KASAN: slab-out-of-bounds Read in hci_le_meta

KASAN: slab-out-of-bounds Read in hci_le_meta_evt (2)
Status: upstream: reported C repro on 2021/05/14 20:19
Reported-by: syzbot+9247eb9ed460108a8883@syzkaller.appspotmail.com
First crash: 367d, last: 217d

Fix bisection: failed (bisect log)

similar bugs (4):
Kernel	Title	Repro	Cause bisect	Fix bisect	Count	Last	Reported	Patched	Status
linux-4.14	KASAN: slab-out-of-bounds Read in hci_le_meta_evt	C		done	15	533d	653d	1/1	fixed on 2020/12/30 13:33
upstream	KASAN: slab-out-of-bounds Read in hci_le_meta_evt (2)	C	inconclusive		2	198d	197d	22/22	fixed on 2022/03/08 16:11
linux-4.19	KASAN: slab-out-of-bounds Read in hci_le_meta_evt	C		done	12	514d	655d	1/1	fixed on 2021/01/18 14:01
upstream	KASAN: slab-out-of-bounds Read in hci_le_meta_evt	C	error	error	45	531d	651d	21/22	fixed on 2021/03/10 01:49

Sample crash report:

Bluetooth: hci0: Dropping invalid advertising data
==================================================================
BUG: KASAN: slab-out-of-bounds in hci_le_adv_report_evt net/bluetooth/hci_event.c:5336 [inline]
BUG: KASAN: slab-out-of-bounds in hci_le_meta_evt+0x363d/0x3e00 net/bluetooth/hci_event.c:5636
Read of size 1 at addr ffff8880a8d5299a by task kworker/u5:1/8105

CPU: 1 PID: 8105 Comm: kworker/u5:1 Not tainted 4.19.190-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Workqueue: hci0 hci_rx_work
Call Trace:
 __dump_stack lib/dump_stack.c:77 [inline]
 dump_stack+0x1fc/0x2ef lib/dump_stack.c:118
 print_address_description.cold+0x54/0x219 mm/kasan/report.c:256
 kasan_report_error.cold+0x8a/0x1b9 mm/kasan/report.c:354
 kasan_report mm/kasan/report.c:412 [inline]
 __asan_report_load1_noabort+0x88/0x90 mm/kasan/report.c:430
 hci_le_adv_report_evt net/bluetooth/hci_event.c:5336 [inline]
 hci_le_meta_evt+0x363d/0x3e00 net/bluetooth/hci_event.c:5636
 hci_event_packet+0x34ad/0x7e20 net/bluetooth/hci_event.c:5901
 hci_rx_work+0x4ad/0xc70 net/bluetooth/hci_core.c:4361
 process_one_work+0x864/0x1570 kernel/workqueue.c:2152
 worker_thread+0x64c/0x1130 kernel/workqueue.c:2295
 kthread+0x33f/0x460 kernel/kthread.c:259
 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:415

Allocated by task 9216:
 __do_kmalloc_node mm/slab.c:3689 [inline]
 __kmalloc_node_track_caller+0x4c/0x70 mm/slab.c:3703
 __kmalloc_reserve net/core/skbuff.c:137 [inline]
 __alloc_skb+0xae/0x560 net/core/skbuff.c:205
 alloc_skb include/linux/skbuff.h:995 [inline]
 bt_skb_alloc include/net/bluetooth/bluetooth.h:339 [inline]
 vhci_get_user drivers/bluetooth/hci_vhci.c:180 [inline]
 vhci_write+0xbd/0x450 drivers/bluetooth/hci_vhci.c:299
 call_write_iter include/linux/fs.h:1821 [inline]
 new_sync_write fs/read_write.c:474 [inline]
 __vfs_write+0x51b/0x770 fs/read_write.c:487
 vfs_write+0x1f3/0x540 fs/read_write.c:549
 ksys_write+0x12b/0x2a0 fs/read_write.c:599
 do_syscall_64+0xf9/0x620 arch/x86/entry/common.c:293
 entry_SYSCALL_64_after_hwframe+0x49/0xbe

Freed by task 4698:
 __cache_free mm/slab.c:3503 [inline]
 kfree+0xcc/0x210 mm/slab.c:3822
 skb_free_head net/core/skbuff.c:563 [inline]
 skb_release_data+0x6de/0x920 net/core/skbuff.c:583
 skb_release_all net/core/skbuff.c:640 [inline]
 __kfree_skb net/core/skbuff.c:654 [inline]
 consume_skb+0x113/0x3d0 net/core/skbuff.c:714
 skb_free_datagram+0x16/0xf0 net/core/datagram.c:329
 netlink_recvmsg+0x627/0xea0 net/netlink/af_netlink.c:1988
 sock_recvmsg_nosec net/socket.c:795 [inline]
 sock_recvmsg net/socket.c:802 [inline]
 sock_recvmsg+0xca/0x110 net/socket.c:798
 ___sys_recvmsg+0x255/0x570 net/socket.c:2277
 __sys_recvmsg net/socket.c:2326 [inline]
 __do_sys_recvmsg net/socket.c:2336 [inline]
 __se_sys_recvmsg net/socket.c:2333 [inline]
 __x64_sys_recvmsg+0x12f/0x220 net/socket.c:2333
 do_syscall_64+0xf9/0x620 arch/x86/entry/common.c:293
 entry_SYSCALL_64_after_hwframe+0x49/0xbe

The buggy address belongs to the object at ffff8880a8d52780
 which belongs to the cache kmalloc-512 of size 512
The buggy address is located 26 bytes to the right of
 512-byte region [ffff8880a8d52780, ffff8880a8d52980)
The buggy address belongs to the page:
page:ffffea0002a35480 count:1 mapcount:0 mapping:ffff88813bff0940 index:0x0
flags: 0xfff00000000100(slab)
raw: 00fff00000000100 ffffea0002a73548 ffffea0002a4d308 ffff88813bff0940
raw: 0000000000000000 ffff8880a8d52000 0000000100000006 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff8880a8d52880: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
 ffff8880a8d52900: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
>ffff8880a8d52980: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
                            ^
 ffff8880a8d52a00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff8880a8d52a80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
==================================================================

Crashes (1):
Manager	Time	Kernel	Commit	Syzkaller	Config	Log	Report	Syz repro	C repro	VM info	Title
ci2-linux-4-19	2021/05/14 20:19	linux-4.19.y	3c8c23092588	8bdd5343	.config	log	report	syz	C		KASAN: slab-out-of-bounds Read in hci_le_meta_evt