| CVE |
Vendors |
Products |
Updated |
CVSS v3.1 |
| In the Linux kernel, the following vulnerability has been resolved:
smb: client: fix smbd_connection leak on cifs_get_tcp_session() error
When an RDMA connection is successfully established via
smbd_get_connection() but cifs_get_tcp_session() later fails (e.g.
kthread_create() returns an error), the error path frees tcp_ses
without first destroying the smbd_connection.
Fix this by calling smbd_destroy() in the out_err cleanup path before
kfree(tcp_ses). smbd_destroy() safely handles the case where
smbd_conn is NULL, so it can be called unconditionally. |
| In the Linux kernel, the following vulnerability has been resolved:
IB/iser: reject a remote invalidation of an unregistered direction
A write command whose data is sent entirely as immediate data is not
registered. iser_reg_mem_fastreg() takes the DMA key path and leaves
rdma_reg[ISER_DIR_OUT].desc at NULL, while iser_dma_map_task_data() has
already set dir[ISER_DIR_OUT].
iser_check_remote_inv() looks at dir[] alone and hands the descriptor to
iser_inv_desc(), which reads desc->sig_protected. A target that answers
such a command with IB_WR_SEND_WITH_INV faults the initiator.
Leaving those commands unregistered is deliberate.
The same function already terminates the connection when a target sends
a remote invalidation the initiator did not ask for. A target that
invalidates a direction that was never registered is in the same class,
so give it the same answer.
Oops: general protection fault, probably for non-canonical address 0xdffffc0000000004: 0000 [#1] SMP KASAN NOPTI
KASAN: null-ptr-deref in range [0x0000000000000020-0x0000000000000027]
CPU: 0 UID: 0 PID: 40 Comm: kworker/u8:2 Not tainted 7.2.0-rc5-ISERHOST-gf5098b6bae76-dirty #3 PREEMPT(lazy)
Hardware name: QEMU Ubuntu 24.04 PC v2 (i440FX + PIIX, arch_caps fix, 1996), BIOS 1.16.3-debian-1.16.3-2 04/01/2014
Workqueue: rxe_wq do_work
RIP: 0010:iser_task_rsp+0x6d6/0xec0
Code: 48 c1 ea 03 80 3c 02 00 0f 85 ba 06 00 00 48 8b 9b 78 01 00 00 48 b8 00 00 00 00 00 fc ff df 48 8d 7b 20 48 89 fa 48 c1 ea 03 <0f> b6 04 02 84 c0 74 06 0f 8e 76 06 00 00 80 7b 20 00 0f 84 3d 04
RSP: 0018:ffff88811b008db8 EFLAGS: 00010202
RAX: dffffc0000000000 RBX: 0000000000000000 RCX: 0000000000001848
RDX: 0000000000000004 RSI: 1ffff11021587b12 RDI: 0000000000000020
RBP: ffff88810adc1ae4 R08: ffff888109b7f860 R09: ffffffff90a922c0
R10: ffff88810adc1a1c R11: 000000000000003c R12: ffff888109b7f800
R13: ffff88810adc1acc R14: ffff888109b7f820 R15: 0000000000000000
FS: 0000000000000000(0000) GS:ffff88818a676000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00000000005afe2b CR3: 000000010af23005 CR4: 0000000000770ef0
PKRU: 55555554
Call Trace:
<IRQ>
__ib_process_cq+0xe1/0x390
ib_poll_handler+0x6e/0x200
irq_poll_softirq+0x1df/0x480
? clockevents_program_event+0x2ba/0x860
? __pfx_irq_poll_softirq+0x10/0x10
handle_softirqs+0x18e/0x590
? __pfx_handle_softirqs+0x10/0x10
? __hrtimer_rearm_deferred+0x156/0x450
do_softirq+0x3b/0x60
</IRQ>
<TASK>
__local_bh_enable_ip+0x61/0x70
__alloc_skb+0x732/0x890
? _raw_spin_lock_irqsave+0x85/0xe0
? __pfx___alloc_skb+0x10/0x10
? _raw_read_unlock_irqrestore+0x16/0x50
rxe_init_packet+0x16b/0x4f0
prepare_ack_packet+0xb8/0x830
rxe_receiver+0x499/0x9980
? __pfx_rxe_receiver+0x10/0x10
? rxe_completer+0x29e5/0x38c0
