In the Linux kernel, the following vulnerability has been resolved:
Bluetooth: hci_uart: fix null-ptr-deref in hci_uart_write_work
hci_uart_set_proto() sets HCI_UART_PROTO_INIT before calling
hci_uart_register_dev(), which calls proto->open() to initialize
hu->priv. However, if a TTY write wakeup occurs during this window,
hci_uart_tx_wakeup() may schedule write_work before hu->priv is
initialized, leading to a NULL pointer dereference in
hci_uart_write_work() when proto->dequeue() accesses hu->priv.
The race condition is:
CPU0 CPU1
---- ----
hci_uart_set_proto()
set_bit(HCI_UART_PROTO_INIT)
hci_uart_register_dev()
tty write wakeup
hci_uart_tty_wakeup()
hci_uart_tx_wakeup()
schedule_work(&hu->write_work)
proto->open(hu)
// initializes hu->priv
hci_uart_write_work()
hci_uart_dequeue()
proto->dequeue(hu)
// accesses hu->priv (NULL!)
Fix this by moving set_bit(HCI_UART_PROTO_INIT) after proto->open()
succeeds, ensuring hu->priv is initialized before any work can be
scheduled.
In the Linux kernel, the following vulnerability has been resolved:
btrfs: zlib: fix the folio leak on S390 hardware acceleration
[BUG]
After commit aa60fe12b4f4 ("btrfs: zlib: refactor S390x HW acceleration
buffer preparation"), we no longer release the folio of the page cache
of folio returned by btrfs_compress_filemap_get_folio() for S390
hardware acceleration path.
[CAUSE]
Before that commit, we call kumap_local() and folio_put() after handling
each folio.
Although the timing is not ideal (it release previous folio at the
beginning of the loop, and rely on some extra cleanup out of the loop),
it at least handles the folio release correctly.
Meanwhile the refactored code is easier to read, it lacks the call to
release the filemap folio.
[FIX]
Add the missing folio_put() for copy_data_into_buffer().
In the Linux kernel, the following vulnerability has been resolved:
nvmet: fix race in nvmet_bio_done() leading to NULL pointer dereference
There is a race condition in nvmet_bio_done() that can cause a NULL
pointer dereference in blk_cgroup_bio_start():
1. nvmet_bio_done() is called when a bio completes
2. nvmet_req_complete() is called, which invokes req->ops->queue_response(req)
3. The queue_response callback can re-queue and re-submit the same request
4. The re-submission reuses the same inline_bio from nvmet_req
5. Meanwhile, nvmet_req_bio_put() (called after nvmet_req_complete)
invokes bio_uninit() for inline_bio, which sets bio->bi_blkg to NULL
6. The re-submitted bio enters submit_bio_noacct_nocheck()
7. blk_cgroup_bio_start() dereferences bio->bi_blkg, causing a crash:
BUG: kernel NULL pointer dereference, address: 0000000000000028
#PF: supervisor read access in kernel mode
RIP: 0010:blk_cgroup_bio_start+0x10/0xd0
Call Trace:
submit_bio_noacct_nocheck+0x44/0x250
nvmet_bdev_execute_rw+0x254/0x370 [nvmet]
process_one_work+0x193/0x3c0
worker_thread+0x281/0x3a0
Fix this by reordering nvmet_bio_done() to call nvmet_req_bio_put()
BEFORE nvmet_req_complete(). This ensures the bio is cleaned up before
the request can be re-submitted, preventing the race condition.
In the Linux kernel, the following vulnerability has been resolved:
drm/bridge: synopsys: dw-dp: fix error paths of dw_dp_bind
Fix several issues in dw_dp_bind() error handling:
1. Missing return after drm_bridge_attach() failure - the function
continued execution instead of returning an error.
