Subject: [syzbot] [bpf?] KASAN: slab-use-after-free Read in htab_map_alloc (2)

From: syzbot <[email-masked]>
Date: Sat, 04 May 2024 03:21:22 -0700

Hello,

syzbot found the following issue on:

HEAD commit:    2506f6229bd0 Merge branch 'net-dsa-adjust_link-removal'
git tree:       net-next
console output: https://syzkaller.appspot.com/x/log.txt?x=11ac64ef180000
kernel config:  https://syzkaller.appspot.com/x/.config?x=15dda165e1d20cf1
dashboard link: https://syzkaller.appspot.com/bug?extid=061f58eec3bde7ee8ffa
compiler:       Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40

Unfortunately, I don't have any reproducer for this issue yet.

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/fc61e6a6e169/disk-2506f622.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/3ed6cc1ccbe5/vmlinux-2506f622.xz
kernel image: https://storage.googleapis.com/syzbot-assets/c6ea42464245/bzImage-2506f622.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: [email-masked]

==================================================================
BUG: KASAN: slab-use-after-free in lockdep_register_key+0x253/0x3f0 kernel/locking/lockdep.c:1225
Read of size 8 at addr ffff88805fe2c298 by task syz-executor.1/5906

CPU: 1 PID: 5906 Comm: syz-executor.1 Not tainted 6.9.0-rc5-syzkaller-01473-g2506f6229bd0 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/27/2024
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
 lockdep_register_key+0x253/0x3f0 kernel/locking/lockdep.c:1225
 htab_map_alloc+0x9b/0xe60 kernel/bpf/hashtab.c:506
 map_create+0x90c/0x1200 kernel/bpf/syscall.c:1333
 __sys_bpf+0x6d1/0x810 kernel/bpf/syscall.c:5659
 __do_sys_bpf kernel/bpf/syscall.c:5784 [inline]
 __se_sys_bpf kernel/bpf/syscall.c:5782 [inline]
 __x64_sys_bpf+0x7c/0x90 kernel/bpf/syscall.c:5782
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xf5/0x240 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f7781e7dea9
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:00007f7782c720c8 EFLAGS: 00000246 ORIG_RAX: 0000000000000141
RAX: ffffffffffffffda RBX: 00007f7781fabf80 RCX: 00007f7781e7dea9
RDX: 0000000000000048 RSI: 0000000020000140 RDI: 0100000000000000
RBP: 00007f7781eca4a4 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 000000000000000b R14: 00007f7781fabf80 R15: 00007ffe14057dd8
 </TASK>

Allocated by task 5593:
 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]
 __do_kmalloc_node mm/slub.c:3966 [inline]
 __kmalloc_node_track_caller+0x24e/0x4e0 mm/slub.c:3986
 kmalloc_reserve+0x111/0x2a0 net/core/skbuff.c:597
 __alloc_skb+0x1f3/0x440 net/core/skbuff.c:666
 alloc_skb include/linux/skbuff.h:1308 [inline]
 alloc_skb_with_frags+0xc3/0x770 net/core/skbuff.c:6455
 sock_alloc_send_pskb+0x91a/0xa60 net/core/sock.c:2794
 sock_alloc_send_skb include/net/sock.h:1766 [inline]
 llc_ui_sendmsg+0x48d/0xf80 net/llc/af_llc.c:971
 sock_sendmsg_nosec net/socket.c:730 [inline]
 __sock_sendmsg+0x221/0x270 net/socket.c:745
 sock_sendmsg+0x134/0x200 net/socket.c:768
 splice_to_socket+0xa13/0x10b0 fs/splice.c:889
 do_splice_from fs/splice.c:941 [inline]
 direct_splice_actor+0x11e/0x220 fs/splice.c:1164
 splice_direct_to_actor+0x58e/0xc90 fs/splice.c:1108
 do_splice_direct_actor fs/splice.c:1207 [inline]
 do_splice_direct+0x28c/0x3e0 fs/splice.c:1233
 do_sendfile+0x56d/0xdc0 fs/read_write.c:1295
 __do_sys_sendfile64 fs/read_write.c:1362 [inline]
 __se_sys_sendfile64+0x17c/0x1e0 fs/read_write.c:1348
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xf5/0x240 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

Freed by task 5593:
 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+0xa6/0xe0 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:2106 [inline]
 slab_free mm/slub.c:4280 [inline]
 kfree+0x153/0x3a0 mm/slub.c:4390
 skb_kfree_head net/core/skbuff.c:1033 [inline]
 skb_free_head net/core/skbuff.c:1045 [inline]
 skb_release_data+0x676/0x880 net/core/skbuff.c:1072
 skb_release_all net/core/skbuff.c:1137 [inline]
 __kfree_skb net/core/skbuff.c:1151 [inline]
 kfree_skb_reason+0x1a3/0x3b0 net/core/skbuff.c:1187
 llc_ui_sendmsg+0xb03/0xf80 net/llc/af_llc.c:1000
 sock_sendmsg_nosec net/socket.c:730 [inline]
 __sock_sendmsg+0x221/0x270 net/socket.c:745
 sock_sendmsg+0x134/0x200 net/socket.c:768
 splice_to_socket+0xa13/0x10b0 fs/splice.c:889
 do_splice_from fs/splice.c:941 [inline]
 direct_splice_actor+0x11e/0x220 fs/splice.c:1164
 splice_direct_to_actor+0x58e/0xc90 fs/splice.c:1108
 do_splice_direct_actor fs/splice.c:1207 [inline]
 do_splice_direct+0x28c/0x3e0 fs/splice.c:1233
 do_sendfile+0x56d/0xdc0 fs/read_write.c:1295
 __do_sys_sendfile64 fs/read_write.c:1362 [inline]
 __se_sys_sendfile64+0x17c/0x1e0 fs/read_write.c:1348
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xf5/0x240 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

