| CVE |
Vendors |
Products |
Updated |
CVSS v3.1 |
| An issue was discovered in the Linux kernel through 5.18.14. xfrm_expand_policies in net/xfrm/xfrm_policy.c can cause a refcount to be dropped twice. |
| A vulnerability was found in Linux Kernel. It has been classified as problematic. Affected is the function nilfs_new_inode of the file fs/nilfs2/inode.c of the component BPF. The manipulation leads to use after free. It is possible to launch the attack remotely. It is recommended to apply a patch to fix this issue. The identifier of this vulnerability is VDB-211992. |
| In the Linux kernel, the following vulnerability has been resolved:
Bluetooth: ISO: Fix parent socket leak in iso_conn_ready()
iso_get_sock() returns the parent socket with a reference held, which is
dropped by sock_put() once the child socket has been set up. The error
path taken when iso_sock_alloc() fails only calls release_sock() and
returns, leaking the reference and thus the parent socket itself.
Drop the reference on that path as well. |
| In the Linux kernel, the following vulnerability has been resolved:
dmaengine: Fix device kref underflow in dma_chan_put()
dma_chan_get() takes chan->device->ref only on the slow path:
/* no kref on fast path */
if (chan->client_count) {
__module_get(owner);
chan->client_count++;
return 0;
}
if (!try_module_get(owner))
return -ENODEV;
if (!dma_device_get(chan->device)) { // calls kref_get_unless_zero()
dma_chan_put() drops the ref unconditionally, so every fast-path
get/put pair drops one extra device reference.
The bug fires when two conditions hold together: a non-private
provider has a persistent client holding chan->client_count > 0
and another client cycles dmaengine_get()/dmaengine_put().
When the kref hits zero, the subsequent dma_find_channel() returns
NULL even though the provider module is still loaded.
Fix this by dropping device->ref only on the last put, matching the
single slow-path get. |
| In the Linux kernel, the following vulnerability has been resolved:
esp: downgrade zerocopy managed frags before mutating skb frags
On the out-of-place output path (esp->inplace == false) ESP rewrites the
skb frag array: esp_output_head() appends a trailer frag and
esp_output_tail() replaces the frags with a destination page, both
referenced with get_page().
When the skb carries zerocopy managed frags (SKBFL_MANAGED_FRAG_REFS) the
payload frags are owned by the ubuf and must not be referenced or
unreferenced individually, but ESP mutates the frag array without ever
downgrading the skb. This breaks the managed-frag invariant two ways:
- esp_ssg_unref() walks the source scatterlist and drops a page
reference for every frag, including the ubuf-owned payload frags,
pushing their refcount below the GUP pin bias while the pages are
still pinned, i.e. a use-after-free of the zerocopy pages;
- esp_output_tail() installs its destination page as frag 0 with
get_page() but leaves SKBFL_MANAGED_FRAG_REFS set, so
skb_release_data() takes the skip_unref branch and never drops that
reference, leaking the x->xfrag page at packet rate.
Fix this the way every other frag-mutating site does (__ip_append_data(),
__ip6_append_data(), tcp_sendmsg_locked()) and call
skb_zcopy_downgrade_managed() before ESP touches the frag array: it takes
a real reference on each existing frag and clears SKBFL_MANAGED_FRAG_REFS,
so the per-frag unref in esp_ssg_unref() and the frag release in
skb_release_data() are both balanced and no mixed-ownership frag array is
left behind. |
| In the Linux kernel, the following vulnerability has been resolved:
wifi: wlcore: release runtime PM ref on regdomain config failure
wlcore_regdomain_config() gets a runtime PM reference before sending
the regulatory-domain command. When
wlcore_cmd_regdomain_config_locked() fails, the function queues recovery
and returns without dropping that reference.
Release the reference after handling the command result so both success
and failure paths balance the preceding
pm_runtime_resume_and_get(). The recovery worker takes a separate
runtime PM reference and cannot release the reference held here. |
| In the Linux kernel, the following vulnerability has been resolved:
net/sched: act_api: release tail references on DELACTION failure
A batched RTM_DELACTION request takes a temporary reference on each
action before attempting any deletion. tcf_action_delete() clears
each processed slot and drops its temporary reference before attempting
the deletion. If deletion fails, tca_action_gd() calls
tcf_action_put_many() to release the remaining references, but its
tcf_act_for_each_action() iterator stops at the first NULL slot.
When a batch stops at an action bound to a filter, this leaks a
reference on each subsequent action. A later delete of an unbound
action can then return success without removing it from the IDR.
