In the Linux kernel, the following vulnerability has been resolved:
tcp: call sk_data_ready() after listener migration
When inet_csk_listen_stop() migrates an established child socket from
a closing listener to another socket in the same SO_REUSEPORT group,
the target listener gets a new accept-queue entry via
inet_csk_reqsk_queue_add(), but that path never notifies the target
listener's waiters. A nonblocking accept() still works because it
checks the queue directly, but poll()/epoll_wait() waiters and
blocking accept() callers can also remain asleep indefinitely.
Call READ_ONCE(nsk->sk_data_ready)(nsk) after a successful migration
in inet_csk_listen_stop().
However, after inet_csk_reqsk_queue_add() succeeds, the ref acquired
in reuseport_migrate_sock() is effectively transferred to
nreq->rsk_listener. Another CPU can then dequeue nreq via accept()
or listener shutdown, hit reqsk_put(), and drop that listener ref.
Since listeners are SOCK_RCU_FREE, wrap the post-queue_add()
dereferences of nsk in rcu_read_lock()/rcu_read_unlock(), which also
covers the existing sock_net(nsk) access in that path.
The reqsk_timer_handler() path does not need the same changes for two
reasons: half-open requests become readable only after the final ACK,
where tcp_child_process() already wakes the listener; and once nreq is
visible via inet_ehash_insert(), the success path no longer touches
nsk directly.
In the Linux kernel, the following vulnerability has been resolved:
net: qrtr: ns: Limit the total number of nodes
Currently, the nameserver doesn't limit the number of nodes it handles.
This can be an attack vector if a malicious client starts registering
random nodes, leading to memory exhaustion.
Hence, limit the maximum number of nodes to 64. Note that, limit of 64 is
chosen based on the current platform requirements. If requirement changes
in the future, this limit can be increased.
In the Linux kernel, the following vulnerability has been resolved:
ALSA: caiaq: Handle probe errors properly
The probe procedure of setup_card() in caiaq driver doesn't treat the
error cases gracefully, e.g. the error from snd_card_register() calls
snd_card_free() but continues. This would lead to a UAF for the
further calls like snd_usb_caiaq_control_init(), as Berk suggested in
another patch in the link below.
However, the problem is not only that; in general, this function drops
the all error handlings (as it's a void function) although its caller
can propagate an error to snd_probe(), which eventually calls
snd_card_free() as a proper error path. That said, we should treat
each error case in setup_card(), and just return the error code
promptly, which is then handled later as a fatal error in snd_probe().
This patch achieves it by changing the setup_card() to return an error
code. Also, the superfluous snd_card_free() call is removed, too.
Note that card->private_free can be set still safely at returning an
error. All called functions in card_free() have checks of the
unassigned resources or NULL checks.
In the Linux kernel, the following vulnerability has been resolved:
xfs: fix a resource leak in xfs_alloc_buftarg()
In the error path, call fs_put_dax() to drop the DAX
device reference.
In the Linux kernel, the following vulnerability has been resolved:
drm/nouveau: fix u32 overflow in pushbuf reloc bounds check
nouveau_gem_pushbuf_reloc_apply() validates each relocation with
if (r->reloc_bo_offset + 4 > nvbo->bo.base.size)
but reloc_bo_offset is __u32 (uapi/drm/nouveau_drm.h) and the integer
literal 4 promotes to unsigned int, so the addition is performed in 32
bits and wraps before the comparison against the size_t bo size.
Cast to u64 so the addition happens in 64-bit arithmetic.
[ Add Fixes: tag. - Danilo ]
In the Linux kernel, the following vulnerability has been resolved:
hwmon: (powerz) Avoid cacheline sharing for DMA buffer
Depending on the architecture the transfer buffer may share a cacheline
with the following mutex. As the buffer may be used for DMA, that is
problematic.
Use the high-level DMA helpers to make sure that cacheline sharing can
not happen.
Also drop the comment, as the helpers are documentation enough.
https://sashiko.dev/#/message/20260408175814.934BFC19421%40smtp.kernel.org
In the Linux kernel, the following vulnerability has been resolved:
mm/damon/core: fix damos_walk() vs kdamond_fn() exit race
When kdamond_fn() main loop is finished, the function cancels remaining
damos_walk() request and unset the damon_ctx->kdamond so that API callers
and API functions themselves can show the context is terminated.
damos_walk() adds the caller's request to the queue first. After that, it
shows if the kdamond of the damon_ctx is still running (damon_ctx->kdamond
is set). Only if the kdamond is running, damos_walk() starts waiting for
the kdamond's handling of the newly added request.
The damos_walk() requests registration and damon_ctx->kdamond unset are
protected by different mutexes, though. Hence, damos_walk() could race
with damon_ctx->kdamond unset, and result in deadlocks.
For example, let's suppose kdamond successfully finished the damow_walk()
request cancelling. Right after that, damos_walk() is called for the
context. It registers the new request, and shows the context is still
running, because damon_ctx->kdamond unset is not yet done. Hence the
damos_walk() caller starts waiting for the handling of the request.
However, the kdamond is already on the termination steps, so it never
handles the new request. As a result, the damos_walk() caller thread
infinitely waits.
Fix this by introducing another damon_ctx field, namely
walk_control_obsolete. It is protected by the
damon_ctx->walk_control_lock, which protects damos_walk() request
registration. Initialize (unset) it in kdamond_fn() before letting
damon_start() returns and set it just before the cancelling of the
remaining damos_walk() request is executed. damos_walk() reads the
obsolete field under the lock and avoids adding a new request.
After this change, only requests that are guaranteed to be handled or
cancelled are registered. Hence the after-registration DAMON context
termination check is no longer needed. Remove it together.
The issue is found by sashiko [1].
In the Linux kernel, the following vulnerability has been resolved:
PCI: endpoint: pci-epf-ntb: Remove duplicate resource teardown
epf_ntb_epc_destroy() duplicates the teardown that the caller is
supposed to do later. This leads to an oops when .allow_link fails or
when .drop_link is performed. Remove the helper.
Also drop pci_epc_put(). EPC device refcounting is tied to configfs EPC
group lifetime, and pci_epc_put() in the .drop_link path is sufficient.
In the Linux kernel, the following vulnerability has been resolved:
rxrpc: Fix error handling in rxgk_extract_token()
Fix a missing bit of error handling in rxgk_extract_token(): in the event
that rxgk_decrypt_skb() returns -ENOMEM, it should just return that rather
than continuing on (for anything else, it generates an abort).
In the Linux kernel, the following vulnerability has been resolved:
io_uring/zcrx: fix user_struct uaf
io_free_rbuf_ring() usees a struct user_struct, which
io_zcrx_ifq_free() puts it down before destroying the ring.