From: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To: linux-kernel@vger.kernel.org
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
stable@vger.kernel.org,
Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>,
syzbot <syzbot+bf89c128e05dd6c62523@syzkaller.appspotmail.com>,
Jan Kara <jack@suse.cz>, Jens Axboe <axboe@kernel.dk>
Subject: [PATCH 4.14 54/59] block/loop: Use global lock for ioctl() operation.
Date: Mon, 21 Jan 2019 14:44:19 +0100 [thread overview]
Message-ID: <20190121122502.991145626@linuxfoundation.org> (raw)
In-Reply-To: <20190121122456.529172919@linuxfoundation.org>
4.14-stable review patch. If anyone has any objections, please let me know.
------------------
From: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
commit 310ca162d779efee8a2dc3731439680f3e9c1e86 upstream.
syzbot is reporting NULL pointer dereference [1] which is caused by
race condition between ioctl(loop_fd, LOOP_CLR_FD, 0) versus
ioctl(other_loop_fd, LOOP_SET_FD, loop_fd) due to traversing other
loop devices at loop_validate_file() without holding corresponding
lo->lo_ctl_mutex locks.
Since ioctl() request on loop devices is not frequent operation, we don't
need fine grained locking. Let's use global lock in order to allow safe
traversal at loop_validate_file().
Note that syzbot is also reporting circular locking dependency between
bdev->bd_mutex and lo->lo_ctl_mutex [2] which is caused by calling
blkdev_reread_part() with lock held. This patch does not address it.
[1] https://syzkaller.appspot.com/bug?id=f3cfe26e785d85f9ee259f385515291d21bd80a3
[2] https://syzkaller.appspot.com/bug?id=bf154052f0eea4bc7712499e4569505907d15889
Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Reported-by: syzbot <syzbot+bf89c128e05dd6c62523@syzkaller.appspotmail.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
drivers/block/loop.c | 58 +++++++++++++++++++++++++--------------------------
drivers/block/loop.h | 1
2 files changed, 29 insertions(+), 30 deletions(-)
--- a/drivers/block/loop.c
+++ b/drivers/block/loop.c
@@ -82,6 +82,7 @@
static DEFINE_IDR(loop_index_idr);
static DEFINE_MUTEX(loop_index_mutex);
+static DEFINE_MUTEX(loop_ctl_mutex);
static int max_part;
static int part_shift;
@@ -1018,7 +1019,7 @@ static int loop_clr_fd(struct loop_devic
*/
if (atomic_read(&lo->lo_refcnt) > 1) {
lo->lo_flags |= LO_FLAGS_AUTOCLEAR;
- mutex_unlock(&lo->lo_ctl_mutex);
+ mutex_unlock(&loop_ctl_mutex);
return 0;
}
@@ -1070,12 +1071,12 @@ static int loop_clr_fd(struct loop_devic
if (!part_shift)
lo->lo_disk->flags |= GENHD_FL_NO_PART_SCAN;
loop_unprepare_queue(lo);
- mutex_unlock(&lo->lo_ctl_mutex);
+ mutex_unlock(&loop_ctl_mutex);
/*
- * Need not hold lo_ctl_mutex to fput backing file.
- * Calling fput holding lo_ctl_mutex triggers a circular
+ * Need not hold loop_ctl_mutex to fput backing file.
+ * Calling fput holding loop_ctl_mutex triggers a circular
* lock dependency possibility warning as fput can take
- * bd_mutex which is usually taken before lo_ctl_mutex.
+ * bd_mutex which is usually taken before loop_ctl_mutex.
