The patch below does not apply to the 4.14-stable tree.
If someone wants it applied there, or to any other stable or longterm
tree, then please email the backport, including the original git commit
id to <stable(a)vger.kernel.org>.
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
>From e93cd35101b61e4c79149be2cfc927c4b28dc60c Mon Sep 17 00:00:00 2001
From: Johan Hovold <johan(a)kernel.org>
Date: Thu, 28 Nov 2019 18:22:00 +0100
Subject: [PATCH] rsi: fix use-after-free on failed probe and unbind
Make sure to stop both URBs before returning after failed probe as well
as on disconnect to avoid use-after-free in the completion handler.
Reported-by: syzbot+b563b7f8dbe8223a51e8(a)syzkaller.appspotmail.com
Fixes: a4302bff28e2 ("rsi: add bluetooth rx endpoint")
Fixes: dad0d04fa7ba ("rsi: Add RS9113 wireless driver")
Cc: stable <stable(a)vger.kernel.org> # 3.15
Cc: Siva Rebbagondla <siva.rebbagondla(a)redpinesignals.com>
Cc: Prameela Rani Garnepudi <prameela.j04cs(a)gmail.com>
Cc: Amitkumar Karwar <amit.karwar(a)redpinesignals.com>
Cc: Fariya Fatima <fariyaf(a)gmail.com>
Signed-off-by: Johan Hovold <johan(a)kernel.org>
Signed-off-by: Kalle Valo <kvalo(a)codeaurora.org>
diff --git a/drivers/net/wireless/rsi/rsi_91x_usb.c b/drivers/net/wireless/rsi/rsi_91x_usb.c
index 53f41fc2cadf..30bed719486e 100644
--- a/drivers/net/wireless/rsi/rsi_91x_usb.c
+++ b/drivers/net/wireless/rsi/rsi_91x_usb.c
@@ -292,6 +292,15 @@ static void rsi_rx_done_handler(struct urb *urb)
dev_kfree_skb(rx_cb->rx_skb);
}
+static void rsi_rx_urb_kill(struct rsi_hw *adapter, u8 ep_num)
+{
+ struct rsi_91x_usbdev *dev = (struct rsi_91x_usbdev *)adapter->rsi_dev;
+ struct rx_usb_ctrl_block *rx_cb = &dev->rx_cb[ep_num - 1];
+ struct urb *urb = rx_cb->rx_urb;
+
+ usb_kill_urb(urb);
+}
+
/**
* rsi_rx_urb_submit() - This function submits the given URB to the USB stack.
* @adapter: Pointer to the adapter structure.
@@ -823,10 +832,13 @@ static int rsi_probe(struct usb_interface *pfunction,
if (adapter->priv->coex_mode > 1) {
status = rsi_rx_urb_submit(adapter, BT_EP);
if (status)
- goto err1;
+ goto err_kill_wlan_urb;
}
return 0;
+
+err_kill_wlan_urb:
+ rsi_rx_urb_kill(adapter, WLAN_EP);
err1:
rsi_deinit_usb_interface(adapter);
err:
@@ -857,6 +869,10 @@ static void rsi_disconnect(struct usb_interface *pfunction)
adapter->priv->bt_adapter = NULL;
}
+ if (adapter->priv->coex_mode > 1)
+ rsi_rx_urb_kill(adapter, BT_EP);
+ rsi_rx_urb_kill(adapter, WLAN_EP);
+
rsi_reset_card(adapter);
rsi_deinit_usb_interface(adapter);
rsi_91x_deinit(adapter);
The patch below does not apply to the 4.19-stable tree.
If someone wants it applied there, or to any other stable or longterm
tree, then please email the backport, including the original git commit
id to <stable(a)vger.kernel.org>.
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
>From 07bfd9bdf568a38d9440c607b72342036011f727 Mon Sep 17 00:00:00 2001
From: Herbert Xu <herbert(a)gondor.apana.org.au>
Date: Tue, 19 Nov 2019 17:41:31 +0800
Subject: [PATCH] crypto: pcrypt - Fix user-after-free on module unload
On module unload of pcrypt we must unregister the crypto algorithms
first and then tear down the padata structure. As otherwise the
crypto algorithms are still alive and can be used while the padata
structure is being freed.
Fixes: 5068c7a883d1 ("crypto: pcrypt - Add pcrypt crypto...")
