The patch below does not apply to the 5.10-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 b4002173b7989588b6feaefc42edaf011b596782 Mon Sep 17 00:00:00 2001
From: Jeff Layton <jlayton(a)kernel.org>
Date: Tue, 27 Jul 2021 15:47:12 -0400
Subject: [PATCH] ceph: cancel delayed work instead of flushing on mdsc
teardown
The first thing metric_delayed_work does is check mdsc->stopping,
and then return immediately if it's set. That's good since we would
have already torn down the metric structures at this point, otherwise,
but there is no locking around mdsc->stopping.
It's possible that the ceph_metric_destroy call could race with the
delayed_work, in which case we could end up with the delayed_work
accessing destroyed percpu variables.
At this point in the mdsc teardown, the "stopping" flag has already been
set, so there's no benefit to flushing the work. Move the work
cancellation in ceph_metric_destroy ahead of the percpu variable
destruction, and eliminate the flush_delayed_work call in
ceph_mdsc_destroy.
Fixes: 18f473b384a6 ("ceph: periodically send perf metrics to MDSes")
Signed-off-by: Jeff Layton <jlayton(a)kernel.org>
Reviewed-by: Xiubo Li <xiubli(a)redhat.com>
Signed-off-by: Ilya Dryomov <idryomov(a)gmail.com>
diff --git a/fs/ceph/mds_client.c b/fs/ceph/mds_client.c
index d98a3eda0d4c..85934091e024 100644
--- a/fs/ceph/mds_client.c
+++ b/fs/ceph/mds_client.c
@@ -4954,7 +4954,6 @@ void ceph_mdsc_destroy(struct ceph_fs_client *fsc)
ceph_metric_destroy(&mdsc->metric);
- flush_delayed_work(&mdsc->metric.delayed_work);
fsc->mdsc = NULL;
kfree(mdsc);
dout("mdsc_destroy %p done\n", mdsc);
diff --git a/fs/ceph/metric.c b/fs/ceph/metric.c
index 5ac151eb0d49..04d5df29bbbf 100644
--- a/fs/ceph/metric.c
+++ b/fs/ceph/metric.c
@@ -302,6 +302,8 @@ void ceph_metric_destroy(struct ceph_client_metric *m)
if (!m)
return;
+ cancel_delayed_work_sync(&m->delayed_work);
+
percpu_counter_destroy(&m->total_inodes);
percpu_counter_destroy(&m->opened_inodes);
percpu_counter_destroy(&m->i_caps_mis);
@@ -309,8 +311,6 @@ void ceph_metric_destroy(struct ceph_client_metric *m)
percpu_counter_destroy(&m->d_lease_mis);
percpu_counter_destroy(&m->d_lease_hit);
- cancel_delayed_work_sync(&m->delayed_work);
-
ceph_put_mds_session(m->session);
}
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 98e2e409e76ef7781d8511f997359e9c504a95c1 Mon Sep 17 00:00:00 2001
From: Zhen Lei <thunder.leizhen(a)huawei.com>
Date: Tue, 7 Sep 2021 20:00:26 -0700
Subject: [PATCH] nilfs2: use refcount_dec_and_lock() to fix potential UAF
When the refcount is decreased to 0, the resource reclamation branch is
entered. Before CPU0 reaches the race point (1), CPU1 may obtain the
spinlock and traverse the rbtree to find 'root', see
nilfs_lookup_root().
Although CPU1 will call refcount_inc() to increase the refcount, it is
obviously too late. CPU0 will release 'root' directly, CPU1 then
accesses 'root' and triggers UAF.
Use refcount_dec_and_lock() to ensure that both the operations of
decrease refcount to 0 and link deletion are lock protected eliminates
this risk.
CPU0 CPU1
nilfs_put_root():
<-------- (1)
spin_lock(&nilfs->ns_cptree_lock);
rb_erase(&root->rb_node, &nilfs->ns_cptree);
spin_unlock(&nilfs->ns_cptree_lock);
kfree(root);
<-------- use-after-free
refcount_t: underflow; use-after-free.
WARNING: CPU: 2 PID: 9476 at lib/refcount.c:28 \
refcount_warn_saturate+0x1cf/0x210 lib/refcount.c:28
Modules linked in:
CPU: 2 PID: 9476 Comm: syz-executor.0 Not tainted 5.10.45-rc1+ #3
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), ...
RIP: 0010:refcount_warn_saturate+0x1cf/0x210 lib/refcount.c:28
... ...
Call Trace:
__refcount_sub_and_test include/linux/refcount.h:283 [inline]
__refcount_dec_and_test include/linux/refcount.h:315 [inline]
refcount_dec_and_test include/linux/refcount.h:333 [inline]
nilfs_put_root+0xc1/0xd0 fs/nilfs2/the_nilfs.c:795
nilfs_segctor_destroy fs/nilfs2/segment.c:2749 [inline]
nilfs_detach_log_writer+0x3fa/0x570 fs/nilfs2/segment.c:2812
nilfs_put_super+0x2f/0xf0 fs/nilfs2/super.c:467
generic_shutdown_super+0xcd/0x1f0 fs/super.c:464
kill_block_super+0x4a/0x90 fs/super.c:1446
deactivate_locked_super+0x6a/0xb0 fs/super.c:335
deactivate_super+0x85/0x90 fs/super.c:366
cleanup_mnt+0x277/0x2e0 fs/namespace.c:1118
__cleanup_mnt+0x15/0x20 fs/namespace.c:1125
task_work_run+0x8e/0x110 kernel/task_work.c:151
tracehook_notify_resume include/linux/tracehook.h:188 [inline]
exit_to_user_mode_loop kernel/entry/common.c:164 [inline]
exit_to_user_mode_prepare+0x13c/0x170 kernel/entry/common.c:191
syscall_exit_to_user_mode+0x16/0x30 kernel/entry/common.c:266
do_syscall_64+0x45/0x80 arch/x86/entry/common.c:56
entry_SYSCALL_64_after_hwframe+0x44/0xa9
There is no reproduction program, and the above is only theoretical
analysis.