*/
fput(filp);
return 0;
@@ -1180,7 +1181,7 @@ loop_get_status(struct loop_device *lo,
int ret;
if (lo->lo_state != Lo_bound) {
- mutex_unlock(&lo->lo_ctl_mutex);
+ mutex_unlock(&loop_ctl_mutex);
return -ENXIO;
}
@@ -1199,10 +1200,10 @@ loop_get_status(struct loop_device *lo,
lo->lo_encrypt_key_size);
}
- /* Drop lo_ctl_mutex while we call into the filesystem. */
+ /* Drop loop_ctl_mutex while we call into the filesystem. */
path = lo->lo_backing_file->f_path;
path_get(&path);
- mutex_unlock(&lo->lo_ctl_mutex);
+ mutex_unlock(&loop_ctl_mutex);
ret = vfs_getattr(&path, &stat, STATX_INO, AT_STATX_SYNC_AS_STAT);
if (!ret) {
info->lo_device = huge_encode_dev(stat.dev);
@@ -1294,7 +1295,7 @@ loop_get_status_old(struct loop_device *
int err;
if (!arg) {
- mutex_unlock(&lo->lo_ctl_mutex);
+ mutex_unlock(&loop_ctl_mutex);
return -EINVAL;
}
err = loop_get_status(lo, &info64);
@@ -1312,7 +1313,7 @@ loop_get_status64(struct loop_device *lo
int err;
if (!arg) {
- mutex_unlock(&lo->lo_ctl_mutex);
+ mutex_unlock(&loop_ctl_mutex);
return -EINVAL;
}
err = loop_get_status(lo, &info64);
@@ -1370,7 +1371,7 @@ static int lo_ioctl(struct block_device
struct loop_device *lo = bdev->bd_disk->private_data;
int err;
- mutex_lock_nested(&lo->lo_ctl_mutex, 1);
+ mutex_lock_nested(&loop_ctl_mutex, 1);
switch (cmd) {
case LOOP_SET_FD:
err = loop_set_fd(lo, mode, bdev, arg);
@@ -1379,7 +1380,7 @@ static int lo_ioctl(struct block_device
err = loop_change_fd(lo, bdev, arg);
break;
case LOOP_CLR_FD:
- /* loop_clr_fd would have unlocked lo_ctl_mutex on success */
+ /* loop_clr_fd would have unlocked loop_ctl_mutex on success */
err = loop_clr_fd(lo);
if (!err)
goto out_unlocked;
@@ -1392,7 +1393,7 @@ static int lo_ioctl(struct block_device
break;
case LOOP_GET_STATUS:
err = loop_get_status_old(lo, (struct loop_info __user *) arg);
- /* loop_get_status() unlocks lo_ctl_mutex */
+ /* loop_get_status() unlocks loop_ctl_mutex */
goto out_unlocked;
case LOOP_SET_STATUS64:
err = -EPERM;
@@ -1402,7 +1403,7 @@ static int lo_ioctl(struct block_device
break;
case LOOP_GET_STATUS64:
err = loop_get_status64(lo, (struct loop_info64 __user *) arg);
- /* loop_get_status() unlocks lo_ctl_mutex */
+ /* loop_get_status() unlocks loop_ctl_mutex */
goto out_unlocked;
case LOOP_SET_CAPACITY:
err = -EPERM;
@@ -1422,7 +1423,7 @@ static int lo_ioctl(struct block_device
default:
err = lo->ioctl ? lo->ioctl(lo, cmd, arg) : -EINVAL;
}
- mutex_unlock(&lo->lo_ctl_mutex);
+ mutex_unlock(&loop_ctl_mutex);
out_unlocked:
return err;
@@ -1539,7 +1540,7 @@ loop_get_status_compat(struct loop_devic
int err;
if (!arg) {
- mutex_unlock(&lo->lo_ctl_mutex);
+ mutex_unlock(&loop_ctl_mutex);
return -EINVAL;
}
err = loop_get_status(lo, &info64);
@@ -1556,16 +1557,16 @@ static int lo_compat_ioctl(struct block_
switch(cmd) {
case LOOP_SET_STATUS:
- mutex_lock(&lo->lo_ctl_mutex);
+ mutex_lock(&loop_ctl_mutex);
err = loop_set_status_compat(
lo, (const struct compat_loop_info __user *) arg);
- mutex_unlock(&lo->lo_ctl_mutex);
+ mutex_unlock(&loop_ctl_mutex);
