| CVE |
Vendors |
Products |
Updated |
CVSS v3.1 |
| A flaw was found in libssh. Logic errors in automatic certificate-based public key authentication can cause libssh clients to loop indefinitely when configured certificates are missing or repeatedly rejected by a server, leading to denial of service. |
| A flaw was found in glib-networking. A remote attacker can exploit this vulnerability by presenting a specially crafted certificate chain to an application that uses glib-networking with the GnuTLS backend enabled and performs certificate verification. This crafted chain, which contains circular issuer relationships, can cause an infinite loop during certificate verification. The unbounded traversal consumes excessive CPU resources, leading to a denial of service for the affected process or worker. |
| In the Linux kernel, the following vulnerability has been resolved:
io_uring: don't flood a cancelling task with task_work
io_ring_exit_work() asks each task which has used the ring to remove its
tctx node, by task_work, and repeats that until the list is empty.
io_tctx_exit_cb() doesn't touch the node while the task is in
io_uring_cancel_generic(), which removes all the nodes at its end. So the
work item queues the callback again as soon as it has completed, for
nothing.
That is more than a waste of time. task_work_run() only returns when it
finds the list empty. If the rings are released from inside the
cancellation, because requests of other rings held the last references to
their files, up to 64 work items keep sending callbacks to the one task
which is running them. It never finds the list empty, never gets back to
the cancellation, the nodes stay, and so it goes on: a task with 60 pairs
of rings which poll each other ran 280000 callbacks in 5 seconds, 20
seconds after exit_group(). It ends when all the senders happen to be late
at the same time. Until then the task keeps a CPU and the work items busy.
An exiting task can't be killed meanwhile. execve() cancels the requests in
the same way, so a live task can get stuck there as well, for minutes. If
it takes more than five, the work items run into the
WARN_ON_ONCE(time_after(jiffies, timeout)) of io_ring_exit_work(). No
privilege is needed for any of this.
If the callback has met a task in cancellation, wait a little before it is
sent again. Nobody has to wake the work item up for that: either the node
is gone by then, or it is the turn of the next round. |
| In the Linux kernel, the following vulnerability has been resolved:
io_uring/wait: don't spin on a stuck overflow list
As long as IO_CHECK_CQ_OVERFLOW_BIT is set, io_cqring_wait_schedule()
returns right away, before it gets to look at signals or arms the timeout,
for io_cqring_wait() to flush the overflow list. If that doesn't empty the
list, and the CQ ring doesn't hold the number of events the caller wants,
the loop starts over, with the same result. The task spins in the kernel,
and can't be killed.
The assumption is that this can't happen: if CQEs can't be flushed, the
ring is full, and min_events is capped to the size of the ring. But:
- With IORING_SETUP_CQE_MIXED a 32b CQE needs two contiguous entries. It
is stuck on the list if a single one is free, and then the ring holds
less than cq_entries events. A single threaded application that asks
for as many events as the ring has entries never gets out of
io_uring_enter().
- Whether the ring is full is up to the CQ head, which the application
can write to. While one thread waits for events on an empty ring,
another one can move the head back so that the ring looks full and
have a CQE overflow. The waiter can't be stopped any more, not even by
SIGKILL.
