In the Linux kernel, the following vulnerability has been resolved:
net/sched: Restrict conditions for adding duplicating netems to qdisc tree
netem_enqueue's duplication prevention logic breaks when a netem
resides in a qdisc tree with other netems - this can lead to a
soft lockup and OOM loop in netem_dequeue, as seen in [1].
Ensure that a duplicating netem cannot exist in a tree with other
netems.
Previous approaches suggested in discussions in chronological order:
1) Track duplication status or ttl in the sk_buff struct. Considered
too specific a use case to extend such a struct, though this would
be a resilient fix and address other previous and potential future
DOS bugs like the one described in loopy fun [2].
2) Restrict netem_enqueue recursion depth like in act_mirred with a
per cpu variable. However, netem_dequeue can call enqueue on its
child, and the depth restriction could be bypassed if the child is a
netem.
3) Use the same approach as in 2, but add metadata in netem_skb_cb
to handle the netem_dequeue case and track a packet's involvement
in duplication. This is an overly complex approach, and Jamal
notes that the skb cb can be overwritten to circumvent this
safeguard.
4) Prevent the addition of a netem to a qdisc tree if its ancestral
path contains a netem. However, filters and actions can cause a
packet to change paths when re-enqueued to the root from netem
duplication, leading us to the current solution: prevent a
duplicating netem from inhabiting the same tree as other netems.
[1] https://lore.kernel.org/netdev/8DuRWwfqjoRDLDmBMlIfbrsZg9Gx50DHJc1ilxsEBNe2D6NMoigR_eIRIG0LOjMc3r10nUUZtArXx4oZBIdUfZQrwjcQhdinnMis_0G7VEk=@willsroot.io/
[2] https://lwn.net/Articles/719297/
In the Linux kernel, the following vulnerability has been resolved:
ipv6: mcast: Delay put pmc->idev in mld_del_delrec()
pmc->idev is still used in ip6_mc_clear_src(), so as mld_clear_delrec()
does, the reference should be put after ip6_mc_clear_src() return.
In the Linux kernel, the following vulnerability has been resolved:
mptcp: plug races between subflow fail and subflow creation
We have races similar to the one addressed by the previous patch between
subflow failing and additional subflow creation. They are just harder to
trigger.
The solution is similar. Use a separate flag to track the condition
'socket state prevent any additional subflow creation' protected by the
fallback lock.
The socket fallback makes such flag true, and also receiving or sending
an MP_FAIL option.
The field 'allow_infinite_fallback' is now always touched under the
relevant lock, we can drop the ONCE annotation on write.
In the Linux kernel, the following vulnerability has been resolved:
net: appletalk: Fix device refcount leak in atrtr_create()
When updating an existing route entry in atrtr_create(), the old device
reference was not being released before assigning the new device,
leading to a device refcount leak. Fix this by calling dev_put() to
release the old device reference before holding the new one.
In the Linux kernel, the following vulnerability has been resolved:
drm/tegra: nvdec: Fix dma_alloc_coherent error check
Check for NULL return value with dma_alloc_coherent, in line with
Robin's fix for vic.c in 'drm/tegra: vic: Fix DMA API misuse'.
In the Linux kernel, the following vulnerability has been resolved:
rxrpc: Fix bug due to prealloc collision
When userspace is using AF_RXRPC to provide a server, it has to preallocate
incoming calls and assign to them call IDs that will be used to thread
related recvmsg() and sendmsg() together. The preallocated call IDs will
automatically be attached to calls as they come in until the pool is empty.
To the kernel, the call IDs are just arbitrary numbers, but userspace can
use the call ID to hold a pointer to prepared structs. In any case, the
user isn't permitted to create two calls with the same call ID (call IDs
become available again when the call ends) and EBADSLT should result from
sendmsg() if an attempt is made to preallocate a call with an in-use call
ID.
However, the cleanup in the error handling will trigger both assertions in
rxrpc_cleanup_call() because the call isn't marked complete and isn't
marked as having been released.
Fix this by setting the call state in rxrpc_service_prealloc_one() and then
marking it as being released before calling the cleanup function.
In the Linux kernel, the following vulnerability has been resolved:
atm: clip: Fix memory leak of struct clip_vcc.
ioctl(ATMARP_MKIP) allocates struct clip_vcc and set it to
vcc->user_back.
The code assumes that vcc_destroy_socket() passes NULL skb
to vcc->push() when the socket is close()d, and then clip_push()
frees clip_vcc.
However, ioctl(ATMARPD_CTRL) sets NULL to vcc->push() in
atm_init_atmarp(), resulting in memory leak.
Let's serialise two ioctl() by lock_sock() and check vcc->push()
in atm_init_atmarp() to prevent memleak.
In the Linux kernel, the following vulnerability has been resolved:
hwmon: (corsair-cpro) Validate the size of the received input buffer
Add buffer_recv_size to store the size of the received bytes.
Validate buffer_recv_size in send_usb_cmd().
In the Linux kernel, the following vulnerability has been resolved:
phy: tegra: xusb: Fix unbalanced regulator disable in UTMI PHY mode
When transitioning from USB_ROLE_DEVICE to USB_ROLE_NONE, the code
assumed that the regulator should be disabled. However, if the regulator
is marked as always-on, regulator_is_enabled() continues to return true,
leading to an incorrect attempt to disable a regulator which is not
enabled.
This can result in warnings such as:
[ 250.155624] WARNING: CPU: 1 PID: 7326 at drivers/regulator/core.c:3004
_regulator_disable+0xe4/0x1a0
[ 250.155652] unbalanced disables for VIN_SYS_5V0
To fix this, we move the regulator control logic into
tegra186_xusb_padctl_id_override() function since it's directly related
to the ID override state. The regulator is now only disabled when the role
transitions from USB_ROLE_HOST to USB_ROLE_NONE, by checking the VBUS_ID
register. This ensures that regulator enable/disable operations are
properly balanced and only occur when actually transitioning to/from host
mode.
In the Linux kernel, the following vulnerability has been resolved:
dmaengine: nbpfaxi: Fix memory corruption in probe()
The nbpf->chan[] array is allocated earlier in the nbpf_probe() function
and it has "num_channels" elements. These three loops iterate one
element farther than they should and corrupt memory.
The changes to the second loop are more involved. In this case, we're
copying data from the irqbuf[] array into the nbpf->chan[] array. If
the data in irqbuf[i] is the error IRQ then we skip it, so the iterators
are not in sync. I added a check to ensure that we don't go beyond the
end of the irqbuf[] array. I'm pretty sure this can't happen, but it
seemed harmless to add a check.
On the other hand, after the loop has ended there is a check to ensure
that the "chan" iterator is where we expect it to be. In the original
code we went one element beyond the end of the array so the iterator
wasn't in the correct place and it would always return -EINVAL. However,
now it will always be in the correct place. I deleted the check since
we know the result.