break;
case LOOP_GET_STATUS:
- mutex_lock(&lo->lo_ctl_mutex);
+ mutex_lock(&loop_ctl_mutex);
err = loop_get_status_compat(
lo, (struct compat_loop_info __user *) arg);
- /* loop_get_status() unlocks lo_ctl_mutex */
+ /* loop_get_status() unlocks loop_ctl_mutex */
break;
case LOOP_SET_CAPACITY:
case LOOP_CLR_FD:
@@ -1609,7 +1610,7 @@ static void __lo_release(struct loop_dev
if (atomic_dec_return(&lo->lo_refcnt))
return;
- mutex_lock(&lo->lo_ctl_mutex);
+ mutex_lock(&loop_ctl_mutex);
if (lo->lo_flags & LO_FLAGS_AUTOCLEAR) {
/*
* In autoclear mode, stop the loop thread
@@ -1627,7 +1628,7 @@ static void __lo_release(struct loop_dev
blk_mq_unfreeze_queue(lo->lo_queue);
}
- mutex_unlock(&lo->lo_ctl_mutex);
+ mutex_unlock(&loop_ctl_mutex);
}
static void lo_release(struct gendisk *disk, fmode_t mode)
@@ -1673,10 +1674,10 @@ static int unregister_transfer_cb(int id
struct loop_device *lo = ptr;
struct loop_func_table *xfer = data;
- mutex_lock(&lo->lo_ctl_mutex);
+ mutex_lock(&loop_ctl_mutex);
if (lo->lo_encryption == xfer)
loop_release_xfer(lo);
- mutex_unlock(&lo->lo_ctl_mutex);
+ mutex_unlock(&loop_ctl_mutex);
return 0;
}
@@ -1849,7 +1850,6 @@ static int loop_add(struct loop_device *
if (!part_shift)
disk->flags |= GENHD_FL_NO_PART_SCAN;
disk->flags |= GENHD_FL_EXT_DEVT;
- mutex_init(&lo->lo_ctl_mutex);
atomic_set(&lo->lo_refcnt, 0);
lo->lo_number = i;
spin_lock_init(&lo->lo_lock);
@@ -1962,19 +1962,19 @@ static long loop_control_ioctl(struct fi
ret = loop_lookup(&lo, parm);
if (ret < 0)
break;
- mutex_lock(&lo->lo_ctl_mutex);
+ mutex_lock(&loop_ctl_mutex);
if (lo->lo_state != Lo_unbound) {
ret = -EBUSY;
- mutex_unlock(&lo->lo_ctl_mutex);
+ mutex_unlock(&loop_ctl_mutex);
break;
}
if (atomic_read(&lo->lo_refcnt) > 0) {
ret = -EBUSY;
- mutex_unlock(&lo->lo_ctl_mutex);
+ mutex_unlock(&loop_ctl_mutex);
break;
}
lo->lo_disk->private_data = NULL;
- mutex_unlock(&lo->lo_ctl_mutex);
+ mutex_unlock(&loop_ctl_mutex);
idr_remove(&loop_index_idr, lo->lo_number);
loop_remove(lo);
break;
--- a/drivers/block/loop.h
+++ b/drivers/block/loop.h
@@ -54,7 +54,6 @@ struct loop_device {
spinlock_t lo_lock;
int lo_state;
- struct mutex lo_ctl_mutex;
struct kthread_worker worker;
struct task_struct *worker_task;
bool use_dio;
next prev parent reply other threads:[~2019-01-21 13:53 UTC|newest]
Thread overview: 65+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-01-21 13:43 [PATCH 4.14 00/59] 4.14.95-stable review Greg Kroah-Hartman
2019-01-21 13:43 ` [PATCH 4.14 01/59] tty/ldsem: Wake up readers after timed out down_write() Greg Kroah-Hartman
2019-01-21 13:43 ` [PATCH 4.14 02/59] tty: Hold tty_ldisc_lock() during tty_reopen() Greg Kroah-Hartman
2019-01-21 13:43 ` [PATCH 4.14 03/59] tty: Simplify tty->count math in tty_reopen() Greg Kroah-Hartman
2019-01-21 13:43 ` [PATCH 4.14 04/59] tty: Dont hold ldisc lock in tty_reopen() if ldisc present Greg Kroah-Hartman
2019-01-21 13:43 ` [PATCH 4.14 05/59] can: gw: ensure DLC boundaries after CAN frame modification Greg Kroah-Hartman