Cc: <stable(a)vger.kernel.org>
Signed-off-by: Herbert Xu <herbert(a)gondor.apana.org.au>
diff --git a/crypto/pcrypt.c b/crypto/pcrypt.c
index 543792e0ebf0..81bbea7f2ba6 100644
--- a/crypto/pcrypt.c
+++ b/crypto/pcrypt.c
@@ -362,11 +362,12 @@ static int __init pcrypt_init(void)
static void __exit pcrypt_exit(void)
{
+ crypto_unregister_template(&pcrypt_tmpl);
+
pcrypt_fini_padata(pencrypt);
pcrypt_fini_padata(pdecrypt);
kset_unregister(pcrypt_kset);
- crypto_unregister_template(&pcrypt_tmpl);
}
subsys_initcall(pcrypt_init);
commit b8511ccc75c033f6d54188ea4df7bf1e85778740 upstream.
A resource group (rdtgrp) contains a reference count (rdtgrp->waitcount)
that indicates how many waiters expect this rdtgrp to exist. Waiters
could be waiting on rdtgroup_mutex or some work sitting on a task's
workqueue for when the task returns from kernel mode or exits.
The deletion of a rdtgrp is intended to have two phases:
(1) while holding rdtgroup_mutex the necessary cleanup is done and
rdtgrp->flags is set to RDT_DELETED,
(2) after releasing the rdtgroup_mutex, the rdtgrp structure is freed
only if there are no waiters and its flag is set to RDT_DELETED. Upon
gaining access to rdtgroup_mutex or rdtgrp, a waiter is required to check
for the RDT_DELETED flag.
When unmounting the resctrl file system or deleting ctrl_mon groups,
all of the subdirectories are removed and the data structure of rdtgrp
is forcibly freed without checking rdtgrp->waitcount. If at this point
there was a waiter on rdtgrp then a use-after-free issue occurs when the
waiter starts running and accesses the rdtgrp structure it was waiting
on.
See kfree() calls in [1], [2] and [3] in these two call paths in
following scenarios:
(1) rdt_kill_sb() -> rmdir_all_sub() -> free_all_child_rdtgrp()
(2) rdtgroup_rmdir() -> rdtgroup_rmdir_ctrl() -> free_all_child_rdtgrp()
There are several scenarios that result in use-after-free issue in
following:
Scenario 1:
-----------
In Thread 1, rdtgroup_tasks_write() adds a task_work callback
move_myself(). If move_myself() is scheduled to execute after Thread 2
rdt_kill_sb() is finished, referring to earlier rdtgrp memory
(rdtgrp->waitcount) which was already freed in Thread 2 results in
use-after-free issue.
Thread 1 (rdtgroup_tasks_write) Thread 2 (rdt_kill_sb)
------------------------------- ----------------------
rdtgroup_kn_lock_live
atomic_inc(&rdtgrp->waitcount)
mutex_lock
rdtgroup_move_task
__rdtgroup_move_task
/*
* Take an extra refcount, so rdtgrp cannot be freed
* before the call back move_myself has been invoked
*/
atomic_inc(&rdtgrp->waitcount)
/* Callback move_myself will be scheduled for later */
task_work_add(move_myself)
rdtgroup_kn_unlock
mutex_unlock
atomic_dec_and_test(&rdtgrp->waitcount)
&& (flags & RDT_DELETED)
mutex_lock
rmdir_all_sub
/*
* sentry and rdtgrp are freed
* without checking refcount
*/
free_all_child_rdtgrp
kfree(sentry)*[1]
kfree(rdtgrp)*[2]
mutex_unlock
/*
* Callback is scheduled to execute
* after rdt_kill_sb is finished
*/
move_myself
/*
* Use-after-free: refer to earlier rdtgrp
* memory which was freed in [1] or [2].
*/
atomic_dec_and_test(&rdtgrp->waitcount)
&& (flags & RDT_DELETED)
kfree(rdtgrp)
Scenario 2:
-----------
In Thread 1, rdtgroup_tasks_write() adds a task_work callback
move_myself(). If move_myself() is scheduled to execute after Thread 2
rdtgroup_rmdir() is finished, referring to earlier rdtgrp memory
(rdtgrp->waitcount) which was already freed in Thread 2 results in
use-after-free issue.
