| CVE |
Vendors |
Products |
Updated |
CVSS v3.1 |
| In the Linux kernel, the following vulnerability has been resolved:
nilfs2: fix use-after-free bug of ns_writer on remount
If a nilfs2 filesystem is downgraded to read-only due to metadata
corruption on disk and is remounted read/write, or if emergency read-only
remount is performed, detaching a log writer and synchronizing the
filesystem can be done at the same time.
In these cases, use-after-free of the log writer (hereinafter
nilfs->ns_writer) can happen as shown in the scenario below:
Task1 Task2
-------------------------------- ------------------------------
nilfs_construct_segment
nilfs_segctor_sync
init_wait
init_waitqueue_entry
add_wait_queue
schedule
nilfs_remount (R/W remount case)
nilfs_attach_log_writer
nilfs_detach_log_writer
nilfs_segctor_destroy
kfree
finish_wait
_raw_spin_lock_irqsave
__raw_spin_lock_irqsave
do_raw_spin_lock
debug_spin_lock_before <-- use-after-free
While Task1 is sleeping, nilfs->ns_writer is freed by Task2. After Task1
waked up, Task1 accesses nilfs->ns_writer which is already freed. This
scenario diagram is based on the Shigeru Yoshida's post [1].
This patch fixes the issue by not detaching nilfs->ns_writer on remount so
that this UAF race doesn't happen. Along with this change, this patch
also inserts a few necessary read-only checks with superblock instance
where only the ns_writer pointer was used to check if the filesystem is
read-only. |
| In the Linux kernel, the following vulnerability has been resolved:
net/9p: use a dedicated spinlock for trans_fd
Shamelessly copying the explanation from Tetsuo Handa's suggested
patch[1] (slightly reworded):
syzbot is reporting inconsistent lock state in p9_req_put()[2],
for p9_tag_remove() from p9_req_put() from IRQ context is using
spin_lock_irqsave() on "struct p9_client"->lock but trans_fd
(not from IRQ context) is using spin_lock().
Since the locks actually protect different things in client.c and in
trans_fd.c, just replace trans_fd.c's lock by a new one specific to the
transport (client.c's protect the idr for fid/tag allocations,
while trans_fd.c's protects its own req list and request status field
that acts as the transport's state machine) |
| In the Linux kernel, the following vulnerability has been resolved:
btrfs: always report error in run_one_delayed_ref()
Currently we have a btrfs_debug() for run_one_delayed_ref() failure, but
if end users hit such problem, there will be no chance that
btrfs_debug() is enabled. This can lead to very little useful info for
debugging.
This patch will:
- Add extra info for error reporting
Including:
* logical bytenr
* num_bytes
* type
* action
* ref_mod
- Replace the btrfs_debug() with btrfs_err()
- Move the error reporting into run_one_delayed_ref()
This is to avoid use-after-free, the @node can be freed in the caller.
This error should only be triggered at most once.
As if run_one_delayed_ref() failed, we trigger the error message, then
causing the call chain to error out:
btrfs_run_delayed_refs()
`- btrfs_run_delayed_refs()
`- btrfs_run_delayed_refs_for_head()
`- run_one_delayed_ref()
And we will abort the current transaction in btrfs_run_delayed_refs().
If we have to run delayed refs for the abort transaction,
run_one_delayed_ref() will just cleanup the refs and do nothing, thus no
new error messages would be output. |
| In the Linux kernel, the following vulnerability has been resolved:
srcu: Tighten cleanup_srcu_struct() GP checks
Currently, cleanup_srcu_struct() checks for a grace period in progress,
but it does not check for a grace period that has not yet started but
which might start at any time. Such a situation could result in a
use-after-free bug, so this commit adds a check for a grace period that
is needed but not yet started to cleanup_srcu_struct(). |
| In the Linux kernel, the following vulnerability has been resolved:
netfilter: nf_tables: avoid skb access on nf_stolen
When verdict is NF_STOLEN, the skb might have been freed.
When tracing is enabled, this can result in a use-after-free:
1. access to skb->nf_trace
2. access to skb->mark
3. computation of trace id
4. dump of packet payload
To avoid 1, keep a cached copy of skb->nf_trace in the
trace state struct.
Refresh this copy whenever verdict is != STOLEN.
Avoid 2 by skipping skb->mark access if verdict is STOLEN.
3 is avoided by precomputing the trace id.
Only dump the packet when verdict is not "STOLEN". |
| In the Linux kernel, the following vulnerability has been resolved:
cifs: fix potential double free during failed mount
RHBZ: https://bugzilla.redhat.com/show_bug.cgi?id=2088799 |
| In the Linux kernel, the following vulnerability has been resolved:
drm/amd/pm: fix double free in si_parse_power_table()
In function si_parse_power_table(), array adev->pm.dpm.ps and its member
is allocated. If the allocation of each member fails, the array itself
is freed and returned with an error code. However, the array is later
freed again in si_dpm_fini() function which is called when the function
returns an error.