Link: https://lkml.kernel.org/r/1629859428-5906-1-git-send-email-konishi.ryusuke@…
Fixes: ba65ae4729bf ("nilfs2: add checkpoint tree to nilfs object")
Link: https://lkml.kernel.org/r/20210723012317.4146-1-thunder.leizhen@huawei.com
Signed-off-by: Zhen Lei <thunder.leizhen(a)huawei.com>
Signed-off-by: Ryusuke Konishi <konishi.ryusuke(a)gmail.com>
Signed-off-by: Andrew Morton <akpm(a)linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds(a)linux-foundation.org>
diff --git a/fs/nilfs2/the_nilfs.c b/fs/nilfs2/the_nilfs.c
index 8b7b01a380ce..c8bfc01da5d7 100644
--- a/fs/nilfs2/the_nilfs.c
+++ b/fs/nilfs2/the_nilfs.c
@@ -792,14 +792,13 @@ nilfs_find_or_create_root(struct the_nilfs *nilfs, __u64 cno)
void nilfs_put_root(struct nilfs_root *root)
{
- if (refcount_dec_and_test(&root->count)) {
- struct the_nilfs *nilfs = root->nilfs;
+ struct the_nilfs *nilfs = root->nilfs;
- nilfs_sysfs_delete_snapshot_group(root);
-
- spin_lock(&nilfs->ns_cptree_lock);
+ if (refcount_dec_and_lock(&root->count, &nilfs->ns_cptree_lock)) {
rb_erase(&root->rb_node, &nilfs->ns_cptree);
spin_unlock(&nilfs->ns_cptree_lock);
+
+ nilfs_sysfs_delete_snapshot_group(root);
iput(root->ifile);
kfree(root);
The patch below does not apply to the 4.9-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 98e2e409e76ef7781d8511f997359e9c504a95c1 Mon Sep 17 00:00:00 2001
From: Zhen Lei <thunder.leizhen(a)huawei.com>
Date: Tue, 7 Sep 2021 20:00:26 -0700
Subject: [PATCH] nilfs2: use refcount_dec_and_lock() to fix potential UAF
When the refcount is decreased to 0, the resource reclamation branch is
entered. Before CPU0 reaches the race point (1), CPU1 may obtain the
spinlock and traverse the rbtree to find 'root', see
nilfs_lookup_root().
Although CPU1 will call refcount_inc() to increase the refcount, it is
obviously too late. CPU0 will release 'root' directly, CPU1 then
accesses 'root' and triggers UAF.
Use refcount_dec_and_lock() to ensure that both the operations of
decrease refcount to 0 and link deletion are lock protected eliminates
this risk.
CPU0 CPU1
nilfs_put_root():
<-------- (1)
spin_lock(&nilfs->ns_cptree_lock);
rb_erase(&root->rb_node, &nilfs->ns_cptree);
spin_unlock(&nilfs->ns_cptree_lock);
kfree(root);
<-------- use-after-free
refcount_t: underflow; use-after-free.
WARNING: CPU: 2 PID: 9476 at lib/refcount.c:28 \
refcount_warn_saturate+0x1cf/0x210 lib/refcount.c:28
Modules linked in:
CPU: 2 PID: 9476 Comm: syz-executor.0 Not tainted 5.10.45-rc1+ #3
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), ...
RIP: 0010:refcount_warn_saturate+0x1cf/0x210 lib/refcount.c:28
... ...
Call Trace:
__refcount_sub_and_test include/linux/refcount.h:283 [inline]
__refcount_dec_and_test include/linux/refcount.h:315 [inline]
refcount_dec_and_test include/linux/refcount.h:333 [inline]
nilfs_put_root+0xc1/0xd0 fs/nilfs2/the_nilfs.c:795
nilfs_segctor_destroy fs/nilfs2/segment.c:2749 [inline]
nilfs_detach_log_writer+0x3fa/0x570 fs/nilfs2/segment.c:2812
nilfs_put_super+0x2f/0xf0 fs/nilfs2/super.c:467
generic_shutdown_super+0xcd/0x1f0 fs/super.c:464
kill_block_super+0x4a/0x90 fs/super.c:1446
deactivate_locked_super+0x6a/0xb0 fs/super.c:335
deactivate_super+0x85/0x90 fs/super.c:366
cleanup_mnt+0x277/0x2e0 fs/namespace.c:1118
__cleanup_mnt+0x15/0x20 fs/namespace.c:1125
task_work_run+0x8e/0x110 kernel/task_work.c:151
tracehook_notify_resume include/linux/tracehook.h:188 [inline]
exit_to_user_mode_loop kernel/entry/common.c:164 [inline]
exit_to_user_mode_prepare+0x13c/0x170 kernel/entry/common.c:191
syscall_exit_to_user_mode+0x16/0x30 kernel/entry/common.c:266
do_syscall_64+0x45/0x80 arch/x86/entry/common.c:56
entry_SYSCALL_64_after_hwframe+0x44/0xa9
There is no reproduction program, and the above is only theoretical
analysis.
Link: https://lkml.kernel.org/r/1629859428-5906-1-git-send-email-konishi.ryusuke@…
Fixes: ba65ae4729bf ("nilfs2: add checkpoint tree to nilfs object")
Link: https://lkml.kernel.org/r/20210723012317.4146-1-thunder.leizhen@huawei.com
Signed-off-by: Zhen Lei <thunder.leizhen(a)huawei.com>
Signed-off-by: Ryusuke Konishi <konishi.ryusuke(a)gmail.com>
Signed-off-by: Andrew Morton <akpm(a)linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds(a)linux-foundation.org>
diff --git a/fs/nilfs2/the_nilfs.c b/fs/nilfs2/the_nilfs.c
index 8b7b01a380ce..c8bfc01da5d7 100644
--- a/fs/nilfs2/the_nilfs.c
+++ b/fs/nilfs2/the_nilfs.c
@@ -792,14 +792,13 @@ nilfs_find_or_create_root(struct the_nilfs *nilfs, __u64 cno)
void nilfs_put_root(struct nilfs_root *root)
{
- if (refcount_dec_and_test(&root->count)) {
- struct the_nilfs *nilfs = root->nilfs;
+ struct the_nilfs *nilfs = root->nilfs;
- nilfs_sysfs_delete_snapshot_group(root);
-
- spin_lock(&nilfs->ns_cptree_lock);
+ if (refcount_dec_and_lock(&root->count, &nilfs->ns_cptree_lock)) {
rb_erase(&root->rb_node, &nilfs->ns_cptree);
spin_unlock(&nilfs->ns_cptree_lock);
+
+ nilfs_sysfs_delete_snapshot_group(root);
iput(root->ifile);
kfree(root);
The patch below does not apply to the 4.4-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 98e2e409e76ef7781d8511f997359e9c504a95c1 Mon Sep 17 00:00:00 2001
From: Zhen Lei <thunder.leizhen(a)huawei.com>
Date: Tue, 7 Sep 2021 20:00:26 -0700
Subject: [PATCH] nilfs2: use refcount_dec_and_lock() to fix potential UAF
When the refcount is decreased to 0, the resource reclamation branch is
entered. Before CPU0 reaches the race point (1), CPU1 may obtain the
spinlock and traverse the rbtree to find 'root', see
nilfs_lookup_root().
Although CPU1 will call refcount_inc() to increase the refcount, it is
obviously too late. CPU0 will release 'root' directly, CPU1 then
accesses 'root' and triggers UAF.
Use refcount_dec_and_lock() to ensure that both the operations of
decrease refcount to 0 and link deletion are lock protected eliminates
this risk.
CPU0 CPU1
nilfs_put_root():
<-------- (1)
spin_lock(&nilfs->ns_cptree_lock);
rb_erase(&root->rb_node, &nilfs->ns_cptree);
spin_unlock(&nilfs->ns_cptree_lock);
kfree(root);
<-------- use-after-free
refcount_t: underflow; use-after-free.
WARNING: CPU: 2 PID: 9476 at lib/refcount.c:28 \
refcount_warn_saturate+0x1cf/0x210 lib/refcount.c:28
Modules linked in:
CPU: 2 PID: 9476 Comm: syz-executor.0 Not tainted 5.10.45-rc1+ #3
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), ...
