In the Linux kernel, the following vulnerability has been resolved:
net: ieee802154: do not leave a dangling sk pointer in ieee802154_create()
sock_init_data() attaches the allocated sk object to the provided sock
object. If ieee802154_create() fails later, the allocated sk object is
freed, but the dangling pointer remains in the provided sock object, which
may allow use-after-free.
Clear the sk pointer in the sock object on error.
In the Linux kernel, the following vulnerability has been resolved:
net: af_can: do not leave a dangling sk pointer in can_create()
On error can_create() frees the allocated sk object, but sock_init_data()
has already attached it to the provided sock object. This will leave a
dangling sk pointer in the sock object and may cause use-after-free later.
In the Linux kernel, the following vulnerability has been resolved:
Bluetooth: RFCOMM: avoid leaving dangling sk pointer in rfcomm_sock_alloc()
bt_sock_alloc() attaches allocated sk object to the provided sock object.
If rfcomm_dlc_alloc() fails, we release the sk object, but leave the
dangling pointer in the sock object, which may cause use-after-free.
Fix this by swapping calls to bt_sock_alloc() and rfcomm_dlc_alloc().
In the Linux kernel, the following vulnerability has been resolved:
Bluetooth: L2CAP: do not leave dangling sk pointer on error in l2cap_sock_create()
bt_sock_alloc() allocates the sk object and attaches it to the provided
sock object. On error l2cap_sock_alloc() frees the sk object, but the
dangling pointer is still attached to the sock object, which may create
use-after-free in other code.
In the Linux kernel, the following vulnerability has been resolved:
Bluetooth: hci_core: Fix not checking skb length on hci_acldata_packet
This fixes not checking if skb really contains an ACL header otherwise
the code may attempt to access some uninitilized/invalid memory past the
valid skb->data.
In the Linux kernel, the following vulnerability has been resolved:
Bluetooth: hci_conn: Use disable_delayed_work_sync
This makes use of disable_delayed_work_sync instead
cancel_delayed_work_sync as it not only cancel the ongoing work but also
disables new submit which is disarable since the object holding the work
is about to be freed.
In the Linux kernel, the following vulnerability has been resolved:
bpf: Call free_htab_elem() after htab_unlock_bucket()
For htab of maps, when the map is removed from the htab, it may hold the
last reference of the map. bpf_map_fd_put_ptr() will invoke
bpf_map_free_id() to free the id of the removed map element. However,
bpf_map_fd_put_ptr() is invoked while holding a bucket lock
(raw_spin_lock_t), and bpf_map_free_id() attempts to acquire map_idr_lock
(spinlock_t), triggering the following lockdep warning:
=============================
[ BUG: Invalid wait context ]
6.11.0-rc4+ #49 Not tainted
-----------------------------
test_maps/4881 is trying to lock:
ffffffff84884578 (map_idr_lock){+...}-{3:3}, at: bpf_map_free_id.part.0+0x21/0x70
other info that might help us debug this:
context-{5:5}
2 locks held by test_maps/4881:
#0: ffffffff846caf60 (rcu_read_lock){....}-{1:3}, at: bpf_fd_htab_map_update_elem+0xf9/0x270
#1: ffff888149ced148 (&htab->lockdep_key#2){....}-{2:2}, at: htab_map_update_elem+0x178/0xa80
stack backtrace:
CPU: 0 UID: 0 PID: 4881 Comm: test_maps Not tainted 6.11.0-rc4+ #49
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), ...