This leads to potential double free of the array adev->pm.dpm.ps, as
well as leak of its array members, since the members are not freed in
the allocation function and the array is not nulled when freed.
In addition adev->pm.dpm.num_ps, which keeps track of the allocated
array member, is not updated until the member allocation is
successfully finished, this could also lead to either use after free,
or uninitialized variable access in si_dpm_fini().
Fix this by postponing the free of the array until si_dpm_fini() and
increment adev->pm.dpm.num_ps everytime the array member is allocated. |
| In the Linux kernel, the following vulnerability has been resolved:
media: pci: cx23885: Fix the error handling in cx23885_initdev()
When the driver fails to call the dma_set_mask(), the driver will get
the following splat:
[ 55.853884] BUG: KASAN: use-after-free in __process_removed_driver+0x3c/0x240
[ 55.854486] Read of size 8 at addr ffff88810de60408 by task modprobe/590
[ 55.856822] Call Trace:
[ 55.860327] __process_removed_driver+0x3c/0x240
[ 55.861347] bus_for_each_dev+0x102/0x160
[ 55.861681] i2c_del_driver+0x2f/0x50
This is because the driver has initialized the i2c related resources
in cx23885_dev_setup() but not released them in error handling, fix this
bug by modifying the error path that jumps after failing to call the
dma_set_mask(). |
| In the Linux kernel, the following vulnerability has been resolved:
ALSA: pcm: Fix races among concurrent hw_params and hw_free calls
Currently we have neither proper check nor protection against the
concurrent calls of PCM hw_params and hw_free ioctls, which may result
in a UAF. Since the existing PCM stream lock can't be used for
protecting the whole ioctl operations, we need a new mutex to protect
those racy calls.
This patch introduced a new mutex, runtime->buffer_mutex, and applies
it to both hw_params and hw_free ioctl code paths. Along with it, the
both functions are slightly modified (the mmap_count check is moved
into the state-check block) for code simplicity. |
| In the Linux kernel, the following vulnerability has been resolved:
ALSA: pcm: Fix races among concurrent prealloc proc writes
We have no protection against concurrent PCM buffer preallocation
changes via proc files, and it may potentially lead to UAF or some
weird problem. This patch applies the PCM open_mutex to the proc
write operation for avoiding the racy proc writes and the PCM stream
open (and further operations). |
| In the Linux kernel, the following vulnerability has been resolved:
perf: Fix perf_pending_task() UaF
Per syzbot it is possible for perf_pending_task() to run after the
event is free()'d. There are two related but distinct cases:
- the task_work was already queued before destroying the event;
- destroying the event itself queues the task_work.
The first cannot be solved using task_work_cancel() since
perf_release() itself might be called from a task_work (____fput),
which means the current->task_works list is already empty and
task_work_cancel() won't be able to find the perf_pending_task()
entry.
The simplest alternative is extending the perf_event lifetime to cover
the task_work.
The second is just silly, queueing a task_work while you know the
event is going away makes no sense and is easily avoided by
re-arranging how the event is marked STATE_DEAD and ensuring it goes
through STATE_OFF on the way down. |
| In the Linux kernel, the following vulnerability has been resolved:
Bluetooth: hci_core: Fix leaking sent_cmd skb
sent_cmd memory is not freed before freeing hci_dev causing it to leak
it contents. |
| In the Linux kernel, the following vulnerability has been resolved:
scsi: pm8001: Fix use-after-free for aborted SSP/STP sas_task
Currently a use-after-free may occur if a sas_task is aborted by the upper
layer before we handle the I/O completion in mpi_ssp_completion() or
mpi_sata_completion().
In this case, the following are the two steps in handling those I/O
completions:
- Call complete() to inform the upper layer handler of completion of
the I/O.
- Release driver resources associated with the sas_task in
pm8001_ccb_task_free() call.
When complete() is called, the upper layer may free the sas_task. As such,
we should not touch the associated sas_task afterwards, but we do so in the
pm8001_ccb_task_free() call.
Fix by swapping the complete() and pm8001_ccb_task_free() calls ordering. |
| In the Linux kernel, the following vulnerability has been resolved:
scsi: pm8001: Fix use-after-free for aborted TMF sas_task
Currently a use-after-free may occur if a TMF sas_task is aborted before we
handle the IO completion in mpi_ssp_completion(). The abort occurs due to
timeout.
When the timeout occurs, the SAS_TASK_STATE_ABORTED flag is set and the
sas_task is freed in pm8001_exec_internal_tmf_task().
However, if the I/O completion occurs later, the I/O completion still
thinks that the sas_task is available. Fix this by clearing the ccb->task
if the TMF times out - the I/O completion handler does nothing if this
pointer is cleared. |
| In the Linux kernel, the following vulnerability has been resolved:
selinux: fix double free of cond_list on error paths
On error path from cond_read_list() and duplicate_policydb_cond_list()
the cond_list_destroy() gets called a second time in caller functions,
resulting in NULL pointer deref. Fix this by resetting the
cond_list_len to 0 in cond_list_destroy(), making subsequent calls a
noop.