? hrtimer_start_range_ns_common+0x75f/0x1730
? hrtimer_start_range_ns+0xa6/0x2c0
? __pfx__raw_spin_lock_irqsave+0x10/0x10
? __pfx_rxe_receiver+0x10/0x10
do_work+0x144/0x470
process_one_work+0x633/0x1030
? assign_work+0x11d/0x370
worker_thread+0x45b/0xd10
? __pfx_worker_thread+0x10/0x10
kthread+0x2c6/0x3b0
? recalc_sigpending+0x15c/0x1e0
? __pfx_kthread+0x10/0x10
ret_from_fork+0x36e/0x5a0
? __pfx_ret_from_fork+0x10/0x10
? __switch_to+0x572/0xdd0
? __pfx_kthread+0x10/0x10
ret_from_fork_asm+0x1a/0x30
</TASK>
Modules linked in:
---[ end trace 0000000000000000 ]--- |
| In the Linux kernel, the following vulnerability has been resolved:
RDMA/rxe: insert mcg into mcg_tree only after rxe_mcast_add() succeeds
rxe_get_mcg() publishes a newly allocated multicast group in
rxe->mcg_tree before programming the backing Ethernet multicast address
with rxe_mcast_add(), which runs outside mcg_lock. A local userspace
RDMA client reaches this path with ATTACH_MCAST on a UD QP; if
rxe_mcast_add() then returns an error (for example -ENODEV when the
backing netdev has been removed, or a propagated dev_mc_add() error),
the unwind frees the published group without removing it from the tree.
A later lookup of the same MGID dereferences the freed struct rxe_mcg
from __rxe_lookup_mcg().
Fix this by keeping the new mcg private until rxe_mcast_add() succeeds.
Split the tree publication into __rxe_publish_mcg(), call rxe_mcast_add()
before taking the tree reference, and free the still-private mcg on
failure. Because the group is never visible in mcg_tree until the
multicast address is programmed, no concurrent caller can look it up or
attach a QP to a group that is about to be torn down, so the error path
needs no conditional unwind. If another caller publishes the same MGID
while the address is being programmed, the post-add re-check under
mcg_lock finds the winner; this caller then drops its private object and
balances its own rxe_mcast_add() with rxe_mcast_del() before returning
the winner.
Reproduced by forcing the rxe_mcast_add() error return under KASAN:
without the change the next attach to the same MGID reports a
slab-use-after-free in __rxe_lookup_mcg(); with it the forced failure
returns cleanly. A no-injection attach/detach regression, including a
two-QP shared join/leave and re-attach, stays KASAN- and leak-clean. |
| In the Linux kernel, the following vulnerability has been resolved:
RDMA/erdma: Use IRQ-safe XArray helpers for QP and CQ tables
Locked QP and CQ lookups from EQ interrupts can deadlock with
create-path XArray updates. If an interrupt arrives while the create
path holds the plain xa_lock, the lookup spins forever trying to
acquire the same lock.
Use IRQ-safe XArray helpers for all QP and CQ create-path updates,
including the GSI QP store and error paths. Initialize both arrays with
XA_FLAGS_LOCK_IRQ so sleeping allocations preserve interrupt state. |
| In the Linux kernel, the following vulnerability has been resolved:
RDMA/mad: Fix receive buffer leak when PKey enforcement fails
ib_mad_complete_recv() initializes mad_recv_wc->rmpp_list and then runs
ib_mad_enforce_security() before linking recv_buf onto that list. On
failure it calls ib_free_recv_mad(), which only walks rmpp_list and frees
the ib_mad_private of every buffer found there. As the list is still
empty at that point, nothing is freed at all.