2. Resource leak: drm_dp_aux_register() is not a devm function, so
drm_dp_aux_unregister() must be called on all error paths after
aux registration succeeds. This affects errors from:
- drm_bridge_attach()
- phy_init()
- devm_add_action_or_reset()
- platform_get_irq()
- devm_request_threaded_irq()
3. Bug fix: platform_get_irq() returns the IRQ number or a negative
error code, but the error path was returning ERR_PTR(ret) instead
of ERR_PTR(dp->irq).
Use a goto label for cleanup to ensure consistent error handling.
In the Linux kernel, the following vulnerability has been resolved:
wifi: ath10k: fix dma_free_coherent() pointer
dma_alloc_coherent() allocates a DMA mapped buffer and stores the
addresses in XXX_unaligned fields. Those should be reused when freeing
the buffer rather than the aligned addresses.
In the Linux kernel, the following vulnerability has been resolved:
slab: fix kmalloc_nolock() context check for PREEMPT_RT
On PREEMPT_RT kernels, local_lock becomes a sleeping lock. The current
check in kmalloc_nolock() only verifies we're not in NMI or hard IRQ
context, but misses the case where preemption is disabled.
When a BPF program runs from a tracepoint with preemption disabled
(preempt_count > 0), kmalloc_nolock() proceeds to call
local_lock_irqsave() which attempts to acquire a sleeping lock,
triggering:
BUG: sleeping function called from invalid context
in_atomic(): 1, irqs_disabled(): 0, non_block: 0, pid: 6128
preempt_count: 2, expected: 0
Fix this by checking !preemptible() on PREEMPT_RT, which directly
expresses the constraint that we cannot take a sleeping lock when
preemption is disabled. This encompasses the previous checks for NMI
and hard IRQ contexts while also catching cases where preemption is
disabled.
In the Linux kernel, the following vulnerability has been resolved:
wifi: ath12k: fix dma_free_coherent() pointer
dma_alloc_coherent() allocates a DMA mapped buffer and stores the
addresses in XXX_unaligned fields. Those should be reused when freeing
the buffer rather than the aligned addresses.
In the Linux kernel, the following vulnerability has been resolved:
libceph: reset sparse-read state in osd_fault()
When a fault occurs, the connection is abandoned, reestablished, and any
pending operations are retried. The OSD client tracks the progress of a
sparse-read reply using a separate state machine, largely independent of
the messenger's state.
If a connection is lost mid-payload or the sparse-read state machine
returns an error, the sparse-read state is not reset. The OSD client
will then interpret the beginning of a new reply as the continuation of
the old one. If this makes the sparse-read machinery enter a failure
state, it may never recover, producing loops like:
libceph: [0] got 0 extents
libceph: data len 142248331 != extent len 0
libceph: osd0 (1)...:6801 socket error on read
libceph: data len 142248331 != extent len 0
libceph: osd0 (1)...:6801 socket error on read
Therefore, reset the sparse-read state in osd_fault(), ensuring retries
start from a clean state.
In the Linux kernel, the following vulnerability has been resolved:
of: unittest: Fix memory leak in unittest_data_add()
In unittest_data_add(), if of_resolve_phandles() fails, the allocated
unittest_data is not freed, leading to a memory leak.
Fix this by using scope-based cleanup helper __free(kfree) for automatic
resource cleanup. This ensures unittest_data is automatically freed when
it goes out of scope in error paths.
For the success path, use retain_and_null_ptr() to transfer ownership
of the memory to the device tree and prevent double freeing.
In the Linux kernel, the following vulnerability has been resolved:
tracing: Add recursion protection in kernel stack trace recording
A bug was reported about an infinite recursion caused by tracing the rcu
events with the kernel stack trace trigger enabled. The stack trace code
called back into RCU which then called the stack trace again.
Expand the ftrace recursion protection to add a set of bits to protect
events from recursion. Each bit represents the context that the event is
in (normal, softirq, interrupt and NMI).
Have the stack trace code use the interrupt context to protect against
recursion.
Note, the bug showed an issue in both the RCU code as well as the tracing
stacktrace code. This only handles the tracing stack trace side of the
bug. The RCU fix will be handled separately.