In the Linux kernel, the following vulnerability has been resolved:
ntfs3: fix circular locking dependency in run_unpack_ex
Syzbot reported a circular locking dependency between wnd->rw_lock
(sbi->used.bitmap) and ni->file.run_lock.
The deadlock scenario:
1. ntfs_extend_mft() takes ni->file.run_lock then wnd->rw_lock.
2. run_unpack_ex() takes wnd->rw_lock then tries to acquire
ni->file.run_lock inside ntfs_refresh_zone().
This creates an AB-BA deadlock.
Fix this by using down_read_trylock() instead of down_read() when
acquiring run_lock in run_unpack_ex(). If the lock is contended,
skip ntfs_refresh_zone() - the MFT zone will be refreshed on the
next MFT operation. This breaks the circular dependency since we
never block waiting for run_lock while holding wnd->rw_lock.
In the Linux kernel, the following vulnerability has been resolved:
ima: verify the previous kernel's IMA buffer lies in addressable RAM
Patch series "Address page fault in ima_restore_measurement_list()", v3.
When the second-stage kernel is booted via kexec with a limiting command
line such as "mem=<size>" we observe a pafe fault that happens.
BUG: unable to handle page fault for address: ffff97793ff47000
RIP: ima_restore_measurement_list+0xdc/0x45a
#PF: error_code(0x0000) not-present page
This happens on x86_64 only, as this is already fixed in aarch64 in
commit: cbf9c4b9617b ("of: check previous kernel's ima-kexec-buffer
against memory bounds")
This patch (of 3):
When the second-stage kernel is booted with a limiting command line (e.g.
"mem=<size>"), the IMA measurement buffer handed over from the previous
kernel may fall outside the addressable RAM of the new kernel. Accessing
such a buffer can fault during early restore.
Introduce a small generic helper, ima_validate_range(), which verifies
that a physical [start, end] range for the previous-kernel IMA buffer lies
within addressable memory:
- On x86, use pfn_range_is_mapped().
- On OF based architectures, use page_is_ram().
In the Linux kernel, the following vulnerability has been resolved:
dlm: validate length in dlm_search_rsb_tree
The len parameter in dlm_dump_rsb_name() is not validated and comes
from network messages. When it exceeds DLM_RESNAME_MAXLEN, it can
cause out-of-bounds write in dlm_search_rsb_tree().
Add length validation to prevent potential buffer overflow.
In the Linux kernel, the following vulnerability has been resolved:
fs/ntfs3: handle attr_set_size() errors when truncating files
If attr_set_size() fails while truncating down, the error is silently
ignored and the inode may be left in an inconsistent state.
In the Linux kernel, the following vulnerability has been resolved:
most: core: fix resource leak in most_register_interface error paths
The function most_register_interface() did not correctly release resources
if it failed early (before registering the device). In these cases, it
returned an error code immediately, leaking the memory allocated for the
interface.
Fix this by initializing the device early via device_initialize() and
calling put_device() on all error paths.
The most_register_interface() is expected to call put_device() on
error which frees the resources allocated in the caller. The
put_device() either calls release_mdev() or dim2_release(),
depending on the caller.
Switch to using device_add() instead of device_register() to handle
the split initialization.
In the Linux kernel, the following vulnerability has been resolved:
wifi: rtw88: Use devm_kmemdup() in rtw_set_supported_band()
Simplify the code by using device managed memory allocations.
This also fixes a memory leak in rtw_register_hw(). The supported bands
were not freed in the error path.
Copied from commit 145df52a8671 ("wifi: rtw89: Convert
rtw89_core_set_supported_band to use devm_*").
In the Linux kernel, the following vulnerability has been resolved:
net: qrtr: Drop the MHI auto_queue feature for IPCR DL channels
MHI stack offers the 'auto_queue' feature, which allows the MHI stack to
auto queue the buffers for the RX path (DL channel). Though this feature
simplifies the client driver design, it introduces race between the client
drivers and the MHI stack. For instance, with auto_queue, the 'dl_callback'
for the DL channel may get called before the client driver is fully probed.
This means, by the time the dl_callback gets called, the client driver's
structures might not be initialized, leading to NULL ptr dereference.
Currently, the drivers have to workaround this issue by initializing the
internal structures before calling mhi_prepare_for_transfer_autoqueue().
But even so, there is a chance that the client driver's internal code path
may call the MHI queue APIs before mhi_prepare_for_transfer_autoqueue() is
called, leading to similar NULL ptr dereference. This issue has been
reported on the Qcom X1E80100 CRD machines affecting boot.
So to properly fix all these races, drop the MHI 'auto_queue' feature
altogether and let the client driver (QRTR) manage the RX buffers manually.
