syzbot


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

Status: upstream: reported on 2025/01/27 07:59
Subsystems: bluetooth net
[Documentation on labels]
Reported-by: syzbot+0cabe82a7ed71379b27d@syzkaller.appspotmail.com
First crash: 115d, last: 93d
Discussions (1)
Title Replies (including bot) Last reply
[syzbot] [bluetooth?] KASAN: slab-use-after-free Read in sock_def_readable 0 (1) 2025/01/27 07:59
Similar bugs (1)
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
linux-4.19 KASAN: use-after-free Read in sock_def_readable 1 1324d 1324d 0/1 auto-closed as invalid on 2022/01/28 14:25

Sample crash report:
kobject: kobject_add_internal failed for hci0:201 with -EEXIST, don't try to register things with the same name in the same directory.
Bluetooth: hci0: failed to register connection device
==================================================================
BUG: KASAN: slab-use-after-free in sock_def_readable+0x5c4/0x610 net/core/sock.c:3474
Read of size 8 at addr ffff8880294a0180 by task kworker/u33:4/5949

CPU: 0 UID: 0 PID: 5949 Comm: kworker/u33:4 Not tainted 6.14.0-rc1-syzkaller-00187-g8f6629c004b1 #0
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2~bpo12+1 04/01/2014
Workqueue: hci0 hci_rx_work
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
 sock_def_readable+0x5c4/0x610 net/core/sock.c:3474
 l2cap_sock_ready_cb+0x108/0x170 net/bluetooth/l2cap_sock.c:1672
 l2cap_chan_ready net/bluetooth/l2cap_core.c:1239 [inline]
 l2cap_le_start+0x1ec/0xe40 net/bluetooth/l2cap_core.c:1368
 l2cap_conn_ready net/bluetooth/l2cap_core.c:1624 [inline]
 l2cap_connect_cfm+0x99f/0xf10 net/bluetooth/l2cap_core.c:7280
 hci_connect_cfm include/net/bluetooth/hci_core.h:2051 [inline]
 le_conn_complete_evt+0x168d/0x1da0 net/bluetooth/hci_event.c:5763
 hci_le_conn_complete_evt+0x23c/0x370 net/bluetooth/hci_event.c:5789
 hci_le_meta_evt+0x2e2/0x5d0 net/bluetooth/hci_event.c:7162
 hci_event_func net/bluetooth/hci_event.c:7470 [inline]
 hci_event_packet+0x666/0x1180 net/bluetooth/hci_event.c:7525
 hci_rx_work+0x2c5/0x16b0 net/bluetooth/hci_core.c:4015
 process_one_work+0x9c5/0x1ba0 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
 </TASK>

Allocated by task 6309:
 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_noprof+0x21c/0x510 mm/slub.c:4306
 kmalloc_noprof include/linux/slab.h:905 [inline]
 sk_prot_alloc+0x1a8/0x2a0 net/core/sock.c:2181
 sk_alloc+0x36/0xb90 net/core/sock.c:2234
 bt_sock_alloc+0x3b/0x3a0 net/bluetooth/af_bluetooth.c:148
 l2cap_sock_alloc.constprop.0+0x33/0x1d0 net/bluetooth/l2cap_sock.c:1879
 l2cap_sock_create+0x123/0x1f0 net/bluetooth/l2cap_sock.c:1921
 bt_sock_create+0x182/0x350 net/bluetooth/af_bluetooth.c:132
 __sock_create+0x335/0x8d0 net/socket.c:1548
 sock_create net/socket.c:1606 [inline]
 __sys_socket_create net/socket.c:1643 [inline]
 __sys_socket+0x14f/0x260 net/socket.c:1690
 __do_sys_socket net/socket.c:1704 [inline]
 __se_sys_socket net/socket.c:1702 [inline]
 __x64_sys_socket+0x72/0xb0 net/socket.c:1702
 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

Freed by task 6309:
 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
 sk_prot_free net/core/sock.c:2217 [inline]
 __sk_destruct+0x5eb/0x720 net/core/sock.c:2309
 sk_destruct+0xc2/0xf0 net/core/sock.c:2324
 __sk_free+0xf4/0x3e0 net/core/sock.c:2335
 sk_free+0x6a/0x90 net/core/sock.c:2346
 sock_put include/net/sock.h:1913 [inline]
 l2cap_sock_kill net/bluetooth/l2cap_sock.c:1252 [inline]
 l2cap_sock_kill+0x171/0x2d0 net/bluetooth/l2cap_sock.c:1237
 l2cap_sock_release+0x189/0x210 net/bluetooth/l2cap_sock.c:1423
 __sock_release+0xb0/0x270 net/socket.c:647
 sock_close+0x1c/0x30 net/socket.c:1398
 __fput+0x3ff/0xb70 fs/file_table.c:464
 task_work_run+0x14e/0x250 kernel/task_work.c:227
 resume_user_mode_work include/linux/resume_user_mode.h:50 [inline]
 exit_to_user_mode_loop kernel/entry/common.c:114 [inline]
 exit_to_user_mode_prepare include/linux/entry-common.h:329 [inline]
 __syscall_exit_to_user_mode_work kernel/entry/common.c:207 [inline]
 syscall_exit_to_user_mode+0x27b/0x2a0 kernel/entry/common.c:218
 do_syscall_64+0xda/0x250 arch/x86/entry/common.c:89
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

