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author | Krzysztof Kozlowski <krzysztof.kozlowski@canonical.com> | 2021-07-28 08:49:09 +0200 |
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committer | David S. Miller <davem@davemloft.net> | 2021-07-28 10:20:16 +0100 |
commit | 5e7b30d24a5b8cb691c173b45b50e3ca0191be19 (patch) | |
tree | f93327c6cd9966b1e8c93fe22b6a0f58ffd72eaf /drivers/nfc/nfcsim.c | |
parent | 76a16be07b209a3f507c72abe823bd3af1c8661a (diff) | |
download | linux-5e7b30d24a5b8cb691c173b45b50e3ca0191be19.tar.bz2 |
nfc: nfcsim: fix use after free during module unload
There is a use after free memory corruption during module exit:
- nfcsim_exit()
- nfcsim_device_free(dev0)
- nfc_digital_unregister_device()
This iterates over command queue and frees all commands,
- dev->up = false
- nfcsim_link_shutdown()
- nfcsim_link_recv_wake()
This wakes the sleeping thread nfcsim_link_recv_skb().
- nfcsim_link_recv_skb()
Wake from wait_event_interruptible_timeout(),
call directly the deb->cb callback even though (dev->up == false),
- digital_send_cmd_complete()
Dereference of "struct digital_cmd" cmd which was freed earlier by
nfc_digital_unregister_device().
This causes memory corruption shortly after (with unrelated stack
trace):
nfc nfc0: NFC: nfcsim_recv_wq: Device is down
llcp: nfc_llcp_recv: err -19
nfc nfc1: NFC: nfcsim_recv_wq: Device is down
BUG: unable to handle page fault for address: ffffffffffffffed
Call Trace:
fsnotify+0x54b/0x5c0
__fsnotify_parent+0x1fe/0x300
? vfs_write+0x27c/0x390
vfs_write+0x27c/0x390
ksys_write+0x63/0xe0
do_syscall_64+0x3b/0x90
entry_SYSCALL_64_after_hwframe+0x44/0xae
KASAN report:
BUG: KASAN: use-after-free in digital_send_cmd_complete+0x16/0x50
Write of size 8 at addr ffff88800a05f720 by task kworker/0:2/71
Workqueue: events nfcsim_recv_wq [nfcsim]
Call Trace:
dump_stack_lvl+0x45/0x59
print_address_description.constprop.0+0x21/0x140
? digital_send_cmd_complete+0x16/0x50
? digital_send_cmd_complete+0x16/0x50
kasan_report.cold+0x7f/0x11b
? digital_send_cmd_complete+0x16/0x50
? digital_dep_link_down+0x60/0x60
digital_send_cmd_complete+0x16/0x50
nfcsim_recv_wq+0x38f/0x3d5 [nfcsim]
? nfcsim_in_send_cmd+0x4a/0x4a [nfcsim]
? lock_is_held_type+0x98/0x110
? finish_wait+0x110/0x110
? rcu_read_lock_sched_held+0x9c/0xd0
? rcu_read_lock_bh_held+0xb0/0xb0
? lockdep_hardirqs_on_prepare+0x12e/0x1f0
This flow of calling digital_send_cmd_complete() callback on driver exit
is specific to nfcsim which implements reading and sending work queues.
Since the NFC digital device was unregistered, the callback should not
be called.
Fixes: 204bddcb508f ("NFC: nfcsim: Make use of the Digital layer")
Cc: <stable@vger.kernel.org>
Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@canonical.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'drivers/nfc/nfcsim.c')
-rw-r--r-- | drivers/nfc/nfcsim.c | 3 |
1 files changed, 1 insertions, 2 deletions
diff --git a/drivers/nfc/nfcsim.c b/drivers/nfc/nfcsim.c index a9864fcdfba6..dd27c85190d3 100644 --- a/drivers/nfc/nfcsim.c +++ b/drivers/nfc/nfcsim.c @@ -192,8 +192,7 @@ static void nfcsim_recv_wq(struct work_struct *work) if (!IS_ERR(skb)) dev_kfree_skb(skb); - - skb = ERR_PTR(-ENODEV); + return; } dev->cb(dev->nfc_digital_dev, dev->arg, skb); |