| CVE |
Vendors |
Products |
Updated |
CVSS v3.1 |
| In the Linux kernel, the following vulnerability has been resolved:
drm/xe: Drop VM dma-resv lock on xe_sync_in_fence_get failure in exec IOCTL
Upon failure all locks need to be dropped before returning to the user.
(cherry picked from commit 7d1a4258e602ffdce529f56686925034c1b3b095) |
| In the Linux kernel, the following vulnerability has been resolved:
mptcp: init: protect sched with rcu_read_lock
Enabling CONFIG_PROVE_RCU_LIST with its dependence CONFIG_RCU_EXPERT
creates this splat when an MPTCP socket is created:
=============================
WARNING: suspicious RCU usage
6.12.0-rc2+ #11 Not tainted
-----------------------------
net/mptcp/sched.c:44 RCU-list traversed in non-reader section!!
other info that might help us debug this:
rcu_scheduler_active = 2, debug_locks = 1
no locks held by mptcp_connect/176.
stack backtrace:
CPU: 0 UID: 0 PID: 176 Comm: mptcp_connect Not tainted 6.12.0-rc2+ #11
Hardware name: Bochs Bochs, BIOS Bochs 01/01/2011
Call Trace:
<TASK>
dump_stack_lvl (lib/dump_stack.c:123)
lockdep_rcu_suspicious (kernel/locking/lockdep.c:6822)
mptcp_sched_find (net/mptcp/sched.c:44 (discriminator 7))
mptcp_init_sock (net/mptcp/protocol.c:2867 (discriminator 1))
? sock_init_data_uid (arch/x86/include/asm/atomic.h:28)
inet_create.part.0.constprop.0 (net/ipv4/af_inet.c:386)
? __sock_create (include/linux/rcupdate.h:347 (discriminator 1))
__sock_create (net/socket.c:1576)
__sys_socket (net/socket.c:1671)
? __pfx___sys_socket (net/socket.c:1712)
? do_user_addr_fault (arch/x86/mm/fault.c:1419 (discriminator 1))
__x64_sys_socket (net/socket.c:1728)
do_syscall_64 (arch/x86/entry/common.c:52 (discriminator 1))
entry_SYSCALL_64_after_hwframe (arch/x86/entry/entry_64.S:130)
That's because when the socket is initialised, rcu_read_lock() is not
used despite the explicit comment written above the declaration of
mptcp_sched_find() in sched.c. Adding the missing lock/unlock avoids the
warning. |
| In the Linux kernel, the following vulnerability has been resolved:
clk: qcom: videocc-sm8350: use HW_CTRL_TRIGGER for vcodec GDSCs
A recent change in the venus driver results in a stuck clock on the
Lenovo ThinkPad X13s, for example, when streaming video in firefox:
video_cc_mvs0_clk status stuck at 'off'
WARNING: CPU: 6 PID: 2885 at drivers/clk/qcom/clk-branch.c:87 clk_branch_wait+0x144/0x15c
...
Call trace:
clk_branch_wait+0x144/0x15c
clk_branch2_enable+0x30/0x40
clk_core_enable+0xd8/0x29c
clk_enable+0x2c/0x4c
vcodec_clks_enable.isra.0+0x94/0xd8 [venus_core]
coreid_power_v4+0x464/0x628 [venus_core]
vdec_start_streaming+0xc4/0x510 [venus_dec]
vb2_start_streaming+0x6c/0x180 [videobuf2_common]
vb2_core_streamon+0x120/0x1dc [videobuf2_common]
vb2_streamon+0x1c/0x6c [videobuf2_v4l2]
v4l2_m2m_ioctl_streamon+0x30/0x80 [v4l2_mem2mem]
v4l_streamon+0x24/0x30 [videodev]
using the out-of-tree sm8350/sc8280xp venus support. [1]
Update also the sm8350/sc8280xp GDSC definitions so that the hw control
mode can be changed at runtime as the venus driver now requires. |
| In the Linux kernel, the following vulnerability has been resolved:
drm/imagination: avoid deadlock on fence release
Do scheduler queue fence release processing on a workqueue, rather
than in the release function itself.
Fixes deadlock issues such as the following:
[ 607.400437] ============================================
[ 607.405755] WARNING: possible recursive locking detected
[ 607.415500] --------------------------------------------
[ 607.420817] weston:zfq0/24149 is trying to acquire lock:
[ 607.426131] ffff000017d041a0 (reservation_ww_class_mutex){+.+.}-{3:3}, at: pvr_gem_object_vunmap+0x40/0xc0 [powervr]
[ 607.436728]
but task is already holding lock:
[ 607.442554] ffff000017d105a0 (reservation_ww_class_mutex){+.+.}-{3:3}, at: dma_buf_ioctl+0x250/0x554
[ 607.451727]
other info that might help us debug this:
[ 607.458245] Possible unsafe locking scenario:
[ 607.464155] CPU0
[ 607.466601] ----
[ 607.469044] lock(reservation_ww_class_mutex);
[ 607.473584] lock(reservation_ww_class_mutex);
[ 607.478114]
*** DEADLOCK *** |
| In the Linux kernel, the following vulnerability has been resolved:
NFS: fix nfs_release_folio() to not deadlock via kcompactd writeback
Add PF_KCOMPACTD flag and current_is_kcompactd() helper to check for it so
nfs_release_folio() can skip calling nfs_wb_folio() from kcompactd.