2019-01-21 13:43 ` [PATCH 4.14 06/59] mmc: sdhci-msm: Disable CDR function on TX Greg Kroah-Hartman
2019-01-21 13:43 ` [PATCH 4.14 07/59] media: em28xx: Fix misplaced reset of dev->v4l::field_count Greg Kroah-Hartman
2019-01-21 13:43 ` [PATCH 4.14 08/59] sched/fair: Fix bandwidth timer clock drift condition Greg Kroah-Hartman
2019-01-21 13:43 ` [PATCH 4.14 09/59] Revert "scsi: target: iscsi: cxgbit: fix csk leak" Greg Kroah-Hartman
2019-01-21 13:43 ` [PATCH 4.14 10/59] scsi: target: iscsi: cxgbit: fix csk leak Greg Kroah-Hartman
2019-01-21 13:43 ` [PATCH 4.14 11/59] arm64/kvm: consistently handle host HCR_EL2 flags Greg Kroah-Hartman
2019-01-21 13:43 ` [PATCH 4.14 12/59] arm64: Dont trap host pointer auth use to EL2 Greg Kroah-Hartman
2019-01-21 13:43 ` [PATCH 4.14 13/59] ipv6: fix kernel-infoleak in ipv6_local_error() Greg Kroah-Hartman
2019-01-21 13:43 ` [PATCH 4.14 14/59] net: bridge: fix a bug on using a neighbour cache entry without checking its state Greg Kroah-Hartman
2019-01-21 13:43 ` [PATCH 4.14 15/59] packet: Do not leak dev refcounts on error exit Greg Kroah-Hartman
2019-01-21 13:43 ` [PATCH 4.14 16/59] bonding: update nest level on unlink Greg Kroah-Hartman
2019-01-21 13:43 ` [PATCH 4.14 17/59] ip: on queued skb use skb_header_pointer instead of pskb_may_pull Greg Kroah-Hartman
2019-01-21 13:43 ` [PATCH 4.14 18/59] crypto: caam - fix zero-length buffer DMA mapping Greg Kroah-Hartman
2019-01-21 13:43 ` [PATCH 4.14 19/59] crypto: authencesn - Avoid twice completion call in decrypt path Greg Kroah-Hartman
2019-01-21 13:43 ` [PATCH 4.14 20/59] crypto: bcm - convert to use crypto_authenc_extractkeys() Greg Kroah-Hartman
2019-01-21 13:43 ` [PATCH 4.14 21/59] crypto: authenc - fix parsing key with misaligned rta_len Greg Kroah-Hartman
2019-01-21 13:43 ` [PATCH 4.14 22/59] Revert "btrfs: balance dirty metadata pages in btrfs_finish_ordered_io" Greg Kroah-Hartman
2019-01-21 13:43 ` [PATCH 4.14 23/59] btrfs: wait on ordered extents on abort cleanup Greg Kroah-Hartman
2019-01-21 13:43 ` [PATCH 4.14 24/59] Yama: Check for pid death before checking ancestry Greg Kroah-Hartman
2019-01-21 13:43 ` [PATCH 4.14 25/59] scsi: core: Synchronize request queue PM status only on successful resume Greg Kroah-Hartman
2019-01-21 13:43 ` [PATCH 4.14 26/59] scsi: sd: Fix cache_type_store() Greg Kroah-Hartman
2019-01-21 13:43 ` [PATCH 4.14 27/59] crypto: talitos - reorder code in talitos_edesc_alloc() Greg Kroah-Hartman
2019-01-21 13:43 ` [PATCH 4.14 28/59] crypto: talitos - fix ablkcipher for CONFIG_VMAP_STACK Greg Kroah-Hartman
2019-01-21 13:43 ` [PATCH 4.14 29/59] mips: fix n32 compat_ipc_parse_version Greg Kroah-Hartman
2019-01-21 13:43 ` [PATCH 4.14 30/59] MIPS: lantiq: Fix IPI interrupt handling Greg Kroah-Hartman
2019-01-21 13:43 ` [PATCH 4.14 31/59] OF: properties: add missing of_node_put Greg Kroah-Hartman
2019-01-21 13:43 ` [PATCH 4.14 32/59] mfd: tps6586x: Handle interrupts on suspend Greg Kroah-Hartman
2019-01-21 13:43 ` [PATCH 4.14 33/59] media: v4l: ioctl: Validate num_planes for debug messages Greg Kroah-Hartman
