From: Ben Hutchings <ben@decadent.org.uk>
To: linux-kernel@vger.kernel.org, stable@vger.kernel.org
Cc: akpm@linux-foundation.org, "Takashi Iwai" <tiwai@suse.de>
Subject: [PATCH 3.2 57/67] ALSA: timer: Fix race at concurrent reads
Date: Tue, 23 Feb 2016 21:42:03 +0000 [thread overview]
Message-ID: <lsq.1456263723.654953452@decadent.org.uk> (raw)
In-Reply-To: <lsq.1456263722.390955919@decadent.org.uk>
3.2.78-rc1 review patch. If anyone has any objections, please let me know.
------------------
From: Takashi Iwai <tiwai@suse.de>
commit 4dff5c7b7093b19c19d3a100f8a3ad87cb7cd9e7 upstream.
snd_timer_user_read() has a potential race among parallel reads, as
qhead and qused are updated outside the critical section due to
copy_to_user() calls. Move them into the critical section, and also
sanitize the relevant code a bit.
Signed-off-by: Takashi Iwai <tiwai@suse.de>
[bwh: Backported to 3.2: there's no check for tu->connected to fix up]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
---
--- a/sound/core/timer.c
+++ b/sound/core/timer.c
@@ -1890,6 +1890,7 @@ static ssize_t snd_timer_user_read(struc
{
struct snd_timer_user *tu;
long result = 0, unit;
+ int qhead;
int err = 0;
tu = file->private_data;
@@ -1901,7 +1902,7 @@ static ssize_t snd_timer_user_read(struc
if ((file->f_flags & O_NONBLOCK) != 0 || result > 0) {
err = -EAGAIN;
- break;
+ goto _error;
}
set_current_state(TASK_INTERRUPTIBLE);
@@ -1916,38 +1917,33 @@ static ssize_t snd_timer_user_read(struc
if (signal_pending(current)) {
err = -ERESTARTSYS;
- break;
+ goto _error;
}
}
+ qhead = tu->qhead++;
+ tu->qhead %= tu->queue_size;
spin_unlock_irq(&tu->qlock);
- if (err < 0)
- goto _error;
if (tu->tread) {
- if (copy_to_user(buffer, &tu->tqueue[tu->qhead++],
- sizeof(struct snd_timer_tread))) {
+ if (copy_to_user(buffer, &tu->tqueue[qhead],
+ sizeof(struct snd_timer_tread)))
err = -EFAULT;
- goto _error;
- }
} else {
- if (copy_to_user(buffer, &tu->queue[tu->qhead++],
- sizeof(struct snd_timer_read))) {
+ if (copy_to_user(buffer, &tu->queue[qhead],
+ sizeof(struct snd_timer_read)))
err = -EFAULT;
- goto _error;
- }
}
- tu->qhead %= tu->queue_size;
-
- result += unit;
- buffer += unit;
-
spin_lock_irq(&tu->qlock);
tu->qused--;
+ if (err < 0)
+ goto _error;
+ result += unit;
+ buffer += unit;
}
- spin_unlock_irq(&tu->qlock);
_error:
+ spin_unlock_irq(&tu->qlock);
return result > 0 ? result : err;
}
next prev parent reply other threads:[~2016-02-23 21:59 UTC|newest]
Thread overview: 74+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-02-23 21:42 [PATCH 3.2 00/67] 3.2.78-rc1 review Ben Hutchings
2016-02-23 21:42 ` [PATCH 3.2 41/67] usb: xhci: apply XHCI_PME_STUCK_QUIRK to Intel Broxton-M platforms Ben Hutchings
2016-02-23 21:42 ` [PATCH 3.2 40/67] Revert "xhci: don't finish a TD if we get a short-transfer event mid TD" Ben Hutchings
2016-02-23 21:42 ` [PATCH 3.2 12/67] USB: visor: fix null-deref at probe Ben Hutchings
2016-02-23 21:42 ` [PATCH 3.2 37/67] ALSA: rawmidi: Make snd_rawmidi_transmit() race-free Ben Hutchings
2016-02-23 21:42 ` [PATCH 3.2 35/67] ALSA: timer: Fix link corruption due to double start or stop Ben Hutchings
2016-02-23 21:42 ` [PATCH 3.2 53/67] ALSA: timer: Fix wrong instance passed to slave callbacks Ben Hutchings
2016-02-23 21:42 ` [PATCH 3.2 66/67] pipe: Fix buffer offset after partially failed read Ben Hutchings
