In the Linux kernel, the following vulnerability has been resolved:
batman-adv: Avoid double-rtnl_lock ELP metric worker
batadv_v_elp_get_throughput() might be called when the RTNL lock is already
held. This could be problematic when the work queue item is cancelled via
cancel_delayed_work_sync() in batadv_v_elp_iface_disable(). In this case,
an rtnl_lock() would cause a deadlock.
To avoid this, rtnl_trylock() was used in this function to skip the
retrieval of the ethtool information in case the RTNL lock was already
held.
But for cfg80211 interfaces, batadv_get_real_netdev() was called - which
also uses rtnl_lock(). The approach for __ethtool_get_link_ksettings() must
also be used instead and the lockless version __batadv_get_real_netdev()
has to be called.
In the Linux kernel, the following vulnerability has been resolved:
net/tcp-md5: Fix MAC comparison to be constant-time
To prevent timing attacks, MACs need to be compared in constant
time. Use the appropriate helper function for this.
In the Linux kernel, the following vulnerability has been resolved:
net/tcp-ao: Fix MAC comparison to be constant-time
To prevent timing attacks, MACs need to be compared in constant
time. Use the appropriate helper function for this.
In the Linux kernel, the following vulnerability has been resolved:
net: Fix rcu_tasks stall in threaded busypoll
I was debugging a NIC driver when I noticed that when I enable
threaded busypoll, bpftrace hangs when starting up. dmesg showed:
rcu_tasks_wait_gp: rcu_tasks grace period number 85 (since boot) is 10658 jiffies old.
rcu_tasks_wait_gp: rcu_tasks grace period number 85 (since boot) is 40793 jiffies old.
rcu_tasks_wait_gp: rcu_tasks grace period number 85 (since boot) is 131273 jiffies old.
rcu_tasks_wait_gp: rcu_tasks grace period number 85 (since boot) is 402058 jiffies old.
INFO: rcu_tasks detected stalls on tasks:
00000000769f52cd: .N nvcsw: 2/2 holdout: 1 idle_cpu: -1/64
task:napi/eth2-8265 state:R running task stack:0 pid:48300 tgid:48300 ppid:2 task_flags:0x208040 flags:0x00004000
Call Trace:
<TASK>
? napi_threaded_poll_loop+0x27c/0x2c0
? __pfx_napi_threaded_poll+0x10/0x10
? napi_threaded_poll+0x26/0x80
? kthread+0xfa/0x240
? __pfx_kthread+0x10/0x10
? ret_from_fork+0x31/0x50
? __pfx_kthread+0x10/0x10
? ret_from_fork_asm+0x1a/0x30
</TASK>
The cause is that in threaded busypoll, the main loop is in
napi_threaded_poll rather than napi_threaded_poll_loop, where the
latter rarely iterates more than once within its loop. For
rcu_softirq_qs_periodic inside napi_threaded_poll_loop to report its
qs state, the last_qs must be 100ms behind, and this can't happen
because napi_threaded_poll_loop rarely iterates in threaded busypoll,
and each time napi_threaded_poll_loop is called last_qs is reset to
latest jiffies.
This patch changes so that in threaded busypoll, last_qs is saved
in the outer napi_threaded_poll, and whether busy_poll_last_qs
is NULL indicates whether napi_threaded_poll_loop is called for
busypoll. This way last_qs would not reset to latest jiffies on
each invocation of napi_threaded_poll_loop.
In the Linux kernel, the following vulnerability has been resolved:
staging: rtl8723bs: fix potential out-of-bounds read in rtw_restruct_wmm_ie
The current code checks 'i + 5 < in_len' at the end of the if statement.
However, it accesses 'in_ie[i + 5]' before that check, which can lead
to an out-of-bounds read. Move the length check to the beginning of the
conditional to ensure the index is within bounds before accessing the
array.
In the Linux kernel, the following vulnerability has been resolved:
drm/amdgpu: Fix use-after-free race in VM acquire
Replace non-atomic vm->process_info assignment with cmpxchg()
to prevent race when parent/child processes sharing a drm_file
both try to acquire the same VM after fork().
(cherry picked from commit c7c573275ec20db05be769288a3e3bb2250ec618)
In the Linux kernel, the following vulnerability has been resolved:
net: macb: Shuffle the tx ring before enabling tx
Quanyang observed that when using an NFS rootfs on an AMD ZynqMp board,
the rootfs may take an extended time to recover after a suspend.
Upon investigation, it was determined that the issue originates from a
problem in the macb driver.
According to the Zynq UltraScale TRM [1], when transmit is disabled,
the transmit buffer queue pointer resets to point to the address
specified by the transmit buffer queue base address register.
In the current implementation, the code merely resets `queue->tx_head`
and `queue->tx_tail` to '0'. This approach presents several issues:
- Packets already queued in the tx ring are silently lost,
leading to memory leaks since the associated skbs cannot be released.
- Concurrent write access to `queue->tx_head` and `queue->tx_tail` may
occur from `macb_tx_poll()` or `macb_start_xmit()` when these values
are reset to '0'.
- The transmission may become stuck on a packet that has already been sent
out, with its 'TX_USED' bit set, but has not yet been processed. However,
due to the manipulation of 'queue->tx_head' and 'queue->tx_tail',
`macb_tx_poll()` incorrectly assumes there are no packets to handle
because `queue->tx_head == queue->tx_tail`. This issue is only resolved
when a new packet is placed at this position. This is the root cause of
the prolonged recovery time observed for the NFS root filesystem.
To resolve this issue, shuffle the tx ring and tx skb array so that
the first unsent packet is positioned at the start of the tx ring.
Additionally, ensure that updates to `queue->tx_head` and
`queue->tx_tail` are properly protected with the appropriate lock.
[1] https://docs.amd.com/v/u/en-US/ug1085-zynq-ultrascale-trm
In the Linux kernel, the following vulnerability has been resolved:
net: dsa: microchip: Fix error path in PTP IRQ setup
If request_threaded_irq() fails during the PTP message IRQ setup, the
newly created IRQ mapping is never disposed. Indeed, the
ksz_ptp_irq_setup()'s error path only frees the mappings that were
successfully set up.
Dispose the newly created mapping if the associated
request_threaded_irq() fails at setup.
In the Linux kernel, the following vulnerability has been resolved:
net: ncsi: fix skb leak in error paths
Early return paths in NCSI RX and AEN handlers fail to release
the received skb, resulting in a memory leak.
Specifically, ncsi_aen_handler() returns on invalid AEN packets
without consuming the skb. Similarly, ncsi_rcv_rsp() exits early
when failing to resolve the NCSI device, response handler, or
request, leaving the skb unfreed.
In the Linux kernel, the following vulnerability has been resolved:
net: nexthop: fix percpu use-after-free in remove_nh_grp_entry
When removing a nexthop from a group, remove_nh_grp_entry() publishes
the new group via rcu_assign_pointer() then immediately frees the
removed entry's percpu stats with free_percpu(). However, the
synchronize_net() grace period in the caller remove_nexthop_from_groups()
runs after the free. RCU readers that entered before the publish still
see the old group and can dereference the freed stats via
nh_grp_entry_stats_inc() -> get_cpu_ptr(nhge->stats), causing a
use-after-free on percpu memory.
Fix by deferring the free_percpu() until after synchronize_net() in the
caller. Removed entries are chained via nh_list onto a local deferred
free list. After the grace period completes and all RCU readers have
finished, the percpu stats are safely freed.