RIP: 0010:refcount_warn_saturate+0x1cf/0x210 lib/refcount.c:28
... ...
Call Trace:
__refcount_sub_and_test include/linux/refcount.h:283 [inline]
__refcount_dec_and_test include/linux/refcount.h:315 [inline]
refcount_dec_and_test include/linux/refcount.h:333 [inline]
nilfs_put_root+0xc1/0xd0 fs/nilfs2/the_nilfs.c:795
nilfs_segctor_destroy fs/nilfs2/segment.c:2749 [inline]
nilfs_detach_log_writer+0x3fa/0x570 fs/nilfs2/segment.c:2812
nilfs_put_super+0x2f/0xf0 fs/nilfs2/super.c:467
generic_shutdown_super+0xcd/0x1f0 fs/super.c:464
kill_block_super+0x4a/0x90 fs/super.c:1446
deactivate_locked_super+0x6a/0xb0 fs/super.c:335
deactivate_super+0x85/0x90 fs/super.c:366
cleanup_mnt+0x277/0x2e0 fs/namespace.c:1118
__cleanup_mnt+0x15/0x20 fs/namespace.c:1125
task_work_run+0x8e/0x110 kernel/task_work.c:151
tracehook_notify_resume include/linux/tracehook.h:188 [inline]
exit_to_user_mode_loop kernel/entry/common.c:164 [inline]
exit_to_user_mode_prepare+0x13c/0x170 kernel/entry/common.c:191
syscall_exit_to_user_mode+0x16/0x30 kernel/entry/common.c:266
do_syscall_64+0x45/0x80 arch/x86/entry/common.c:56
entry_SYSCALL_64_after_hwframe+0x44/0xa9
There is no reproduction program, and the above is only theoretical
analysis.
Link: https://lkml.kernel.org/r/1629859428-5906-1-git-send-email-konishi.ryusuke@…
Fixes: ba65ae4729bf ("nilfs2: add checkpoint tree to nilfs object")
Link: https://lkml.kernel.org/r/20210723012317.4146-1-thunder.leizhen@huawei.com
Signed-off-by: Zhen Lei <thunder.leizhen(a)huawei.com>
Signed-off-by: Ryusuke Konishi <konishi.ryusuke(a)gmail.com>
Signed-off-by: Andrew Morton <akpm(a)linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds(a)linux-foundation.org>
diff --git a/fs/nilfs2/the_nilfs.c b/fs/nilfs2/the_nilfs.c
index 8b7b01a380ce..c8bfc01da5d7 100644
--- a/fs/nilfs2/the_nilfs.c
+++ b/fs/nilfs2/the_nilfs.c
@@ -792,14 +792,13 @@ nilfs_find_or_create_root(struct the_nilfs *nilfs, __u64 cno)
void nilfs_put_root(struct nilfs_root *root)
{
- if (refcount_dec_and_test(&root->count)) {
- struct the_nilfs *nilfs = root->nilfs;
+ struct the_nilfs *nilfs = root->nilfs;
- nilfs_sysfs_delete_snapshot_group(root);
-
- spin_lock(&nilfs->ns_cptree_lock);
+ if (refcount_dec_and_lock(&root->count, &nilfs->ns_cptree_lock)) {
rb_erase(&root->rb_node, &nilfs->ns_cptree);
spin_unlock(&nilfs->ns_cptree_lock);
+
+ nilfs_sysfs_delete_snapshot_group(root);
iput(root->ifile);
kfree(root);
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 0394b5048efd73b04276979d014a67f30c0ad699 Mon Sep 17 00:00:00 2001
From: Sergey Samoylenko <s.samoylenko(a)yadro.com>
Date: Tue, 3 Aug 2021 17:54:10 +0300
Subject: [PATCH] scsi: target: Fix sense key for invalid EXTENDED COPY request
TCM fails to pass the following tests in libiscsi:
SCSI.ExtendedCopy.DescrType
SCSI.ExtendedCopy.DescrLimits
SCSI.ExtendedCopy.ParamHdr
SCSI.ExtendedCopy.ValidSegDescr
SCSI.ExtendedCopy.ValidTgtDescr
The xcopy code always returns the same NOT READY sense key for all detected
errors. Change the sense key for invalid requests to ILLEGAL REQUEST, and
for aborted transfers to COPY ABORTED.
Link: https://lore.kernel.org/r/20210803145410.80147-3-s.samoylenko@yadro.com
Fixes: d877d7275be3 ("target: Fix a deadlock between the XCOPY code and iSCSI session shutdown")
Reviewed-by: David Disseldorp <ddiss(a)suse.de>
Reviewed-by: Roman Bolshakov <r.bolshakov(a)yadro.com>
Reviewed-by: Konstantin Shelekhin <k.shelekhin(a)yadro.com>
Signed-off-by: Sergey Samoylenko <s.samoylenko(a)yadro.com>
Signed-off-by: Martin K. Petersen <martin.petersen(a)oracle.com>
diff --git a/drivers/target/target_core_xcopy.c b/drivers/target/target_core_xcopy.c
index 0f1319336f3e..d4fe7cb2bd00 100644
--- a/drivers/target/target_core_xcopy.c
+++ b/drivers/target/target_core_xcopy.c
@@ -674,12 +674,16 @@ static void target_xcopy_do_work(struct work_struct *work)
unsigned int max_sectors;
int rc = 0;
unsigned short nolb, max_nolb, copied_nolb = 0;
+ sense_reason_t sense_rc;
- if (target_parse_xcopy_cmd(xop) != TCM_NO_SENSE)
+ sense_rc = target_parse_xcopy_cmd(xop);
+ if (sense_rc != TCM_NO_SENSE)
goto err_free;
- if (WARN_ON_ONCE(!xop->src_dev) || WARN_ON_ONCE(!xop->dst_dev))
+ if (WARN_ON_ONCE(!xop->src_dev) || WARN_ON_ONCE(!xop->dst_dev)) {
+ sense_rc = TCM_INVALID_PARAMETER_LIST;
goto err_free;
+ }
src_dev = xop->src_dev;
dst_dev = xop->dst_dev;
@@ -762,20 +766,20 @@ static void target_xcopy_do_work(struct work_struct *work)
return;
out:
+ /*
+ * The XCOPY command was aborted after some data was transferred.
+ * Terminate command with CHECK CONDITION status, with the sense key
+ * set to COPY ABORTED.