The buggy address belongs to the object at ffff8880294a0000
 which belongs to the cache kmalloc-2k of size 2048
The buggy address is located 384 bytes inside of
 freed 2048-byte region [ffff8880294a0000, ffff8880294a0800)

The buggy address belongs to the physical page:
page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x294a0
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 ffff88801b042f00 dead000000000100 dead000000000122
raw: 0000000000000000 0000000000080008 00000000f5000000 0000000000000000
head: 00fff00000000040 ffff88801b042f00 dead000000000100 dead000000000122
head: 0000000000000000 0000000000080008 00000000f5000000 0000000000000000
head: 00fff00000000003 ffffea0000a52801 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 0xd2820(GFP_ATOMIC|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 0, tgid 0 (swapper/0), ts 47024667822, free_ts 46991487570
 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+0xc5d/0x1720 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_node_track_caller_noprof+0x2f1/0x510 mm/slub.c:4313
 kmalloc_reserve+0xef/0x2c0 net/core/skbuff.c:609
 __alloc_skb+0x164/0x380 net/core/skbuff.c:678
 alloc_skb include/linux/skbuff.h:1331 [inline]
 igmpv3_newpack+0x1bd/0x11e0 net/ipv4/igmp.c:364
 add_grhead+0x26a/0x310 net/ipv4/igmp.c:445
 add_grec+0xf6d/0x11e0 net/ipv4/igmp.c:579
 igmpv3_send_cr net/ipv4/igmp.c:716 [inline]
 igmp_ifc_timer_expire+0x634/0x1020 net/ipv4/igmp.c:815
 call_timer_fn+0x1a0/0x610 kernel/time/timer.c:1789
 expire_timers kernel/time/timer.c:1840 [inline]
 __run_timers+0x6e8/0x930 kernel/time/timer.c:2414
page last free pid 5355 tgid 5355 stack trace:
 reset_page_owner include/linux/page_owner.h:25 [inline]
 free_pages_prepare mm/page_alloc.c:1127 [inline]
 free_frozen_pages+0x6db/0xfb0 mm/page_alloc.c:2660
 qlink_free mm/kasan/quarantine.c:163 [inline]
 qlist_free_all+0x4e/0x120 mm/kasan/quarantine.c:179
 kasan_quarantine_reduce+0x195/0x1e0 mm/kasan/quarantine.c:286
 __kasan_slab_alloc+0x69/0x90 mm/kasan/common.c:329
 kasan_slab_alloc include/linux/kasan.h:250 [inline]
 slab_post_alloc_hook mm/slub.c:4115 [inline]
 slab_alloc_node mm/slub.c:4164 [inline]
 kmem_cache_alloc_lru_noprof+0x226/0x3d0 mm/slub.c:4183
 shmem_alloc_inode+0x25/0x50 mm/shmem.c:5137
 alloc_inode+0x5d/0x230 fs/inode.c:336
 new_inode_pseudo fs/inode.c:1174 [inline]
 new_inode+0x22/0x210 fs/inode.c:1193
 __shmem_get_inode mm/shmem.c:3035 [inline]
 shmem_get_inode+0x194/0xf00 mm/shmem.c:3109
 shmem_mknod+0x1a8/0x450 mm/shmem.c:3831
 lookup_open.isra.0+0x11d2/0x1580 fs/namei.c:3651
 open_last_lookups fs/namei.c:3750 [inline]
 path_openat+0x904/0x2d80 fs/namei.c:3986
 do_filp_open+0x20c/0x470 fs/namei.c:4016
 do_sys_openat2+0x17a/0x1e0 fs/open.c:1428
 do_sys_open fs/open.c:1443 [inline]
 __do_sys_openat fs/open.c:1459 [inline]
 __se_sys_openat fs/open.c:1454 [inline]
 __x64_sys_openat+0x175/0x210 fs/open.c:1454
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xcd/0x250 arch/x86/entry/common.c:83

Memory state around the buggy address:
 ffff8880294a0080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff8880294a0100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>ffff8880294a0180: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                   ^
 ffff8880294a0200: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff8880294a0280: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
==================================================================

Crashes (3):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2025/02/09 00:32 upstream 8f6629c004b1 ef44b750 .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream KASAN: slab-use-after-free Read in sock_def_readable
2025/01/21 21:26 upstream 95ec54a420b8 da72ac06 .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream-386 KASAN: slab-use-after-free Read in sock_def_readable
2025/02/13 01:55 upstream 4dc1d1bec898 b27c2402 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs KASAN: wild-memory-access Read in sock_def_readable
* Struck through repros no longer work on HEAD.