The caller cannot clean up either: ib_mad_recv_done() sets recv to NULL
right after ib_mad_complete_recv() returns, assuming the MAD layer took
ownership of the buffer. Every MAD that fails the PKey check therefore
leaks one ib_mad_private (about 300 bytes per IB port MAD, ~2K for OPA),
and a remote node can trigger this repeatedly by sending MADs with a
wrong PKey.
Link recv_buf onto rmpp_list right after the list is initialized, so the
error path has something to free. |
| In the Linux kernel, the following vulnerability has been resolved:
xfrm: add missing rcu_read_lock(), skb_dst_force() and dev_hold() for xfrm_trans_reinject()
syzbot reported a suspicious RCU usage warning in ip6_pkt_drop():
WARNING: suspicious RCU usage in ip6_pkt_drop
include/net/addrconf.h:389 suspicious rcu_dereference_check() usage!
Call Trace:
__in6_dev_get_safely include/net/addrconf.h:389 [inline]
ip6_pkt_drop+0x596/0x610 net/ipv6/route.c:4620
ip6_pkt_discard+0x1c/0x30 net/ipv6/route.c:4651
xfrm_trans_reinject+0x324/0x630 net/xfrm/xfrm_input.c:806
process_one_work kernel/workqueue.c:3322 [inline]
process_scheduled_works+0xa8e/0x14e0 kernel/workqueue.c:3405
worker_thread+0xa47/0xfb0 kernel/workqueue.c:3486
When commit 4f4920669d21 ("xfrm: Reinject transport-mode packets through
workqueue") converted xfrm_trans_reinject from a tasklet to a workqueue,
the reinjection loop ceased running in softirq context. Workqueue workers
run in process context where local_bh_disable() does not enter an RCU
read-side critical section under CONFIG_PREEMPT_RCU.
Because finish callbacks (such as ip6_rcv_finish) expect to run under an
RCU read lock (performing route lookups, l3mdev lookups, and accessing
RCU-protected data structures), invoking them in workqueue context without
rcu_read_lock() triggers RCU lockdep warnings.
Furthermore, packets queued to the workqueue via xfrm_trans_queue_net()
may carry non-refcounted (noref) dst entries (e.g. from ip_route_input_noref).
Additionally, on netdevice unregistration, dst_dev_put() replaces dst->dev
with blackhole_netdev, so dst entries do not keep skb->dev alive while
queued in the workqueue.
Fix these issues by:
1. Calling skb_dst_force(skb) in xfrm_trans_queue_net() while still in the
caller's RCU section to ensure dst is reference-counted before queuing.
2. Holding a reference on skb->dev via dev_hold()/dev_put() across workqueue
deferral so skb->dev remains valid during finish() callback processing.
3. Acquiring rcu_read_lock() around the finish callback invocation loop in
xfrm_trans_reinject(). |
| In the Linux kernel, the following vulnerability has been resolved:
RDMA/core: Reject unregistering netdevs in ib_get_eth_speed
ib_device_get_netdev() intentionally returns a referenced net_device even
when it is unregistering, so matching and cleanup callers can still find
the association. The reference keeps struct net_device allocated, but does
not guarantee that the device remains operational.
ib_get_eth_speed() uses the returned device operationally by invoking its
ethtool callback. Although that call is made under RTNL, the function does
not verify the registration state first. An asynchronous RDMA port query
can therefore call into a netdev after NETDEV_UNREGISTER and ndo_uninit
have completed.
Check for NETREG_REGISTERED while holding RTNL and return -ENODEV for a
device which is being unregistered. Keeping RTNL across the check and the
ethtool operation prevents unregister from starting between them.
Keep the speed fallback and warning under RTNL as well, so the warning can
safely read netdev->name. Drop the netdev reference before releasing RTNL
once all accesses to the device are complete. |
| In the Linux kernel, the following vulnerability has been resolved:
net: lan743x: fix RX checksum use-after-free
lan743x_rx_process_buffer() adds each non-first receive buffer to the
head skb's frag_list. On the last descriptor, lan743x_rx_trim_skb()
linearizes the head and frees the fragment skb metadata.
The checksum-success path then writes ip_summed through the local skb
pointer, which still points to the final fragment. This causes a
use-after-free write when a packet spans more than one receive buffer.