+ */
+ sense_rc = TCM_COPY_TARGET_DEVICE_NOT_REACHABLE;
xcopy_pt_undepend_remotedev(xop);
target_free_sgl(xop->xop_data_sg, xop->xop_data_nents);
err_free:
kfree(xop);
- /*
- * Don't override an error scsi status if it has already been set
- */
- if (ec_cmd->scsi_status == SAM_STAT_GOOD) {
- pr_warn_ratelimited("target_xcopy_do_work: rc: %d, Setting X-COPY"
- " CHECK_CONDITION -> sending response\n", rc);
- ec_cmd->scsi_status = SAM_STAT_CHECK_CONDITION;
- }
- target_complete_cmd(ec_cmd, ec_cmd->scsi_status);
+ pr_warn_ratelimited("target_xcopy_do_work: rc: %d, sense: %u, XCOPY operation failed\n",
+ rc, sense_rc);
+ target_complete_cmd_with_sense(ec_cmd, SAM_STAT_CHECK_CONDITION, sense_rc);
}
/*
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 0394b5048efd73b04276979d014a67f30c0ad699 Mon Sep 17 00:00:00 2001
From: Sergey Samoylenko <s.samoylenko(a)yadro.com>
Date: Tue, 3 Aug 2021 17:54:10 +0300
Subject: [PATCH] scsi: target: Fix sense key for invalid EXTENDED COPY request
TCM fails to pass the following tests in libiscsi:
SCSI.ExtendedCopy.DescrType
SCSI.ExtendedCopy.DescrLimits
SCSI.ExtendedCopy.ParamHdr
SCSI.ExtendedCopy.ValidSegDescr
SCSI.ExtendedCopy.ValidTgtDescr
The xcopy code always returns the same NOT READY sense key for all detected
errors. Change the sense key for invalid requests to ILLEGAL REQUEST, and
for aborted transfers to COPY ABORTED.
Link: https://lore.kernel.org/r/20210803145410.80147-3-s.samoylenko@yadro.com
Fixes: d877d7275be3 ("target: Fix a deadlock between the XCOPY code and iSCSI session shutdown")
Reviewed-by: David Disseldorp <ddiss(a)suse.de>
Reviewed-by: Roman Bolshakov <r.bolshakov(a)yadro.com>
Reviewed-by: Konstantin Shelekhin <k.shelekhin(a)yadro.com>
Signed-off-by: Sergey Samoylenko <s.samoylenko(a)yadro.com>
Signed-off-by: Martin K. Petersen <martin.petersen(a)oracle.com>
diff --git a/drivers/target/target_core_xcopy.c b/drivers/target/target_core_xcopy.c
index 0f1319336f3e..d4fe7cb2bd00 100644
--- a/drivers/target/target_core_xcopy.c
+++ b/drivers/target/target_core_xcopy.c
@@ -674,12 +674,16 @@ static void target_xcopy_do_work(struct work_struct *work)
unsigned int max_sectors;
int rc = 0;
unsigned short nolb, max_nolb, copied_nolb = 0;
+ sense_reason_t sense_rc;
- if (target_parse_xcopy_cmd(xop) != TCM_NO_SENSE)
+ sense_rc = target_parse_xcopy_cmd(xop);
+ if (sense_rc != TCM_NO_SENSE)
goto err_free;
- if (WARN_ON_ONCE(!xop->src_dev) || WARN_ON_ONCE(!xop->dst_dev))
+ if (WARN_ON_ONCE(!xop->src_dev) || WARN_ON_ONCE(!xop->dst_dev)) {
+ sense_rc = TCM_INVALID_PARAMETER_LIST;
goto err_free;
+ }
src_dev = xop->src_dev;
dst_dev = xop->dst_dev;
@@ -762,20 +766,20 @@ static void target_xcopy_do_work(struct work_struct *work)
return;
out:
+ /*
+ * The XCOPY command was aborted after some data was transferred.
+ * Terminate command with CHECK CONDITION status, with the sense key
+ * set to COPY ABORTED.
+ */
+ sense_rc = TCM_COPY_TARGET_DEVICE_NOT_REACHABLE;
xcopy_pt_undepend_remotedev(xop);
target_free_sgl(xop->xop_data_sg, xop->xop_data_nents);
err_free:
kfree(xop);
- /*
- * Don't override an error scsi status if it has already been set
- */
- if (ec_cmd->scsi_status == SAM_STAT_GOOD) {
- pr_warn_ratelimited("target_xcopy_do_work: rc: %d, Setting X-COPY"
- " CHECK_CONDITION -> sending response\n", rc);
- ec_cmd->scsi_status = SAM_STAT_CHECK_CONDITION;
- }
- target_complete_cmd(ec_cmd, ec_cmd->scsi_status);
+ pr_warn_ratelimited("target_xcopy_do_work: rc: %d, sense: %u, XCOPY operation failed\n",
+ rc, sense_rc);
+ target_complete_cmd_with_sense(ec_cmd, SAM_STAT_CHECK_CONDITION, sense_rc);
}
/*
The patch below does not apply to the 4.4-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 58ce6d5b271ab25fb2056f84a8e5546945eb5fc9 Mon Sep 17 00:00:00 2001
From: Tetsuo Handa <penguin-kernel(a)I-love.SAKURA.ne.jp>
Date: Tue, 27 Jul 2021 06:12:04 +0900
Subject: [PATCH] Bluetooth: defer cleanup of resources in hci_unregister_dev()
syzbot is hitting might_sleep() warning at hci_sock_dev_event()
due to calling lock_sock() with rw spinlock held [1].
It seems that history of this locking problem is a trial and error.
Commit b40df5743ee8aed8 ("[PATCH] bluetooth: fix socket locking in
hci_sock_dev_event()") in 2.6.21-rc4 changed bh_lock_sock() to lock_sock()
as an attempt to fix lockdep warning.
Then, commit 4ce61d1c7a8ef4c1 ("[BLUETOOTH]: Fix locking in
hci_sock_dev_event().") in 2.6.22-rc2 changed lock_sock() to
local_bh_disable() + bh_lock_sock_nested() as an attempt to fix
sleep in atomic context warning.
Then, commit 4b5dd696f81b210c ("Bluetooth: Remove local_bh_disable() from
hci_sock.c") in 3.3-rc1 removed local_bh_disable().
Then, commit e305509e678b3a4a ("Bluetooth: use correct lock to prevent UAF
of hdev object") in 5.13-rc5 again changed bh_lock_sock_nested() to
lock_sock() as an attempt to fix CVE-2021-3573.
This difficulty comes from current implementation that
hci_sock_dev_event(HCI_DEV_UNREG) is responsible for dropping all
references from sockets because hci_unregister_dev() immediately reclaims
resources as soon as returning from hci_sock_dev_event(HCI_DEV_UNREG).
But the history suggests that hci_sock_dev_event(HCI_DEV_UNREG) was not
doing what it should do.
Therefore, instead of trying to detach sockets from device, let's accept
not detaching sockets from device at hci_sock_dev_event(HCI_DEV_UNREG),
by moving actual cleanup of resources from hci_unregister_dev() to
hci_release_dev() which is called by bt_host_release when all references
to this unregistered device (which is a kobject) are gone.