Otherwise NFS can deadlock waiting for kcompactd enduced writeback which
recurses back to NFS (which triggers writeback to NFSD via NFS loopback
mount on the same host, NFSD blocks waiting for XFS's call to
__filemap_get_folio):
6070.550357] INFO: task kcompactd0:58 blocked for more than 4435 seconds.
{---
[58] "kcompactd0"
[<0>] folio_wait_bit+0xe8/0x200
[<0>] folio_wait_writeback+0x2b/0x80
[<0>] nfs_wb_folio+0x80/0x1b0 [nfs]
[<0>] nfs_release_folio+0x68/0x130 [nfs]
[<0>] split_huge_page_to_list_to_order+0x362/0x840
[<0>] migrate_pages_batch+0x43d/0xb90
[<0>] migrate_pages_sync+0x9a/0x240
[<0>] migrate_pages+0x93c/0x9f0
[<0>] compact_zone+0x8e2/0x1030
[<0>] compact_node+0xdb/0x120
[<0>] kcompactd+0x121/0x2e0
[<0>] kthread+0xcf/0x100
[<0>] ret_from_fork+0x31/0x40
[<0>] ret_from_fork_asm+0x1a/0x30
---}
[[email protected]: fix build] |
| In the Linux kernel, the following vulnerability has been resolved:
drm/i915/gt: Use spin_lock_irqsave() in interruptible context
spin_lock/unlock() functions used in interrupt contexts could
result in a deadlock, as seen in GitLab issue #13399,
which occurs when interrupt comes in while holding a lock.
Try to remedy the problem by saving irq state before spin lock
acquisition.
v2: add irqs' state save/restore calls to all locks/unlocks in
signal_irq_work() execution (Maciej)
v3: use with spin_lock_irqsave() in guc_lrc_desc_unpin() instead
of other lock/unlock calls and add Fixes and Cc tags (Tvrtko);
change title and commit message
(cherry picked from commit c088387ddd6482b40f21ccf23db1125e8fa4af7e) |
| In the Linux kernel, the following vulnerability has been resolved:
net/mlx5e: Fix inversion dependency warning while enabling IPsec tunnel
Attempt to enable IPsec packet offload in tunnel mode in debug kernel
generates the following kernel panic, which is happening due to two
issues:
1. In SA add section, the should be _bh() variant when marking SA mode.
2. There is not needed flush_workqueue in SA delete routine. It is not
needed as at this stage as it is removed from SADB and the running work
will be canceled later in SA free.
=====================================================
WARNING: SOFTIRQ-safe -> SOFTIRQ-unsafe lock order detected
6.12.0+ #4 Not tainted
-----------------------------------------------------
charon/1337 [HC0[0]:SC0[4]:HE1:SE0] is trying to acquire:
ffff88810f365020 (&xa->xa_lock#24){+.+.}-{3:3}, at: mlx5e_xfrm_del_state+0xca/0x1e0 [mlx5_core]
and this task is already holding:
ffff88813e0f0d48 (&x->lock){+.-.}-{3:3}, at: xfrm_state_delete+0x16/0x30
which would create a new lock dependency:
(&x->lock){+.-.}-{3:3} -> (&xa->xa_lock#24){+.+.}-{3:3}
but this new dependency connects a SOFTIRQ-irq-safe lock:
(&x->lock){+.-.}-{3:3}
... which became SOFTIRQ-irq-safe at:
lock_acquire+0x1be/0x520
_raw_spin_lock_bh+0x34/0x40
xfrm_timer_handler+0x91/0xd70
__hrtimer_run_queues+0x1dd/0xa60
hrtimer_run_softirq+0x146/0x2e0
handle_softirqs+0x266/0x860
irq_exit_rcu+0x115/0x1a0
sysvec_apic_timer_interrupt+0x6e/0x90
asm_sysvec_apic_timer_interrupt+0x16/0x20
default_idle+0x13/0x20
default_idle_call+0x67/0xa0
do_idle+0x2da/0x320
cpu_startup_entry+0x50/0x60
start_secondary+0x213/0x2a0
common_startup_64+0x129/0x138
to a SOFTIRQ-irq-unsafe lock:
(&xa->xa_lock#24){+.+.}-{3:3}
... which became SOFTIRQ-irq-unsafe at:
...
