2024-04-22 06:47:40

by syzbot

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Subject: [syzbot] [bluetooth?] KASAN: slab-use-after-free Read in skb_release_head_state

Hello,

syzbot found the following issue on:

HEAD commit: fe46a7dd189e Merge tag 'sound-6.9-rc1' of git://git.kernel..
git tree: upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=14dce3f3180000
kernel config: https://syzkaller.appspot.com/x/.config?x=4d90a36f0cab495a
dashboard link: https://syzkaller.appspot.com/bug?extid=d863bc2d28ef7ff42984
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/f6c04726a2ae/disk-fe46a7dd.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/09c26ce901ea/vmlinux-fe46a7dd.xz
kernel image: https://storage.googleapis.com/syzbot-assets/134acf7f5322/bzImage-fe46a7dd.xz

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

==================================================================
BUG: KASAN: slab-use-after-free in skb_dst_drop include/net/dst.h:274 [inline]
BUG: KASAN: slab-use-after-free in skb_release_head_state+0x39/0x250 net/core/skbuff.c:1185
Read of size 8 at addr ffff88801e90fa58 by task syz-executor.0/19245

CPU: 1 PID: 19245 Comm: syz-executor.0 Not tainted 6.8.0-syzkaller-08951-gfe46a7dd189e #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
skb_dst_drop include/net/dst.h:274 [inline]
skb_release_head_state+0x39/0x250 net/core/skbuff.c:1185
skb_release_all net/core/skbuff.c:1200 [inline]
__kfree_skb net/core/skbuff.c:1216 [inline]
kfree_skb_reason+0x15d/0x390 net/core/skbuff.c:1252
kfree_skb include/linux/skbuff.h:1267 [inline]
__hci_req_sync+0x62f/0x950 net/bluetooth/hci_request.c:182
hci_req_sync+0xa9/0xd0 net/bluetooth/hci_request.c:204
hci_inquiry+0x44b/0x870 net/bluetooth/hci_core.c:425
sock_do_ioctl+0x158/0x460 net/socket.c:1222
sock_ioctl+0x629/0x8e0 net/socket.c:1341
vfs_ioctl fs/ioctl.c:51 [inline]
__do_sys_ioctl fs/ioctl.c:904 [inline]
__se_sys_ioctl+0xfc/0x170 fs/ioctl.c:890
do_syscall_64+0xfb/0x240
entry_SYSCALL_64_after_hwframe+0x6d/0x75
RIP: 0033:0x7f8668c7de69
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:00007f8669aaf0c8 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007f8668dabf80 RCX: 00007f8668c7de69
RDX: 0000000020001c80 RSI: 00000000800448f0 RDI: 0000000000000009
RBP: 00007f8668cca47a R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 000000000000000b R14: 00007f8668dabf80 R15: 00007ffd40ae2748
</TASK>

Allocated by task 4457:
kasan_save_stack mm/kasan/common.c:47 [inline]
kasan_save_track+0x3f/0x80 mm/kasan/common.c:68
unpoison_slab_object mm/kasan/common.c:312 [inline]
__kasan_slab_alloc+0x66/0x80 mm/kasan/common.c:338
kasan_slab_alloc include/linux/kasan.h:201 [inline]
slab_post_alloc_hook mm/slub.c:3798 [inline]
slab_alloc_node mm/slub.c:3845 [inline]
kmem_cache_alloc+0x174/0x340 mm/slub.c:3852
skb_clone+0x20c/0x390 net/core/skbuff.c:2063
hci_send_cmd_sync net/bluetooth/hci_core.c:4220 [inline]
hci_cmd_work+0x29c/0x660 net/bluetooth/hci_core.c:4240
process_one_work kernel/workqueue.c:3254 [inline]
process_scheduled_works+0xa00/0x1770 kernel/workqueue.c:3335
worker_thread+0x86d/0xd70 kernel/workqueue.c:3416
kthread+0x2f0/0x390 kernel/kthread.c:388
ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:243

Freed by task 4457:
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]
kmem_cache_free+0x102/0x2b0 mm/slub.c:4344
kfree_skb include/linux/skbuff.h:1267 [inline]
hci_send_cmd_sync net/bluetooth/hci_core.c:4219 [inline]
hci_cmd_work+0x271/0x660 net/bluetooth/hci_core.c:4240
process_one_work kernel/workqueue.c:3254 [inline]
process_scheduled_works+0xa00/0x1770 kernel/workqueue.c:3335
worker_thread+0x86d/0xd70 kernel/workqueue.c:3416
kthread+0x2f0/0x390 kernel/kthread.c:388
ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:243

