0 net/netfilter/nf_tables_api.c:4001
netlink_dump+0x4b9/0xb70 net/netlink/af_netlink.c:2278
__netlink_dump_start+0x642/0x900 net/netlink/af_netlink.c:2383
netlink_dump_start include/linux/netlink.h:258 [inline]
nft_netlink_dump_start_rcu+0x83/0x1c0 net/netfilter/nf_tables_api.c:859
nf_tables_getset+0x71d/0x860 net/netfilter/nf_tables_api.c:4083
nfnetlink_rcv_msg+0x659/0x13f0 net/netfilter/nfnetlink.c:285
netlink_rcv_skb+0x153/0x420 net/netlink/af_netlink.c:2504
nfnetlink_rcv+0x1ac/0x420 net/netfilter/nfnetlink.c:654
netlink_unicast_kernel net/netlink/af_netlink.c:1314 [inline]
netlink_unicast+0x533/0x7d0 net/netlink/af_netlink.c:1340
netlink_sendmsg+0x86d/0xdb0 net/netlink/af_netlink.c:1929
sock_sendmsg_nosec net/socket.c:704 [inline]
sock_sendmsg+0xcf/0x120 net/socket.c:724
____sys_sendmsg+0x6e8/0x810 net/socket.c:2403
___sys_sendmsg+0xf3/0x170 net/socket.c:2457
__sys_sendmsg+0xe5/0x1b0 net/socket.c:2486
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x44/0xae
RIP: 0033:0x4665e9
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 bc ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f2c24718188 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 000000000056bf80 RCX: 00000000004665e9
RDX: 0000000000000000 RSI: 0000000020000d80 RDI: 0000000000000004
RBP: 00000000004bfcc4 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 000000000056bf80
R13: 00007fffb1c1ca2f R14: 00007f2c24718300 R15: 0000000000022000

Allocated by task 26444:
kasan_save_stack+0x1b/0x40 mm/kasan/common.c:38
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 mm/kasan/common.c:472 [inline]
__kasan_kmalloc+0x9b/0xd0 mm/kasan/common.c:522
nf_tables_newtable+0xe3e/0x1b40 net/netfilter/nf_tables_api.c:1112
nfnetlink_rcv_batch+0x1710/0x25f0 net/netfilter/nfnetlink.c:513
nfnetlink_rcv_skb_batch net/netfilter/nfnetlink.c:634 [inline]
nfnetlink_rcv+0x3af/0x420 net/netfilter/nfnetlink.c:652
netlink_unicast_kernel net/netlink/af_netlink.c:1314 [inline]
netlink_unicast+0x533/0x7d0 net/netlink/af_netlink.c:1340
netlink_sendmsg+0x86d/0xdb0 net/netlink/af_netlink.c:1929
sock_sendmsg_nosec net/socket.c:704 [inline]
sock_sendmsg+0xcf/0x120 net/socket.c:724
____sys_sendmsg+0x6e8/0x810 net/socket.c:2403
___sys_sendmsg+0xf3/0x170 net/socket.c:2457
__sys_sendmsg+0xe5/0x1b0 net/socket.c:2486
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x44/0xae

Freed by task 26443:
kasan_save_stack+0x1b/0x40 mm/kasan/common.c:38
kasan_set_track+0x1c/0x30 mm/kasan/common.c:46
kasan_set_free_info+0x20/0x30 mm/kasan/generic.c:360
____kasan_slab_free mm/kasan/common.c:366 [inline]
____kasan_slab_free mm/kasan/common.c:328 [inline]
__kasan_slab_free+0xfb/0x130 mm/kasan/common.c:374
kasan_slab_free include/linux/kasan.h:230 [inline]
slab_free_hook mm/slub.c:1625 [inline]
slab_free_freelist_hook+0xdf/0x240 mm/slub.c:1650
slab_free mm/slub.c:3210 [inline]
kfree+0xe4/0x530 mm/slub.c:4264
nf_tables_table_destroy+0x13f/0x1b0 net/netfilter/nf_tables_api.c:1315
__nft_release_table+0xabc/0xe30 net/netfilter/nf_tables_api.c:9603
nft_rcv_nl_event+0x4af/0x590 net/netfilter/nf_tables_api.c:9645
notifier_call_chain+0xb5/0x200 kernel/notifier.c:83
blocking_notifier_call_chain kernel/notifier.c:337 [inline]
blocking_notifier_call_chain+0x67/0x90 kernel/notifier.c:325
netlink_release+0xcb8/0x1dd0 net/netlink/af_netlink.c:785
__sock_release+0xcd/0x280 net/socket.c:649
sock_close+0x18/0x20 net/socket.c:1311
__fput+0x288/0x920 fs/file_table.c:280
task_work_run+0xdd/0x1a0 kernel/task_work.c:164
tracehook_notify_resume include/linux/tracehook.h:189 [inline]
exit_to_user_mode_loop kernel/entry/common.c:175 [inline]
exit_to_user_mode_prepare+0x27e/0x290 kernel/entry/common.c:209
__syscall_exit_to_user_mode_work kernel/entry/common.c:291 [inline]
syscall_exit_to_user_mode+0x19/0x60 kernel/entry/common.c:302
do_syscall_64+0x42/0xb0 arch/x86/entry/common.c:86
entry_SYSCALL_64_after_hwframe+0x44/0xae

