| CVE |
Vendors |
Products |
Updated |
CVSS v3.1 |
| In the Linux kernel, the following vulnerability has been resolved:
scsi: core: Fill in DMA padding bytes in scsi_alloc_sgtables()
During fuzz testing, the following issue was discovered:
BUG: KMSAN: uninit-value in __dma_map_sg_attrs+0x217/0x310
__dma_map_sg_attrs+0x217/0x310
dma_map_sg_attrs+0x4a/0x70
ata_qc_issue+0x9f8/0x1420
__ata_scsi_queuecmd+0x1657/0x1740
ata_scsi_queuecmd+0x79a/0x920
scsi_queue_rq+0x4472/0x4f40
blk_mq_dispatch_rq_list+0x1cca/0x3ee0
__blk_mq_sched_dispatch_requests+0x458/0x630
blk_mq_sched_dispatch_requests+0x15b/0x340
__blk_mq_run_hw_queue+0xe5/0x250
__blk_mq_delay_run_hw_queue+0x138/0x780
blk_mq_run_hw_queue+0x4bb/0x7e0
blk_mq_sched_insert_request+0x2a7/0x4c0
blk_execute_rq+0x497/0x8a0
sg_io+0xbe0/0xe20
scsi_ioctl+0x2b36/0x3c60
sr_block_ioctl+0x319/0x440
blkdev_ioctl+0x80f/0xd70
__se_sys_ioctl+0x219/0x420
__x64_sys_ioctl+0x93/0xe0
x64_sys_call+0x1d6c/0x3ad0
do_syscall_64+0x4c/0xa0
entry_SYSCALL_64_after_hwframe+0x6e/0xd8
Uninit was created at:
__alloc_pages+0x5c0/0xc80
alloc_pages+0xe0e/0x1050
blk_rq_map_user_iov+0x2b77/0x6100
blk_rq_map_user_io+0x2fa/0x4d0
sg_io+0xad6/0xe20
scsi_ioctl+0x2b36/0x3c60
sr_block_ioctl+0x319/0x440
blkdev_ioctl+0x80f/0xd70
__se_sys_ioctl+0x219/0x420
__x64_sys_ioctl+0x93/0xe0
x64_sys_call+0x1d6c/0x3ad0
do_syscall_64+0x4c/0xa0
entry_SYSCALL_64_after_hwframe+0x6e/0xd8
Bytes 14-15 of 16 are uninitialized
Memory access of size 16 starts at ffff88800cbdb000
When processing the last unaligned element of the scatterlist, it is
supplemented with missing bytes in the amount of pad_len. These bytes
remain uninitialized, which leads to a problem.
Extend last_sg->length by pad_len first, then use sg_zero_buffer() to
zero those pad_len bytes. sg_zero_buffer() uses sg_miter internally,
which correctly handles sg entries spanning multiple pages and padding
that crosses a page boundary.
Found by Linux Verification Center (linuxtesting.org) with Syzkaller. |
| In the Linux kernel, the following vulnerability has been resolved:
RDMA/cxgb4: Cancel reg_work before freeing device on remove
c4iw_uld_state_change() queues reg_work to register the RDMA device.
c4iw_remove() can free ctx->dev while this work is pending or running,
leaving c4iw_register_device() accessing the freed device.
Cancel reg_work before removing the device. The registration work can
tear down ctx->dev when registration fails, so do not unregister or
deallocate it again in that case.
This issue was found by an in-house static analysis tool. |
| In the Linux kernel, the following vulnerability has been resolved:
regulator: as3722_get_regulator_dt_data: fix premature of_node_put leaving dangling of_node pointer
In as3722_get_regulator_dt_data(), of_get_child_by_name() acquires a
reference on np, which is then assigned to pdev->dev.of_node. The
function immediately calls of_node_put(np), releasing the reference and
leaving pdev->dev.of_node as a dangling pointer.
Remove the of_node_put(np) call to let the device hold the reference. |
| In the Linux kernel, the following vulnerability has been resolved:
openrisc: fix arbitrary kernel memory access via or1k_atomic syscall
sys_or1k_atomic() (syscall 244 in the "or1k" ABI) takes two user
pointers, v1 and v2, and swaps the words they point to in hand-written
assembly.
l.lwz r29,0(r4)
l.lwz r27,0(r5)
l.sw 0(r4),r27
l.sw 0(r5),r29
The pointers are not checked with access_ok(). The four memory
accesses also have no exception table entries.
A caller passes a kernel address as either pointer, and the syscall
reads from and writes to it directly.
This gives an unprivileged process a kernel read/write primitive. It
overwrites kernel data such as the sys_call_table, gaining code
execution in kernel context.
Check both pointers before entering the critical section. Add fixups
for the four memory accesses so faults on valid but unmapped user
addresses return -EFAULT.
[shorne@gmail.com: fix comment style] |
| In the Linux kernel, the following vulnerability has been resolved:
openvswitch: Fix CT limit teardown use-after-free
Packet processing uses CT limit state under RCU, while netns teardown
frees that state under ovs_mutex. The CT limit pointer was neither removed
from readers nor protected by a grace period, allowing packet processing to
dereference the freed state.