Only the application can make room in the CQ ring. Return to it if the
list could not be flushed. |
| A flaw was found in the SAML 1.1 assertion parser of Keycloak, a tool used for identity and access management. The issue occurs when the parser handles a specific element called AuthorityBinding within an authentication statement. Due to an incomplete fix for a previous vulnerability, the parser can enter an infinite loop that consumes all available memory, causing the entire Keycloak service to crash and become unavailable to users. |
| A flaw was found in the SAML 1.1 XML parsing logic of Keycloak, an open-source identity and access management solution. The issue occurs when the parser encounters unexpected elements within a security token's key information section, causing the processing thread to enter an infinite loop. An unauthenticated remote attacker could exploit this by sending specially crafted requests, leading to 100% CPU usage and a total denial of service that requires a server restart to resolve. |
| Fluxbox through 1.3.7 contains an infinite loop vulnerability in Menu::updateMenu() in src/FbTk/Menu.cc that allows attackers to hang the window manager via crafted style geometry values. Attackers can supply a style with an oversized unbounded menu.titleHeight so the column loop never terminates, causing sustained CPU use and denial of service at startup. |
| A flaw was found in json-glib. The JSONPath slice evaluator used by json_path_query() can enter an infinite loop when given a slice expression with a negative step. An application that evaluates attacker-controlled JSONPath expressions can be forced into a hang, leading to a denial of service. |
| A flaw was found in sssd. A local user can cause a Denial of Service (DoS) by exhausting the responder service's available file descriptors (system handles used for open connections). By opening and maintaining many concurrent connections to a responder socket while continuing to queue new connection attempts, an attacker can trigger an unthrottled retry loop. This condition leads to high CPU utilization and stalls the service, preventing legitimate identity and authentication requests from being processed. |
| In the Linux kernel, the following vulnerability has been resolved:
Bluetooth: L2CAP: Fix ERTM re-init and zero pdu_len infinite loop
l2cap_config_req() processes CONFIG_REQ for channels in BT_CONNECTED
state to support L2CAP reconfiguration (e.g. MTU changes). However,
since both CONF_INPUT_DONE and CONF_OUTPUT_DONE are already set from
the initial configuration, the reconfiguration path falls through to
l2cap_ertm_init(), which re-initializes tx_q, srej_q, srej_list, and
retrans_list without freeing the previous allocations and sets
chan->sdu to NULL without freeing the existing skb. This leaks all
previously allocated ERTM resources.
Additionally, l2cap_parse_conf_req() does not validate the minimum
value of remote_mps derived from the RFC max_pdu_size option. A zero
value propagates to l2cap_segment_sdu() where pdu_len becomes zero,
causing the while loop to never terminate since len is never
decremented, exhausting all available memory.
Fix the double-init by skipping l2cap_ertm_init() and
l2cap_chan_ready() when the channel is already in BT_CONNECTED state,
while still allowing the reconfiguration parameters to be updated
through l2cap_parse_conf_req(). Also add a pdu_len zero check in
l2cap_segment_sdu() as a safeguard. |
| In the Linux kernel, the following vulnerability has been resolved:
serial: core: fix infinite loop in handle_tx() for PORT_UNKNOWN
uart_write_room() and uart_write() behave inconsistently when
xmit_buf is NULL (which happens for PORT_UNKNOWN ports that were
never properly initialized):
- uart_write_room() returns kfifo_avail() which can be > 0
- uart_write() checks xmit_buf and returns 0 if NULL
This inconsistency causes an infinite loop in drivers that rely on
tty_write_room() to determine if they can write:
while (tty_write_room(tty) > 0) {
written = tty->ops->write(...);
// written is always 0, loop never exits
}
For example, caif_serial's handle_tx() enters an infinite loop when
used with PORT_UNKNOWN serial ports, causing system hangs.
Fix by making uart_write_room() also check xmit_buf and return 0 if
it's NULL, consistent with uart_write().
Reproducer: https://gist.github.com/mrpre/d9a694cc0e19828ee3bc3b37983fde13 |
| In the Linux kernel, the following vulnerability has been resolved:
can: ucan: Fix infinite loop from zero-length messages
If a broken ucan device gets a message with the message length field set
to 0, then the driver will loop for forever in
ucan_read_bulk_callback(), hanging the system. If the length is 0, just
skip the message and go on to the next one.
This has been fixed in the kvaser_usb driver in the past in commit
0c73772cd2b8 ("can: kvaser_usb: leaf: Fix potential infinite loop in
command parsers"), so there must be some broken devices out there like
this somewhere. |
| In the Linux kernel, the following vulnerability has been resolved:
net: add xmit recursion limit to tunnel xmit functions
Tunnel xmit functions (iptunnel_xmit, ip6tunnel_xmit) lack their own
recursion limit. When a bond device in broadcast mode has GRE tap
interfaces as slaves, and those GRE tunnels route back through the
bond, multicast/broadcast traffic triggers infinite recursion between
bond_xmit_broadcast() and ip_tunnel_xmit()/ip6_tnl_xmit(), causing
kernel stack overflow.