lock_acquire+0x1be/0x520
_raw_spin_lock+0x2c/0x40
xa_set_mark+0x70/0x110
mlx5e_xfrm_add_state+0xe48/0x2290 [mlx5_core]
xfrm_dev_state_add+0x3bb/0xd70
xfrm_add_sa+0x2451/0x4a90
xfrm_user_rcv_msg+0x493/0x880
netlink_rcv_skb+0x12e/0x380
xfrm_netlink_rcv+0x6d/0x90
netlink_unicast+0x42f/0x740
netlink_sendmsg+0x745/0xbe0
__sock_sendmsg+0xc5/0x190
__sys_sendto+0x1fe/0x2c0
__x64_sys_sendto+0xdc/0x1b0
do_syscall_64+0x6d/0x140
entry_SYSCALL_64_after_hwframe+0x4b/0x53
other info that might help us debug this:
Possible interrupt unsafe locking scenario:
CPU0 CPU1
---- ----
lock(&xa->xa_lock#24);
local_irq_disable();
lock(&x->lock);
lock(&xa->xa_lock#24);
<Interrupt>
lock(&x->lock);
*** DEADLOCK ***
2 locks held by charon/1337:
#0: ffffffff87f8f858 (&net->xfrm.xfrm_cfg_mutex){+.+.}-{4:4}, at: xfrm_netlink_rcv+0x5e/0x90
#1: ffff88813e0f0d48 (&x->lock){+.-.}-{3:3}, at: xfrm_state_delete+0x16/0x30
the dependencies between SOFTIRQ-irq-safe lock and the holding lock:
-> (&x->lock){+.-.}-{3:3} ops: 29 {
HARDIRQ-ON-W at:
lock_acquire+0x1be/0x520
_raw_spin_lock_bh+0x34/0x40
xfrm_alloc_spi+0xc0/0xe60
xfrm_alloc_userspi+0x5f6/0xbc0
xfrm_user_rcv_msg+0x493/0x880
netlink_rcv_skb+0x12e/0x380
xfrm_netlink_rcv+0x6d/0x90
netlink_unicast+0x42f/0x740
netlink_sendmsg+0x745/0xbe0
__sock_sendmsg+0xc5/0x190
__sys_sendto+0x1fe/0x2c0
__x64_sys_sendto+0xdc/0x1b0
do_syscall_64+0x6d/0x140
entry_SYSCALL_64_after_hwframe+0x4b/0x53
IN-SOFTIRQ-W at:
lock_acquire+0x1be/0x520
_raw_spin_lock_bh+0x34/0x40
xfrm_timer_handler+0x91/0xd70
__hrtimer_run_queues+0x1dd/0xa60
---truncated--- |
| In the Linux kernel, the following vulnerability has been resolved:
afs: Fix merge preference rule failure condition
syzbot reported a lock held when returning to userspace[1]. This is
because if argc is less than 0 and the function returns directly, the held
inode lock is not released.
Fix this by store the error in ret and jump to done to clean up instead of
returning directly.
[dh: Modified Lizhi Xu's original patch to make it honour the error code
from afs_split_string()]
[1]
WARNING: lock held when returning to user space!
6.13.0-rc3-syzkaller-00209-g499551201b5f #0 Not tainted
------------------------------------------------
syz-executor133/5823 is leaving the kernel with locks still held!
1 lock held by syz-executor133/5823:
#0: ffff888071cffc00 (&sb->s_type->i_mutex_key#9){++++}-{4:4}, at: inode_lock include/linux/fs.h:818 [inline]
#0: ffff888071cffc00 (&sb->s_type->i_mutex_key#9){++++}-{4:4}, at: afs_proc_addr_prefs_write+0x2bb/0x14e0 fs/afs/addr_prefs.c:388 |
| In the Linux kernel, the following vulnerability has been resolved:
cgroup/cpuset: remove kernfs active break
A warning was found:
WARNING: CPU: 10 PID: 3486953 at fs/kernfs/file.c:828
CPU: 10 PID: 3486953 Comm: rmdir Kdump: loaded Tainted: G
RIP: 0010:kernfs_should_drain_open_files+0x1a1/0x1b0
RSP: 0018:ffff8881107ef9e0 EFLAGS: 00010202
RAX: 0000000080000002 RBX: ffff888154738c00 RCX: dffffc0000000000
RDX: 0000000000000007 RSI: 0000000000000004 RDI: ffff888154738c04
RBP: ffff888154738c04 R08: ffffffffaf27fa15 R09: ffffed102a8e7180
R10: ffff888154738c07 R11: 0000000000000000 R12: ffff888154738c08
R13: ffff888750f8c000 R14: ffff888750f8c0e8 R15: ffff888154738ca0
FS: 00007f84cd0be740(0000) GS:ffff8887ddc00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000555f9fbe00c8 CR3: 0000000153eec001 CR4: 0000000000370ee0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
kernfs_drain+0x15e/0x2f0
__kernfs_remove+0x165/0x300
kernfs_remove_by_name_ns+0x7b/0xc0
cgroup_rm_file+0x154/0x1c0
cgroup_addrm_files+0x1c2/0x1f0
css_clear_dir+0x77/0x110
kill_css+0x4c/0x1b0
cgroup_destroy_locked+0x194/0x380
cgroup_rmdir+0x2a/0x140
It can be explained by:
rmdir echo 1 > cpuset.cpus
kernfs_fop_write_iter // active=0
cgroup_rm_file
kernfs_remove_by_name_ns kernfs_get_active // active=1
__kernfs_remove // active=0x80000002
kernfs_drain cpuset_write_resmask
wait_event
//waiting (active == 0x80000001)
kernfs_break_active_protection
// active = 0x80000001
// continue
kernfs_unbreak_active_protection
// active = 0x80000002
...
kernfs_should_drain_open_files
// warning occurs
kernfs_put_active
This warning is caused by 'kernfs_break_active_protection' when it is
writing to cpuset.cpus, and the cgroup is removed concurrently.
The commit 3a5a6d0c2b03 ("cpuset: don't nest cgroup_mutex inside
get_online_cpus()") made cpuset_hotplug_workfn asynchronous, This change
involves calling flush_work(), which can create a multiple processes
circular locking dependency that involve cgroup_mutex, potentially leading
to a deadlock. To avoid deadlock. the commit 76bb5ab8f6e3 ("cpuset: break
kernfs active protection in cpuset_write_resmask()") added
'kernfs_break_active_protection' in the cpuset_write_resmask. This could
lead to this warning.