Thread 1 (rdtgroup_tasks_write) Thread 2 (rdtgroup_rmdir)
------------------------------- -------------------------
rdtgroup_kn_lock_live
atomic_inc(&rdtgrp->waitcount)
mutex_lock
rdtgroup_move_task
__rdtgroup_move_task
/*
* Take an extra refcount, so rdtgrp cannot be freed
* before the call back move_myself has been invoked
*/
atomic_inc(&rdtgrp->waitcount)
/* Callback move_myself will be scheduled for later */
task_work_add(move_myself)
rdtgroup_kn_unlock
mutex_unlock
atomic_dec_and_test(&rdtgrp->waitcount)
&& (flags & RDT_DELETED)
rdtgroup_kn_lock_live
atomic_inc(&rdtgrp->waitcount)
mutex_lock
rdtgroup_rmdir_ctrl
free_all_child_rdtgrp
/*
* sentry is freed without
* checking refcount
*/
kfree(sentry)*[3]
rdtgroup_ctrl_remove
rdtgrp->flags = RDT_DELETED
rdtgroup_kn_unlock
mutex_unlock
atomic_dec_and_test(
&rdtgrp->waitcount)
&& (flags & RDT_DELETED)
kfree(rdtgrp)
/*
* Callback is scheduled to execute
* after rdt_kill_sb is finished
*/
move_myself
/*
* Use-after-free: refer to earlier rdtgrp
* memory which was freed in [3].
*/
atomic_dec_and_test(&rdtgrp->waitcount)
&& (flags & RDT_DELETED)
kfree(rdtgrp)
If CONFIG_DEBUG_SLAB=y, Slab corruption on kmalloc-2k can be observed
like following. Note that "0x6b" is POISON_FREE after kfree(). The
corrupted bits "0x6a", "0x64" at offset 0x424 correspond to
waitcount member of struct rdtgroup which was freed:
Slab corruption (Not tainted): kmalloc-2k start=ffff9504c5b0d000, len=2048
420: 6b 6b 6b 6b 6a 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b kkkkjkkkkkkkkkkk
Single bit error detected. Probably bad RAM.
Run memtest86+ or a similar memory test tool.
Next obj: start=ffff9504c5b0d800, len=2048
000: 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b kkkkkkkkkkkkkkkk
010: 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b kkkkkkkkkkkkkkkk
Slab corruption (Not tainted): kmalloc-2k start=ffff9504c58ab800, len=2048
420: 6b 6b 6b 6b 64 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b kkkkdkkkkkkkkkkk
Prev obj: start=ffff9504c58ab000, len=2048
000: 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b kkkkkkkkkkkkkkkk
010: 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b kkkkkkkkkkkkkkkk
Fix this by taking reference count (waitcount) of rdtgrp into account in
the two call paths that currently do not do so. Instead of always
freeing the resource group it will only be freed if there are no waiters
on it. If there are waiters, the resource group will have its flags set
to RDT_DELETED.
It will be left to the waiter to free the resource group when it starts
running and finding that it was the last waiter and the resource group
has been removed (rdtgrp->flags & RDT_DELETED) since. (1) rdt_kill_sb()
-> rmdir_all_sub() -> free_all_child_rdtgrp() (2) rdtgroup_rmdir() ->
rdtgroup_rmdir_ctrl() -> free_all_child_rdtgrp()
Backporting notes:
Since upstream commit fa7d949337cc ("x86/resctrl: Rename and move rdt
files to a separate directory"), the file
arch/x86/kernel/cpu/intel_rdt_rdtgroup.c has been renamed and moved to
arch/x86/kernel/cpu/resctrl/rdtgroup.c.
Apply the change against file arch/x86/kernel/cpu/intel_rdt_rdtgroup.c
in older stable trees.