Set ip_summed on the surviving head skb instead. Multi-buffer receive
can occur after a live MTU increase because existing ring entries keep
their old buffer size until they are replenished.
A KUnit test invoking lan743x_rx_process_buffer() with a two-buffer
packet produced a one-byte KASAN use-after-free write before this change.
The same test passed after the change. The driver object also builds
with W=1. This was not tested on physical LAN743x hardware. |
| In the Linux kernel, the following vulnerability has been resolved:
ipv6: xfrm: use full sockets in local error paths
xfrm6_local_rxpmtu() and xfrm6_local_error() dereference skb->sk as if it
always pointed at a full IPv6 socket.
That is not guaranteed. TCP SYN-ACK skbs can be owned by a
TCP_NEW_SYN_RECV request_sock while the output path itself is driven by the
full listener. If rerouting selects an IPv6 XFRM tunnel route with a lower
MTU, the local PMTU/error handling path can reach these callbacks with that
mini-socket still attached to the skb.
The callbacks then miscast the request socket as a full inet/IPv6 socket and
can read beyond the request_sock allocation when they access inet_sock or
ipv6_pinfo state.
Resolve the owner with skb_to_full_sk() in both callbacks and bail out when
no full socket is attached. This matches the surrounding XFRM IPv6 PMTU/error
logic, which already reasons about full sockets with skb_to_full_sk(). |
| In the Linux kernel, the following vulnerability has been resolved:
powerpc/iommu: Fix the overflow validation in iommu_tce_check_ioba
The commit b1af23d836f8 ("KVM: PPC: iommu: Unify TCE checking") unified
IOBA parameter checking across KVM and VFIO into iommu_tce_check_ioba().
While doing so, the passed in argument npages is ignored and constant
value '1' is used leaving out a possible overflow as the callers can
legitimately be using npages > 1 for H_STUFF_TCE or H_PUT_TCE_INDIRECT
cases.
Fix this by accounting for 'npages', checking for arithmetic overflow,
and verifying that the entire requested range (ioba - offset + npages)
does not exceed the table capacity 'size'. |
| In the Linux kernel, the following vulnerability has been resolved:
IB/isert: wait for deferred control PDU completions before releasing the connection
isert_send_done() hands ISTATE_SEND_TASKMGTRSP, ISTATE_SEND_REJECT and
ISTATE_SEND_TEXTRSP completions off to isert_comp_wq and returns. The work
item then runs isert_completion_put() -> isert_put_cmd(), which reads
isert_conn->conn and takes conn->cmd_lock.
Nothing orders that work item against teardown. isert_wait_conn() queues
isert_release_work, which frees isert_conn, and iscsit_close_connection()
frees the iscsit_conn right after it returns, so the queued work can run
against freed memory.
Count the deferred control PDU completions per connection and let
isert_wait_conn() wait for them before the release work is queued.
ISTATE_SEND_LOGOUTRSP is deliberately not counted: that branch runs
iscsit_logout_post_handler(), which ends up waiting for
conn->conn_wait_comp, and that completion is only sent by
iscsit_close_connection() after it has called iscsit_wait_conn().
Waiting for it here would deadlock. Its wait stays the existing
isert_wait4logout().