The existing XMIT_RECURSION_LIMIT (8) in the no-qdisc path is not
sufficient because tunnel recursion involves route lookups and full IP
output, consuming much more stack per level. Use a lower limit of 4
(IP_TUNNEL_RECURSION_LIMIT) to prevent overflow.
Add recursion detection using dev_xmit_recursion helpers directly in
iptunnel_xmit() and ip6tunnel_xmit() to cover all IPv4/IPv6 tunnel
paths including UDP encapsulated tunnels (VXLAN, Geneve, etc.).
Move dev_xmit_recursion helpers from net/core/dev.h to public header
include/linux/netdevice.h so they can be used by tunnel code.
BUG: KASAN: stack-out-of-bounds in blake2s.constprop.0+0xe7/0x160
Write of size 32 at addr ffff88810033fed0 by task kworker/0:1/11
Workqueue: mld mld_ifc_work
Call Trace:
<TASK>
__build_flow_key.constprop.0 (net/ipv4/route.c:515)
ip_rt_update_pmtu (net/ipv4/route.c:1073)
iptunnel_xmit (net/ipv4/ip_tunnel_core.c:84)
ip_tunnel_xmit (net/ipv4/ip_tunnel.c:847)
gre_tap_xmit (net/ipv4/ip_gre.c:779)
dev_hard_start_xmit (net/core/dev.c:3887)
sch_direct_xmit (net/sched/sch_generic.c:347)
__dev_queue_xmit (net/core/dev.c:4802)
bond_dev_queue_xmit (drivers/net/bonding/bond_main.c:312)
bond_xmit_broadcast (drivers/net/bonding/bond_main.c:5279)
bond_start_xmit (drivers/net/bonding/bond_main.c:5530)
dev_hard_start_xmit (net/core/dev.c:3887)
__dev_queue_xmit (net/core/dev.c:4841)
ip_finish_output2 (net/ipv4/ip_output.c:237)
ip_output (net/ipv4/ip_output.c:438)
iptunnel_xmit (net/ipv4/ip_tunnel_core.c:86)
gre_tap_xmit (net/ipv4/ip_gre.c:779)
dev_hard_start_xmit (net/core/dev.c:3887)
sch_direct_xmit (net/sched/sch_generic.c:347)
__dev_queue_xmit (net/core/dev.c:4802)
bond_dev_queue_xmit (drivers/net/bonding/bond_main.c:312)
bond_xmit_broadcast (drivers/net/bonding/bond_main.c:5279)
bond_start_xmit (drivers/net/bonding/bond_main.c:5530)
dev_hard_start_xmit (net/core/dev.c:3887)
__dev_queue_xmit (net/core/dev.c:4841)
ip_finish_output2 (net/ipv4/ip_output.c:237)
ip_output (net/ipv4/ip_output.c:438)
iptunnel_xmit (net/ipv4/ip_tunnel_core.c:86)
ip_tunnel_xmit (net/ipv4/ip_tunnel.c:847)
gre_tap_xmit (net/ipv4/ip_gre.c:779)
dev_hard_start_xmit (net/core/dev.c:3887)
sch_direct_xmit (net/sched/sch_generic.c:347)
__dev_queue_xmit (net/core/dev.c:4802)
bond_dev_queue_xmit (drivers/net/bonding/bond_main.c:312)
bond_xmit_broadcast (drivers/net/bonding/bond_main.c:5279)
bond_start_xmit (drivers/net/bonding/bond_main.c:5530)
dev_hard_start_xmit (net/core/dev.c:3887)
__dev_queue_xmit (net/core/dev.c:4841)
mld_sendpack
mld_ifc_work
process_one_work
worker_thread
</TASK> |
| P-Net before 1.0.3 enters an infinite loop when handling a read request for the PDPortDataCheck record with subslot 0 (whole module). The loop over the ports never advanced to the next port, so the request never completes and the device stops responding. A remote unauthenticated attacker can use this to cause a denial of service. |
| In the Linux kernel, the following vulnerability has been resolved:
exfat: add cluster chain loop check for dir
An infinite loop may occur if the following conditions occur due to
file system corruption.