Walk the full array in tcf_action_put_many() and skip NULL slots to
release the references held on the unprocessed actions. |
| In the Linux kernel, the following vulnerability has been resolved:
ASoC: Intel: avs: Fix unbalanced module reference count
strace_open() invokes try_module_get() which on success takes
the module reference. If any follow up operation causes
strace_open() to fail, the refcount shall be put down. |
| Multidict is an implementation of a multidict data structure. From 6.7.0 until 6.9.1, the C extension's items-view reflected union operation, operand | d.items(), in multidict_itemsview_or2_impl and subtraction operation, d.items() - operand, in multidict_itemsview_sub1_impl fail to release new key-identity and value references returned for each operand element. Applications that perform these operations over attacker-influenced sequences can leak two strong references per element, and garbage collection cannot reclaim them, so repeated operations can cause unbounded process memory growth and denial of service. Forward union, intersection, non-tuple operand elements, and pure-Python builds are not affected by this reference leak. This issue is fixed in version 6.9.1. |
| In the Linux kernel, the following vulnerability has been resolved:
watchdog: msc313e: Fix clock leak and spurious timer in settimeout()
msc313e_wdt_settimeout() unconditionally calls msc313e_wdt_start() which
introduces two severe bugs:
1. If the watchdog is already active, calling start() again will
increase the reference count of the clock again. However stop() is
only called once, the reference count is unbalance.
2. If the watchdog is stopped, calling settimeout() will start
the hardware timer accidentally.
Factor out the register-writing logic into a helper function. Only call
it in settimeout() if the watchdog is running. Otherwise, simply update
`wdev->timeout`. |
| In the Linux kernel, the following vulnerability has been resolved:
smb: client: pin DFS superblock in iterator callback
tcon_super_cb() stores a raw superblock pointer, but __cifs_get_super()
takes its active reference only after iterate_supers_type() has dropped
s_umount and its passive reference. Concurrent DFS automount expiry can
therefore free the superblock before cifs_sb_active() uses it.
A deterministic KASAN test reproduces the race as:
BUG: KASAN: slab-use-after-free in cifs_sb_active+0x77/0x80
The same test passes with this change applied.
Take the active reference in the callback while iterate_supers_type()
still holds s_umount shared. cifs_put_tcp_super() remains the matching
release. |
| In the Linux kernel, the following vulnerability has been resolved:
smb: client: avoid leaking refcount in cifs_queue_oplock_break()
cifs_queue_oplock_break() unconditionally takes a reference on the
target file before queueing cifs_oplock_break(). Only that work item
decreases the reference counter again.
If another oplock break arrives while that work is still queued,
queue_work() will return false and not queue this second work item. As a
result, we will never reach the point to drop the file reference again
and are leaking this reference. This can be triggered when interacting
with a slow-responding server.
As a result, later unmount operations for this file system will fail with
BUG: Dentry ... still in use (1) [unmount of cifs cifs]
VFS: Busy inodes after unmount of cifs (cifs)
kernel BUG at fs/super.c:777!
Fix this by only incrementing the reference count if the work has been
queued successfully. Taking it after queue_work() is safe because all
three callers hold tcon->open_file_lock across the call and
_cifsFileInfo_put() decrements under that same lock, so a worker that
starts the handler in the window cannot drop the reference before it has
been taken. |
| In the Linux kernel, the following vulnerability has been resolved:
smb: client: avoid leaking refcount when cifs_sb_tlink() fails
cifs_oplock_break() takes over the reference that
cifs_queue_oplock_break() acquired when it queued the work, and drops it
with _cifsFileInfo_put() once the break has been processed.
Only in setups with "-o multiuser", cifs_sb_tlink() may fail, at which
point cifs_oplock_break() returns without putting the file reference,
mirroring the reference leak we already fixed in the companion patch to
cifs_queue_oplock_break().
This would trigger a crash due to busy inodes on the next unmount:
BUG: Dentry ... still in use (1) [unmount of cifs cifs]
VFS: Busy inodes after unmount of cifs (cifs)
Drop the reference on that path as well. Doing so before the out label
mirrors the normal path, which also puts the reference before
cifs_done_oplock_break().
Found by Sashiko code review. The failure path was not exercised at
runtime. |
| In the Linux kernel, the following vulnerability has been resolved:
net: qrtr: fix node refcount leak on ctrl packet alloc failure
qrtr_send_resume_tx() calls qrtr_node_lookup() which takes a
reference on the returned node. If the subsequent call to
qrtr_alloc_ctrl_packet() fails due to memory allocation failure, the
function returns -ENOMEM without calling qrtr_node_release() to
release the node reference.