An unprivileged user can trigger this bug from a user and network
namespace, causing a slab-use-after-free in ovs_ct_execute() when the
netns is torn down.
Publish the CT limit pointer through RCU, remove it before teardown, and
wait for readers before freeing its contents. Keep ovs_mutex around
individual CT limit updates, and use the RCU read-side lock while GET
traverses the RCU-protected limit lists.
Netns teardown detaches the RCU-protected CT limit state in the pernet
.pre_exit callback while holding ovs_mutex. The pernet core guarantees an
RCU grace period between the .pre_exit and .exit callbacks, so the .exit
callback completes the teardown without adding any extra synchronization.
The netlink command handlers do not need NULL checks because the userspace
netlink socket holds an active reference to its network namespace while a
request is processed. The per-netns exit path therefore cannot run
concurrently with SET, DEL, or GET for that socket's namespace. |
| In the Linux kernel, the following vulnerability has been resolved:
lockd: pin next file across nlm_inspect_file lock-drop
nlm_traverse_files() pins the current file with f_count++ across
a mutex_unlock for nlm_inspect_file(), but nothing pins the saved
next pointer. A concurrent nlm_release_file() can kfree the next
file during the unlock window, and the iterator dereferences freed
memory on the next loop step.
Pin both current and next before the lock-drop. Advance by
swapping the pinned cursors at the end of each iteration so next
is always held alive across the unlock.
Always call nlm_file_release() after dropping the iteration pin,
regardless of whether the file matched the predicate. Use
nlm_file_inuse(), which does a live walk of the inode lock list,
rather than the cached f_locks field, so skipped files that never
ran nlm_inspect_file() are evaluated correctly.
Because every file in a hash bucket is now pinned and released,
files skipped by the is_failover_file predicate that have no
locks, blocks, shares, or external references are deleted during
traversal. The old code never evaluated skipped files for
cleanup. The new behavior is intentional: such files are stale
and should not persist in the table. |
| In the Linux kernel, the following vulnerability has been resolved:
nvme: zero the discard fallback page
nvme_setup_discard() always maps sizeof(struct nvme_dsm_range) *
NVME_DSM_MAX_RANGES = 4096 bytes as the DSM payload however many ranges
the command declares, because some devices ignore the 'Number of Ranges'
field - the Fixes: commit records two that read past the declared ranges.
A single-range discard fills only the first 16 bytes.
Normally the buffer comes from kzalloc() and the other 4080 bytes are
zero. When that allocation fails the code falls back to the
per-controller ctrl->discard_page, which nvme_init_ctrl() obtains with
alloc_page(GFP_KERNEL) and nothing ever zeroes, so those 4080 bytes are
whatever the page last held and are handed to the controller. Reaching
it requires the kzalloc(GFP_ATOMIC | __GFP_NOWARN) to fail, that is
memory pressure; it is not remotely triggerable. Failing the allocation
under KMSAN reproduces it, with the leaked tail full of vmemmap struct
page pointers. The extent in the report is a partial transfer of the
payload, not the whole 4096 bytes; the 16-byte boundary in it is the one
declared range:
[ 11.991601] BUG: KMSAN: uninit-value in dma_map_phys+0x14c8/0x1900
[ 11.991969] dma_map_phys+0x14c8/0x1900
[ 11.992220] dma_map_page_attrs+0xcf/0x130
[ 11.992485] e1000_xmit_frame+0x4099/0x6d10
[ 11.992768] dev_hard_start_xmit+0x22f/0xa80
[ 11.993068] sch_direct_xmit+0x35c/0xcb0
[ 11.993315] __dev_queue_xmit+0x1ee5/0x5eb0
[ 11.993608] ip_finish_output2+0x1903/0x1c30
[ 11.993881] ip_finish_output+0x288/0x870
[ 11.994125] ip_output+0x15e/0x400
[ 11.994365] __ip_queue_xmit+0x1e85/0x1fb0
[ 11.994639] ip_queue_xmit+0x60/0x80
[ 11.994899] __tcp_transmit_skb+0x4e71/0x5fa0
[ 11.995210] tcp_write_xmit+0x3a36/0x9160
[ 11.995533] __tcp_push_pending_frames+0xc5/0x3c0
[ 11.995854] tcp_push+0x7dc/0x840
[ 11.996076] tcp_sendmsg_locked+0x766c/0x8400
[ 11.996371] tcp_sendmsg+0x4b/0x90
[ 11.996572] inet_sendmsg+0x134/0x2a0
[ 11.996823] __sock_sendmsg+0x265/0x360
[ 11.997076] sock_sendmsg+0x100/0x1e0
[ 11.997293] nvme_tcp_try_send+0x196f/0x6370
[ 11.997605] nvme_tcp_queue_rq+0x1d54/0x20b0
[ 11.997882] blk_mq_dispatch_rq_list+0x5ee/0x2e50
[ 11.998175] __blk_mq_sched_dispatch_requests+0x16dc/0x24a0
