Subject: KASAN: slab-out-of-bounds Read in ath9k_hif_usb_rx_cb

From: syzbot <[email-masked]>
Date: Sun, 17 May 2020 08:32:19 -0700

Hello,

syzbot found the following crash on:

HEAD commit:    806d8acc USB: dummy-hcd: use configurable endpoint naming ..
git tree:       https://github.com/google/kasan.git usb-fuzzer
console output: https://syzkaller.appspot.com/x/log.txt?x=1147bce6100000
kernel config:  https://syzkaller.appspot.com/x/.config?x=d800e9bad158025f
dashboard link: https://syzkaller.appspot.com/bug?extid=c15a0a825788b6ba2bc4
compiler:       gcc (GCC) 9.0.0 20181231 (experimental)

Unfortunately, I don't have any reproducer for this crash yet.

IMPORTANT: if you fix the bug, please add the following tag to the commit:
Reported-by: [email-masked]

==================================================================
BUG: KASAN: slab-out-of-bounds in ath9k_hif_usb_rx_stream drivers/net/wireless/ath/ath9k/hif_usb.c:580 [inline]
BUG: KASAN: slab-out-of-bounds in ath9k_hif_usb_rx_cb+0xad3/0xf90 drivers/net/wireless/ath/ath9k/hif_usb.c:666
Read of size 4 at addr ffff8881cca0c0dc by task kworker/1:3/3075

CPU: 1 PID: 3075 Comm: kworker/1:3 Not tainted 5.7.0-rc5-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Workqueue: events request_firmware_work_func
Call Trace:
 <IRQ>
 __dump_stack lib/dump_stack.c:77 [inline]
 dump_stack+0xef/0x16e lib/dump_stack.c:118
 print_address_description.constprop.0.cold+0xd3/0x314 mm/kasan/report.c:382
 __kasan_report.cold+0x37/0x92 mm/kasan/report.c:511
 kasan_report+0x33/0x50 mm/kasan/common.c:625
 ath9k_hif_usb_rx_stream drivers/net/wireless/ath/ath9k/hif_usb.c:580 [inline]
 ath9k_hif_usb_rx_cb+0xad3/0xf90 drivers/net/wireless/ath/ath9k/hif_usb.c:666
 __usb_hcd_giveback_urb+0x1f2/0x470 drivers/usb/core/hcd.c:1648
 usb_hcd_giveback_urb+0x368/0x420 drivers/usb/core/hcd.c:1713
 dummy_timer+0x125e/0x32b4 drivers/usb/gadget/udc/dummy_hcd.c:1966
 call_timer_fn+0x1ac/0x700 kernel/time/timer.c:1405
 expire_timers kernel/time/timer.c:1450 [inline]
 __run_timers kernel/time/timer.c:1774 [inline]
 __run_timers kernel/time/timer.c:1741 [inline]
 run_timer_softirq+0x5f9/0x1500 kernel/time/timer.c:1787
 __do_softirq+0x21e/0x9aa kernel/softirq.c:292
 invoke_softirq kernel/softirq.c:373 [inline]
 irq_exit+0x178/0x1a0 kernel/softirq.c:413
 exiting_irq arch/x86/include/asm/apic.h:546 [inline]
 smp_apic_timer_interrupt+0x141/0x540 arch/x86/kernel/apic/apic.c:1140
 apic_timer_interrupt+0xf/0x20 arch/x86/entry/entry_64.S:829
 </IRQ>
RIP: 0010:arch_local_irq_restore arch/x86/include/asm/irqflags.h:85 [inline]
RIP: 0010:console_trylock_spinning kernel/printk/printk.c:1779 [inline]
RIP: 0010:vprintk_emit+0x3d0/0x3e0 kernel/printk/printk.c:2020
Code: 00 83 fb ff 75 d6 e9 d8 fc ff ff e8 7a 2f 16 00 e8 55 8b 1b 00 41 56 9d e9 aa fd ff ff e8 68 2f 16 00 e8 43 8b 1b 00 41 56 9d <e9> 2a ff ff ff 90 66 2e 0f 1f 84 00 00 00 00 00 55 48 89 f5 53 48
RSP: 0018:ffff8881d5f8fab8 EFLAGS: 00000293 ORIG_RAX: ffffffffffffff13
RAX: 0000000000000007 RBX: 0000000000000200 RCX: 1ffffffff1270ab2
RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffff8881d5aeeb7c
RBP: ffff8881d5f8fb00 R08: 0000000000000001 R09: fffffbfff126c8c8
R10: ffffffff8936463f R11: fffffbfff126c8c7 R12: 000000000000002a
R13: ffff8881d5e48000 R14: 0000000000000293 R15: 0000000000000000
 vprintk_func+0x75/0x113 kernel/printk/printk_safe.c:385
 printk+0xba/0xed kernel/printk/printk.c:2081
 ath9k_htc_hw_init.cold+0x17/0x2a drivers/net/wireless/ath/ath9k/htc_hst.c:502
 ath9k_hif_usb_firmware_cb+0x274/0x510 drivers/net/wireless/ath/ath9k/hif_usb.c:1187
 request_firmware_work_func+0x126/0x242 drivers/base/firmware_loader/main.c:1005
 process_one_work+0x965/0x1630 kernel/workqueue.c:2268
 worker_thread+0x96/0xe20 kernel/workqueue.c:2414
 kthread+0x326/0x430 kernel/kthread.c:268
 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:351