After the commit 2125c0034c5d ("cgroup/cpuset: Make cpuset hotplug
processing synchronous"), the cpuset_write_resmask no longer needs to
wait the hotplug to finish, which means that concurrent hotplug and cpuset
operations are no longer possible. Therefore, the deadlock doesn't exist
anymore and it does not have to 'break active protection' now. To fix this
warning, just remove kernfs_break_active_protection operation in the
'cpuset_write_resmask'. |
| In the Linux kernel, the following vulnerability has been resolved:
bpf: Fix deadlock when freeing cgroup storage
The following commit
bc235cdb423a ("bpf: Prevent deadlock from recursive bpf_task_storage_[get|delete]")
first introduced deadlock prevention for fentry/fexit programs attaching
on bpf_task_storage helpers. That commit also employed the logic in map
free path in its v6 version.
Later bpf_cgrp_storage was first introduced in
c4bcfb38a95e ("bpf: Implement cgroup storage available to non-cgroup-attached bpf progs")
which faces the same issue as bpf_task_storage, instead of its busy
counter, NULL was passed to bpf_local_storage_map_free() which opened
a window to cause deadlock:
<TASK>
(acquiring local_storage->lock)
_raw_spin_lock_irqsave+0x3d/0x50
bpf_local_storage_update+0xd1/0x460
bpf_cgrp_storage_get+0x109/0x130
bpf_prog_a4d4a370ba857314_cgrp_ptr+0x139/0x170
? __bpf_prog_enter_recur+0x16/0x80
bpf_trampoline_6442485186+0x43/0xa4
cgroup_storage_ptr+0x9/0x20
(holding local_storage->lock)
bpf_selem_unlink_storage_nolock.constprop.0+0x135/0x160
bpf_selem_unlink_storage+0x6f/0x110
bpf_local_storage_map_free+0xa2/0x110
bpf_map_free_deferred+0x5b/0x90
process_one_work+0x17c/0x390
worker_thread+0x251/0x360
kthread+0xd2/0x100
ret_from_fork+0x34/0x50
ret_from_fork_asm+0x1a/0x30
</TASK>
Progs:
- A: SEC("fentry/cgroup_storage_ptr")
- cgid (BPF_MAP_TYPE_HASH)
Record the id of the cgroup the current task belonging
to in this hash map, using the address of the cgroup
as the map key.
- cgrpa (BPF_MAP_TYPE_CGRP_STORAGE)
If current task is a kworker, lookup the above hash
map using function parameter @owner as the key to get
its corresponding cgroup id which is then used to get
a trusted pointer to the cgroup through
bpf_cgroup_from_id(). This trusted pointer can then
be passed to bpf_cgrp_storage_get() to finally trigger
the deadlock issue.
- B: SEC("tp_btf/sys_enter")
- cgrpb (BPF_MAP_TYPE_CGRP_STORAGE)
The only purpose of this prog is to fill Prog A's
hash map by calling bpf_cgrp_storage_get() for as
many userspace tasks as possible.
Steps to reproduce:
- Run A;
- while (true) { Run B; Destroy B; }
Fix this issue by passing its busy counter to the free procedure so
it can be properly incremented before storage/smap locking. |
| In the Linux kernel, the following vulnerability has been resolved:
media: uvcvideo: Fix deadlock during uvc_probe
If uvc_probe() fails, it can end up calling uvc_status_unregister() before
uvc_status_init() is called.
Fix this by checking if dev->status is NULL or not in
uvc_status_unregister(). |
| In the Linux kernel, the following vulnerability has been resolved:
rhashtable: Fix potential deadlock by moving schedule_work outside lock
Move the hash table growth check and work scheduling outside the
rht lock to prevent a possible circular locking dependency.
The original implementation could trigger a lockdep warning due to
a potential deadlock scenario involving nested locks between
rhashtable bucket, rq lock, and dsq lock. By relocating the
growth check and work scheduling after releasing the rth lock, we break
this potential deadlock chain.
This change expands the flexibility of rhashtable by removing
restrictive locking that previously limited its use in scheduler
and workqueue contexts.
Import to say that this calls rht_grow_above_75(), which reads from
struct rhashtable without holding the lock, if this is a problem, we can
move the check to the lock, and schedule the workqueue after the lock.
Modified so that atomic_inc is also moved outside of the bucket
lock along with the growth above 75% check. |
| In the Linux kernel, the following vulnerability has been resolved:
drm/nouveau/gr/gf100: Fix missing unlock in gf100_gr_chan_new()
When the call to gf100_grctx_generate() fails, unlock gr->fecs.mutex
before returning the error.
Fixes smatch warning:
drivers/gpu/drm/nouveau/nvkm/engine/gr/gf100.c:480 gf100_gr_chan_new() warn: inconsistent returns '&gr->fecs.mutex'. |
| In the Linux kernel, the following vulnerability has been resolved:
nfs_common: must not hold RCU while calling nfsd_file_put_local
Move holding the RCU from nfs_to_nfsd_file_put_local to
nfs_to_nfsd_net_put. It is the call to nfs_to->nfsd_serv_put that
requires the RCU anyway (the puts for nfsd_file and netns were
combined to avoid an extra indirect reference but that
micro-optimization isn't possible now).