Link: https://syzkaller.appspot.com/bug?extid=a5df189917e79d5e59c9 [1]
Reported-by: syzbot <syzbot+a5df189917e79d5e59c9(a)syzkaller.appspotmail.com>
Signed-off-by: Tetsuo Handa <penguin-kernel(a)I-love.SAKURA.ne.jp>
Tested-by: syzbot <syzbot+a5df189917e79d5e59c9(a)syzkaller.appspotmail.com>
Fixes: e305509e678b3a4a ("Bluetooth: use correct lock to prevent UAF of hdev object")
Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz(a)intel.com>
diff --git a/include/net/bluetooth/hci_core.h b/include/net/bluetooth/hci_core.h
index a53e94459ecd..4abe3c494002 100644
--- a/include/net/bluetooth/hci_core.h
+++ b/include/net/bluetooth/hci_core.h
@@ -1230,6 +1230,7 @@ struct hci_dev *hci_alloc_dev(void);
void hci_free_dev(struct hci_dev *hdev);
int hci_register_dev(struct hci_dev *hdev);
void hci_unregister_dev(struct hci_dev *hdev);
+void hci_release_dev(struct hci_dev *hdev);
int hci_suspend_dev(struct hci_dev *hdev);
int hci_resume_dev(struct hci_dev *hdev);
int hci_reset_dev(struct hci_dev *hdev);
diff --git a/net/bluetooth/hci_core.c b/net/bluetooth/hci_core.c
index 2560ed2f144d..2b78e1336c53 100644
--- a/net/bluetooth/hci_core.c
+++ b/net/bluetooth/hci_core.c
@@ -3996,14 +3996,10 @@ EXPORT_SYMBOL(hci_register_dev);
/* Unregister HCI device */
void hci_unregister_dev(struct hci_dev *hdev)
{
- int id;
-
BT_DBG("%p name %s bus %d", hdev, hdev->name, hdev->bus);
hci_dev_set_flag(hdev, HCI_UNREGISTER);
- id = hdev->id;
-
write_lock(&hci_dev_list_lock);
list_del(&hdev->list);
write_unlock(&hci_dev_list_lock);
@@ -4038,7 +4034,13 @@ void hci_unregister_dev(struct hci_dev *hdev)
}
device_del(&hdev->dev);
+ hci_dev_put(hdev);
+}
+EXPORT_SYMBOL(hci_unregister_dev);
+/* Release HCI device */
+void hci_release_dev(struct hci_dev *hdev)
+{
debugfs_remove_recursive(hdev->debugfs);
kfree_const(hdev->hw_info);
kfree_const(hdev->fw_info);
@@ -4063,11 +4065,10 @@ void hci_unregister_dev(struct hci_dev *hdev)
hci_blocked_keys_clear(hdev);
hci_dev_unlock(hdev);
- hci_dev_put(hdev);
-
- ida_simple_remove(&hci_index_ida, id);
+ ida_simple_remove(&hci_index_ida, hdev->id);
+ kfree(hdev);
}
-EXPORT_SYMBOL(hci_unregister_dev);
+EXPORT_SYMBOL(hci_release_dev);
/* Suspend HCI device */
int hci_suspend_dev(struct hci_dev *hdev)
diff --git a/net/bluetooth/hci_sock.c b/net/bluetooth/hci_sock.c
index b04a5a02ecf3..d810a5adf064 100644
--- a/net/bluetooth/hci_sock.c
+++ b/net/bluetooth/hci_sock.c
@@ -759,19 +759,13 @@ void hci_sock_dev_event(struct hci_dev *hdev, int event)
if (event == HCI_DEV_UNREG) {
struct sock *sk;
- /* Detach sockets from device */
+ /* Wake up sockets using this dead device */
read_lock(&hci_sk_list.lock);
sk_for_each(sk, &hci_sk_list.head) {
- lock_sock(sk);
if (hci_pi(sk)->hdev == hdev) {
- hci_pi(sk)->hdev = NULL;
sk->sk_err = EPIPE;
- sk->sk_state = BT_OPEN;
sk->sk_state_change(sk);
-
- hci_dev_put(hdev);
}
- release_sock(sk);
}
read_unlock(&hci_sk_list.lock);
}
@@ -1103,6 +1097,18 @@ static int hci_sock_bind(struct socket *sock, struct sockaddr *addr,
lock_sock(sk);
+ /* Allow detaching from dead device and attaching to alive device, if
+ * the caller wants to re-bind (instead of close) this socket in
+ * response to hci_sock_dev_event(HCI_DEV_UNREG) notification.
+ */
+ hdev = hci_pi(sk)->hdev;
+ if (hdev && hci_dev_test_flag(hdev, HCI_UNREGISTER)) {
+ hci_pi(sk)->hdev = NULL;
+ sk->sk_state = BT_OPEN;
+ hci_dev_put(hdev);
+ }
+ hdev = NULL;
+
if (sk->sk_state == BT_BOUND) {
err = -EALREADY;
goto done;
diff --git a/net/bluetooth/hci_sysfs.c b/net/bluetooth/hci_sysfs.c
index 9874844a95a9..ebf282d1eb2b 100644
--- a/net/bluetooth/hci_sysfs.c
+++ b/net/bluetooth/hci_sysfs.c
@@ -83,7 +83,7 @@ void hci_conn_del_sysfs(struct hci_conn *conn)
static void bt_host_release(struct device *dev)
{
struct hci_dev *hdev = to_hci_dev(dev);
- kfree(hdev);
+ hci_release_dev(hdev);
module_put(THIS_MODULE);
}
The patch below does not apply to the 4.9-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 58ce6d5b271ab25fb2056f84a8e5546945eb5fc9 Mon Sep 17 00:00:00 2001
From: Tetsuo Handa <penguin-kernel(a)I-love.SAKURA.ne.jp>
Date: Tue, 27 Jul 2021 06:12:04 +0900
Subject: [PATCH] Bluetooth: defer cleanup of resources in hci_unregister_dev()
syzbot is hitting might_sleep() warning at hci_sock_dev_event()
due to calling lock_sock() with rw spinlock held [1].
It seems that history of this locking problem is a trial and error.
Commit b40df5743ee8aed8 ("[PATCH] bluetooth: fix socket locking in
hci_sock_dev_event()") in 2.6.21-rc4 changed bh_lock_sock() to lock_sock()
as an attempt to fix lockdep warning.
Then, commit 4ce61d1c7a8ef4c1 ("[BLUETOOTH]: Fix locking in
hci_sock_dev_event().") in 2.6.22-rc2 changed lock_sock() to
local_bh_disable() + bh_lock_sock_nested() as an attempt to fix
sleep in atomic context warning.
Then, commit 4b5dd696f81b210c ("Bluetooth: Remove local_bh_disable() from
hci_sock.c") in 3.3-rc1 removed local_bh_disable().
Then, commit e305509e678b3a4a ("Bluetooth: use correct lock to prevent UAF
of hdev object") in 5.13-rc5 again changed bh_lock_sock_nested() to
lock_sock() as an attempt to fix CVE-2021-3573.
This difficulty comes from current implementation that
hci_sock_dev_event(HCI_DEV_UNREG) is responsible for dropping all
references from sockets because hci_unregister_dev() immediately reclaims
resources as soon as returning from hci_sock_dev_event(HCI_DEV_UNREG).
But the history suggests that hci_sock_dev_event(HCI_DEV_UNREG) was not
doing what it should do.