The buggy address belongs to the object at ffff88805fe2c000
 which belongs to the cache kmalloc-2k of size 2048
The buggy address is located 664 bytes inside of
 freed 2048-byte region [ffff88805fe2c000, ffff88805fe2c800)

The buggy address belongs to the physical page:
page: refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x5fe28
head: order:3 entire_mapcount:0 nr_pages_mapped:0 pincount:0
flags: 0xfff80000000840(slab|head|node=0|zone=1|lastcpupid=0xfff)
page_type: 0xffffffff()
raw: 00fff80000000840 ffff888015042000 dead000000000100 dead000000000122
raw: 0000000000000000 0000000000080008 00000001ffffffff 0000000000000000
head: 00fff80000000840 ffff888015042000 dead000000000100 dead000000000122
head: 0000000000000000 0000000000080008 00000001ffffffff 0000000000000000
head: 00fff80000000003 ffffea00017f8a01 dead000000000122 00000000ffffffff
head: 0000000800000000 0000000000000000 00000000ffffffff 0000000000000000
page dumped because: kasan: bad access detected
page_owner tracks the page as allocated
page last allocated via order 3, migratetype Unmovable, gfp_mask 0xd20c0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 5095, tgid 21395662 (syz-executor.0), ts 5095, free_ts 13812911031
 set_page_owner include/linux/page_owner.h:32 [inline]
 post_alloc_hook+0x1ea/0x210 mm/page_alloc.c:1534
 prep_new_page mm/page_alloc.c:1541 [inline]
 get_page_from_freelist+0x3410/0x35b0 mm/page_alloc.c:3317
 __alloc_pages+0x256/0x6c0 mm/page_alloc.c:4575
 __alloc_pages_node include/linux/gfp.h:238 [inline]
 alloc_pages_node include/linux/gfp.h:261 [inline]
 alloc_slab_page+0x5f/0x160 mm/slub.c:2175
 allocate_slab mm/slub.c:2338 [inline]
 new_slab+0x84/0x2f0 mm/slub.c:2391
 ___slab_alloc+0xc73/0x1260 mm/slub.c:3525
 __slab_alloc mm/slub.c:3610 [inline]
 __slab_alloc_node mm/slub.c:3663 [inline]
 slab_alloc_node mm/slub.c:3835 [inline]
 kmalloc_trace+0x269/0x360 mm/slub.c:3992
 kmalloc include/linux/slab.h:628 [inline]
 rtnl_newlink+0xf2/0x20a0 net/core/rtnetlink.c:3723
 rtnetlink_rcv_msg+0x89b/0x10d0 net/core/rtnetlink.c:6594
 netlink_rcv_skb+0x1e3/0x430 net/netlink/af_netlink.c:2564
 netlink_unicast_kernel net/netlink/af_netlink.c:1335 [inline]
 netlink_unicast+0x7ea/0x980 net/netlink/af_netlink.c:1361
 netlink_sendmsg+0x8e1/0xcb0 net/netlink/af_netlink.c:1905
 sock_sendmsg_nosec net/socket.c:730 [inline]
 __sock_sendmsg+0x221/0x270 net/socket.c:745
 __sys_sendto+0x3a4/0x4f0 net/socket.c:2191
 __do_sys_sendto net/socket.c:2203 [inline]
 __se_sys_sendto net/socket.c:2199 [inline]
 __x64_sys_sendto+0xde/0x100 net/socket.c:2199
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xf5/0x240 arch/x86/entry/common.c:83
page last free pid 1 tgid 1 stack trace:
 reset_page_owner include/linux/page_owner.h:25 [inline]
 free_pages_prepare mm/page_alloc.c:1141 [inline]
 free_unref_page_prepare+0x986/0xab0 mm/page_alloc.c:2347
 free_unref_page+0x37/0x3f0 mm/page_alloc.c:2487
 free_contig_range+0x9e/0x160 mm/page_alloc.c:6572
 destroy_args+0x8a/0x890 mm/debug_vm_pgtable.c:1036
 debug_vm_pgtable+0x4be/0x550 mm/debug_vm_pgtable.c:1416
 do_one_initcall+0x248/0x880 init/main.c:1245
 do_initcall_level+0x157/0x210 init/main.c:1307
 do_initcalls+0x3f/0x80 init/main.c:1323
 kernel_init_freeable+0x435/0x5d0 init/main.c:1555
 kernel_init+0x1d/0x2b0 init/main.c:1444
 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244

Memory state around the buggy address:
 ffff88805fe2c180: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff88805fe2c200: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>ffff88805fe2c280: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                            ^
 ffff88805fe2c300: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff88805fe2c380: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
==================================================================

---
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