(1) Condition for exfat_count_dir_entries() to loop infinitely.
- The cluster chain includes a loop.
- There is no UNUSED entry in the cluster chain.
(2) Condition for exfat_create_upcase_table() to loop infinitely.
- The cluster chain of the root directory includes a loop.
- There are no UNUSED entry and up-case table entry in the cluster
chain of the root directory.
(3) Condition for exfat_load_bitmap() to loop infinitely.
- The cluster chain of the root directory includes a loop.
- There are no UNUSED entry and bitmap entry in the cluster chain
of the root directory.
(4) Condition for exfat_find_dir_entry() to loop infinitely.
- The cluster chain includes a loop.
- The unused directory entries were exhausted by some operation.
(5) Condition for exfat_check_dir_empty() to loop infinitely.
- The cluster chain includes a loop.
- The unused directory entries were exhausted by some operation.
- All files and sub-directories under the directory are deleted.
This commit adds checks to break the above infinite loop. |
| In the Linux kernel, the following vulnerability has been resolved:
ipv6: prevent infinite loop in rt6_nlmsg_size()
While testing prior patch, I was able to trigger
an infinite loop in rt6_nlmsg_size() in the following place:
list_for_each_entry_rcu(sibling, &f6i->fib6_siblings,
fib6_siblings) {
rt6_nh_nlmsg_size(sibling->fib6_nh, &nexthop_len);
}
This is because fib6_del_route() and fib6_add_rt2node()
uses list_del_rcu(), which can confuse rcu readers,
because they might no longer see the head of the list.
Restart the loop if f6i->fib6_nsiblings is zero. |
| In the Linux kernel, the following vulnerability has been resolved:
ipv6: fix possible infinite loop in fib6_info_uses_dev()
fib6_info_uses_dev() seems to rely on RCU without an explicit
protection.
Like the prior fix in rt6_nlmsg_size(),
we need to make sure fib6_del_route() or fib6_add_rt2node()
have not removed the anchor from the list, or we risk an infinite loop. |
| A flaw was found in libcupsfilters. The cfIEEE1284NormalizeMakeModel() function enters an infinite loop when processing a printer-advertised IEEE-1284 device ID with an empty model field, causing sustained CPU consumption. A network-adjacent attacker could exploit this by broadcasting a specially crafted printer advertisement, leading to denial of service. |
| pypdf is a free and open-source pure-python PDF library. Prior to 6.20.1, calling PdfWriter.find_outline_item on a crafted PDF with a cyclic outline hierarchy can enter an infinite loop and block the current process. This issue is fixed in version 6.20.1. |
| Kafka Streams derives its stream-time clock from record timestamps. PunctuationSchedule.next() computed the next punctuation time as timestamp + (intervalsMissed + 1) * interval with no overflow check. A record with a timestamp at or near Long.MAX_VALUE advances stream time to that value, so the next stream-time punctuation overflows to a negative time. PunctuationQueue then re-queues that time and loops on it indefinitely while holding a lock, stalling the StreamThread.
Impact:
A single record is enough. The affected StreamThread stops processing, and because the record stays in the topic the hang returns on restart; an application whose partitions are all affected becomes unresponsive. Only the Streams application is affected, not the brokers or the cluster. Triggering it needs write access to a source topic whose topology uses stream-time punctuation, and a broker that stores the record: brokers from Apache Kafka 4.0.0 reject such a timestamp by default (log.message.timestamp.after.max.ms, one hour), so it is reachable only on older brokers or where that bound has been relaxed.
Mitigation:
Upgrade Kafka Streams to 4.2.2, 4.3.2, or 4.4.0. As defense in depth, keep log.message.timestamp.after.max.ms bounded on source topics and restrict write access to them.
Resolution:
From Apache Kafka 4.2.2, 4.3.2, and 4.4.0: the next punctuation time is computed with overflow-checked arithmetic (clamped to Long.MAX_VALUE), and a rescheduled punctuation is re-queued only when its time moves forward. |