Fixes: f3cbeacaa06e ("x86/intel_rdt/cqm: Add rmdir support")
Fixes: 60cf5e101fd4 ("x86/intel_rdt: Add mkdir to resctrl file system")
Suggested-by: Reinette Chatre <reinette.chatre(a)intel.com>
Signed-off-by: Xiaochen Shen <xiaochen.shen(a)intel.com>
Signed-off-by: Borislav Petkov <bp(a)suse.de>
Reviewed-by: Reinette Chatre <reinette.chatre(a)intel.com>
Reviewed-by: Tony Luck <tony.luck(a)intel.com>
Acked-by: Thomas Gleixner <tglx(a)linutronix.de>
Cc: stable(a)vger.kernel.org
Link: https://lkml.kernel.org/r/1578500886-21771-2-git-send-email-xiaochen.shen@i…
---
arch/x86/kernel/cpu/intel_rdt_rdtgroup.c | 12 ++++++++++--
1 file changed, 10 insertions(+), 2 deletions(-)
diff --git a/arch/x86/kernel/cpu/intel_rdt_rdtgroup.c b/arch/x86/kernel/cpu/intel_rdt_rdtgroup.c
index 841a024..db22ba0 100644
--- a/arch/x86/kernel/cpu/intel_rdt_rdtgroup.c
+++ b/arch/x86/kernel/cpu/intel_rdt_rdtgroup.c
@@ -2167,7 +2167,11 @@ static void free_all_child_rdtgrp(struct rdtgroup *rdtgrp)
list_for_each_entry_safe(sentry, stmp, head, mon.crdtgrp_list) {
free_rmid(sentry->mon.rmid);
list_del(&sentry->mon.crdtgrp_list);
- kfree(sentry);
+
+ if (atomic_read(&sentry->waitcount) != 0)
+ sentry->flags = RDT_DELETED;
+ else
+ kfree(sentry);
}
}
@@ -2205,7 +2209,11 @@ static void rmdir_all_sub(void)
kernfs_remove(rdtgrp->kn);
list_del(&rdtgrp->rdtgroup_list);
- kfree(rdtgrp);
+
+ if (atomic_read(&rdtgrp->waitcount) != 0)
+ rdtgrp->flags = RDT_DELETED;
+ else
+ kfree(rdtgrp);
}
/* Notify online CPUs to update per cpu storage and PQR_ASSOC MSR */
update_closid_rmid(cpu_online_mask, &rdtgroup_default);
--
1.8.3.1
Commit f3ee99087c8ca0ecfdd549ef5a94f557c42d5428 ("ASoC: tegra: Allow
24bit and 32bit samples") added 24-bit and 32-bit support for to the
Tegra30 I2S driver. However, there are two additional commits that are
also needed to get 24-bit and 32-bit support to work correctly. These
commits are not yet applied because there are still some review comments
that need to be addressed. With only this change applied, 24-bit and
32-bit support is advertised by the I2S driver, but it does not work and
the audio is distorted. Therefore, revert this patch for now until the
other changes are also ready.
Furthermore, a clock issue with 24-bit support has been identified with
this change and so if we revert this now, we can also fix that in the
updated version.
Cc: stable(a)vger.kernel.org
Reported-by: Dmitry Osipenko <digetx(a)gmail.com>
Signed-off-by: Jon Hunter <jonathanh(a)nvidia.com>
---
sound/soc/tegra/tegra30_i2s.c | 25 +++++--------------------
1 file changed, 5 insertions(+), 20 deletions(-)
diff --git a/sound/soc/tegra/tegra30_i2s.c b/sound/soc/tegra/tegra30_i2s.c
index dbed3c5408e7..d59882ec48f1 100644
--- a/sound/soc/tegra/tegra30_i2s.c
+++ b/sound/soc/tegra/tegra30_i2s.c
@@ -127,7 +127,7 @@ static int tegra30_i2s_hw_params(struct snd_pcm_substream *substream,
struct device *dev = dai->dev;
struct tegra30_i2s *i2s = snd_soc_dai_get_drvdata(dai);
unsigned int mask, val, reg;
- int ret, sample_size, srate, i2sclock, bitcnt, audio_bits;
+ int ret, sample_size, srate, i2sclock, bitcnt;
struct tegra30_ahub_cif_conf cif_conf;
if (params_channels(params) != 2)
