syzbot


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

Status: upstream: reported on 2024/09/04 12:35
Subsystems: bpf net
[Documentation on labels]
Reported-by: syzbot+b4bc25bfaad44df51f05@syzkaller.appspotmail.com
First crash: 161d, last: 3d20h
Discussions (1)
Title Replies (including bot) Last reply
[syzbot] [bpf?] [net?] KASAN: slab-use-after-free Read in sk_filter_trim_cap 0 (1) 2024/09/04 12:35
Similar bugs (2)
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
linux-4.19 KASAN: use-after-free Read in sk_filter_trim_cap 1 1071d 1071d 0/1 auto-closed as invalid on 2022/07/07 20:56
linux-6.1 KASAN: use-after-free Read in sk_filter_trim_cap 1 208d 208d 0/3 auto-obsoleted due to no activity on 2024/10/27 21:54

Sample crash report:
==================================================================
BUG: KASAN: slab-use-after-free in sk_filter_trim_cap+0x270/0xa80 net/core/filter.c:156
Read of size 8 at addr ffff8881476ff178 by task syz.1.1205/10184

CPU: 1 UID: 0 PID: 10184 Comm: syz.1.1205 Not tainted 6.14.0-rc1-syzkaller-00092-g011b03359038 #0
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+0x241/0x360 lib/dump_stack.c:120
 print_address_description mm/kasan/report.c:378 [inline]
 print_report+0x169/0x550 mm/kasan/report.c:489
 kasan_report+0x143/0x180 mm/kasan/report.c:602
 sk_filter_trim_cap+0x270/0xa80 net/core/filter.c:156
 sk_filter include/linux/filter.h:1062 [inline]
 sock_queue_rcv_skb_reason+0x28/0xf0 net/core/sock.c:527
 sock_queue_rcv_skb include/net/sock.h:2402 [inline]
 mgmt_cmd_status+0x28d/0x4d0 net/bluetooth/mgmt_util.c:156
 cmd_status_rsp net/bluetooth/mgmt.c:1458 [inline]
 cmd_complete_rsp+0x114/0x180 net/bluetooth/mgmt.c:1478
 mgmt_pending_foreach+0xd1/0x130 net/bluetooth/mgmt_util.c:259
 __mgmt_power_off+0x183/0x430 net/bluetooth/mgmt.c:9463
 hci_dev_close_sync+0x6c4/0x11c0 net/bluetooth/hci_sync.c:5193
 hci_dev_do_close net/bluetooth/hci_core.c:482 [inline]
 hci_dev_close+0x112/0x210 net/bluetooth/hci_core.c:507
 sock_do_ioctl+0x158/0x460 net/socket.c:1194
 sock_ioctl+0x626/0x8e0 net/socket.c:1313
 vfs_ioctl fs/ioctl.c:51 [inline]
 __do_sys_ioctl fs/ioctl.c:906 [inline]
 __se_sys_ioctl+0xf5/0x170 fs/ioctl.c:892
 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
RIP: 0033:0x7f4ff498cde9
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:00007f4ff5838038 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007f4ff4ba5fa0 RCX: 00007f4ff498cde9
RDX: 0000000000000000 RSI: 00000000400448ca RDI: 0000000000000006
RBP: 00007f4ff4a0e2a0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 00007f4ff4ba5fa0 R15: 00007fffe8945718
 </TASK>

Allocated by task 7365:
 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:377 [inline]
 __kasan_kmalloc+0x98/0xb0 mm/kasan/common.c:394
 kasan_kmalloc include/linux/kasan.h:260 [inline]
 __do_kmalloc_node mm/slub.c:4294 [inline]
 __kmalloc_noprof+0x285/0x4c0 mm/slub.c:4306
 kmalloc_noprof include/linux/slab.h:905 [inline]
 sk_prot_alloc+0xe0/0x210 net/core/sock.c:2181
 sk_alloc+0x38/0x370 net/core/sock.c:2234
 bt_sock_alloc+0x3c/0x340 net/bluetooth/af_bluetooth.c:148
 hci_sock_create+0xa1/0x190 net/bluetooth/hci_sock.c:2202
 bt_sock_create+0x161/0x230 net/bluetooth/af_bluetooth.c:132
 __sock_create+0x4c0/0xa30 net/socket.c:1543
 sock_create net/socket.c:1601 [inline]
 __sys_socket_create net/socket.c:1638 [inline]
 __sys_socket+0x150/0x3c0 net/socket.c:1685
 __do_sys_socket net/socket.c:1699 [inline]
 __se_sys_socket net/socket.c:1697 [inline]
 __x64_sys_socket+0x7a/0x90 net/socket.c:1697
 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 10186:
 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:576
 poison_slab_object mm/kasan/common.c:247 [inline]
 __kasan_slab_free+0x59/0x70 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+0x196/0x430 mm/slub.c:4757
 sk_prot_free net/core/sock.c:2217 [inline]
 __sk_destruct+0x479/0x5f0 net/core/sock.c:2309
 sock_put include/net/sock.h:1913 [inline]
 mgmt_pending_free net/bluetooth/mgmt_util.c:307 [inline]
 mgmt_pending_remove+0x13e/0x1a0 net/bluetooth/mgmt_util.c:315
 mgmt_pending_foreach+0xd1/0x130 net/bluetooth/mgmt_util.c:259
 mgmt_index_removed+0x133/0x390 net/bluetooth/mgmt.c:9396
 hci_sock_bind+0xcce/0x1150 net/bluetooth/hci_sock.c:1307
 __sys_bind_socket net/socket.c:1812 [inline]
 __sys_bind+0x1e4/0x290 net/socket.c:1843
 __do_sys_bind net/socket.c:1848 [inline]
 __se_sys_bind net/socket.c:1846 [inline]
 __x64_sys_bind+0x7a/0x90 net/socket.c:1846
 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 ffff8881476ff000
 which belongs to the cache kmalloc-2k of size 2048
The buggy address is located 376 bytes inside of
 freed 2048-byte region [ffff8881476ff000, ffff8881476ff800)

