[syzbot] [bluetooth?] KASAN: slab-use-after-free Read in l2cap_sock_ready_cb

From: syzbot
Date: Fri May 31 2024 - 10:22:02 EST

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Hello,

syzbot found the following issue on:

HEAD commit: 66ad4829ddd0 Merge tag 'net-6.10-rc1' of git://git.kernel...
git tree: net-next
console output: https://syzkaller.appspot.com/x/log.txt?x=149350d8980000
kernel config: https://syzkaller.appspot.com/x/.config?x=48c05addbb27f3b0
dashboard link: https://syzkaller.appspot.com/bug?extid=542cd57c45c01d9c33f8
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/32f7723d467f/disk-66ad4829.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/2cb82a76d362/vmlinux-66ad4829.xz
kernel image: https://storage.googleapis.com/syzbot-assets/07340808386b/bzImage-66ad4829.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+542cd57c45c01d9c33f8@xxxxxxxxxxxxxxxxxxxxxxxxx

==================================================================
BUG: KASAN: slab-use-after-free in l2cap_sock_ready_cb+0xd7/0x140 net/bluetooth/l2cap_sock.c:1662
Read of size 8 at addr ffff88806c4de188 by task kworker/1:1/17633

CPU: 1 PID: 17633 Comm: kworker/1:1 Not tainted 6.9.0-syzkaller-12071-g66ad4829ddd0 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/02/2024
Workqueue: events l2cap_info_timeout
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
l2cap_sock_ready_cb+0xd7/0x140 net/bluetooth/l2cap_sock.c:1662
l2cap_chan_ready net/bluetooth/l2cap_core.c:1256 [inline]
l2cap_conn_start+0x8db/0x1140 net/bluetooth/l2cap_core.c:1506
process_one_work kernel/workqueue.c:3231 [inline]
process_scheduled_works+0xa2c/0x1830 kernel/workqueue.c:3312
worker_thread+0x86d/0xd70 kernel/workqueue.c:3393
kthread+0x2f0/0x390 kernel/kthread.c:389
ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244
</TASK>

Allocated by task 27936:
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:4121 [inline]
__kmalloc_noprof+0x1f9/0x400 mm/slub.c:4134
kmalloc_noprof include/linux/slab.h:664 [inline]
sk_prot_alloc+0xe0/0x210 net/core/sock.c:2080
sk_alloc+0x38/0x370 net/core/sock.c:2133
bt_sock_alloc+0x3c/0x340 net/bluetooth/af_bluetooth.c:148
l2cap_sock_alloc net/bluetooth/l2cap_sock.c:1869 [inline]
l2cap_sock_create+0x13f/0x2d0 net/bluetooth/l2cap_sock.c:1909
bt_sock_create+0x161/0x230 net/bluetooth/af_bluetooth.c:132
__sock_create+0x490/0x920 net/socket.c:1571
sock_create net/socket.c:1622 [inline]
__sys_socket_create net/socket.c:1659 [inline]
__sys_socket+0x150/0x3c0 net/socket.c:1706
__do_sys_socket net/socket.c:1720 [inline]
__se_sys_socket net/socket.c:1718 [inline]
__x64_sys_socket+0x7a/0x90 net/socket.c:1718
do_syscall_x64 arch/x86/entry/common.c:52 [inline]
do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83
entry_SYSCALL_64_after_hwframe+0x77/0x7f

Freed by task 27935:
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+0xe0/0x150 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:2195 [inline]
slab_free mm/slub.c:4436 [inline]
kfree+0x149/0x360 mm/slub.c:4557
sk_prot_free net/core/sock.c:2116 [inline]
__sk_destruct+0x476/0x5f0 net/core/sock.c:2208
l2cap_sock_release+0x15b/0x1d0 net/bluetooth/l2cap_sock.c:1417
__sock_release net/socket.c:659 [inline]
sock_close+0xbc/0x240 net/socket.c:1421
__fput+0x406/0x8b0 fs/file_table.c:422
__do_sys_close fs/open.c:1555 [inline]
__se_sys_close fs/open.c:1540 [inline]
__x64_sys_close+0x7f/0x110 fs/open.c:1540
do_syscall_x64 arch/x86/entry/common.c:52 [inline]
do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83
entry_SYSCALL_64_after_hwframe+0x77/0x7f

The buggy address belongs to the object at ffff88806c4de000
which belongs to the cache kmalloc-2k of size 2048
The buggy address is located 392 bytes inside of
freed 2048-byte region [ffff88806c4de000, ffff88806c4de800)