Therefore, instead of trying to detach sockets from device, let's accept
not detaching sockets from device at hci_sock_dev_event(HCI_DEV_UNREG),
by moving actual cleanup of resources from hci_unregister_dev() to
hci_release_dev() which is called by bt_host_release when all references
to this unregistered device (which is a kobject) are gone.
Link: https://syzkaller.appspot.com/bug?extid=a5df189917e79d5e59c9 [1]
Reported-by: syzbot <syzbot+a5df189917e79d5e59c9(a)syzkaller.appspotmail.com>
Signed-off-by: Tetsuo Handa <penguin-kernel(a)I-love.SAKURA.ne.jp>
Tested-by: syzbot <syzbot+a5df189917e79d5e59c9(a)syzkaller.appspotmail.com>
Fixes: e305509e678b3a4a ("Bluetooth: use correct lock to prevent UAF of hdev object")
Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz(a)intel.com>
diff --git a/include/net/bluetooth/hci_core.h b/include/net/bluetooth/hci_core.h
index a53e94459ecd..4abe3c494002 100644
--- a/include/net/bluetooth/hci_core.h
+++ b/include/net/bluetooth/hci_core.h
@@ -1230,6 +1230,7 @@ struct hci_dev *hci_alloc_dev(void);
void hci_free_dev(struct hci_dev *hdev);
int hci_register_dev(struct hci_dev *hdev);
void hci_unregister_dev(struct hci_dev *hdev);
+void hci_release_dev(struct hci_dev *hdev);
int hci_suspend_dev(struct hci_dev *hdev);
int hci_resume_dev(struct hci_dev *hdev);
int hci_reset_dev(struct hci_dev *hdev);
diff --git a/net/bluetooth/hci_core.c b/net/bluetooth/hci_core.c
index 2560ed2f144d..2b78e1336c53 100644
--- a/net/bluetooth/hci_core.c
+++ b/net/bluetooth/hci_core.c
@@ -3996,14 +3996,10 @@ EXPORT_SYMBOL(hci_register_dev);
/* Unregister HCI device */
void hci_unregister_dev(struct hci_dev *hdev)
{
- int id;
-
BT_DBG("%p name %s bus %d", hdev, hdev->name, hdev->bus);
hci_dev_set_flag(hdev, HCI_UNREGISTER);
- id = hdev->id;
-
write_lock(&hci_dev_list_lock);
list_del(&hdev->list);
write_unlock(&hci_dev_list_lock);
@@ -4038,7 +4034,13 @@ void hci_unregister_dev(struct hci_dev *hdev)
}
device_del(&hdev->dev);
+ hci_dev_put(hdev);
+}
+EXPORT_SYMBOL(hci_unregister_dev);
+/* Release HCI device */
+void hci_release_dev(struct hci_dev *hdev)
+{
debugfs_remove_recursive(hdev->debugfs);
kfree_const(hdev->hw_info);
kfree_const(hdev->fw_info);
@@ -4063,11 +4065,10 @@ void hci_unregister_dev(struct hci_dev *hdev)
hci_blocked_keys_clear(hdev);
hci_dev_unlock(hdev);
- hci_dev_put(hdev);
-
- ida_simple_remove(&hci_index_ida, id);
+ ida_simple_remove(&hci_index_ida, hdev->id);
+ kfree(hdev);
}
-EXPORT_SYMBOL(hci_unregister_dev);
+EXPORT_SYMBOL(hci_release_dev);
/* Suspend HCI device */
int hci_suspend_dev(struct hci_dev *hdev)
diff --git a/net/bluetooth/hci_sock.c b/net/bluetooth/hci_sock.c
index b04a5a02ecf3..d810a5adf064 100644
--- a/net/bluetooth/hci_sock.c
+++ b/net/bluetooth/hci_sock.c
@@ -759,19 +759,13 @@ void hci_sock_dev_event(struct hci_dev *hdev, int event)
if (event == HCI_DEV_UNREG) {
struct sock *sk;
- /* Detach sockets from device */
+ /* Wake up sockets using this dead device */
read_lock(&hci_sk_list.lock);
sk_for_each(sk, &hci_sk_list.head) {
- lock_sock(sk);
if (hci_pi(sk)->hdev == hdev) {
- hci_pi(sk)->hdev = NULL;
sk->sk_err = EPIPE;
- sk->sk_state = BT_OPEN;
sk->sk_state_change(sk);
-
- hci_dev_put(hdev);
}
- release_sock(sk);
}
read_unlock(&hci_sk_list.lock);
}
@@ -1103,6 +1097,18 @@ static int hci_sock_bind(struct socket *sock, struct sockaddr *addr,
lock_sock(sk);
+ /* Allow detaching from dead device and attaching to alive device, if
+ * the caller wants to re-bind (instead of close) this socket in
+ * response to hci_sock_dev_event(HCI_DEV_UNREG) notification.
+ */
+ hdev = hci_pi(sk)->hdev;
+ if (hdev && hci_dev_test_flag(hdev, HCI_UNREGISTER)) {
+ hci_pi(sk)->hdev = NULL;
+ sk->sk_state = BT_OPEN;
+ hci_dev_put(hdev);
+ }
+ hdev = NULL;
+
if (sk->sk_state == BT_BOUND) {
err = -EALREADY;
goto done;
diff --git a/net/bluetooth/hci_sysfs.c b/net/bluetooth/hci_sysfs.c
index 9874844a95a9..ebf282d1eb2b 100644
--- a/net/bluetooth/hci_sysfs.c
+++ b/net/bluetooth/hci_sysfs.c
@@ -83,7 +83,7 @@ void hci_conn_del_sysfs(struct hci_conn *conn)
static void bt_host_release(struct device *dev)
{
struct hci_dev *hdev = to_hci_dev(dev);
- kfree(hdev);
+ hci_release_dev(hdev);
module_put(THIS_MODULE);
}
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 58ce6d5b271ab25fb2056f84a8e5546945eb5fc9 Mon Sep 17 00:00:00 2001
From: Tetsuo Handa <penguin-kernel(a)I-love.SAKURA.ne.jp>
Date: Tue, 27 Jul 2021 06:12:04 +0900
Subject: [PATCH] Bluetooth: defer cleanup of resources in hci_unregister_dev()
syzbot is hitting might_sleep() warning at hci_sock_dev_event()
due to calling lock_sock() with rw spinlock held [1].
It seems that history of this locking problem is a trial and error.
Commit b40df5743ee8aed8 ("[PATCH] bluetooth: fix socket locking in
hci_sock_dev_event()") in 2.6.21-rc4 changed bh_lock_sock() to lock_sock()
as an attempt to fix lockdep warning.
Then, commit 4ce61d1c7a8ef4c1 ("[BLUETOOTH]: Fix locking in
hci_sock_dev_event().") in 2.6.22-rc2 changed lock_sock() to
local_bh_disable() + bh_lock_sock_nested() as an attempt to fix
sleep in atomic context warning.
Then, commit 4b5dd696f81b210c ("Bluetooth: Remove local_bh_disable() from
hci_sock.c") in 3.3-rc1 removed local_bh_disable().