@@ -137,19 +137,8 @@ static int tegra30_i2s_hw_params(struct snd_pcm_substream *substream,
switch (params_format(params)) {
case SNDRV_PCM_FORMAT_S16_LE:
val = TEGRA30_I2S_CTRL_BIT_SIZE_16;
- audio_bits = TEGRA30_AUDIOCIF_BITS_16;
sample_size = 16;
break;
- case SNDRV_PCM_FORMAT_S24_LE:
- val = TEGRA30_I2S_CTRL_BIT_SIZE_24;
- audio_bits = TEGRA30_AUDIOCIF_BITS_24;
- sample_size = 24;
- break;
- case SNDRV_PCM_FORMAT_S32_LE:
- val = TEGRA30_I2S_CTRL_BIT_SIZE_32;
- audio_bits = TEGRA30_AUDIOCIF_BITS_32;
- sample_size = 32;
- break;
default:
return -EINVAL;
}
@@ -181,8 +170,8 @@ static int tegra30_i2s_hw_params(struct snd_pcm_substream *substream,
cif_conf.threshold = 0;
cif_conf.audio_channels = 2;
cif_conf.client_channels = 2;
- cif_conf.audio_bits = audio_bits;
- cif_conf.client_bits = audio_bits;
+ cif_conf.audio_bits = TEGRA30_AUDIOCIF_BITS_16;
+ cif_conf.client_bits = TEGRA30_AUDIOCIF_BITS_16;
cif_conf.expand = 0;
cif_conf.stereo_conv = 0;
cif_conf.replicate = 0;
@@ -317,18 +306,14 @@ static const struct snd_soc_dai_driver tegra30_i2s_dai_template = {
.channels_min = 2,
.channels_max = 2,
.rates = SNDRV_PCM_RATE_8000_96000,
- .formats = SNDRV_PCM_FMTBIT_S32_LE |
- SNDRV_PCM_FMTBIT_S24_LE |
- SNDRV_PCM_FMTBIT_S16_LE,
+ .formats = SNDRV_PCM_FMTBIT_S16_LE,
},
.capture = {
.stream_name = "Capture",
.channels_min = 2,
.channels_max = 2,
.rates = SNDRV_PCM_RATE_8000_96000,
- .formats = SNDRV_PCM_FMTBIT_S32_LE |
- SNDRV_PCM_FMTBIT_S24_LE |
- SNDRV_PCM_FMTBIT_S16_LE,
+ .formats = SNDRV_PCM_FMTBIT_S16_LE,
},
.ops = &tegra30_i2s_dai_ops,
.symmetric_rates = 1,
--
2.17.1
commit 334b0f4e9b1b4a1d475f803419d202f6c5e4d18e upstream.
There is a race condition which results in a deadlock when rmdir and
mkdir execute concurrently:
$ ls /sys/fs/resctrl/c1/mon_groups/m1/
cpus cpus_list mon_data tasks
Thread 1: rmdir /sys/fs/resctrl/c1
Thread 2: mkdir /sys/fs/resctrl/c1/mon_groups/m1
3 locks held by mkdir/48649:
#0: (sb_writers#17){.+.+}, at: [<ffffffffb4ca2aa0>] mnt_want_write+0x20/0x50
#1: (&type->i_mutex_dir_key#8/1){+.+.}, at: [<ffffffffb4c8c13b>] filename_create+0x7b/0x170
#2: (rdtgroup_mutex){+.+.}, at: [<ffffffffb4a4389d>] rdtgroup_kn_lock_live+0x3d/0x70
4 locks held by rmdir/48652:
#0: (sb_writers#17){.+.+}, at: [<ffffffffb4ca2aa0>] mnt_want_write+0x20/0x50
#1: (&type->i_mutex_dir_key#8/1){+.+.}, at: [<ffffffffb4c8c3cf>] do_rmdir+0x13f/0x1e0
#2: (&type->i_mutex_dir_key#8){++++}, at: [<ffffffffb4c86d5d>] vfs_rmdir+0x4d/0x120
#3: (rdtgroup_mutex){+.+.}, at: [<ffffffffb4a4389d>] rdtgroup_kn_lock_live+0x3d/0x70
Thread 1 is deleting control group "c1". Holding rdtgroup_mutex,
kernfs_remove() removes all kernfs nodes under directory "c1"
recursively, then waits for sub kernfs node "mon_groups" to drop active
reference.
Thread 2 is trying to create a subdirectory "m1" in the "mon_groups"
directory. The wrapper kernfs_iop_mkdir() takes an active reference to
the "mon_groups" directory but the code drops the active reference to
the parent directory "c1" instead.
As a result, Thread 1 is blocked on waiting for active reference to drop
and never release rdtgroup_mutex, while Thread 2 is also blocked on
trying to get rdtgroup_mutex.