2016-02-23 21:42 ` [PATCH 3.2 17/67] USB: serial: ftdi_sio: add support for Yaesu SCU-18 cable Ben Hutchings
2016-02-23 21:42 ` [PATCH 3.2 30/67] intel_scu_ipcutil: underflow in scu_reg_access() Ben Hutchings
2016-02-23 21:42 ` [PATCH 3.2 22/67] perf annotate browser: Fix behaviour of Shift-Tab with nothing focussed Ben Hutchings
2016-02-23 21:42 ` [PATCH 3.2 20/67] virtio_pci: fix use after free on release Ben Hutchings
2016-02-23 21:42 ` [PATCH 3.2 29/67] crypto: algif_hash - wait for crypto_ahash_init() to complete Ben Hutchings
2016-02-23 21:42 ` [PATCH 3.2 64/67] pipe: limit the per-user amount of pages allocated in pipes Ben Hutchings
2016-02-23 21:42 ` [PATCH 3.2 54/67] ARM: 8517/1: ICST: avoid arithmetic overflow in icst_hz() Ben Hutchings
2016-02-23 21:42 ` [PATCH 3.2 03/67] timerfd: Handle relative timers with CONFIG_TIME_LOW_RES proper Ben Hutchings
2016-02-23 21:42 ` [PATCH 3.2 05/67] itimers: " Ben Hutchings
2016-02-23 21:42 ` [PATCH 3.2 52/67] ALSA: dummy: Implement timer backend switching more safely Ben Hutchings
2016-02-23 21:42 ` [PATCH 3.2 13/67] USB: serial: visor: fix crash on detecting device without write_urbs Ben Hutchings
2016-02-23 21:42 ` [PATCH 3.2 55/67] sctp: translate network order to host order when users get a hmacid Ben Hutchings
2016-02-23 21:42 ` [PATCH 3.2 24/67] tty: Fix unsafe ldisc reference via ioctl(TIOCGETD) Ben Hutchings
2016-02-23 21:42 ` [PATCH 3.2 15/67] ALSA: seq: Fix incorrect sanity check at snd_seq_oss_synth_cleanup() Ben Hutchings
2016-02-23 21:42 ` [PATCH 3.2 31/67] ALSA: seq: Fix race at closing in virmidi driver Ben Hutchings
2016-02-23 21:42 ` [PATCH 3.2 21/67] rfkill: fix rfkill_fop_read wait_event usage Ben Hutchings
2016-02-23 21:42 ` [PATCH 3.2 45/67] [media] saa7134-alsa: Only frees registered sound cards Ben Hutchings
2016-02-23 21:42 ` [PATCH 3.2 32/67] ALSA: rawmidi: Remove kernel WARNING for NULL user-space buffer check Ben Hutchings
2016-02-23 21:42 ` [PATCH 3.2 46/67] scsi_dh_rdac: always retry MODE SELECT on command lock violation Ben Hutchings
2016-02-23 21:42 ` [PATCH 3.2 14/67] USB: serial: option: Adding support for Telit LE922 Ben Hutchings
2016-02-23 21:42 ` [PATCH 3.2 59/67] ARM: 8519/1: ICST: try other dividends than 1 Ben Hutchings
2016-02-23 21:42 ` [PATCH 3.2 47/67] mm, vmstat: fix wrong WQ sleep when memory reclaim doesn't make any progress Ben Hutchings
2016-02-23 21:42 ` [PATCH 3.2 62/67] unix: properly account for FDs passed over unix sockets Ben Hutchings
2016-02-23 21:42 ` [PATCH 3.2 01/67] KVM: vmx: fix MPX detection Ben Hutchings
2016-02-23 21:42 ` [PATCH 3.2 65/67] iw_cxgb3: Fix incorrectly returning error on success Ben Hutchings
2016-02-23 21:42 ` [PATCH 3.2 48/67] ocfs2/dlm: clear refmap bit of recovery lock while doing local recovery cleanup Ben Hutchings
2016-02-23 21:42 ` [PATCH 3.2 18/67] PCI/AER: Flush workqueue on device remove to avoid use-after-free Ben Hutchings
2016-02-23 21:42 ` [PATCH 3.2 08/67] af_unix: fix struct pid memory leak Ben Hutchings
2016-02-23 22:07 ` Rainer Weikusat
2016-02-24 21:24 ` Ben Hutchings
2016-02-25 7:26 ` Willy Tarreau
2016-02-23 21:42 ` [PATCH 3.2 39/67] ALSA: seq: Fix lockdep warnings due to double mutex locks Ben Hutchings
2016-02-23 21:42 ` [PATCH 3.2 28/67] x86/mm/pat: Avoid truncation when converting cpa->numpages to address Ben Hutchings