Then, commit e305509e678b3a4a ("Bluetooth: use correct lock to prevent UAF
of hdev object") in 5.13-rc5 again changed bh_lock_sock_nested() to
lock_sock() as an attempt to fix CVE-2021-3573.
This difficulty comes from current implementation that
hci_sock_dev_event(HCI_DEV_UNREG) is responsible for dropping all
references from sockets because hci_unregister_dev() immediately reclaims
resources as soon as returning from hci_sock_dev_event(HCI_DEV_UNREG).
But the history suggests that hci_sock_dev_event(HCI_DEV_UNREG) was not
doing what it should do.
Therefore, instead of trying to detach sockets from device, let's accept
not detaching sockets from device at hci_sock_dev_event(HCI_DEV_UNREG),
by moving actual cleanup of resources from hci_unregister_dev() to
hci_release_dev() which is called by bt_host_release when all references
to this unregistered device (which is a kobject) are gone.
Link: https://syzkaller.appspot.com/bug?extid=a5df189917e79d5e59c9 [1]
Reported-by: syzbot <syzbot+a5df189917e79d5e59c9(a)syzkaller.appspotmail.com>
Signed-off-by: Tetsuo Handa <penguin-kernel(a)I-love.SAKURA.ne.jp>
Tested-by: syzbot <syzbot+a5df189917e79d5e59c9(a)syzkaller.appspotmail.com>
Fixes: e305509e678b3a4a ("Bluetooth: use correct lock to prevent UAF of hdev object")
Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz(a)intel.com>
diff --git a/include/net/bluetooth/hci_core.h b/include/net/bluetooth/hci_core.h
index a53e94459ecd..4abe3c494002 100644
--- a/include/net/bluetooth/hci_core.h
+++ b/include/net/bluetooth/hci_core.h
@@ -1230,6 +1230,7 @@ struct hci_dev *hci_alloc_dev(void);
void hci_free_dev(struct hci_dev *hdev);
int hci_register_dev(struct hci_dev *hdev);
void hci_unregister_dev(struct hci_dev *hdev);
+void hci_release_dev(struct hci_dev *hdev);
int hci_suspend_dev(struct hci_dev *hdev);
int hci_resume_dev(struct hci_dev *hdev);
int hci_reset_dev(struct hci_dev *hdev);
diff --git a/net/bluetooth/hci_core.c b/net/bluetooth/hci_core.c
index 2560ed2f144d..2b78e1336c53 100644
--- a/net/bluetooth/hci_core.c
+++ b/net/bluetooth/hci_core.c
@@ -3996,14 +3996,10 @@ EXPORT_SYMBOL(hci_register_dev);
/* Unregister HCI device */
void hci_unregister_dev(struct hci_dev *hdev)
{
- int id;
-
BT_DBG("%p name %s bus %d", hdev, hdev->name, hdev->bus);
hci_dev_set_flag(hdev, HCI_UNREGISTER);
- id = hdev->id;
-
write_lock(&hci_dev_list_lock);
list_del(&hdev->list);
write_unlock(&hci_dev_list_lock);
@@ -4038,7 +4034,13 @@ void hci_unregister_dev(struct hci_dev *hdev)
}
device_del(&hdev->dev);
+ hci_dev_put(hdev);
+}
+EXPORT_SYMBOL(hci_unregister_dev);
+/* Release HCI device */
+void hci_release_dev(struct hci_dev *hdev)
+{
debugfs_remove_recursive(hdev->debugfs);
kfree_const(hdev->hw_info);
kfree_const(hdev->fw_info);
@@ -4063,11 +4065,10 @@ void hci_unregister_dev(struct hci_dev *hdev)
hci_blocked_keys_clear(hdev);
hci_dev_unlock(hdev);
- hci_dev_put(hdev);
-
- ida_simple_remove(&hci_index_ida, id);
+ ida_simple_remove(&hci_index_ida, hdev->id);
+ kfree(hdev);
}
-EXPORT_SYMBOL(hci_unregister_dev);
+EXPORT_SYMBOL(hci_release_dev);
/* Suspend HCI device */
int hci_suspend_dev(struct hci_dev *hdev)
diff --git a/net/bluetooth/hci_sock.c b/net/bluetooth/hci_sock.c
index b04a5a02ecf3..d810a5adf064 100644
--- a/net/bluetooth/hci_sock.c
+++ b/net/bluetooth/hci_sock.c
@@ -759,19 +759,13 @@ void hci_sock_dev_event(struct hci_dev *hdev, int event)
if (event == HCI_DEV_UNREG) {
struct sock *sk;
- /* Detach sockets from device */
+ /* Wake up sockets using this dead device */
read_lock(&hci_sk_list.lock);
sk_for_each(sk, &hci_sk_list.head) {
- lock_sock(sk);
if (hci_pi(sk)->hdev == hdev) {
- hci_pi(sk)->hdev = NULL;
sk->sk_err = EPIPE;
- sk->sk_state = BT_OPEN;
sk->sk_state_change(sk);
-
- hci_dev_put(hdev);
}
- release_sock(sk);
}
read_unlock(&hci_sk_list.lock);
}
@@ -1103,6 +1097,18 @@ static int hci_sock_bind(struct socket *sock, struct sockaddr *addr,
lock_sock(sk);
+ /* Allow detaching from dead device and attaching to alive device, if
+ * the caller wants to re-bind (instead of close) this socket in
+ * response to hci_sock_dev_event(HCI_DEV_UNREG) notification.
+ */
+ hdev = hci_pi(sk)->hdev;
+ if (hdev && hci_dev_test_flag(hdev, HCI_UNREGISTER)) {
+ hci_pi(sk)->hdev = NULL;
+ sk->sk_state = BT_OPEN;
+ hci_dev_put(hdev);
+ }
+ hdev = NULL;
+
if (sk->sk_state == BT_BOUND) {
err = -EALREADY;
goto done;
diff --git a/net/bluetooth/hci_sysfs.c b/net/bluetooth/hci_sysfs.c
index 9874844a95a9..ebf282d1eb2b 100644
--- a/net/bluetooth/hci_sysfs.c
+++ b/net/bluetooth/hci_sysfs.c
@@ -83,7 +83,7 @@ void hci_conn_del_sysfs(struct hci_conn *conn)
static void bt_host_release(struct device *dev)
{
struct hci_dev *hdev = to_hci_dev(dev);
- kfree(hdev);
+ hci_release_dev(hdev);
module_put(THIS_MODULE);
}
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 58ce6d5b271ab25fb2056f84a8e5546945eb5fc9 Mon Sep 17 00:00:00 2001
From: Tetsuo Handa <penguin-kernel(a)I-love.SAKURA.ne.jp>
Date: Tue, 27 Jul 2021 06:12:04 +0900
Subject: [PATCH] Bluetooth: defer cleanup of resources in hci_unregister_dev()
syzbot is hitting might_sleep() warning at hci_sock_dev_event()
due to calling lock_sock() with rw spinlock held [1].
It seems that history of this locking problem is a trial and error.