Allocated by task 147:
 save_stack+0x1b/0x40 mm/kasan/common.c:49
 set_track mm/kasan/common.c:57 [inline]
 __kasan_kmalloc mm/kasan/common.c:495 [inline]
 __kasan_kmalloc.constprop.0+0xbf/0xd0 mm/kasan/common.c:468
 slab_post_alloc_hook mm/slab.h:586 [inline]
 slab_alloc_node mm/slub.c:2797 [inline]
 slab_alloc mm/slub.c:2805 [inline]
 kmem_cache_alloc+0xd8/0x300 mm/slub.c:2810
 getname_flags fs/namei.c:138 [inline]
 getname_flags+0xd2/0x5b0 fs/namei.c:128
 user_path_at_empty+0x2a/0x50 fs/namei.c:2632
 user_path_at include/linux/namei.h:59 [inline]
 vfs_statx+0x119/0x1e0 fs/stat.c:197
 vfs_lstat include/linux/fs.h:3284 [inline]
 __do_sys_newlstat+0x96/0x120 fs/stat.c:364
 do_syscall_64+0xb6/0x5a0 arch/x86/entry/common.c:295
 entry_SYSCALL_64_after_hwframe+0x49/0xb3

Freed by task 147:
 save_stack+0x1b/0x40 mm/kasan/common.c:49
 set_track mm/kasan/common.c:57 [inline]
 kasan_set_free_info mm/kasan/common.c:317 [inline]
 __kasan_slab_free+0x117/0x160 mm/kasan/common.c:456
 slab_free_hook mm/slub.c:1455 [inline]
 slab_free_freelist_hook mm/slub.c:1488 [inline]
 slab_free mm/slub.c:3045 [inline]
 kmem_cache_free+0x9b/0x360 mm/slub.c:3061
 putname+0xe1/0x120 fs/namei.c:259
 filename_lookup+0x282/0x3e0 fs/namei.c:2362
 user_path_at include/linux/namei.h:59 [inline]
 vfs_statx+0x119/0x1e0 fs/stat.c:197
 vfs_lstat include/linux/fs.h:3284 [inline]
 __do_sys_newlstat+0x96/0x120 fs/stat.c:364
 do_syscall_64+0xb6/0x5a0 arch/x86/entry/common.c:295
 entry_SYSCALL_64_after_hwframe+0x49/0xb3

The buggy address belongs to the object at ffff8881cca0b300
 which belongs to the cache names_cache of size 4096
The buggy address is located 3548 bytes inside of
 4096-byte region [ffff8881cca0b300, ffff8881cca0c300)
The buggy address belongs to the page:
page:ffffea0007328200 refcount:1 mapcount:0 mapping:0000000063d385a8 index:0x0 head:ffffea0007328200 order:3 compound_mapcount:0 compound_pincount:0
flags: 0x200000000010200(slab|head)
raw: 0200000000010200 dead000000000100 dead000000000122 ffff8881da11e000
raw: 0000000000000000 0000000000070007 00000001ffffffff 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff8881cca0bf80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff8881cca0c000: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>ffff8881cca0c080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                                                    ^
 ffff8881cca0c100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff8881cca0c180: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
==================================================================

---
This bug is generated by a bot. It may contain errors.
See https://goo.gl/tpsmEJ for more information about syzbot.
syzbot engineers can be reached at [email-masked].

syzbot will keep track of this bug report. See:
https://goo.gl/tpsmEJ#status for how to communicate with syzbot.