syzbot


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

Status: upstream: reported on 2024/12/26 18:45
Subsystems: bluetooth
[Documentation on labels]
Reported-by: syzbot+8def80b4fcd383be0e59@syzkaller.appspotmail.com
First crash: 53d, last: 4d23h
Discussions (1)
Title Replies (including bot) Last reply
[syzbot] [bluetooth?] KASAN: slab-use-after-free Read in msft_opcode_get 0 (1) 2024/12/26 18:45

Sample crash report:
==================================================================
BUG: KASAN: slab-use-after-free in msft_opcode_get+0x6d/0x80 drivers/bluetooth/hci_vhci.c:222
Read of size 2 at addr ffff888024021a32 by task syz.2.2625/16923

CPU: 1 UID: 0 PID: 16923 Comm: syz.2.2625 Tainted: G     U             6.14.0-rc1-syzkaller-00187-g8f6629c004b1 #0
Tainted: [U]=USER
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 12/27/2024
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
 msft_opcode_get+0x6d/0x80 drivers/bluetooth/hci_vhci.c:222
 simple_attr_read+0x169/0x300 fs/libfs.c:1334
 debugfs_attr_read+0x76/0xa0 fs/debugfs/file.c:534
 full_proxy_read+0x13c/0x200 fs/debugfs/file.c:393
 vfs_read+0x1df/0xbf0 fs/read_write.c:563
 ksys_read+0x12b/0x250 fs/read_write.c:708
 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
RIP: 0033:0x7f95ddd8cde9
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:00007f95deb00038 EFLAGS: 00000246 ORIG_RAX: 0000000000000000
RAX: ffffffffffffffda RBX: 00007f95ddfa5fa0 RCX: 00007f95ddd8cde9
RDX: 000000000000ffff RSI: 0000400000006740 RDI: 0000000000000003
RBP: 00007f95dde0e2a0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 00007f95ddfa5fa0 R15: 00007ffe7163c938
 </TASK>

Allocated by task 6434:
 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_node_track_caller_noprof+0x21d/0x520 mm/slub.c:4313
 kmalloc_reserve+0xef/0x2c0 net/core/skbuff.c:609
 pskb_expand_head+0x236/0x1170 net/core/skbuff.c:2275
 __skb_cow include/linux/skbuff.h:3769 [inline]
 skb_cow_head include/linux/skbuff.h:3803 [inline]
 batadv_skb_head_push+0xf5/0x290 net/batman-adv/soft-interface.c:72
 batadv_send_skb_packet+0x115/0x770 net/batman-adv/send.c:86
 batadv_iv_ogm_send_to_if net/batman-adv/bat_iv_ogm.c:392 [inline]
 batadv_iv_ogm_emit net/batman-adv/bat_iv_ogm.c:420 [inline]
 batadv_iv_send_outstanding_bat_ogm_packet+0x70a/0x8d0 net/batman-adv/bat_iv_ogm.c:1700
 process_one_work+0x958/0x1b30 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

Freed by task 6434:
 kasan_save_stack+0x33/0x60 mm/kasan/common.c:47
 kasan_save_track+0x14/0x30 mm/kasan/common.c:68
 kasan_save_free_info+0x3b/0x60 mm/kasan/generic.c:576
 poison_slab_object mm/kasan/common.c:247 [inline]
 __kasan_slab_free+0x51/0x70 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:4609 [inline]
 kfree+0x2c4/0x4d0 mm/slub.c:4757
 skb_kfree_head net/core/skbuff.c:1086 [inline]
 skb_free_head+0x108/0x1d0 net/core/skbuff.c:1098
 skb_release_data+0x560/0x730 net/core/skbuff.c:1125
 skb_release_all net/core/skbuff.c:1190 [inline]
 __kfree_skb net/core/skbuff.c:1204 [inline]
 sk_skb_reason_drop+0x129/0x1a0 net/core/skbuff.c:1242
 kfree_skb_reason include/linux/skbuff.h:1271 [inline]
 __netif_receive_skb_core.constprop.0+0x575/0x4330 net/core/dev.c:5802
 __netif_receive_skb_one_core+0xb1/0x1e0 net/core/dev.c:5826
 __netif_receive_skb+0x1d/0x160 net/core/dev.c:5941
 process_backlog+0x443/0x15f0 net/core/dev.c:6289
 __napi_poll.constprop.0+0xb7/0x550 net/core/dev.c:7106
 napi_poll net/core/dev.c:7175 [inline]
 net_rx_action+0xa94/0x1010 net/core/dev.c:7297
 handle_softirqs+0x213/0x8f0 kernel/softirq.c:561
 do_softirq kernel/softirq.c:462 [inline]
 do_softirq+0xb2/0xf0 kernel/softirq.c:449
 __local_bh_enable_ip+0x100/0x120 kernel/softirq.c:389
 local_bh_enable include/linux/bottom_half.h:33 [inline]
 rcu_read_unlock_bh include/linux/rcupdate.h:919 [inline]
 __dev_queue_xmit+0x8b0/0x43e0 net/core/dev.c:4611
 dev_queue_xmit include/linux/netdevice.h:3305 [inline]
 batadv_send_skb_packet+0x588/0x770 net/batman-adv/send.c:108
 batadv_iv_ogm_send_to_if net/batman-adv/bat_iv_ogm.c:392 [inline]
 batadv_iv_ogm_emit net/batman-adv/bat_iv_ogm.c:420 [inline]
 batadv_iv_send_outstanding_bat_ogm_packet+0x70a/0x8d0 net/batman-adv/bat_iv_ogm.c:1700
 process_one_work+0x958/0x1b30 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 ffff888024021800
 which belongs to the cache kmalloc-1k of size 1024
The buggy address is located 562 bytes inside of
 freed 1024-byte region [ffff888024021800, ffff888024021c00)