2016-02-23 21:42 ` [PATCH 3.2 63/67] unix: correctly track in-flight fds in sending process user_struct Ben Hutchings
2016-02-23 21:42 ` [PATCH 3.2 07/67] cdc-acm:exclude Samsung phone 04e8:685d Ben Hutchings
2016-02-23 21:42 ` [PATCH 3.2 49/67] crypto: user - lock crypto_alg_list on alg dump Ben Hutchings
2016-02-23 21:42 ` [PATCH 3.2 38/67] ALSA: rawmidi: Fix race at copying & updating the position Ben Hutchings
2016-02-23 21:42 ` [PATCH 3.2 27/67] drm/vmwgfx: respect 'nomodeset' Ben Hutchings
2016-02-23 21:42 ` [PATCH 3.2 10/67] sctp: allow setting SCTP_SACK_IMMEDIATELY by the application Ben Hutchings
2016-02-23 21:42 ` [PATCH 3.2 43/67] [media] tda1004x: only update the frontend properties if locked Ben Hutchings
2016-02-23 21:42 ` [PATCH 3.2 02/67] hrtimer: Handle remaining time proper for TIME_LOW_RES Ben Hutchings
2016-02-23 21:42 ` [PATCH 3.2 25/67] crypto: shash - Fix has_key setting Ben Hutchings
2016-02-23 21:42 ` [PATCH 3.2 50/67] crypto: algif_skcipher - Do not dereference ctx without socket lock Ben Hutchings
2016-02-23 21:42 ` [PATCH 3.2 44/67] ALSA: timer: Fix leftover link at closing Ben Hutchings
2016-02-23 21:42 ` [PATCH 3.2 34/67] ALSA: seq: Fix yet another races among ALSA timer accesses Ben Hutchings
2016-02-23 21:42 ` [PATCH 3.2 67/67] sched: fix __sched_setscheduler() vs load balancing race Ben Hutchings
2016-02-23 21:42 ` [PATCH 3.2 23/67] SCSI: fix crashes in sd and sr runtime PM Ben Hutchings
2016-02-23 21:42 ` [PATCH 3.2 51/67] klist: fix starting point removed bug in klist iterators Ben Hutchings
2016-02-23 21:42 ` [PATCH 3.2 11/67] USB: cp210x: add ID for IAI USB to RS485 adaptor Ben Hutchings
2016-02-23 21:42 ` [PATCH 3.2 61/67] ALSA: usb-audio: avoid freeing umidi object twice Ben Hutchings
2016-02-23 21:42 ` [PATCH 3.2 06/67] usb: cdc-acm: send zero packet for intel 7260 modem Ben Hutchings
2016-02-23 21:42 ` [PATCH 3.2 04/67] posix-timers: Handle relative timers with CONFIG_TIME_LOW_RES proper Ben Hutchings
2016-02-23 21:42 ` [PATCH 3.2 33/67] ALSA: pcm: Fix potential deadlock in OSS emulation Ben Hutchings
2016-02-23 21:42 ` [PATCH 3.2 56/67] ALSA: timer: Fix race between stop and interrupt Ben Hutchings
2016-02-23 21:42 ` [PATCH 3.2 58/67] ahci: Intel DNV device IDs SATA Ben Hutchings
2016-02-23 21:42 ` [PATCH 3.2 60/67] btrfs: properly set the termination value of ctx->pos in readdir Ben Hutchings
2016-02-23 21:42 ` [PATCH 3.2 26/67] ALSA: dummy: Disable switching timer backend via sysfs Ben Hutchings
2016-02-23 21:42 ` [PATCH 3.2 42/67] xhci: Fix list corruption in urb dequeue at host removal Ben Hutchings
2016-02-23 21:42 ` Ben Hutchings [this message]
2016-02-23 21:42 ` [PATCH 3.2 36/67] libata: fix sff host state machine locking while polling Ben Hutchings
2016-02-23 21:42 ` [PATCH 3.2 16/67] ALSA: seq: Degrade the error message for too many opens Ben Hutchings
2016-02-23 21:42 ` [PATCH 3.2 09/67] pptp: fix illegal memory access caused by multiple bind()s Ben Hutchings
2016-02-23 21:42 ` [PATCH 3.2 19/67] libata: disable forced PORTS_IMPL for >= AHCI 1.3 Ben Hutchings
2016-02-24 0:48 ` [PATCH 3.2 00/67] 3.2.78-rc1 review Ben Hutchings
2016-02-24 2:48 ` Guenter Roeck
2016-02-24 14:41 ` Ben Hutchings
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