The buggy address belongs to the physical page:
page: refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x6c4d8
head: order:3 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0
anon flags: 0xfff00000000040(head|node=0|zone=1|lastcpupid=0x7ff)
page_type: 0xffffefff(slab)
raw: 00fff00000000040 ffff888015042000 0000000000000000 dead000000000001
raw: 0000000000000000 0000000000080008 00000001ffffefff 0000000000000000
head: 00fff00000000040 ffff888015042000 0000000000000000 dead000000000001
head: 0000000000000000 0000000000080008 00000001ffffefff 0000000000000000
head: 00fff00000000003 ffffea0001b13601 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 0x1d20c0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC|__GFP_HARDWALL), pid 26413, tgid 26413 (syz-executor.2), ts 1938838512727, free_ts 1929373430793
set_page_owner include/linux/page_owner.h:32 [inline]
post_alloc_hook+0x1f3/0x230 mm/page_alloc.c:1468
prep_new_page mm/page_alloc.c:1476 [inline]
get_page_from_freelist+0x2e2d/0x2ee0 mm/page_alloc.c:3402
__alloc_pages_noprof+0x256/0x6c0 mm/page_alloc.c:4660
__alloc_pages_node_noprof include/linux/gfp.h:269 [inline]
alloc_pages_node_noprof include/linux/gfp.h:296 [inline]
alloc_slab_page+0x5f/0x120 mm/slub.c:2264
allocate_slab+0x5a/0x2e0 mm/slub.c:2427
new_slab mm/slub.c:2480 [inline]
___slab_alloc+0xcd1/0x14b0 mm/slub.c:3666
__slab_alloc+0x58/0xa0 mm/slub.c:3756
__slab_alloc_node mm/slub.c:3809 [inline]
slab_alloc_node mm/slub.c:3988 [inline]
__do_kmalloc_node mm/slub.c:4120 [inline]
kmalloc_node_track_caller_noprof+0x281/0x440 mm/slub.c:4141
kmemdup_noprof+0x2a/0x60 mm/util.c:131
ip_vs_control_net_init_sysctl net/netfilter/ipvs/ip_vs_ctl.c:4284 [inline]
ip_vs_control_net_init+0x7da/0x17f0 net/netfilter/ipvs/ip_vs_ctl.c:4463
__ip_vs_init+0x2d2/0x460 net/netfilter/ipvs/ip_vs_core.c:2308
ops_init+0x359/0x610 net/core/net_namespace.c:139
setup_net+0x515/0xca0 net/core/net_namespace.c:343
copy_net_ns+0x4e2/0x7b0 net/core/net_namespace.c:508
create_new_namespaces+0x425/0x7b0 kernel/nsproxy.c:110
unshare_nsproxy_namespaces+0x124/0x180 kernel/nsproxy.c:228
page last free pid 26200 tgid 26200 stack trace:
reset_page_owner include/linux/page_owner.h:25 [inline]
free_pages_prepare mm/page_alloc.c:1088 [inline]
free_unref_page+0xd22/0xea0 mm/page_alloc.c:2565
vfree+0x186/0x2e0 mm/vmalloc.c:3346
kcov_put kernel/kcov.c:429 [inline]
kcov_close+0x2b/0x50 kernel/kcov.c:525
__fput+0x406/0x8b0 fs/file_table.c:422
task_work_run+0x24f/0x310 kernel/task_work.c:180
exit_task_work include/linux/task_work.h:38 [inline]
do_exit+0xa27/0x27e0 kernel/exit.c:874
do_group_exit+0x207/0x2c0 kernel/exit.c:1023
get_signal+0x16a1/0x1740 kernel/signal.c:2909
arch_do_signal_or_restart+0x96/0x860 arch/x86/kernel/signal.c:310
exit_to_user_mode_loop kernel/entry/common.c:111 [inline]
exit_to_user_mode_prepare include/linux/entry-common.h:328 [inline]
__syscall_exit_to_user_mode_work kernel/entry/common.c:207 [inline]
syscall_exit_to_user_mode+0xc9/0x370 kernel/entry/common.c:218
do_syscall_64+0x100/0x230 arch/x86/entry/common.c:89
entry_SYSCALL_64_after_hwframe+0x77/0x7f

Memory state around the buggy address:
ffff88806c4de080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
ffff88806c4de100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>ffff88806c4de180: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
^
ffff88806c4de200: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
ffff88806c4de280: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
==================================================================

---
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Next message: Eric W. Biederman: "Re: [PATCH v9 06/19] x86: Add early SHA-1 support for Secure Launch early measurements"
Previous message: Shuah Khan: "Re: [PATCH] Documentation/accel/qaic: Fix typo 'phsyical'"
Messages sorted by: [ date ] [ thread ] [ subject ] [ author ]