The buggy address belongs to the physical page:
page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x1476f8
head: order:3 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0
anon flags: 0x57ff00000000040(head|node=1|zone=2|lastcpupid=0x7ff)
page_type: f5(slab)
raw: 057ff00000000040 ffff88801ac42000 0000000000000000 dead000000000001
raw: 0000000000000000 0000000000080008 00000000f5000000 0000000000000000
head: 057ff00000000040 ffff88801ac42000 0000000000000000 dead000000000001
head: 0000000000000000 0000000000080008 00000000f5000000 0000000000000000
head: 057ff00000000003 ffffea00051dbe01 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 1, tgid 1 (swapper/0), ts 6107539473, free_ts 0
 set_page_owner include/linux/page_owner.h:32 [inline]
 post_alloc_hook+0x1f4/0x240 mm/page_alloc.c:1551
 prep_new_page mm/page_alloc.c:1559 [inline]
 get_page_from_freelist+0x365c/0x37a0 mm/page_alloc.c:3477
 __alloc_frozen_pages_noprof+0x292/0x710 mm/page_alloc.c:4739
 alloc_pages_mpol+0x311/0x660 mm/mempolicy.c:2270
 alloc_slab_page mm/slub.c:2423 [inline]
 allocate_slab+0x8f/0x3a0 mm/slub.c:2587
 new_slab mm/slub.c:2640 [inline]
 ___slab_alloc+0xc27/0x14a0 mm/slub.c:3826
 __slab_alloc+0x58/0xa0 mm/slub.c:3916
 __slab_alloc_node mm/slub.c:3991 [inline]
 slab_alloc_node mm/slub.c:4152 [inline]
 __kmalloc_cache_noprof+0x27b/0x390 mm/slub.c:4320
 kmalloc_noprof include/linux/slab.h:901 [inline]
 kzalloc_noprof include/linux/slab.h:1037 [inline]
 device_create_groups_vargs drivers/base/core.c:4329 [inline]
 device_create_with_groups+0x121/0x2e0 drivers/base/core.c:4427
 misc_register+0x3ea/0x670 drivers/char/misc.c:264
 fuse_dev_init+0xa9/0x130 fs/fuse/dev.c:2517
 fuse_init+0x5a/0x160 fs/fuse/inode.c:2184
 do_one_initcall+0x248/0x870 init/main.c:1257
 do_initcall_level+0x157/0x210 init/main.c:1319
 do_initcalls+0x3f/0x80 init/main.c:1335
 kernel_init_freeable+0x435/0x5d0 init/main.c:1568
page_owner free stack trace missing

Memory state around the buggy address:
 ffff8881476ff000: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff8881476ff080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>ffff8881476ff100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                                                                ^
 ffff8881476ff180: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff8881476ff200: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
==================================================================

Crashes (6):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2025/02/09 01:27 net 011b03359038 ef44b750 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-net-this-kasan-gce KASAN: slab-use-after-free Read in sk_filter_trim_cap
2025/02/07 06:41 net 2a64c96356c8 53657d1b .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-net-this-kasan-gce KASAN: slab-use-after-free Read in sk_filter_trim_cap
2025/01/21 06:58 net d640627663bf 6e87cfa2 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-net-this-kasan-gce KASAN: slab-use-after-free Read in sk_filter_trim_cap
2024/12/04 06:44 net af8edaeddbc5 b50eb251 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-net-this-kasan-gce KASAN: slab-use-after-free Read in sk_filter_trim_cap
2024/09/04 06:58 net 33f339a1ba54 9d47f20a .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-net-this-kasan-gce KASAN: slab-use-after-free Read in sk_filter_trim_cap
2024/11/03 00:35 net-next dbb9a7ef3478 f00eed24 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-net-kasan-gce KASAN: slab-use-after-free Read in sk_filter_trim_cap
* Struck through repros no longer work on HEAD.