Thread 1 (rdtgroup_rmdir) Thread 2 (rdtgroup_mkdir)
(rmdir /sys/fs/resctrl/c1) (mkdir /sys/fs/resctrl/c1/mon_groups/m1)
------------------------- -------------------------
kernfs_iop_mkdir
/*
* kn: "m1", parent_kn: "mon_groups",
* prgrp_kn: parent_kn->parent: "c1",
*
* "mon_groups", parent_kn->active++: 1
*/
kernfs_get_active(parent_kn)
kernfs_iop_rmdir
/* "c1", kn->active++ */
kernfs_get_active(kn)
rdtgroup_kn_lock_live
atomic_inc(&rdtgrp->waitcount)
/* "c1", kn->active-- */
kernfs_break_active_protection(kn)
mutex_lock
rdtgroup_rmdir_ctrl
free_all_child_rdtgrp
sentry->flags = RDT_DELETED
rdtgroup_ctrl_remove
rdtgrp->flags = RDT_DELETED
kernfs_get(kn)
kernfs_remove(rdtgrp->kn)
__kernfs_remove
/* "mon_groups", sub_kn */
atomic_add(KN_DEACTIVATED_BIAS, &sub_kn->active)
kernfs_drain(sub_kn)
/*
* sub_kn->active == KN_DEACTIVATED_BIAS + 1,
* waiting on sub_kn->active to drop, but it
* never drops in Thread 2 which is blocked
* on getting rdtgroup_mutex.
*/
Thread 1 hangs here ---->
wait_event(sub_kn->active == KN_DEACTIVATED_BIAS)
...
rdtgroup_mkdir
rdtgroup_mkdir_mon(parent_kn, prgrp_kn)
mkdir_rdt_prepare(parent_kn, prgrp_kn)
rdtgroup_kn_lock_live(prgrp_kn)
atomic_inc(&rdtgrp->waitcount)
/*
* "c1", prgrp_kn->active--
*
* The active reference on "c1" is
* dropped, but not matching the
* actual active reference taken
* on "mon_groups", thus causing
* Thread 1 to wait forever while
* holding rdtgroup_mutex.
*/
kernfs_break_active_protection(
prgrp_kn)
/*
* Trying to get rdtgroup_mutex
* which is held by Thread 1.
*/
Thread 2 hangs here ----> mutex_lock
...
The problem is that the creation of a subdirectory in the "mon_groups"
directory incorrectly releases the active protection of its parent
directory instead of itself before it starts waiting for rdtgroup_mutex.
This is triggered by the rdtgroup_mkdir() flow calling
rdtgroup_kn_lock_live()/rdtgroup_kn_unlock() with kernfs node of the
parent control group ("c1") as argument. It should be called with kernfs
node "mon_groups" instead. What is currently missing is that the
kn->priv of "mon_groups" is NULL instead of pointing to the rdtgrp.
Fix it by pointing kn->priv to rdtgrp when "mon_groups" is created. Then
it could be passed to rdtgroup_kn_lock_live()/rdtgroup_kn_unlock()
instead. And then it operates on the same rdtgroup structure but handles
the active reference of kernfs node "mon_groups" to prevent deadlock.
The same changes are also made to the "mon_data" directories.
This results in some unused function parameters that will be cleaned up
in follow-up patch as the focus here is on the fix only in support of
backporting efforts.
Backporting notes:
Since upstream commit fa7d949337cc ("x86/resctrl: Rename and move rdt
files to a separate directory"), the file
arch/x86/kernel/cpu/intel_rdt_rdtgroup.c has been renamed and moved to
arch/x86/kernel/cpu/resctrl/rdtgroup.c.
Apply the change against file arch/x86/kernel/cpu/intel_rdt_rdtgroup.c
for older stable trees.