Commit b40df5743ee8aed8 ("[PATCH] bluetooth: fix socket locking in
hci_sock_dev_event()") in 2.6.21-rc4 changed bh_lock_sock() to lock_sock()
as an attempt to fix lockdep warning.
Then, commit 4ce61d1c7a8ef4c1 ("[BLUETOOTH]: Fix locking in
hci_sock_dev_event().") in 2.6.22-rc2 changed lock_sock() to
local_bh_disable() + bh_lock_sock_nested() as an attempt to fix
sleep in atomic context warning.
Then, commit 4b5dd696f81b210c ("Bluetooth: Remove local_bh_disable() from
hci_sock.c") in 3.3-rc1 removed local_bh_disable().
Then, commit e305509e678b3a4a ("Bluetooth: use correct lock to prevent UAF
of hdev object") in 5.13-rc5 again changed bh_lock_sock_nested() to
lock_sock() as an attempt to fix CVE-2021-3573.
This difficulty comes from current implementation that
hci_sock_dev_event(HCI_DEV_UNREG) is responsible for dropping all
references from sockets because hci_unregister_dev() immediately reclaims
resources as soon as returning from hci_sock_dev_event(HCI_DEV_UNREG).
But the history suggests that hci_sock_dev_event(HCI_DEV_UNREG) was not
doing what it should do.
Therefore, instead of trying to detach sockets from device, let's accept
not detaching sockets from device at hci_sock_dev_event(HCI_DEV_UNREG),
by moving actual cleanup of resources from hci_unregister_dev() to
hci_release_dev() which is called by bt_host_release when all references
to this unregistered device (which is a kobject) are gone.
Link: https://syzkaller.appspot.com/bug?extid=a5df189917e79d5e59c9 [1]
Reported-by: syzbot <syzbot+a5df189917e79d5e59c9(a)syzkaller.appspotmail.com>
Signed-off-by: Tetsuo Handa <penguin-kernel(a)I-love.SAKURA.ne.jp>
Tested-by: syzbot <syzbot+a5df189917e79d5e59c9(a)syzkaller.appspotmail.com>
Fixes: e305509e678b3a4a ("Bluetooth: use correct lock to prevent UAF of hdev object")
Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz(a)intel.com>
diff --git a/include/net/bluetooth/hci_core.h b/include/net/bluetooth/hci_core.h
index a53e94459ecd..4abe3c494002 100644
--- a/include/net/bluetooth/hci_core.h
+++ b/include/net/bluetooth/hci_core.h
@@ -1230,6 +1230,7 @@ struct hci_dev *hci_alloc_dev(void);
void hci_free_dev(struct hci_dev *hdev);
int hci_register_dev(struct hci_dev *hdev);
void hci_unregister_dev(struct hci_dev *hdev);
+void hci_release_dev(struct hci_dev *hdev);
int hci_suspend_dev(struct hci_dev *hdev);
int hci_resume_dev(struct hci_dev *hdev);
int hci_reset_dev(struct hci_dev *hdev);
diff --git a/net/bluetooth/hci_core.c b/net/bluetooth/hci_core.c
index 2560ed2f144d..2b78e1336c53 100644
--- a/net/bluetooth/hci_core.c
+++ b/net/bluetooth/hci_core.c
@@ -3996,14 +3996,10 @@ EXPORT_SYMBOL(hci_register_dev);
/* Unregister HCI device */
void hci_unregister_dev(struct hci_dev *hdev)
{
- int id;
-
BT_DBG("%p name %s bus %d", hdev, hdev->name, hdev->bus);
hci_dev_set_flag(hdev, HCI_UNREGISTER);
- id = hdev->id;
-
write_lock(&hci_dev_list_lock);
list_del(&hdev->list);
write_unlock(&hci_dev_list_lock);
@@ -4038,7 +4034,13 @@ void hci_unregister_dev(struct hci_dev *hdev)
}
device_del(&hdev->dev);
+ hci_dev_put(hdev);
+}
+EXPORT_SYMBOL(hci_unregister_dev);
+/* Release HCI device */
+void hci_release_dev(struct hci_dev *hdev)
+{
debugfs_remove_recursive(hdev->debugfs);
kfree_const(hdev->hw_info);
kfree_const(hdev->fw_info);
@@ -4063,11 +4065,10 @@ void hci_unregister_dev(struct hci_dev *hdev)
hci_blocked_keys_clear(hdev);
hci_dev_unlock(hdev);
- hci_dev_put(hdev);
-
- ida_simple_remove(&hci_index_ida, id);
+ ida_simple_remove(&hci_index_ida, hdev->id);
+ kfree(hdev);
}
-EXPORT_SYMBOL(hci_unregister_dev);
+EXPORT_SYMBOL(hci_release_dev);
/* Suspend HCI device */
int hci_suspend_dev(struct hci_dev *hdev)
diff --git a/net/bluetooth/hci_sock.c b/net/bluetooth/hci_sock.c
index b04a5a02ecf3..d810a5adf064 100644
--- a/net/bluetooth/hci_sock.c
+++ b/net/bluetooth/hci_sock.c
@@ -759,19 +759,13 @@ void hci_sock_dev_event(struct hci_dev *hdev, int event)
if (event == HCI_DEV_UNREG) {
struct sock *sk;
- /* Detach sockets from device */
+ /* Wake up sockets using this dead device */
read_lock(&hci_sk_list.lock);
sk_for_each(sk, &hci_sk_list.head) {
- lock_sock(sk);
if (hci_pi(sk)->hdev == hdev) {
- hci_pi(sk)->hdev = NULL;
sk->sk_err = EPIPE;
- sk->sk_state = BT_OPEN;
sk->sk_state_change(sk);
-
- hci_dev_put(hdev);
}
- release_sock(sk);
}
read_unlock(&hci_sk_list.lock);
}
@@ -1103,6 +1097,18 @@ static int hci_sock_bind(struct socket *sock, struct sockaddr *addr,
lock_sock(sk);
+ /* Allow detaching from dead device and attaching to alive device, if
+ * the caller wants to re-bind (instead of close) this socket in
+ * response to hci_sock_dev_event(HCI_DEV_UNREG) notification.
+ */
+ hdev = hci_pi(sk)->hdev;
+ if (hdev && hci_dev_test_flag(hdev, HCI_UNREGISTER)) {
+ hci_pi(sk)->hdev = NULL;
+ sk->sk_state = BT_OPEN;
+ hci_dev_put(hdev);
+ }
+ hdev = NULL;
+
if (sk->sk_state == BT_BOUND) {
err = -EALREADY;
goto done;
diff --git a/net/bluetooth/hci_sysfs.c b/net/bluetooth/hci_sysfs.c
index 9874844a95a9..ebf282d1eb2b 100644
--- a/net/bluetooth/hci_sysfs.c
+++ b/net/bluetooth/hci_sysfs.c
@@ -83,7 +83,7 @@ void hci_conn_del_sysfs(struct hci_conn *conn)
static void bt_host_release(struct device *dev)
{
struct hci_dev *hdev = to_hci_dev(dev);
- kfree(hdev);
+ hci_release_dev(hdev);
module_put(THIS_MODULE);
}