The splat below is from a kernel with tracing printk()s and an msleep(200)
injected into isert_do_control_comp() to widen the window:
BUG: KASAN: slab-use-after-free in isert_put_cmd+0x53d/0x620
Read of size 8 at addr ffff8881054f1038 by task kworker/u17:1/182
CPU: 0 UID: 0 PID: 182 Comm: kworker/u17:1 Tainted: G B 7.2.0-rc5-TWIDE-gb8babf08acc7 #1 PREEMPT(lazy)
Tainted: [B]=BAD_PAGE
Hardware name: QEMU Ubuntu 24.04 PC v2 (i440FX + PIIX, arch_caps fix, 1996), BIOS 1.16.3-debian-1.16.3-2 04/01/2014
Workqueue: isert_comp_wq isert_do_control_comp
Call Trace:
<TASK>
dump_stack_lvl+0x53/0x70
print_report+0xd0/0x630
? __pfx__raw_spin_lock_irqsave+0x10/0x10
? _raw_spin_unlock_irqrestore+0x3e/0x70
? isert_put_cmd+0x53d/0x620
kasan_report+0xce/0x100
? isert_put_cmd+0x53d/0x620
isert_put_cmd+0x53d/0x620
? isert_completion_put+0x305/0x330
? isert_do_control_comp+0x2ef/0x310
process_one_work+0x633/0x1030
? assign_work+0x11d/0x370
worker_thread+0x45b/0xd10
? __pfx_worker_thread+0x10/0x10
? __pfx_worker_thread+0x10/0x10
kthread+0x2c6/0x3b0
? recalc_sigpending+0x15c/0x1e0
? __pfx_kthread+0x10/0x10
ret_from_fork+0x36e/0x5a0
? __pfx_ret_from_fork+0x10/0x10
? __switch_to+0x572/0xdd0
? __pfx_kthread+0x10/0x10
ret_from_fork_asm+0x1a/0x30
</TASK>
Allocated by task 48:
kasan_save_stack+0x33/0x60
kasan_save_track+0x14/0x30
__kasan_kmalloc+0x8f/0xa0
__kmalloc_cache_noprof+0x158/0x370
isert_cma_handler+0x1e3/0x2ae0
cma_cm_event_handler+0x3e/0x240
cma_ib_req_handler+0x17d9/0x4490
cm_process_work+0x41/0x330
cm_work_handler+0x5727/0xc160
process_one_work+0x633/0x1030
worker_thread+0x45b/0xd10
kthread+0x2c6/0x3b0
ret_from_fork+0x36e/0x5a0
ret_from_fork_asm+0x1a/0x30
Freed by task 184:
kasan_save_stack+0x33/0x60
kasan_save_track+0x14/0x30
kasan_save_free_info+0x3b/0x60
__kasan_slab_free+0x43/0x70
kfree+0x121/0x380
iscsit_close_connection+0x7cf/0x1e60
iscsit_take_action_for_connection_exit+0x1b6/0x360
iscsi_target_tx_thread+0x472/0x690
kthread+0x2c6/0x3b0
ret_from_fork+0x36e/0x5a0
ret_from_fork_asm+0x1a/0x30 |
| In the Linux kernel, the following vulnerability has been resolved:
cifs: Fix server use-after-free in cifs_chan_skip_or_disable()
When a secondary channel is no longer supported by the server,
cifs_chan_skip_or_disable() drops the channel reference with
cifs_put_tcp_session() and then continues to use the server pointer by
calling cifs_signal_cifsd_for_reconnect() on it and reading its
primary_server pointer. cifs_put_tcp_session() can drop the last
reference of the channel and tear it down, so both the channel and the
primary server (whose reference is also dropped by
cifs_put_tcp_session()) can be freed before they are signaled for
reconnect.
Signal the channel and the primary server and capture the primary
server pointer before dropping the channel reference with
cifs_put_tcp_session(). |
| In the Linux kernel, the following vulnerability has been resolved:
smb: client: fix use-after-free of iface in cifs_try_adding_channels()
cifs_try_adding_channels() iterates ses->iface_list with
list_for_each_entry_safe_from(), which captures the next entry
(niface) under iface_lock. The loop body then drops iface_lock for
the whole duration of cifs_ses_add_channel().
A concurrent interface refresh (SMB3_request_interfaces() ->
parse_server_interfaces()) marks all ifaces inactive and removes and
frees any that are not re-advertised via list_del() + kref_put(),
where release_iface() is a bare kfree(). Since niface typically has
no channel holding a reference, the list reference is its last and it
can be freed inside the unlocked window. On continue, the iterator
advance step then dereferences niface->iface_head.next, and the loop
body reads iface->rdma_capable/is_active, both on freed memory.
Fix this by never keeping an unreferenced list pointer across the
unlocked window. Each channel attempt now re-scans the list from the
head under iface_lock, takes a kref on the selected candidate, and
passes only that referenced candidate to cifs_ses_add_channel().
weight_fulfilled still tracks selection progress, so restarting the
scan preserves the original weighted distribution and the
weight_fulfilled-before-kref_put ordering on the failure path.
