Hello,
syzbot has tested the proposed patch but the reproducer is still triggering an issue:
KASAN: slab-use-after-free Write in sco_conn_del
==================================================================
BUG: KASAN: slab-use-after-free in instrument_atomic_read_write include/linux/instrumented.h:96 [inline]
BUG: KASAN: slab-use-after-free in atomic_fetch_add_relaxed include/linux/atomic/atomic-instrumented.h:252 [inline]
BUG: KASAN: slab-use-after-free in __refcount_add include/linux/refcount.h:184 [inline]
BUG: KASAN: slab-use-after-free in __refcount_inc include/linux/refcount.h:241 [inline]
BUG: KASAN: slab-use-after-free in refcount_inc include/linux/refcount.h:258 [inline]
BUG: KASAN: slab-use-after-free in sock_hold include/net/sock.h:781 [inline]
BUG: KASAN: slab-use-after-free in sco_conn_del+0xa5/0x310 net/bluetooth/sco.c:220
Write of size 4 at addr ffff88807bd72080 by task syz-executor.0/5406
CPU: 0 UID: 0 PID: 5406 Comm: syz-executor.0 Not tainted 6.12.0-rc4-syzkaller-gc2ee9f594da8-dirty #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024
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:377 [inline]
print_report+0x169/0x550 mm/kasan/report.c:488
kasan_report+0x143/0x180 mm/kasan/report.c:601
kasan_check_range+0x282/0x290 mm/kasan/generic.c:189
instrument_atomic_read_write include/linux/instrumented.h:96 [inline]
atomic_fetch_add_relaxed include/linux/atomic/atomic-instrumented.h:252 [inline]
__refcount_add include/linux/refcount.h:184 [inline]
__refcount_inc include/linux/refcount.h:241 [inline]
refcount_inc include/linux/refcount.h:258 [inline]
sock_hold include/net/sock.h:781 [inline]
sco_conn_del+0xa5/0x310 net/bluetooth/sco.c:220
hci_disconn_cfm include/net/bluetooth/hci_core.h:1975 [inline]
hci_conn_hash_flush+0x101/0x240 net/bluetooth/hci_conn.c:2592
hci_dev_close_sync+0x9ef/0x11a0 net/bluetooth/hci_sync.c:5195
hci_dev_do_close net/bluetooth/hci_core.c:483 [inline]
hci_unregister_dev+0x20b/0x510 net/bluetooth/hci_core.c:2698
vhci_release+0x80/0xd0 drivers/bluetooth/hci_vhci.c:664
__fput+0x241/0x880 fs/file_table.c:431
task_work_run+0x251/0x310 kernel/task_work.c:239
exit_task_work include/linux/task_work.h:43 [inline]
do_exit+0xa2f/0x28e0 kernel/exit.c:939
do_group_exit+0x207/0x2c0 kernel/exit.c:1088
__do_sys_exit_group kernel/exit.c:1099 [inline]
__se_sys_exit_group kernel/exit.c:1097 [inline]
__x64_sys_exit_group+0x3f/0x40 kernel/exit.c:1097
x64_sys_call+0x2634/0x2640 arch/x86/include/generated/asm/syscalls_64.h:232
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: 0033:0x7f018087de69
Code: Unable to access opcode bytes at 0x7f018087de3f.
RSP: 002b:00007fffa31fb468 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f018087de69
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000043
RBP: 00007f01808ca45b R08: 00007fffa31f9207 R09: 000000000006d03d
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000006
R13: 000000000006d03d R14: 000000000006ccf5 R15: 0000000000000004
</TASK>
Allocated by task 5400:
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:319 [inline]
__kasan_slab_alloc+0x66/0x80 mm/kasan/common.c:345
kasan_slab_alloc include/linux/kasan.h:247 [inline]
slab_post_alloc_hook mm/slub.c:4085 [inline]
slab_alloc_node mm/slub.c:4134 [inline]
kmem_cache_alloc_noprof+0x135/0x2a0 mm/slub.c:4141
getname_flags+0xb7/0x540 fs/namei.c:139
getname fs/namei.c:225 [inline]
__do_sys_unlink fs/namei.c:4581 [inline]
__se_sys_unlink fs/namei.c:4579 [inline]
__x64_sys_unlink+0x3a/0x50 fs/namei.c:4579
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 5400:
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 mm/kasan/common.c:247 [inline]
__kasan_slab_free+0x59/0x70 mm/kasan/common.c:264
kasan_slab_free include/linux/kasan.h:230 [inline]
slab_free_hook mm/slub.c:2342 [inline]
slab_free mm/slub.c:4579 [inline]
kmem_cache_free+0x1a2/0x420 mm/slub.c:4681
do_unlinkat+0x7b0/0x830 fs/namei.c:4556
__do_sys_unlink fs/namei.c:4581 [inline]
__se_sys_unlink fs/namei.c:4579 [inline]
__x64_sys_unlink+0x47/0x50 fs/namei.c:4579
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 ffff88807bd71100