The buggy address belongs to the object at ffff8880166ab400
which belongs to the cache kmalloc-512 of size 512
The buggy address is located 384 bytes inside of
512-byte region [ffff8880166ab400, ffff8880166ab600)
The buggy address belongs to the page:
page:ffffea000059aa00 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x166a8
head:ffffea000059aa00 order:2 compound_mapcount:0 compound_pincount:0
flags: 0xfff00000010200(slab|head|node=0|zone=1|lastcpupid=0x7ff)
raw: 00fff00000010200 ffffea00009eb300 0000000400000004 ffff888010841c80
raw: 0000000000000000 0000000000100010 00000001ffffffff 0000000000000000
page dumped because: kasan: bad access detected
page_owner tracks the page as allocated
page last allocated via order 2, migratetype Unmovable, gfp_mask 0xd28c0(GFP_NOWAIT|__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 23643, ts 1730415746365, free_ts 1727523669671
prep_new_page mm/page_alloc.c:2436 [inline]
get_page_from_freelist+0xa72/0x2f80 mm/page_alloc.c:4169
__alloc_pages+0x1b2/0x500 mm/page_alloc.c:5391
alloc_pages+0x18c/0x2a0 mm/mempolicy.c:2244
alloc_slab_page mm/slub.c:1688 [inline]
allocate_slab+0x32e/0x4b0 mm/slub.c:1828
new_slab mm/slub.c:1891 [inline]
new_slab_objects mm/slub.c:2637 [inline]
___slab_alloc+0x4ba/0x820 mm/slub.c:2800
__slab_alloc.constprop.0+0xa7/0xf0 mm/slub.c:2840
slab_alloc_node mm/slub.c:2922 [inline]
__kmalloc_node_track_caller+0x2e3/0x360 mm/slub.c:4650
kmalloc_reserve net/core/skbuff.c:355 [inline]
pskb_expand_head+0x15e/0x1060 net/core/skbuff.c:1700
netlink_trim+0x1ea/0x240 net/netlink/af_netlink.c:1296
netlink_unicast+0xb9/0x7d0 net/netlink/af_netlink.c:1330
nlmsg_unicast include/net/netlink.h:1050 [inline]
nlmsg_notify+0x106/0x290 net/netlink/af_netlink.c:2555
nf_tables_gen_notify net/netfilter/nf_tables_api.c:7882 [inline]
nf_tables_commit+0x1c1e/0x47f0 net/netfilter/nf_tables_api.c:8714
nfnetlink_rcv_batch+0xbac/0x25f0 net/netfilter/nfnetlink.c:562
nfnetlink_rcv_skb_batch net/netfilter/nfnetlink.c:634 [inline]
nfnetlink_rcv+0x3af/0x420 net/netfilter/nfnetlink.c:652
netlink_unicast_kernel net/netlink/af_netlink.c:1314 [inline]
netlink_unicast+0x533/0x7d0 net/netlink/af_netlink.c:1340
netlink_sendmsg+0x86d/0xdb0 net/netlink/af_netlink.c:1929
page last free stack trace:
reset_page_owner include/linux/page_owner.h:24 [inline]
free_pages_prepare mm/page_alloc.c:1346 [inline]
free_pcp_prepare+0x2c5/0x780 mm/page_alloc.c:1397
free_unref_page_prepare mm/page_alloc.c:3332 [inline]
free_unref_page+0x19/0x690 mm/page_alloc.c:3411
qlink_free mm/kasan/quarantine.c:146 [inline]
qlist_free_all+0x5a/0xc0 mm/kasan/quarantine.c:165
kasan_quarantine_reduce+0x180/0x200 mm/kasan/quarantine.c:272
__kasan_slab_alloc+0x8e/0xa0 mm/kasan/common.c:444
kasan_slab_alloc include/linux/kasan.h:254 [inline]
slab_post_alloc_hook mm/slab.h:519 [inline]
slab_alloc_node mm/slub.c:2956 [inline]
slab_alloc mm/slub.c:2964 [inline]
kmem_cache_alloc+0x285/0x4a0 mm/slub.c:2969
getname_flags.part.0+0x50/0x4f0 fs/namei.c:138
getname_flags include/linux/audit.h:319 [inline]
getname fs/namei.c:209 [inline]
__do_sys_unlink fs/namei.c:4149 [inline]
__se_sys_unlink fs/namei.c:4147 [inline]
__x64_sys_unlink+0xb1/0x100 fs/namei.c:4147
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x44/0xae

Memory state around the buggy address:
ffff8880166ab480: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
ffff8880166ab500: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>ffff8880166ab580: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
^
ffff8880166ab600: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
ffff8880166ab680: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
==================================================================

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