This fixes xfstests generic/013 and it triggering:
"Voluntary context switch within RCU read-side critical section!"
[ 143.545738] Call Trace:
[ 143.546206] <TASK>
[ 143.546625] ? show_regs+0x6d/0x80
[ 143.547267] ? __warn+0x91/0x140
[ 143.547951] ? rcu_note_context_switch+0x496/0x5d0
[ 143.548856] ? report_bug+0x193/0x1a0
[ 143.549557] ? handle_bug+0x63/0xa0
[ 143.550214] ? exc_invalid_op+0x1d/0x80
[ 143.550938] ? asm_exc_invalid_op+0x1f/0x30
[ 143.551736] ? rcu_note_context_switch+0x496/0x5d0
[ 143.552634] ? wakeup_preempt+0x62/0x70
[ 143.553358] __schedule+0xaa/0x1380
[ 143.554025] ? _raw_spin_unlock_irqrestore+0x12/0x40
[ 143.554958] ? try_to_wake_up+0x1fe/0x6b0
[ 143.555715] ? wake_up_process+0x19/0x20
[ 143.556452] schedule+0x2e/0x120
[ 143.557066] schedule_preempt_disabled+0x19/0x30
[ 143.557933] rwsem_down_read_slowpath+0x24d/0x4a0
[ 143.558818] ? xfs_efi_item_format+0x50/0xc0 [xfs]
[ 143.559894] down_read+0x4e/0xb0
[ 143.560519] xlog_cil_commit+0x1b2/0xbc0 [xfs]
[ 143.561460] ? _raw_spin_unlock+0x12/0x30
[ 143.562212] ? xfs_inode_item_precommit+0xc7/0x220 [xfs]
[ 143.563309] ? xfs_trans_run_precommits+0x69/0xd0 [xfs]
[ 143.564394] __xfs_trans_commit+0xb5/0x330 [xfs]
[ 143.565367] xfs_trans_roll+0x48/0xc0 [xfs]
[ 143.566262] xfs_defer_trans_roll+0x57/0x100 [xfs]
[ 143.567278] xfs_defer_finish_noroll+0x27a/0x490 [xfs]
[ 143.568342] xfs_defer_finish+0x1a/0x80 [xfs]
[ 143.569267] xfs_bunmapi_range+0x4d/0xb0 [xfs]
[ 143.570208] xfs_itruncate_extents_flags+0x13d/0x230 [xfs]
[ 143.571353] xfs_free_eofblocks+0x12e/0x190 [xfs]
[ 143.572359] xfs_file_release+0x12d/0x140 [xfs]
[ 143.573324] __fput+0xe8/0x2d0
[ 143.573922] __fput_sync+0x1d/0x30
[ 143.574574] nfsd_filp_close+0x33/0x60 [nfsd]
[ 143.575430] nfsd_file_free+0x96/0x150 [nfsd]
[ 143.576274] nfsd_file_put+0xf7/0x1a0 [nfsd]
[ 143.577104] nfsd_file_put_local+0x18/0x30 [nfsd]
[ 143.578070] nfs_close_local_fh+0x101/0x110 [nfs_localio]
[ 143.579079] __put_nfs_open_context+0xc9/0x180 [nfs]
[ 143.580031] nfs_file_clear_open_context+0x4a/0x60 [nfs]
[ 143.581038] nfs_file_release+0x3e/0x60 [nfs]
[ 143.581879] __fput+0xe8/0x2d0
[ 143.582464] __fput_sync+0x1d/0x30
[ 143.583108] __x64_sys_close+0x41/0x80
[ 143.583823] x64_sys_call+0x189a/0x20d0
[ 143.584552] do_syscall_64+0x64/0x170
[ 143.585240] entry_SYSCALL_64_after_hwframe+0x76/0x7e
[ 143.586185] RIP: 0033:0x7f3c5153efd7 |
| In the Linux kernel, the following vulnerability has been resolved:
block: Prevent potential deadlocks in zone write plug error recovery
Zone write plugging for handling writes to zones of a zoned block
device always execute a zone report whenever a write BIO to a zone
fails. The intent of this is to ensure that the tracking of a zone write
pointer is always correct to ensure that the alignment to a zone write
pointer of write BIOs can be checked on submission and that we can
always correctly emulate zone append operations using regular write
BIOs.
However, this error recovery scheme introduces a potential deadlock if a
device queue freeze is initiated while BIOs are still plugged in a zone
write plug and one of these write operation fails. In such case, the
disk zone write plug error recovery work is scheduled and executes a
report zone. This in turn can result in a request allocation in the
underlying driver to issue the report zones command to the device. But
with the device queue freeze already started, this allocation will
block, preventing the report zone execution and the continuation of the
processing of the plugged BIOs. As plugged BIOs hold a queue usage
reference, the queue freeze itself will never complete, resulting in a
deadlock.
Avoid this problem by completely removing from the zone write plugging
code the use of report zones operations after a failed write operation,
instead relying on the device user to either execute a report zones,
reset the zone, finish the zone, or give up writing to the device (which
is a fairly common pattern for file systems which degrade to read-only
after write failures). This is not an unreasonnable requirement as all
well-behaved applications, FSes and device mapper already use report
zones to recover from write errors whenever possible by comparing the
current position of a zone write pointer with what their assumption
about the position is.