Add qrtr_node_release(node) before returning on the allocation failure
path to properly release the reference. |
| In the Linux kernel, the following vulnerability has been resolved:
smb: client: fix busy dentry warning on unmount after DIO
Commit c68337442f03 ("cifs: Fix busy dentry used after unmounting") fixed
the issue in cifs where deferred close of a file led to a dentry reference
count not being released in umount, by flushing deferredclose_wq in
cifs_kill_sb() to solve it.
However, the cifs DIO path suffers from the same busy-dentry problem caused
by a delayed dentry reference-count release:
[dio] [cifsd] [close + umount]
netfs_unbuffered_write_iter_locked
...
cifs_demultiplex_thread
netfs_unbuffered_write
cifs_issue_write
netfs_wait_for_in_progress_stream [1]
...
netfs_write_subrequest_terminated
netfs_subreq_clear_in_progress
netfs_wake_collector // wake [1]
netfs_put_subrequest
netfs_put_request
queue_work(system_dfl_wq, xxx) [2]
// dio write return cifs_close
_cifsFileInfo_put
// cfile->count 2->1
--cfile->count [3]
// umount
cifs_kill_sb
kill_anon_super
// warning triggered!
shrink_dcache_for_umount [4]
[system_dfl_wq] [5]
netfs_free_request
...
_cifsFileInfo_put
// cfile->count 1->0
--cfile->count
queue_work(fileinfo_put_wq, xxx)
[fileinfo_put_wq] [6]
cifsFileInfo_put_work
cifsFileInfo_put_final
dput
If the umount path is triggered before [5], it results warning:
BUG: Dentry 00000000eab1f070{i=9a917b66ae404fec,n=test} still in use (1)
[unmount of cifs cifs]
The existing per-inode ictx->io_count wait in cifs_evict_inode() does not
help: it lives in the inode eviction path, which runs after
shrink_dcache_for_umount() has already warned about the busy dentries.
Fix it by adding a per-superblock outstanding-rreq counter that is
incremented in cifs_init_request() and decremented in cifs_free_request().
In cifs_kill_sb(), before kill_anon_super(), wait for this counter to reach
0 - which guarantees that all cleanup_work for this sb have run and thus
all relevant cfile puts are queued on fileinfo_put_wq or serverclose_wq.
Then drain the workqueue so the dentry refs are dropped.
This is a targeted wait, not a flush of the system-wide system_dfl_wq. |
| In the Linux kernel, the following vulnerability has been resolved:
drm/amdgpu/pm: fix SmartShift bias sysfs store PM refcount on parse error
Return the parse error before acquiring PM access. |
| In the Linux kernel, the following vulnerability has been resolved:
x86/amd_node: Fix PCI device reference counting in amd_smn_init()
The local "root" pointer is a temporary variable used during the device
search. Therefore, refcount related to the search iterators should be cleaned
up after the search is complete.
Use the __free() cleanup macro to ensure the refcount is decremented when the
temporary pointer goes out of scope.
Additionally, increment the refcount when caching a root pointer. This ensures
the in-use refcount is separate from the temporary search refcounting.
Finally, drop the redundant "root = NULL" before the second search loop. The
pci_get_class() iterator always decrements the refcount of its "from"
argument, so the first loop can only fall through with "root" already NULL. |
| In the Linux kernel, the following vulnerability has been resolved:
net: macb: put the "mdio" child node reference on success
macb_mii_init() holds the reference returned by of_get_child_by_name()
for macb_mdiobus_register() and drops it only on the error paths, so
every successful probe leaks a node reference. On a CM5, overlay
removal after four bind cycles reports
OF: ERROR: memory leak, expected refcount 1 instead of 5
Drop the reference after registration, where __mdiobus_register() has
already taken its own for the lifetime of the bus. |
| In the Linux kernel, the following vulnerability has been resolved:
accel/amdxdna: put the chained BO when its mapping fails
amdxdna_cmd_set_error() looks up the first BO of a command chain, which
takes a reference, and drops it at the end of the function. The mapping of
that BO is established in between, and the failure path returns without the
put, so the reference is leaked.
Ordinary use does not reach it. The chain has been submitted before any of
this runs, so aie2_cmdlist_fill_slot() has already called
amdxdna_cmd_get_op() on that BO and amdxdna_gem_vmap() has cached its
address. What makes it reachable is that the BO is resolved again by
handle here, and the handle is userspace's to recycle: closing it after
submission and importing a dma-buf whose exporter implements no vmap onto
the same id leaves amdxdna_gem_get_obj() returning an object this cannot
map, since prime_import() types every import AMDXDNA_BO_SHARE. |
| In the Linux kernel, the following vulnerability has been resolved:
netfs: Fix subreq ref leak
Fix a subrequest ref leak in netfs_unbuffered_write() in the event that
subreq->io_iter ends up zero length during preparation. |