Add a per-pass attempts cap so a flapping interface refresh cannot
keep the inner loop spinning within a single tries increment. |
| In the Linux kernel, the following vulnerability has been resolved:
smb: client: fix rlist race and missing initialization
TCP_Server_Info.rlist is allocated via kzalloc which zeros both ->next
and ->prev to NULL instead of pointing to itself, making list_empty()
always return false and list_add() dereference a NULL ->prev pointer.
Also, cifs_signal_cifsd_for_reconnect() can be called concurrently
from multiple cifsd threads, allowing the same server's rlist node to
be added twice into the local list, corrupting it. |
| In the Linux kernel, the following vulnerability has been resolved:
dma-buf/dma-fence: fix checking signaling bit for timeline and driver name v3
The patch "dma-buf: dma-fence: Fix potential NULL pointer dereference"
changed the check to test for the ops pointer instead of the signaled
bit to avoid a potential NULL dereference when the ops pointer has been
cleared.
The problem is now that the ops pointer is cleared only when neither the
release nor the wait callback is implemented and this isn't true for a lot
of dma_fence implementations yet. So those implementations lost the RCU
protection after signaling of the returned string resulting in potential
use after free.
Add the signaling check additional to the ops pointer check so that we
have both the protection against NULL dereference as well as the RCU
protection after signaling for the returned string.
v2: improve comments to note RCU protection and explain why we check
both signaling state and ops pointer
v3: some comment improvements suggested by Philip |
| In the Linux kernel, the following vulnerability has been resolved:
openvswitch: avoid reallocating confirmed conntrack labels
ovs_ct_get_conn_labels() adds the labels extension when a conntrack
entry does not have one. Confirmed conntracks can be read locklessly,
so adding an extension may reallocate and free the extension block
while another CPU accesses it.
Only add the extension for unconfirmed conntracks. A confirmed
conntrack without labels now fails the caller's label operation instead
of reallocating its extension storage. |
| In the Linux kernel, the following vulnerability has been resolved:
signal: Prevent exec() race
Hyunwoo debugged the following KASAN UAF splat:
BUG: KASAN: slab-use-after-free in __send_signal_locked+0xb27/0xba0
Write of size 8 at addr ffff888007ed80c8 by task poc/79
...
Call Trace:
__send_signal_locked+0xb27/0xba0
do_send_sig_info+0xa7/0x160
do_send_specific+0x76/0xa0
__x64_sys_tgkill+0x193/0x270
...
Allocated by task 80:
do_timer_create+0x1a4/0x1030
__x64_sys_timer_create+0x145/0x190
...
Freed by task 12:
kmem_cache_free_bulk+0x1f8/0x4a0
kvfree_rcu_bulk+0x14f/0x1c0
kfree_rcu_work+0x128/0x1a0
...
Last potentially related work creation:
kvfree_call_rcu+0x39/0x390
__flush_itimer_signals+0x211/0x320
flush_itimer_signals+0x47/0x90
begin_new_exec+0xa6b/0x28c0
It turned out that this happens with a non-leader exec() as Hyunwoo
explained:
de_thread() calls exchange_tids() before release_task(leader), so the
struct pid held by a SIGEV_THREAD_ID timer created against the leader's tid
now points to the thread which called execve(). pid_task() returns that
thread and lock_task_sighand() on it succeeds.
If the timer signal is blocked, its sigqueue stays queued on the leader's
task::pending. The next expiry of that timer can then run while
release_task() flushes the queue.
posixtimer_send_sigqueue() checks whether the sigqueue is already queued
with a plain list_empty(), which only reads list_head::next.
list_del_init() is not atomic and INIT_LIST_HEAD() stores list_head::next
before list_head::prev, so the check can pass in between. list_add_tail()
queues the entry on the task::pending of the live thread, and the
list_head::prev store from the flush then overwrites the list_head::prev
link that list_add_tail() has just set.
