In the Linux kernel, the following vulnerability has been resolved:
net: atm: fix /proc/net/atm/lec handling
/proc/net/atm/lec must ensure safety against dev_lec[] changes.
It appears it had dev_put() calls without prior dev_hold(),
leading to imbalance and UAF.
In the Linux kernel, the following vulnerability has been resolved:
sch_hfsc: make hfsc_qlen_notify() idempotent
hfsc_qlen_notify() is not idempotent either and not friendly
to its callers, like fq_codel_dequeue(). Let's make it idempotent
to ease qdisc_tree_reduce_backlog() callers' life:
1. update_vf() decreases cl->cl_nactive, so we can check whether it is
non-zero before calling it.
2. eltree_remove() always removes RB node cl->el_node, but we can use
RB_EMPTY_NODE() + RB_CLEAR_NODE() to make it safe.
In the Linux kernel, the following vulnerability has been resolved:
Bluetooth: Disable SCO support if READ_VOICE_SETTING is unsupported/broken
A SCO connection without the proper voice_setting can cause
the controller to lock up.
In the Linux kernel, the following vulnerability has been resolved:
ALSA: usb-audio: Kill timer properly at removal
The USB-audio MIDI code initializes the timer, but in a rare case, the
driver might be freed without the disconnect call. This leaves the
timer in an active state while the assigned object is released via
snd_usbmidi_free(), which ends up with a kernel warning when the debug
configuration is enabled, as spotted by fuzzer.
For avoiding the problem, put timer_shutdown_sync() at
snd_usbmidi_free(), so that the timer can be killed properly.
While we're at it, replace the existing timer_delete_sync() at the
disconnect callback with timer_shutdown_sync(), too.
In the Linux kernel, the following vulnerability has been resolved:
wifi: iwlwifi: don't warn when if there is a FW error
iwl_trans_reclaim is warning if it is called when the FW is not alive.
But if it is called when there is a pending restart, i.e. after a FW
error, there is no need to warn, instead - return silently.
In the Linux kernel, the following vulnerability has been resolved:
mm/hugetlb: fix huge_pmd_unshare() vs GUP-fast race
huge_pmd_unshare() drops a reference on a page table that may have
previously been shared across processes, potentially turning it into a
normal page table used in another process in which unrelated VMAs can
afterwards be installed.
If this happens in the middle of a concurrent gup_fast(), gup_fast() could
end up walking the page tables of another process. While I don't see any
way in which that immediately leads to kernel memory corruption, it is
really weird and unexpected.
Fix it with an explicit broadcast IPI through tlb_remove_table_sync_one(),
just like we do in khugepaged when removing page tables for a THP
collapse.
In the Linux kernel, the following vulnerability has been resolved:
mm/hugetlb: unshare page tables during VMA split, not before
Currently, __split_vma() triggers hugetlb page table unsharing through
vm_ops->may_split(). This happens before the VMA lock and rmap locks are
taken - which is too early, it allows racing VMA-locked page faults in our
process and racing rmap walks from other processes to cause page tables to
be shared again before we actually perform the split.
Fix it by explicitly calling into the hugetlb unshare logic from
__split_vma() in the same place where THP splitting also happens. At that
point, both the VMA and the rmap(s) are write-locked.
An annoying detail is that we can now call into the helper
hugetlb_unshare_pmds() from two different locking contexts:
1. from hugetlb_split(), holding:
- mmap lock (exclusively)
- VMA lock
- file rmap lock (exclusively)
2. hugetlb_unshare_all_pmds(), which I think is designed to be able to
call us with only the mmap lock held (in shared mode), but currently
only runs while holding mmap lock (exclusively) and VMA lock
Backporting note:
This commit fixes a racy protection that was introduced in commit
b30c14cd6102 ("hugetlb: unshare some PMDs when splitting VMAs"); that
commit claimed to fix an issue introduced in 5.13, but it should actually
also go all the way back.
[jannh@google.com: v2]
In the Linux kernel, the following vulnerability has been resolved:
scsi: sg: Allow waiting for commands to complete on removed device
When a SCSI device is removed while in active use, currently sg will
immediately return -ENODEV on any attempt to wait for active commands that
were sent before the removal. This is problematic for commands that use
SG_FLAG_DIRECT_IO since the data buffer may still be in use by the kernel
when userspace frees or reuses it after getting ENODEV, leading to
corrupted userspace memory (in the case of READ-type commands) or corrupted
data being sent to the device (in the case of WRITE-type commands). This
has been seen in practice when logging out of a iscsi_tcp session, where
the iSCSI driver may still be processing commands after the device has been
marked for removal.
Change the policy to allow userspace to wait for active sg commands even
when the device is being removed. Return -ENODEV only when there are no
more responses to read.
In the Linux kernel, the following vulnerability has been resolved:
ARM: OMAP2+: display: Fix refcount leak bug
In omapdss_init_fbdev(), of_find_node_by_name() will return a node
pointer with refcount incremented. We should use of_node_put() when
it is not used anymore.
In the Linux kernel, the following vulnerability has been resolved:
ARM: OMAP2+: pdata-quirks: Fix refcount leak bug
In pdata_quirks_init_clocks(), the loop contains
of_find_node_by_name() but without corresponding of_node_put().