2019-01-21 13:43 ` [PATCH 4.14 34/59] pstore/ram: Avoid allocation and leak of platform data Greg Kroah-Hartman
2019-01-21 13:44 ` [PATCH 4.14 35/59] arm64: kaslr: ensure randomized quantities are clean to the PoC Greg Kroah-Hartman
2019-01-21 13:44 ` [PATCH 4.14 36/59] Disable MSI also when pcie-octeon.pcie_disable on Greg Kroah-Hartman
2019-01-21 13:44 ` [PATCH 4.14 37/59] omap2fb: Fix stack memory disclosure Greg Kroah-Hartman
2019-01-21 13:44 ` [PATCH 4.14 38/59] media: vivid: fix error handling of kthread_run Greg Kroah-Hartman
2019-01-21 13:44 ` [PATCH 4.14 39/59] media: vivid: set min width/height to a value > 0 Greg Kroah-Hartman
2019-01-21 13:44 ` [PATCH 4.14 40/59] bpf: in __bpf_redirect_no_mac pull mac only if present Greg Kroah-Hartman
2019-01-21 13:44 ` [PATCH 4.14 41/59] LSM: Check for NULL cred-security on free Greg Kroah-Hartman
2019-01-21 13:44 ` [PATCH 4.14 42/59] media: vb2: vb2_mmap: move lock up Greg Kroah-Hartman
2019-01-21 13:44 ` [PATCH 4.14 43/59] sunrpc: handle ENOMEM in rpcb_getport_async Greg Kroah-Hartman
2019-01-21 13:44 ` [PATCH 4.14 44/59] netfilter: ebtables: account ebt_table_info to kmemcg Greg Kroah-Hartman
2019-01-21 13:44 ` [PATCH 4.14 45/59] selinux: fix GPF on invalid policy Greg Kroah-Hartman
2019-01-21 13:44 ` [PATCH 4.14 46/59] blockdev: Fix livelocks on loop device Greg Kroah-Hartman
2019-01-21 13:44 ` [PATCH 4.14 47/59] sctp: allocate sctp_sockaddr_entry with kzalloc Greg Kroah-Hartman
2019-01-21 13:44 ` [PATCH 4.14 48/59] tipc: fix uninit-value in tipc_nl_compat_link_reset_stats Greg Kroah-Hartman
2019-01-21 13:44 ` [PATCH 4.14 49/59] tipc: fix uninit-value in tipc_nl_compat_bearer_enable Greg Kroah-Hartman
2019-01-21 13:44 ` [PATCH 4.14 50/59] tipc: fix uninit-value in tipc_nl_compat_link_set Greg Kroah-Hartman
2019-01-21 13:44 ` [PATCH 4.14 51/59] tipc: fix uninit-value in tipc_nl_compat_name_table_dump Greg Kroah-Hartman
2019-01-21 13:44 ` [PATCH 4.14 52/59] tipc: fix uninit-value in tipc_nl_compat_doit Greg Kroah-Hartman
2019-01-21 13:44 ` [PATCH 4.14 53/59] block/loop: Dont grab "struct file" for vfs_getattr() operation Greg Kroah-Hartman
2019-01-21 13:44 ` Greg Kroah-Hartman [this message]
2019-01-21 13:44 ` [PATCH 4.14 55/59] loop: Fold __loop_release into loop_release Greg Kroah-Hartman
2019-01-21 13:44 ` [PATCH 4.14 56/59] loop: Get rid of loop_index_mutex Greg Kroah-Hartman
2019-01-21 13:44 ` [PATCH 4.14 57/59] loop: Fix double mutex_unlock(&loop_ctl_mutex) in loop_control_ioctl() Greg Kroah-Hartman
2019-01-21 13:44 ` [PATCH 4.14 58/59] loop: drop caches if offset or block_size are changed Greg Kroah-Hartman
2019-01-21 13:44 ` [PATCH 4.14 59/59] drm/fb-helper: Ignore the value of fb_var_screeninfo.pixclock Greg Kroah-Hartman
2019-01-22 3:07 ` [PATCH 4.14 00/59] 4.14.95-stable review Naresh Kamboju
2019-01-22 19:23 ` Guenter Roeck
2019-01-22 22:31 ` shuah
2019-01-23 9:07 ` Jon Hunter
2019-01-23 12:55 ` Greg Kroah-Hartman
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