The buggy address belongs to the physical page:
page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x24020
head: order:3 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0
flags: 0xfff00000000040(head|node=0|zone=1|lastcpupid=0x7ff)
page_type: f5(slab)
raw: 00fff00000000040 ffff88801b041dc0 ffffea0000a36400 dead000000000002
raw: 0000000000000000 0000000000100010 00000000f5000000 0000000000000000
head: 00fff00000000040 ffff88801b041dc0 ffffea0000a36400 dead000000000002
head: 0000000000000000 0000000000100010 00000000f5000000 0000000000000000
head: 00fff00000000003 ffffea0000900801 ffffffffffffffff 0000000000000000
head: 0000000000000008 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 5177, tgid 5177 (init), ts 25301747756, 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+0xbfa/0x1600 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]
 __do_kmalloc_node mm/slub.c:4293 [inline]
 __kmalloc_noprof+0x2de/0x4f0 mm/slub.c:4306
 kmalloc_noprof include/linux/slab.h:905 [inline]
 load_elf_phdrs+0x103/0x210 fs/binfmt_elf.c:532
 load_elf_binary+0x1518/0x4ff0 fs/binfmt_elf.c:961
 search_binary_handler fs/exec.c:1775 [inline]
 exec_binprm fs/exec.c:1807 [inline]
 bprm_execve fs/exec.c:1859 [inline]
 bprm_execve+0x8dd/0x16d0 fs/exec.c:1835
 do_execveat_common.isra.0+0x4a2/0x610 fs/exec.c:1966
 do_execve fs/exec.c:2040 [inline]
 __do_sys_execve fs/exec.c:2116 [inline]
 __se_sys_execve fs/exec.c:2111 [inline]
 __x64_sys_execve+0x8c/0xb0 fs/exec.c:2111
 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
page_owner free stack trace missing

Memory state around the buggy address:
 ffff888024021900: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff888024021980: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>ffff888024021a00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                                     ^
 ffff888024021a80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff888024021b00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
==================================================================

Crashes (10):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2025/02/09 00:04 upstream 8f6629c004b1 ef44b750 .config console log report info [disk image] [vmlinux] [kernel image] ci-qemu-gce-upstream-auto KASAN: slab-use-after-free Read in msft_opcode_get
2025/02/06 15:23 upstream 92514ef226f5 1e1faf27 .config console log report info [disk image] [vmlinux] [kernel image] ci-qemu-gce-upstream-auto KASAN: slab-use-after-free Read in msft_opcode_get
2025/02/03 01:00 upstream 69e858e0b8b2 568559e4 .config console log report info [disk image] [vmlinux] [kernel image] ci-qemu-gce-upstream-auto KASAN: slab-use-after-free Read in msft_opcode_get
2025/01/28 08:09 upstream 805ba04cb7cc 18070896 .config console log report info [disk image] [vmlinux] [kernel image] ci-qemu-gce-upstream-auto KASAN: slab-use-after-free Read in msft_opcode_get
2025/01/12 15:21 upstream b62cef9a5c67 6dbc6a9b .config console log report info [disk image] [vmlinux] [kernel image] ci-qemu-gce-upstream-auto KASAN: slab-use-after-free Read in msft_opcode_get
2024/12/28 01:33 upstream 8379578b11d5 d3ccff63 .config console log report info [disk image] [vmlinux] [kernel image] ci-qemu-gce-upstream-auto KASAN: slab-use-after-free Read in msft_opcode_get
2024/12/26 06:32 upstream 9b2ffa6148b1 444551c4 .config console log report info [disk image] [vmlinux] [kernel image] ci-qemu-gce-upstream-auto KASAN: slab-use-after-free Read in msft_opcode_get
2024/12/25 14:44 upstream 9b2ffa6148b1 444551c4 .config console log report info [disk image] [vmlinux] [kernel image] ci-qemu-gce-upstream-auto KASAN: slab-use-after-free Read in msft_opcode_get
2024/12/22 17:48 upstream bcde95ce32b6 b4fbdbd4 .config console log report info [disk image] [vmlinux] [kernel image] ci-qemu-gce-upstream-auto KASAN: slab-use-after-free Read in msft_opcode_get
2024/12/22 17:48 upstream bcde95ce32b6 b4fbdbd4 .config console log report info [disk image] [vmlinux] [kernel image] ci-qemu-gce-upstream-auto KASAN: slab-use-after-free Read in msft_opcode_get
* Struck through repros no longer work on HEAD.