Fixes: c7d9aac61311 ("x86/intel_rdt/cqm: Add mkdir support for RDT monitoring")
Suggested-by: Reinette Chatre <reinette.chatre(a)intel.com>
Signed-off-by: Xiaochen Shen <xiaochen.shen(a)intel.com>
Signed-off-by: Borislav Petkov <bp(a)suse.de>
Reviewed-by: Reinette Chatre <reinette.chatre(a)intel.com>
Reviewed-by: Tony Luck <tony.luck(a)intel.com>
Acked-by: Thomas Gleixner <tglx(a)linutronix.de>
Cc: stable(a)vger.kernel.org
Link: https://lkml.kernel.org/r/1578500886-21771-4-git-send-email-xiaochen.shen@i…
---
arch/x86/kernel/cpu/intel_rdt_rdtgroup.c | 16 ++++++++--------
1 file changed, 8 insertions(+), 8 deletions(-)
diff --git a/arch/x86/kernel/cpu/intel_rdt_rdtgroup.c b/arch/x86/kernel/cpu/intel_rdt_rdtgroup.c
index 77770ca..11c5acc 100644
--- a/arch/x86/kernel/cpu/intel_rdt_rdtgroup.c
+++ b/arch/x86/kernel/cpu/intel_rdt_rdtgroup.c
@@ -2005,7 +2005,7 @@ static struct dentry *rdt_mount(struct file_system_type *fs_type,
if (rdt_mon_capable) {
ret = mongroup_create_dir(rdtgroup_default.kn,
- NULL, "mon_groups",
+ &rdtgroup_default, "mon_groups",
&kn_mongrp);
if (ret) {
dentry = ERR_PTR(ret);
@@ -2415,7 +2415,7 @@ static int mkdir_mondata_all(struct kernfs_node *parent_kn,
/*
* Create the mon_data directory first.
*/
- ret = mongroup_create_dir(parent_kn, NULL, "mon_data", &kn);
+ ret = mongroup_create_dir(parent_kn, prgrp, "mon_data", &kn);
if (ret)
return ret;
@@ -2568,7 +2568,7 @@ static int mkdir_rdt_prepare(struct kernfs_node *parent_kn,
uint files = 0;
int ret;
- prdtgrp = rdtgroup_kn_lock_live(prgrp_kn);
+ prdtgrp = rdtgroup_kn_lock_live(parent_kn);
rdt_last_cmd_clear();
if (!prdtgrp) {
ret = -ENODEV;
@@ -2643,7 +2643,7 @@ static int mkdir_rdt_prepare(struct kernfs_node *parent_kn,
kernfs_activate(kn);
/*
- * The caller unlocks the prgrp_kn upon success.
+ * The caller unlocks the parent_kn upon success.
*/
return 0;
@@ -2654,7 +2654,7 @@ static int mkdir_rdt_prepare(struct kernfs_node *parent_kn,
out_free_rgrp:
kfree(rdtgrp);
out_unlock:
- rdtgroup_kn_unlock(prgrp_kn);
+ rdtgroup_kn_unlock(parent_kn);
return ret;
}
@@ -2692,7 +2692,7 @@ static int rdtgroup_mkdir_mon(struct kernfs_node *parent_kn,
*/
list_add_tail(&rdtgrp->mon.crdtgrp_list, &prgrp->mon.crdtgrp_list);
- rdtgroup_kn_unlock(prgrp_kn);
+ rdtgroup_kn_unlock(parent_kn);
return ret;
}
@@ -2735,7 +2735,7 @@ static int rdtgroup_mkdir_ctrl_mon(struct kernfs_node *parent_kn,
* Create an empty mon_groups directory to hold the subset
* of tasks and cpus to monitor.
*/
- ret = mongroup_create_dir(kn, NULL, "mon_groups", NULL);
+ ret = mongroup_create_dir(kn, rdtgrp, "mon_groups", NULL);
if (ret) {
rdt_last_cmd_puts("kernfs subdir error\n");
goto out_del_list;
@@ -2751,7 +2751,7 @@ static int rdtgroup_mkdir_ctrl_mon(struct kernfs_node *parent_kn,
out_common_fail:
mkdir_rdt_prepare_clean(rdtgrp);
out_unlock:
- rdtgroup_kn_unlock(prgrp_kn);
+ rdtgroup_kn_unlock(parent_kn);
return ret;
}
--
1.8.3.1
commit 074fadee59ee7a9d2b216e9854bd4efb5dad679f upstream.
There is a race condition in the following scenario which results in an
use-after-free issue when reading a monitoring file and deleting the
parent ctrl_mon group concurrently:
Thread 1 calls atomic_inc() to take refcount of rdtgrp and then calls
kernfs_break_active_protection() to drop the active reference of kernfs
node in rdtgroup_kn_lock_live().
In Thread 2, kernfs_remove() is a blocking routine. It waits on all sub
kernfs nodes to drop the active reference when removing all subtree
kernfs nodes recursively. Thread 2 could block on kernfs_remove() until
Thread 1 calls kernfs_break_active_protection(). Only after
kernfs_remove() completes the refcount of rdtgrp could be trusted.