In the QRTR driver, queue the RX buffers based on the ring length during
probe and recycle the buffers in 'dl_callback' once they are consumed. This
also warrants removing the setting of 'auto_queue' flag from controller
drivers.
Currently, this 'auto_queue' feature is only enabled for IPCR DL channel.
So only the QRTR client driver requires the modification.
In the Linux kernel, the following vulnerability has been resolved:
srcu: Use irq_work to start GP in tiny SRCU
Tiny SRCU's srcu_gp_start_if_needed() directly calls schedule_work(),
which acquires the workqueue pool->lock.
This causes a lockdep splat when call_srcu() is called with a scheduler
lock held, due to:
call_srcu() [holding pi_lock]
srcu_gp_start_if_needed()
schedule_work() -> pool->lock
workqueue_init() / create_worker() [holding pool->lock]
wake_up_process() -> try_to_wake_up() -> pi_lock
Also add irq_work_sync() to cleanup_srcu_struct() to prevent a
use-after-free if a queued irq_work fires after cleanup begins.
Tested with rcutorture SRCU-T and no lockdep warnings.
[ Thanks to Boqun for similar fix in patch "rcu: Use an intermediate irq_work
to start process_srcu()" ]
In the Linux kernel, the following vulnerability has been resolved:
netfilter: ctnetlink: ensure safe access to master conntrack
Holding reference on the expectation is not sufficient, the master
conntrack object can just go away, making exp->master invalid.
To access exp->master safely:
- Grab the nf_conntrack_expect_lock, this gets serialized with
clean_from_lists() which also holds this lock when the master
conntrack goes away.
- Hold reference on master conntrack via nf_conntrack_find_get().
Not so easy since the master tuple to look up for the master conntrack
is not available in the existing problematic paths.
This patch goes for extending the nf_conntrack_expect_lock section
to address this issue for simplicity, in the cases that are described
below this is just slightly extending the lock section.
The add expectation command already holds a reference to the master
conntrack from ctnetlink_create_expect().
However, the delete expectation command needs to grab the spinlock
before looking up for the expectation. Expand the existing spinlock
section to address this to cover the expectation lookup. Note that,
the nf_ct_expect_iterate_net() calls already grabs the spinlock while
iterating over the expectation table, which is correct.
The get expectation command needs to grab the spinlock to ensure master
conntrack does not go away. This also expands the existing spinlock
section to cover the expectation lookup too. I needed to move the
netlink skb allocation out of the spinlock to keep it GFP_KERNEL.
For the expectation events, the IPEXP_DESTROY event is already delivered
under the spinlock, just move the delivery of IPEXP_NEW under the
spinlock too because the master conntrack event cache is reached through
exp->master.
While at it, add lockdep notations to help identify what codepaths need
to grab the spinlock.
In the Linux kernel, the following vulnerability has been resolved:
btrfs: fix zero size inode with non-zero size after log replay
When logging that an inode exists, as part of logging a new name or
logging new dir entries for a directory, we always set the generation of
the logged inode item to 0. This is to signal during log replay (in
overwrite_item()), that we should not set the i_size since we only logged
that an inode exists, so the i_size of the inode in the subvolume tree
must be preserved (as when we log new names or that an inode exists, we
don't log extents).
This works fine except when we have already logged an inode in full mode
or it's the first time we are logging an inode created in a past
transaction, that inode has a new i_size of 0 and then we log a new name
for the inode (due to a new hardlink or a rename), in which case we log
an i_size of 0 for the inode and a generation of 0, which causes the log
replay code to not update the inode's i_size to 0 (in overwrite_item()).
An example scenario:
mkdir /mnt/dir
xfs_io -f -c "pwrite 0 64K" /mnt/dir/foo
sync
xfs_io -c "truncate 0" -c "fsync" /mnt/dir/foo
ln /mnt/dir/foo /mnt/dir/bar
xfs_io -c "fsync" /mnt/dir
<power fail>
After log replay the file remains with a size of 64K. This is because when
we first log the inode, when we fsync file foo, we log its current i_size
of 0, and then when we create a hard link we log again the inode in exists
mode (LOG_INODE_EXISTS) but we set a generation of 0 for the inode item we
add to the log tree, so during log replay overwrite_item() sees that the
generation is 0 and i_size is 0 so we skip updating the inode's i_size
from 64K to 0.
Fix this by making sure at fill_inode_item() we always log the real
generation of the inode if it was logged in the current transaction with
the i_size we logged before. Also if an inode created in a previous
transaction is logged in exists mode only, make sure we log the i_size
stored in the inode item located from the commit root, so that if we log
multiple times that the inode exists we get the correct i_size.
A test case for fstests will follow soon.