Call Trace:
<TASK>
dump_stack_lvl+0x6e/0xb0
dump_stack+0x10/0x20
__lock_acquire+0x73e/0x36c0
lock_acquire+0x182/0x450
_raw_spin_lock_irqsave+0x43/0x70
bpf_map_free_id.part.0+0x21/0x70
bpf_map_put+0xcf/0x110
bpf_map_fd_put_ptr+0x9a/0xb0
free_htab_elem+0x69/0xe0
htab_map_update_elem+0x50f/0xa80
bpf_fd_htab_map_update_elem+0x131/0x270
htab_map_update_elem+0x50f/0xa80
bpf_fd_htab_map_update_elem+0x131/0x270
bpf_map_update_value+0x266/0x380
__sys_bpf+0x21bb/0x36b0
__x64_sys_bpf+0x45/0x60
x64_sys_call+0x1b2a/0x20d0
do_syscall_64+0x5d/0x100
entry_SYSCALL_64_after_hwframe+0x76/0x7e
One way to fix the lockdep warning is using raw_spinlock_t for
map_idr_lock as well. However, bpf_map_alloc_id() invokes
idr_alloc_cyclic() after acquiring map_idr_lock, it will trigger a
similar lockdep warning because the slab's lock (s->cpu_slab->lock) is
still a spinlock.
Instead of changing map_idr_lock's type, fix the issue by invoking
htab_put_fd_value() after htab_unlock_bucket(). However, only deferring
the invocation of htab_put_fd_value() is not enough, because the old map
pointers in htab of maps can not be saved during batched deletion.
Therefore, also defer the invocation of free_htab_elem(), so these
to-be-freed elements could be linked together similar to lru map.
There are four callers for ->map_fd_put_ptr:
(1) alloc_htab_elem() (through htab_put_fd_value())
It invokes ->map_fd_put_ptr() under a raw_spinlock_t. The invocation of
htab_put_fd_value() can not simply move after htab_unlock_bucket(),
because the old element has already been stashed in htab->extra_elems.
It may be reused immediately after htab_unlock_bucket() and the
invocation of htab_put_fd_value() after htab_unlock_bucket() may release
the newly-added element incorrectly. Therefore, saving the map pointer
of the old element for htab of maps before unlocking the bucket and
releasing the map_ptr after unlock. Beside the map pointer in the old
element, should do the same thing for the special fields in the old
element as well.
(2) free_htab_elem() (through htab_put_fd_value())
Its caller includes __htab_map_lookup_and_delete_elem(),
htab_map_delete_elem() and __htab_map_lookup_and_delete_batch().
For htab_map_delete_elem(), simply invoke free_htab_elem() after
htab_unlock_bucket(). For __htab_map_lookup_and_delete_batch(), just
like lru map, linking the to-be-freed element into node_to_free list
and invoking free_htab_elem() for these element after unlock. It is safe
to reuse batch_flink as the link for node_to_free, because these
elements have been removed from the hash llist.
Because htab of maps doesn't support lookup_and_delete operation,
__htab_map_lookup_and_delete_elem() doesn't have the problem, so kept
it as
---truncated---
In the Linux kernel, the following vulnerability has been resolved:
wifi: brcmfmac: Fix oops due to NULL pointer dereference in brcmf_sdiod_sglist_rw()
This patch fixes a NULL pointer dereference bug in brcmfmac that occurs
when a high 'sd_sgentry_align' value applies (e.g. 512) and a lot of queued SKBs
are sent from the pkt queue.
The problem is the number of entries in the pre-allocated sgtable, it is
nents = max(rxglom_size, txglom_size) + max(rxglom_size, txglom_size) >> 4 + 1.
Given the default [rt]xglom_size=32 it's actually 35 which is too small.
Worst case, the pkt queue can end up with 64 SKBs. This occurs when a new SKB
is added for each original SKB if tailroom isn't enough to hold tail_pad.
At least one sg entry is needed for each SKB. So, eventually the "skb_queue_walk loop"
in brcmf_sdiod_sglist_rw may run out of sg entries. This makes sg_next return
NULL and this causes the oops.
The patch sets nents to max(rxglom_size, txglom_size) * 2 to be able handle
the worst-case.
Btw. this requires only 64-35=29 * 16 (or 20 if CONFIG_NEED_SG_DMA_LENGTH) = 464
additional bytes of memory.