lkml.org 
[lkml]   [2022]   [Dec]   [18]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    Patch in this message
    /
    From
    Subject[PATCH AUTOSEL 5.10 04/39] wifi: ar5523: Fix use-after-free on ar5523_cmd() timed out
    Date
    From: Shigeru Yoshida <syoshida@redhat.com>

    [ Upstream commit b6702a942a069c2a975478d719e98d83cdae1797 ]

    syzkaller reported use-after-free with the stack trace like below [1]:

    [ 38.960489][ C3] ==================================================================
    [ 38.963216][ C3] BUG: KASAN: use-after-free in ar5523_cmd_tx_cb+0x220/0x240
    [ 38.964950][ C3] Read of size 8 at addr ffff888048e03450 by task swapper/3/0
    [ 38.966363][ C3]
    [ 38.967053][ C3] CPU: 3 PID: 0 Comm: swapper/3 Not tainted 6.0.0-09039-ga6afa4199d3d-dirty #18
    [ 38.968464][ C3] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.16.0-1.fc36 04/01/2014
    [ 38.969959][ C3] Call Trace:
    [ 38.970841][ C3] <IRQ>
    [ 38.971663][ C3] dump_stack_lvl+0xfc/0x174
    [ 38.972620][ C3] print_report.cold+0x2c3/0x752
    [ 38.973626][ C3] ? ar5523_cmd_tx_cb+0x220/0x240
    [ 38.974644][ C3] kasan_report+0xb1/0x1d0
    [ 38.975720][ C3] ? ar5523_cmd_tx_cb+0x220/0x240
    [ 38.976831][ C3] ar5523_cmd_tx_cb+0x220/0x240
    [ 38.978412][ C3] __usb_hcd_giveback_urb+0x353/0x5b0
    [ 38.979755][ C3] usb_hcd_giveback_urb+0x385/0x430
    [ 38.981266][ C3] dummy_timer+0x140c/0x34e0
    [ 38.982925][ C3] ? notifier_call_chain+0xb5/0x1e0
    [ 38.984761][ C3] ? rcu_read_lock_sched_held+0xb/0x60
    [ 38.986242][ C3] ? lock_release+0x51c/0x790
    [ 38.987323][ C3] ? _raw_read_unlock_irqrestore+0x37/0x70
    [ 38.988483][ C3] ? __wake_up_common_lock+0xde/0x130
    [ 38.989621][ C3] ? reacquire_held_locks+0x4a0/0x4a0
    [ 38.990777][ C3] ? lock_acquire+0x472/0x550
    [ 38.991919][ C3] ? rcu_read_lock_sched_held+0xb/0x60
    [ 38.993138][ C3] ? lock_acquire+0x472/0x550
    [ 38.994890][ C3] ? dummy_urb_enqueue+0x860/0x860
    [ 38.996266][ C3] ? do_raw_spin_unlock+0x16f/0x230
    [ 38.997670][ C3] ? dummy_urb_enqueue+0x860/0x860
    [ 38.999116][ C3] call_timer_fn+0x1a0/0x6a0
    [ 39.000668][ C3] ? add_timer_on+0x4a0/0x4a0
    [ 39.002137][ C3] ? reacquire_held_locks+0x4a0/0x4a0
    [ 39.003809][ C3] ? __next_timer_interrupt+0x226/0x2a0
    [ 39.005509][ C3] __run_timers.part.0+0x69a/0xac0
    [ 39.007025][ C3] ? dummy_urb_enqueue+0x860/0x860
    [ 39.008716][ C3] ? call_timer_fn+0x6a0/0x6a0
    [ 39.010254][ C3] ? cpuacct_percpu_seq_show+0x10/0x10
    [ 39.011795][ C3] ? kvm_sched_clock_read+0x14/0x40
    [ 39.013277][ C3] ? sched_clock_cpu+0x69/0x2b0
    [ 39.014724][ C3] run_timer_softirq+0xb6/0x1d0
    [ 39.016196][ C3] __do_softirq+0x1d2/0x9be
    [ 39.017616][ C3] __irq_exit_rcu+0xeb/0x190
    [ 39.019004][ C3] irq_exit_rcu+0x5/0x20
    [ 39.020361][ C3] sysvec_apic_timer_interrupt+0x8f/0xb0
    [ 39.021965][ C3] </IRQ>
    [ 39.023237][ C3] <TASK>

    In ar5523_probe(), ar5523_host_available() calls ar5523_cmd() as below
    (there are other functions which finally call ar5523_cmd()):

    ar5523_probe()
    -> ar5523_host_available()
    -> ar5523_cmd_read()
    -> ar5523_cmd()

    If ar5523_cmd() timed out, then ar5523_host_available() failed and
    ar5523_probe() freed the device structure. So, ar5523_cmd_tx_cb()
    might touch the freed structure.

    This patch fixes this issue by canceling in-flight tx cmd if submitted
    urb timed out.

    Link: https://syzkaller.appspot.com/bug?id=9e12b2d54300842b71bdd18b54971385ff0d0d3a [1]
    Reported-by: syzbot+95001b1fd6dfcc716c29@syzkaller.appspotmail.com
    Signed-off-by: Shigeru Yoshida <syoshida@redhat.com>
    Signed-off-by: Kalle Valo <quic_kvalo@quicinc.com>
    Link: https://lore.kernel.org/r/20221009183223.420015-1-syoshida@redhat.com
    Signed-off-by: Sasha Levin <sashal@kernel.org>
    ---
    drivers/net/wireless/ath/ar5523/ar5523.c | 6 ++++++
    1 file changed, 6 insertions(+)

    diff --git a/drivers/net/wireless/ath/ar5523/ar5523.c b/drivers/net/wireless/ath/ar5523/ar5523.c
    index 1baec4b412c8..efe38b2c1df7 100644
    --- a/drivers/net/wireless/ath/ar5523/ar5523.c
    +++ b/drivers/net/wireless/ath/ar5523/ar5523.c
    @@ -241,6 +241,11 @@ static void ar5523_cmd_tx_cb(struct urb *urb)
    }
    }

    +static void ar5523_cancel_tx_cmd(struct ar5523 *ar)
    +{
    + usb_kill_urb(ar->tx_cmd.urb_tx);
    +}
    +
    static int ar5523_cmd(struct ar5523 *ar, u32 code, const void *idata,
    int ilen, void *odata, int olen, int flags)
    {
    @@ -280,6 +285,7 @@ static int ar5523_cmd(struct ar5523 *ar, u32 code, const void *idata,
    }

    if (!wait_for_completion_timeout(&cmd->done, 2 * HZ)) {
    + ar5523_cancel_tx_cmd(ar);
    cmd->odata = NULL;
    ar5523_err(ar, "timeout waiting for command %02x reply\n",
    code);
    --
    2.35.1
    \
     
     \ /
      Last update: 2022-12-18 17:49    [W:2.053 / U:0.012 seconds]
    ©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site