__flush_itimer_signals() does not undo that either. With list_head::prev
pointing at the entry itself, its list_del_init() only stores the same
values again, so the entry is not removed from the list. It is still there
after the last reference is dropped and the timer is freed by RCU, and the
list_add_tail() of a later tgkill() follows that list_head::prev into the
freed timer.
This problem surfaced with the recent commit which moved the sigqueue flush
out of the sighand lock held region.
Hyonwoo proposed to fix this by using list_del_init_careful(), but that
just papers over the problem. After some disucssions and various attempts
to solve it, Eric pointed out that there is no reason to flush
task::pending late in release_task() and it should be done in
exit_signals() already.
As nothing can collect and deliver signals which are queued in a dying
task's pending queue, there is no reason to delay it further.
But it has to be ensured that no signals can be queued into it after that
point. exit_signals() sets PF_EXITING in task::flags, which can be used as
an indicator for this.
Cure it by:
- Preventing signal queueing for task private signals (PIDTYPE_PID) when
the task has PF_EXITING set in __send_signal_locked() and in
posixtimer_send_sigqueue().
- Protecting the unlocked setting of PF_EXITING in exit_signals() for the
task group empty and the group exit case with sighand lock
- Flushing task::pending signals right there.
Optimize that by moving the whole pending list to an on-stack list head
under sighand lock and free the signals without the lock held.
There has been quite some discussion about the lockless flush and the
non-leader exec case on weakly ordered systems. The problem is that a third
party which tries to send a posix timer signal relies on the PID lookup to
find the target task and that lookup might result in the new leader when
the signal was originaly directed to the old leader. In case that the
signal was queued on the old leader then the lockless flush raised a
concern over the following situation:
old_leader new_leader third party
A: flush_list() // list_del_in
---truncated--- |
| In the Linux kernel, the following vulnerability has been resolved:
Bluetooth: RFCOMM: avoid socket lock inversion in listener cleanup
rfcomm_sock_cleanup_listen() closes unaccepted child sockets through
rfcomm_sock_close(), which takes the child socket lock before
rfcomm_dlc_close() acquires rfcomm_mutex. The RFCOMM worker takes these
locks in reverse order while handling connections and DLC state changes,
so lockdep reports a possible deadlock.
Close dequeued children without taking their socket lock. The accept queue
owns a reference to each child, and bt_accept_dequeue() locks the child
while unlinking it and clearing its parent pointer.
Dropping the child lock makes it important to prevent a concurrent
rfcomm_connect_ind() from enqueueing a new child after cleanup observes an
empty queue. Set a listening socket to BT_CLOSED while its lock is still
held, before dropping the lock and draining the queue. The state check in
rfcomm_connect_ind() then rejects new children once cleanup starts. |
| In the Linux kernel, the following vulnerability has been resolved:
ntfs: protect runlist updates with the runlist lock
ntfs_non_resident_attr_shrink() calls runlist helpers that require the
runlist write lock, but did not hold it while freeing clusters and
truncating the runlist. Serialize those operations and the resident
conversion with the runlist lock.
ntfs_attr_map_cluster() can merge a newly allocated run before updating
mapping pairs. If the update fails, free the clusters and restore both
the in-memory runlist and on-disk mapping pairs from a saved runlist.
Mark the volume in error if either rollback step fails. |
| In the Linux kernel, the following vulnerability has been resolved:
smb: client: validate absolute native symlink targets before NT fixups
With symlinkroot unset, an absolute target is copied without conversion
to an NT drive path. Later code still assumes an NT prefix is present
when modifying the target and calculating the print name length.
For "/ab", this causes two failures: sym[5] and path[5] are written
past their allocations, and plen -= 2 * poff subtracts an assumed
8-byte prefix from a 6-byte UTF-16 target, wrapping u16 plen to 65534.
That underflow causes another overflow: memcpy() copies 65534 bytes
into a 24-byte buffer. A user with write access to a mounted share
can trigger these bugs with default settings.
Validate the NT drive prefix, including an ASCII drive letter, before
accessing fixed offsets or subtracting the prefix length. |