Also consistently reset the cond_list pointer to NULL after freeing.
[PM: fix line lengths in the description] |
| In the Linux kernel, the following vulnerability has been resolved:
btrfs: fix use-after-free after failure to create a snapshot
At ioctl.c:create_snapshot(), we allocate a pending snapshot structure and
then attach it to the transaction's list of pending snapshots. After that
we call btrfs_commit_transaction(), and if that returns an error we jump
to 'fail' label, where we kfree() the pending snapshot structure. This can
result in a later use-after-free of the pending snapshot:
1) We allocated the pending snapshot and added it to the transaction's
list of pending snapshots;
2) We call btrfs_commit_transaction(), and it fails either at the first
call to btrfs_run_delayed_refs() or btrfs_start_dirty_block_groups().
In both cases, we don't abort the transaction and we release our
transaction handle. We jump to the 'fail' label and free the pending
snapshot structure. We return with the pending snapshot still in the
transaction's list;
3) Another task commits the transaction. This time there's no error at
all, and then during the transaction commit it accesses a pointer
to the pending snapshot structure that the snapshot creation task
has already freed, resulting in a user-after-free.
This issue could actually be detected by smatch, which produced the
following warning:
fs/btrfs/ioctl.c:843 create_snapshot() warn: '&pending_snapshot->list' not removed from list
So fix this by not having the snapshot creation ioctl directly add the
pending snapshot to the transaction's list. Instead add the pending
snapshot to the transaction handle, and then at btrfs_commit_transaction()
we add the snapshot to the list only when we can guarantee that any error
returned after that point will result in a transaction abort, in which
case the ioctl code can safely free the pending snapshot and no one can
access it anymore. |
| In the Linux kernel, the following vulnerability has been resolved:
moxart: fix potential use-after-free on remove path
It was reported that the mmc host structure could be accessed after it
was freed in moxart_remove(), so fix this by saving the base register of
the device and using it instead of the pointer dereference. |
| A use-after-free in the MPEG1or2Demux::newElementaryStream() function of Live555 Streaming Media v2018.09.02 allows attackers to cause a Denial of Service (DoS) via supplying a crafted MPEG Program stream. |
| In the Linux kernel, the following vulnerability has been resolved:
nbd: fix uaf in nbd_genl_connect() error path
There is a use-after-free issue in nbd:
block nbd6: Receive control failed (result -104)
block nbd6: shutting down sockets
==================================================================
BUG: KASAN: slab-use-after-free in recv_work+0x694/0xa80 drivers/block/nbd.c:1022
Write of size 4 at addr ffff8880295de478 by task kworker/u33:0/67
CPU: 2 UID: 0 PID: 67 Comm: kworker/u33:0 Not tainted 6.15.0-rc5-syzkaller-00123-g2c89c1b655c0 #0 PREEMPT(full)
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2~bpo12+1 04/01/2014
Workqueue: nbd6-recv recv_work
Call Trace:
<TASK>
__dump_stack lib/dump_stack.c:94 [inline]
dump_stack_lvl+0x116/0x1f0 lib/dump_stack.c:120
print_address_description mm/kasan/report.c:408 [inline]
print_report+0xc3/0x670 mm/kasan/report.c:521
kasan_report+0xe0/0x110 mm/kasan/report.c:634
check_region_inline mm/kasan/generic.c:183 [inline]
kasan_check_range+0xef/0x1a0 mm/kasan/generic.c:189
instrument_atomic_read_write include/linux/instrumented.h:96 [inline]
atomic_dec include/linux/atomic/atomic-instrumented.h:592 [inline]
recv_work+0x694/0xa80 drivers/block/nbd.c:1022
process_one_work+0x9cc/0x1b70 kernel/workqueue.c:3238
process_scheduled_works kernel/workqueue.c:3319 [inline]
worker_thread+0x6c8/0xf10 kernel/workqueue.c:3400
kthread+0x3c2/0x780 kernel/kthread.c:464
ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:153
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
</TASK>
nbd_genl_connect() does not properly stop the device on certain
error paths after nbd_start_device() has been called. This causes
the error path to put nbd->config while recv_work continue to use
the config after putting it, leading to use-after-free in recv_work.
This patch moves nbd_start_device() after the backend file creation. |
| In the Linux kernel, the following vulnerability has been resolved:
KVM: arm64: Make ICC_*SGI*_EL1 undef in the absence of a vGICv3
On a system with a GICv3, if a guest hasn't been configured with
GICv3 and that the host is not capable of GICv2 emulation,
a write to any of the ICC_*SGI*_EL1 registers is trapped to EL2.
We therefore try to emulate the SGI access, only to hit a NULL
pointer as no private interrupt is allocated (no GIC, remember?).
The obvious fix is to give the guest what it deserves, in the
shape of a UNDEF exception. |
