In the Linux kernel, the following vulnerability has been resolved:
ALSA: aloop: Fix racy access at PCM trigger
The PCM trigger callback of aloop driver tries to check the PCM state
and stop the stream of the tied substream in the corresponding cable.
Since both check and stop operations are performed outside the cable
lock, this may result in UAF when a program attempts to trigger
frequently while opening/closing the tied stream, as spotted by
fuzzers.
For addressing the UAF, this patch changes two things:
- It covers the most of code in loopback_check_format() with
cable->lock spinlock, and add the proper NULL checks. This avoids
already some racy accesses.
- In addition, now we try to check the state of the capture PCM stream
that may be stopped in this function, which was the major pain point
leading to UAF.
In the Linux kernel, the following vulnerability has been resolved:
riscv: Sanitize syscall table indexing under speculation
The syscall number is a user-controlled value used to index into the
syscall table. Use array_index_nospec() to clamp this value after the
bounds check to prevent speculative out-of-bounds access and subsequent
data leakage via cache side channels.
In the Linux kernel, the following vulnerability has been resolved:
smb/server: fix refcount leak in parse_durable_handle_context()
When the command is a replay operation and -ENOEXEC is returned,
the refcount of ksmbd_file must be released.
In the Linux kernel, the following vulnerability has been resolved:
smb/server: call ksmbd_session_rpc_close() on error path in create_smb2_pipe()
When ksmbd_iov_pin_rsp() fails, we should call ksmbd_session_rpc_close().
In the Linux kernel, the following vulnerability has been resolved:
dmaengine: mmp_pdma: Fix race condition in mmp_pdma_residue()
Add proper locking in mmp_pdma_residue() to prevent use-after-free when
accessing descriptor list and descriptor contents.
The race occurs when multiple threads call tx_status() while the tasklet
on another CPU is freeing completed descriptors:
CPU 0 CPU 1
----- -----
mmp_pdma_tx_status()
mmp_pdma_residue()
-> NO LOCK held
list_for_each_entry(sw, ..)
DMA interrupt
dma_do_tasklet()
-> spin_lock(&desc_lock)
list_move(sw->node, ...)
spin_unlock(&desc_lock)
| dma_pool_free(sw) <- FREED!
-> access sw->desc <- UAF!
This issue can be reproduced when running dmatest on the same channel with
multiple threads (threads_per_chan > 1).
Fix by protecting the chain_running list iteration and descriptor access
with the chan->desc_lock spinlock.
In the Linux kernel, the following vulnerability has been resolved:
wifi: wlcore: ensure skb headroom before skb_push
This avoids occasional skb_under_panic Oops from wl1271_tx_work. In this case, headroom is
less than needed (typically 110 - 94 = 16 bytes).
In the Linux kernel, the following vulnerability has been resolved:
smb/server: fix refcount leak in smb2_open()
When ksmbd_vfs_getattr() fails, the reference count of ksmbd_file
must be released.
In the Linux kernel, the following vulnerability has been resolved:
flex_proportions: make fprop_new_period() hardirq safe
Bernd has reported a lockdep splat from flexible proportions code that is
essentially complaining about the following race:
<timer fires>
run_timer_softirq - we are in softirq context
call_timer_fn
writeout_period
fprop_new_period
write_seqcount_begin(&p->sequence);
<hardirq is raised>
...
blk_mq_end_request()
blk_update_request()
ext4_end_bio()
folio_end_writeback()
__wb_writeout_add()
__fprop_add_percpu_max()
if (unlikely(max_frac < FPROP_FRAC_BASE)) {
fprop_fraction_percpu()
seq = read_seqcount_begin(&p->sequence);
- sees odd sequence so loops indefinitely
Note that a deadlock like this is only possible if the bdi has configured
maximum fraction of writeout throughput which is very rare in general but
frequent for example for FUSE bdis. To fix this problem we have to make
sure write section of the sequence counter is irqsafe.
In the Linux kernel, the following vulnerability has been resolved:
mptcp: fix race in mptcp_pm_nl_flush_addrs_doit()
syzbot and Eulgyu Kim reported crashes in mptcp_pm_nl_get_local_id()
and/or mptcp_pm_nl_is_backup()
Root cause is list_splice_init() in mptcp_pm_nl_flush_addrs_doit()
which is not RCU ready.
list_splice_init_rcu() can not be called here while holding pernet->lock
spinlock.
Many thanks to Eulgyu Kim for providing a repro and testing our patches.
In the Linux kernel, the following vulnerability has been resolved:
drm/imx/tve: fix probe device leak
Make sure to drop the reference taken to the DDC device during probe on
probe failure (e.g. probe deferral) and on driver unbind.