The changes to remove the automatic error recovery are as follows:
- Completely remove the error recovery work and its associated
resources (zone write plug list head, disk error list, and disk
zone_wplugs_work work struct). This also removes the functions
disk_zone_wplug_set_error() and disk_zone_wplug_clear_error().
- Change the BLK_ZONE_WPLUG_ERROR zone write plug flag into
BLK_ZONE_WPLUG_NEED_WP_UPDATE. This new flag is set for a zone write
plug whenever a write opration targetting the zone of the zone write
plug fails. This flag indicates that the zone write pointer offset is
not reliable and that it must be updated when the next report zone,
reset zone, finish zone or disk revalidation is executed.
- Modify blk_zone_write_plug_bio_endio() to set the
BLK_ZONE_WPLUG_NEED_WP_UPDATE flag for the target zone of a failed
write BIO.
- Modify the function disk_zone_wplug_set_wp_offset() to clear this
new flag, thus implementing recovery of a correct write pointer
offset with the reset (all) zone and finish zone operations.
- Modify blkdev_report_zones() to always use the disk_report_zones_cb()
callback so that disk_zone_wplug_sync_wp_offset() can be called for
any zone marked with the BLK_ZONE_WPLUG_NEED_WP_UPDATE flag.
This implements recovery of a correct write pointer offset for zone
write plugs marked with BLK_ZONE_WPLUG_NEED_WP_UPDATE and within
the range of the report zones operation executed by the user.
- Modify blk_revalidate_seq_zone() to call
disk_zone_wplug_sync_wp_offset() for all sequential write required
zones when a zoned block device is revalidated, thus always resolving
any inconsistency between the write pointer offset of zone write
plugs and the actual write pointer position of sequential zones. |
| In the Linux kernel, the following vulnerability has been resolved:
netfilter: IDLETIMER: Fix for possible ABBA deadlock
Deletion of the last rule referencing a given idletimer may happen at
the same time as a read of its file in sysfs:
| ======================================================
| WARNING: possible circular locking dependency detected
| 6.12.0-rc7-01692-g5e9a28f41134-dirty #594 Not tainted
| ------------------------------------------------------
| iptables/3303 is trying to acquire lock:
| ffff8881057e04b8 (kn->active#48){++++}-{0:0}, at: __kernfs_remove+0x20
|
| but task is already holding lock:
| ffffffffa0249068 (list_mutex){+.+.}-{3:3}, at: idletimer_tg_destroy_v]
|
| which lock already depends on the new lock.
A simple reproducer is:
| #!/bin/bash
|
| while true; do
| iptables -A INPUT -i foo -j IDLETIMER --timeout 10 --label "testme"
| iptables -D INPUT -i foo -j IDLETIMER --timeout 10 --label "testme"
| done &
| while true; do
| cat /sys/class/xt_idletimer/timers/testme >/dev/null
| done
Avoid this by freeing list_mutex right after deleting the element from
the list, then continuing with the teardown. |
| In the Linux kernel, the following vulnerability has been resolved:
Bluetooth: iso: Fix circular lock in iso_listen_bis
This fixes the circular locking dependency warning below, by
releasing the socket lock before enterning iso_listen_bis, to
avoid any potential deadlock with hdev lock.
[ 75.307983] ======================================================
[ 75.307984] WARNING: possible circular locking dependency detected
[ 75.307985] 6.12.0-rc6+ #22 Not tainted
[ 75.307987] ------------------------------------------------------
[ 75.307987] kworker/u81:2/2623 is trying to acquire lock:
[ 75.307988] ffff8fde1769da58 (sk_lock-AF_BLUETOOTH-BTPROTO_ISO)
at: iso_connect_cfm+0x253/0x840 [bluetooth]
[ 75.308021]
but task is already holding lock:
[ 75.308022] ffff8fdd61a10078 (&hdev->lock)
at: hci_le_per_adv_report_evt+0x47/0x2f0 [bluetooth]
[ 75.308053]
which lock already depends on the new lock.