which belongs to the cache names_cache of size 4096
The buggy address is located 3968 bytes inside of
freed 4096-byte region [ffff88807bd71100, ffff88807bd72100)
The buggy address belongs to the physical page:
page: refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x7bd70
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 ffff8880162f4780 dead000000000122 0000000000000000
raw: 0000000000000000 0000000000070007 00000001f5000000 0000000000000000
head: 00fff00000000040 ffff8880162f4780 dead000000000122 0000000000000000
head: 0000000000000000 0000000000070007 00000001f5000000 0000000000000000
head: 00fff00000000003 ffffea0001ef5c01 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 5400, tgid 5400 (udevd), ts 432009536360, free_ts 431999575653
set_page_owner include/linux/page_owner.h:32 [inline]
post_alloc_hook+0x1f3/0x230 mm/page_alloc.c:1537
prep_new_page mm/page_alloc.c:1545 [inline]
get_page_from_freelist+0x3045/0x3190 mm/page_alloc.c:3457
__alloc_pages_noprof+0x292/0x710 mm/page_alloc.c:4733
alloc_pages_mpol_noprof+0x3e8/0x680 mm/mempolicy.c:2265
alloc_slab_page+0x6a/0x120 mm/slub.c:2412
allocate_slab+0x5a/0x2f0 mm/slub.c:2578
new_slab mm/slub.c:2631 [inline]
___slab_alloc+0xcd1/0x14b0 mm/slub.c:3818
__slab_alloc+0x58/0xa0 mm/slub.c:3908
__slab_alloc_node mm/slub.c:3961 [inline]
slab_alloc_node mm/slub.c:4122 [inline]
kmem_cache_alloc_noprof+0x1c1/0x2a0 mm/slub.c:4141
getname_flags+0xb7/0x540 fs/namei.c:139
vfs_fstatat+0x12c/0x190 fs/stat.c:340
__do_sys_newfstatat fs/stat.c:505 [inline]
__se_sys_newfstatat fs/stat.c:499 [inline]
__x64_sys_newfstatat+0x11d/0x1a0 fs/stat.c:499
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
page last free pid 4552 tgid 4552 stack trace:
reset_page_owner include/linux/page_owner.h:25 [inline]
free_pages_prepare mm/page_alloc.c:1108 [inline]
free_unref_page+0xcfb/0xf20 mm/page_alloc.c:2638
discard_slab mm/slub.c:2677 [inline]
__put_partials+0xeb/0x130 mm/slub.c:3145
put_cpu_partial+0x17c/0x250 mm/slub.c:3220
__slab_free+0x2ea/0x3d0 mm/slub.c:4449
qlink_free mm/kasan/quarantine.c:163 [inline]
qlist_free_all+0x9a/0x140 mm/kasan/quarantine.c:179
kasan_quarantine_reduce+0x14f/0x170 mm/kasan/quarantine.c:286
__kasan_slab_alloc+0x23/0x80 mm/kasan/common.c:329
kasan_slab_alloc include/linux/kasan.h:247 [inline]
slab_post_alloc_hook mm/slub.c:4085 [inline]
slab_alloc_node mm/slub.c:4134 [inline]
__do_kmalloc_node mm/slub.c:4263 [inline]
__kmalloc_noprof+0x1a6/0x400 mm/slub.c:4276
kmalloc_noprof include/linux/slab.h:882 [inline]
tomoyo_realpath_from_path+0xcf/0x5e0 security/tomoyo/realpath.c:251
tomoyo_get_realpath security/tomoyo/file.c:151 [inline]
tomoyo_path_perm+0x2b7/0x740 security/tomoyo/file.c:822
security_inode_getattr+0x130/0x330 security/security.c:2373
vfs_getattr+0x45/0x430 fs/stat.c:204
vfs_fstat fs/stat.c:229 [inline]
vfs_fstatat+0xe4/0x190 fs/stat.c:338
__do_sys_newfstatat fs/stat.c:505 [inline]
__se_sys_newfstatat fs/stat.c:499 [inline]
__x64_sys_newfstatat+0x11d/0x1a0 fs/stat.c:499
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
Memory state around the buggy address:
ffff88807bd71f80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
ffff88807bd72000: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>ffff88807bd72080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
^
ffff88807bd72100: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
ffff88807bd72180: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
==================================================================
Tested on:
commit: c2ee9f59 KVM: selftests: Fix build on on non-x86 archi..
git tree: upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=103ff430580000
kernel config: https://syzkaller.appspot.com/x/.config?x=346c6d758171538d
dashboard link: https://syzkaller.appspot.com/bug?extid=4c0d0c4cde787116d465
compiler: Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40
patch: https://syzkaller.appspot.com/x/patch.diff?x=13264a5f980000