Before Thread 1 calls atomic_inc() and kernfs_break_active_protection(),
Thread 2 could call kfree() when the refcount of rdtgrp (sentry) is 0
instead of 1 due to the race.
In Thread 1, in rdtgroup_kn_unlock(), referring to earlier rdtgrp memory
(rdtgrp->waitcount) which was already freed in Thread 2 results in
use-after-free issue.
Thread 1 (rdtgroup_mondata_show) Thread 2 (rdtgroup_rmdir)
-------------------------------- -------------------------
rdtgroup_kn_lock_live
/*
* kn active protection until
* kernfs_break_active_protection(kn)
*/
rdtgrp = kernfs_to_rdtgroup(kn)
rdtgroup_kn_lock_live
atomic_inc(&rdtgrp->waitcount)
mutex_lock
rdtgroup_rmdir_ctrl
free_all_child_rdtgrp
/*
* sentry->waitcount should be 1
* but is 0 now due to the race.
*/
kfree(sentry)*[1]
/*
* Only after kernfs_remove()
* completes, the refcount of
* rdtgrp could be trusted.
*/
atomic_inc(&rdtgrp->waitcount)
/* kn->active-- */
kernfs_break_active_protection(kn)
rdtgroup_ctrl_remove
rdtgrp->flags = RDT_DELETED
/*
* Blocking routine, wait for
* all sub kernfs nodes to drop
* active reference in
* kernfs_break_active_protection.
*/
kernfs_remove(rdtgrp->kn)
rdtgroup_kn_unlock
mutex_unlock
atomic_dec_and_test(
&rdtgrp->waitcount)
&& (flags & RDT_DELETED)
kernfs_unbreak_active_protection(kn)
kfree(rdtgrp)
mutex_lock
mon_event_read
rdtgroup_kn_unlock
mutex_unlock
/*
* Use-after-free: refer to earlier rdtgrp
* memory which was freed in [1].
*/
atomic_dec_and_test(&rdtgrp->waitcount)
&& (flags & RDT_DELETED)
/* kn->active++ */
kernfs_unbreak_active_protection(kn)
kfree(rdtgrp)
Fix it by moving free_all_child_rdtgrp() to after kernfs_remove() in
rdtgroup_rmdir_ctrl() to ensure it has the accurate refcount of rdtgrp.
Backporting notes:
Since upstream commit fa7d949337cc ("x86/resctrl: Rename and move rdt
files to a separate directory"), the file
arch/x86/kernel/cpu/intel_rdt_rdtgroup.c has been renamed and moved to
arch/x86/kernel/cpu/resctrl/rdtgroup.c.
Apply the change against file arch/x86/kernel/cpu/intel_rdt_rdtgroup.c
for older stable trees.
Fixes: f3cbeacaa06e ("x86/intel_rdt/cqm: Add rmdir support")
Suggested-by: Reinette Chatre <reinette.chatre(a)intel.com>
Signed-off-by: Xiaochen Shen <xiaochen.shen(a)intel.com>
Signed-off-by: Borislav Petkov <bp(a)suse.de>
Reviewed-by: Reinette Chatre <reinette.chatre(a)intel.com>
Reviewed-by: Tony Luck <tony.luck(a)intel.com>
Acked-by: Thomas Gleixner <tglx(a)linutronix.de>
Cc: stable(a)vger.kernel.org
Link: https://lkml.kernel.org/r/1578500886-21771-3-git-send-email-xiaochen.shen@i…
---
arch/x86/kernel/cpu/intel_rdt_rdtgroup.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/arch/x86/kernel/cpu/intel_rdt_rdtgroup.c b/arch/x86/kernel/cpu/intel_rdt_rdtgroup.c
index db22ba0..77770ca 100644
--- a/arch/x86/kernel/cpu/intel_rdt_rdtgroup.c
+++ b/arch/x86/kernel/cpu/intel_rdt_rdtgroup.c
@@ -2877,13 +2877,13 @@ static int rdtgroup_rmdir_ctrl(struct kernfs_node *kn, struct rdtgroup *rdtgrp,
closid_free(rdtgrp->closid);
free_rmid(rdtgrp->mon.rmid);
+ rdtgroup_ctrl_remove(kn, rdtgrp);
+
/*
* Free all the child monitor group rmids.
*/
free_all_child_rdtgrp(rdtgrp);
- rdtgroup_ctrl_remove(kn, rdtgrp);
-
return 0;
}
--
1.8.3.1