[ 75.308054]
the existing dependency chain (in reverse order) is:
[ 75.308055]
-> #1 (&hdev->lock){+.+.}-{3:3}:
[ 75.308057] __mutex_lock+0xad/0xc50
[ 75.308061] mutex_lock_nested+0x1b/0x30
[ 75.308063] iso_sock_listen+0x143/0x5c0 [bluetooth]
[ 75.308085] __sys_listen_socket+0x49/0x60
[ 75.308088] __x64_sys_listen+0x4c/0x90
[ 75.308090] x64_sys_call+0x2517/0x25f0
[ 75.308092] do_syscall_64+0x87/0x150
[ 75.308095] entry_SYSCALL_64_after_hwframe+0x76/0x7e
[ 75.308098]
-> #0 (sk_lock-AF_BLUETOOTH-BTPROTO_ISO){+.+.}-{0:0}:
[ 75.308100] __lock_acquire+0x155e/0x25f0
[ 75.308103] lock_acquire+0xc9/0x300
[ 75.308105] lock_sock_nested+0x32/0x90
[ 75.308107] iso_connect_cfm+0x253/0x840 [bluetooth]
[ 75.308128] hci_connect_cfm+0x6c/0x190 [bluetooth]
[ 75.308155] hci_le_per_adv_report_evt+0x27b/0x2f0 [bluetooth]
[ 75.308180] hci_le_meta_evt+0xe7/0x200 [bluetooth]
[ 75.308206] hci_event_packet+0x21f/0x5c0 [bluetooth]
[ 75.308230] hci_rx_work+0x3ae/0xb10 [bluetooth]
[ 75.308254] process_one_work+0x212/0x740
[ 75.308256] worker_thread+0x1bd/0x3a0
[ 75.308258] kthread+0xe4/0x120
[ 75.308259] ret_from_fork+0x44/0x70
[ 75.308261] ret_from_fork_asm+0x1a/0x30
[ 75.308263]
other info that might help us debug this:
[ 75.308264] Possible unsafe locking scenario:
[ 75.308264] CPU0 CPU1
[ 75.308265] ---- ----
[ 75.308265] lock(&hdev->lock);
[ 75.308267] lock(sk_lock-
AF_BLUETOOTH-BTPROTO_ISO);
[ 75.308268] lock(&hdev->lock);
[ 75.308269] lock(sk_lock-AF_BLUETOOTH-BTPROTO_ISO);
[ 75.308270]
*** DEADLOCK ***
[ 75.308271] 4 locks held by kworker/u81:2/2623:
[ 75.308272] #0: ffff8fdd66e52148 ((wq_completion)hci0#2){+.+.}-{0:0},
at: process_one_work+0x443/0x740
[ 75.308276] #1: ffffafb488b7fe48 ((work_completion)(&hdev->rx_work)),
at: process_one_work+0x1ce/0x740
[ 75.308280] #2: ffff8fdd61a10078 (&hdev->lock){+.+.}-{3:3}
at: hci_le_per_adv_report_evt+0x47/0x2f0 [bluetooth]
[ 75.308304] #3: ffffffffb6ba4900 (rcu_read_lock){....}-{1:2},
at: hci_connect_cfm+0x29/0x190 [bluetooth] |
| In the Linux kernel, the following vulnerability has been resolved:
Bluetooth: iso: Fix circular lock in iso_conn_big_sync
This fixes the circular locking dependency warning below, by reworking
iso_sock_recvmsg, to ensure that the socket lock is always released
before calling a function that locks hdev.
[ 561.670344] ======================================================
[ 561.670346] WARNING: possible circular locking dependency detected
[ 561.670349] 6.12.0-rc6+ #26 Not tainted
[ 561.670351] ------------------------------------------------------
[ 561.670353] iso-tester/3289 is trying to acquire lock:
[ 561.670355] ffff88811f600078 (&hdev->lock){+.+.}-{3:3},
at: iso_conn_big_sync+0x73/0x260 [bluetooth]
[ 561.670405]
but task is already holding lock:
[ 561.670407] ffff88815af58258 (sk_lock-AF_BLUETOOTH){+.+.}-{0:0},
at: iso_sock_recvmsg+0xbf/0x500 [bluetooth]
[ 561.670450]
which lock already depends on the new lock.
[ 561.670452]
the existing dependency chain (in reverse order) is:
[ 561.670453]
-> #2 (sk_lock-AF_BLUETOOTH){+.+.}-{0:0}:
[ 561.670458] lock_acquire+0x7c/0xc0
[ 561.670463] lock_sock_nested+0x3b/0xf0
[ 561.670467] bt_accept_dequeue+0x1a5/0x4d0 [bluetooth]
[ 561.670510] iso_sock_accept+0x271/0x830 [bluetooth]
[ 561.670547] do_accept+0x3dd/0x610
[ 561.670550] __sys_accept4+0xd8/0x170
[ 561.670553] __x64_sys_accept+0x74/0xc0
[ 561.670556] x64_sys_call+0x17d6/0x25f0
[ 561.670559] do_syscall_64+0x87/0x150
[ 561.670563] entry_SYSCALL_64_after_hwframe+0x76/0x7e
[ 561.670567]
-> #1 (sk_lock-AF_BLUETOOTH-BTPROTO_ISO){+.+.}-{0:0}:
[ 561.670571] lock_acquire+0x7c/0xc0
[ 561.670574] lock_sock_nested+0x3b/0xf0
[ 561.670577] iso_sock_listen+0x2de/0xf30 [bluetooth]
[ 561.670617] __sys_listen_socket+0xef/0x130
[ 561.670620] __x64_sys_listen+0xe1/0x190
[ 561.670623] x64_sys_call+0x2517/0x25f0
[ 561.670626] do_syscall_64+0x87/0x150
[ 561.670629] entry_SYSCALL_64_after_hwframe+0x76/0x7e
[ 561.670632]
-> #0 (&hdev->lock){+.+.}-{3:3}:
[ 561.670636] __lock_acquire+0x32ad/0x6ab0
[ 561.670639] lock_acquire.part.0+0x118/0x360
[ 561.670642] lock_acquire+0x7c/0xc0
[ 561.670644] __mutex_lock+0x18d/0x12f0
[ 561.670647] mutex_lock_nested+0x1b/0x30
[ 561.670651] iso_conn_big_sync+0x73/0x260 [bluetooth]
[ 561.670687] iso_sock_recvmsg+0x3e9/0x500 [bluetooth]
[ 561.670722] sock_recvmsg+0x1d5/0x240
[ 561.670725] sock_read_iter+0x27d/0x470
[ 561.670727] vfs_read+0x9a0/0xd30
[ 561.670731] ksys_read+0x1a8/0x250
[ 561.670733] __x64_sys_read+0x72/0xc0
[ 561.670736] x64_sys_call+0x1b12/0x25f0
[ 561.670738] do_syscall_64+0x87/0x150
[ 561.670741] entry_SYSCALL_64_after_hwframe+0x76/0x7e
[ 561.670744]
other info that might help us debug this:
[ 561.670745] Chain exists of:
&hdev->lock --> sk_lock-AF_BLUETOOTH-BTPROTO_ISO --> sk_lock-AF_BLUETOOTH
[ 561.670751] Possible unsafe locking scenario:
[ 561.670753] CPU0 CPU1
[ 561.670754] ---- ----
[ 561.670756] lock(sk_lock-AF_BLUETOOTH);
[ 561.670758] lock(sk_lock
AF_BLUETOOTH-BTPROTO_ISO);
[ 561.670761] lock(sk_lock-AF_BLUETOOTH);
[ 561.670764] lock(&hdev->lock);
[ 561.670767]
*** DEADLOCK *** |
| In the Linux kernel, the following vulnerability has been resolved:
ptdma: pt_core_execute_cmd() should use spinlock
The interrupt handler (pt_core_irq_handler()) of the ptdma
driver can be called from interrupt context. The code flow
in this function can lead down to pt_core_execute_cmd() which
will attempt to grab a mutex, which is not appropriate in
interrupt context and ultimately leads to a kernel panic.