The buggy address belongs to the object at ffff88801e90fa00
which belongs to the cache skbuff_head_cache of size 240
The buggy address is located 88 bytes inside of
freed 240-byte region [ffff88801e90fa00, ffff88801e90faf0)

The buggy address belongs to the physical page:
page:ffffea00007a43c0 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x1e90f
ksm flags: 0xfff00000000800(slab|node=0|zone=1|lastcpupid=0x7ff)
page_type: 0xffffffff()
raw: 00fff00000000800 ffff88801968f780 ffffea0001bd7680 dead000000000003
raw: 0000000000000000 00000000000c000c 00000001ffffffff 0000000000000000
page dumped because: kasan: bad access detected
page_owner tracks the page as allocated
page last allocated via order 0, migratetype Unmovable, gfp_mask 0x112820(GFP_ATOMIC|__GFP_NOWARN|__GFP_NORETRY|__GFP_HARDWALL), pid 5060, tgid 5059 (syz-fuzzer), ts 415373569576, free_ts 415310225812
set_page_owner include/linux/page_owner.h:31 [inline]
post_alloc_hook+0x1ea/0x210 mm/page_alloc.c:1533
prep_new_page mm/page_alloc.c:1540 [inline]
get_page_from_freelist+0x33ea/0x3580 mm/page_alloc.c:3311
__alloc_pages+0x256/0x680 mm/page_alloc.c:4569
__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
__kmem_cache_alloc_bulk mm/slub.c:4555 [inline]
kmem_cache_alloc_bulk+0x22e/0x790 mm/slub.c:4629
napi_skb_cache_get+0x166/0x230 net/core/skbuff.c:348
__napi_build_skb net/core/skbuff.c:527 [inline]
__napi_alloc_skb+0x217/0x540 net/core/skbuff.c:846
napi_alloc_skb include/linux/skbuff.h:3363 [inline]
page_to_skb+0x275/0x9b0 drivers/net/virtio_net.c:569
receive_mergeable drivers/net/virtio_net.c:1683 [inline]
receive_buf+0x3b3/0x3890 drivers/net/virtio_net.c:1804
virtnet_receive drivers/net/virtio_net.c:2110 [inline]
virtnet_poll+0x720/0x18f0 drivers/net/virtio_net.c:2203
__napi_poll+0xcb/0x490 net/core/dev.c:6632
napi_poll net/core/dev.c:6701 [inline]
net_rx_action+0x7bb/0x1090 net/core/dev.c:6813
__do_softirq+0x2bc/0x943 kernel/softirq.c:554
page last free pid 12584 tgid 12583 stack trace:
reset_page_owner include/linux/page_owner.h:24 [inline]
free_pages_prepare mm/page_alloc.c:1140 [inline]
free_unref_page_prepare+0x95d/0xa80 mm/page_alloc.c:2346
free_unref_page_list+0x5a3/0x850 mm/page_alloc.c:2532
release_pages+0x2117/0x2400 mm/swap.c:1042
tlb_batch_pages_flush mm/mmu_gather.c:98 [inline]
tlb_flush_mmu_free mm/mmu_gather.c:293 [inline]
tlb_flush_mmu+0x34d/0x4e0 mm/mmu_gather.c:300
tlb_finish_mmu+0xd4/0x200 mm/mmu_gather.c:392
exit_mmap+0x4b6/0xd40 mm/mmap.c:3300
__mmput+0x115/0x3c0 kernel/fork.c:1345
exit_mm+0x220/0x310 kernel/exit.c:569
do_exit+0x99e/0x27e0 kernel/exit.c:865
do_group_exit+0x207/0x2c0 kernel/exit.c:1027
get_signal+0x176e/0x1850 kernel/signal.c:2907
arch_do_signal_or_restart+0x96/0x860 arch/x86/kernel/signal.c:310
exit_to_user_mode_loop kernel/entry/common.c:105 [inline]
exit_to_user_mode_prepare include/linux/entry-common.h:328 [inline]
__syscall_exit_to_user_mode_work kernel/entry/common.c:201 [inline]
syscall_exit_to_user_mode+0xc9/0x360 kernel/entry/common.c:212
do_syscall_64+0x10a/0x240 arch/x86/entry/common.c:89
entry_SYSCALL_64_after_hwframe+0x6d/0x75

Memory state around the buggy address:
ffff88801e90f900: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
ffff88801e90f980: fb fb fb fb fb fb fc fc fc fc fc fc fc fc fc fc
>ffff88801e90fa00: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
^
ffff88801e90fa80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fc fc
ffff88801e90fb00: fc fc fc fc fc fc fc fc fa fb fb fb fb fb fb fb
==================================================================


---
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