The fix here changes this mutex to a spinlock, which has
been verified to resolve the issue. |
| In the Linux kernel, the following vulnerability has been resolved:
btrfs: fix deadlock between concurrent dio writes when low on free data space
When reserving data space for a direct IO write we can end up deadlocking
if we have multiple tasks attempting a write to the same file range, there
are multiple extents covered by that file range, we are low on available
space for data and the writes don't expand the inode's i_size.
The deadlock can happen like this:
1) We have a file with an i_size of 1M, at offset 0 it has an extent with
a size of 128K and at offset 128K it has another extent also with a
size of 128K;
2) Task A does a direct IO write against file range [0, 256K), and because
the write is within the i_size boundary, it takes the inode's lock (VFS
level) in shared mode;
3) Task A locks the file range [0, 256K) at btrfs_dio_iomap_begin(), and
then gets the extent map for the extent covering the range [0, 128K).
At btrfs_get_blocks_direct_write(), it creates an ordered extent for
that file range ([0, 128K));
4) Before returning from btrfs_dio_iomap_begin(), it unlocks the file
range [0, 256K);
5) Task A executes btrfs_dio_iomap_begin() again, this time for the file
range [128K, 256K), and locks the file range [128K, 256K);
6) Task B starts a direct IO write against file range [0, 256K) as well.
It also locks the inode in shared mode, as it's within the i_size limit,
and then tries to lock file range [0, 256K). It is able to lock the
subrange [0, 128K) but then blocks waiting for the range [128K, 256K),
as it is currently locked by task A;
7) Task A enters btrfs_get_blocks_direct_write() and tries to reserve data
space. Because we are low on available free space, it triggers the
async data reclaim task, and waits for it to reserve data space;
8) The async reclaim task decides to wait for all existing ordered extents
to complete (through btrfs_wait_ordered_roots()).
It finds the ordered extent previously created by task A for the file
range [0, 128K) and waits for it to complete;
9) The ordered extent for the file range [0, 128K) can not complete
because it blocks at btrfs_finish_ordered_io() when trying to lock the
file range [0, 128K).
This results in a deadlock, because:
- task B is holding the file range [0, 128K) locked, waiting for the
range [128K, 256K) to be unlocked by task A;
- task A is holding the file range [128K, 256K) locked and it's waiting
for the async data reclaim task to satisfy its space reservation
request;
- the async data reclaim task is waiting for ordered extent [0, 128K)
to complete, but the ordered extent can not complete because the
file range [0, 128K) is currently locked by task B, which is waiting
on task A to unlock file range [128K, 256K) and task A waiting
on the async data reclaim task.
This results in a deadlock between 4 task: task A, task B, the async
data reclaim task and the task doing ordered extent completion (a work
queue task).
This type of deadlock can sporadically be triggered by the test case
generic/300 from fstests, and results in a stack trace like the following:
[12084.033689] INFO: task kworker/u16:7:123749 blocked for more than 241 seconds.
[12084.034877] Not tainted 5.18.0-rc2-btrfs-next-115 #1
[12084.035562] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
[12084.036548] task:kworker/u16:7 state:D stack: 0 pid:123749 ppid: 2 flags:0x00004000
[12084.036554] Workqueue: btrfs-flush_delalloc btrfs_work_helper [btrfs]
[12084.036599] Call Trace:
[12084.036601] <TASK>
[12084.036606] __schedule+0x3cb/0xed0
[12084.036616] schedule+0x4e/0xb0
[12084.036620] btrfs_start_ordered_extent+0x109/0x1c0 [btrfs]
[12084.036651] ? prepare_to_wait_exclusive+0xc0/0xc0
[12084.036659] btrfs_run_ordered_extent_work+0x1a/0x30 [btrfs]
[12084.036688] btrfs_work_helper+0xf8/0x400 [btrfs]
[12084.0367
---truncated--- |