[ 11.998539] blk_mq_sched_dispatch_requests+0x11b/0x2c0
[ 11.998865] blk_mq_run_work_fn+0x13b/0x280
[ 11.999146] process_scheduled_works+0x966/0x1ad0
[ 11.999465] worker_thread+0xe44/0x1480
[ 11.999709] kthread+0x53b/0x600
[ 11.999927] ret_from_fork+0x29f/0x7c0
[ 12.000191] ret_from_fork_asm+0x1a/0x30
[ 12.000460]
[ 12.000558] Uninit was created at:
[ 12.000788] __alloc_frozen_pages_noprof+0x8bf/0xd30
[ 12.001096] alloc_pages_mpol+0x1d0/0x5f0
[ 12.001326] alloc_pages_noprof+0x102/0x290
[ 12.001627] nvme_init_ctrl+0x5a3/0x9f0
[ 12.001891] nvme_tcp_create_ctrl+0xd75/0x19b0
[ 12.002170] nvmf_dev_write+0x4c68/0x4fd0
[ 12.002426] vfs_write+0x587/0x1a10
[ 12.002636] __x64_sys_write+0x207/0x4f0
[ 12.002874] x64_sys_call+0x2ff0/0x3ea0
[ 12.003123] do_syscall_64+0x147/0x3b0
[ 12.003400] entry_SYSCALL_64_after_hwframe+0x77/0x7f
[ 12.003680]
[ 12.003777] Bytes 16-2843 of 2844 are uninitialized
[ 12.004068] Memory access of size 2844 starts at ffff888109f82000
[ 12.004412]
[ 12.004530] CPU: 0 UID: 0 PID: 101 Comm: kworker/0:1H Not tainted 7.2.0-rc5-NVMECTL-gf5098b6bae76 #1 PREEMPT(lazy)
[ 12.005127] Hardware name: QEMU Ubuntu 24.04 PC v2 (i440FX + PIIX, arch_caps fix, 1996), BIOS 1.16.3-debian-1.16.3-2 04/01/2014
[ 12.005762] Workqueue: kblockd blk_mq_run_work_fn
[ 12.006073] =====================================================
Allocate the page with __GFP_ZERO. The single allocation site covers
every use of it: bytes no discard has written stay zero, and bytes one
did write hold that controller's own range list, which it has already
been sent. |
| In the Linux kernel, the following vulnerability has been resolved:
sctp: stop processing a packet once its association is deleted
sctp_endpoint_bh_rcv() looks the association up only when chunk->asoc is
NULL, and caches the result in chunk->asoc and chunk->transport without
taking a reference.
A packet that matches no association is handed to the endpoint, so a peer
can bundle COOKIE ECHO, SHUTDOWN and SHUTDOWN ACK in one packet. The
COOKIE ECHO creates the association, the SHUTDOWN chunk caches it, and
with the outqueue empty the SHUTDOWN ACK reaches sctp_sf_do_9_2_final(),
so the association and its transports are freed.
The endpoint loop has no counterpart to the asoc->base.dead check in
sctp_assoc_bh_rcv(). The next chunk writes to last_time_heard in the freed
transport and is then passed to sctp_do_sm() with the freed association.
The transport is freed through RCU, so this needs the packet to come off
the socket backlog, where the loop runs in task context.
The endpoint loop cannot do the same check: it holds no reference on the
association, so reading asoc->base.dead would itself be a use-after-free.
Mark the packet for discard in the command interpreter, just before it
deletes the association. That is also before sctp_inq_free() releases the
chunk on the association receive path.
sctp_sf_do_5_2_4_dupcook() issues SCTP_CMD_DELETE_TCB for the temporary
association, while the one the packet belongs to stays alive. A restarting
peer can bundle DATA behind its COOKIE ECHO, so compare against
chunk->asoc and leave that case alone. |
| In the Linux kernel, the following vulnerability has been resolved:
sctp: drop a chunk if its transport was removed
sctp_rcv() resolves the transport once per packet and leaves it in
chunk->transport. The lookup reference, or the one sctp_add_backlog() takes
if the socket is owned by userspace, keeps it around until the chunk has
been processed.
An authenticated ASCONF DEL-IP can remove it in the meantime.
sctp_assoc_rm_peer() takes the transport out of the association and calls
sctp_transport_free(), which tags it dead and drops the reference the
association held. There is a window on both paths: the packet can sit on
the socket backlog, and on the direct path the lookup completes before
bh_lock_sock().
The DATA chunk in that packet puts the removed transport back into
asoc->peer.last_data_from. Once the packet is done that reference goes
away and the transport is freed by RCU, so the next delayed SACK carries
the pointer into the SACK chunk and sctp_outq_select_transport() reads the
freed transport's state.
Drop the chunk in sctp_inq_push(), next to the existing rcvr->dead check.
Both paths reach it with the association's socket lock held. The peer
retransmits it. |
| In the Linux kernel, the following vulnerability has been resolved:
power: supply: bq24257: fix use-after-free on remove
The STAT-pin interrupt is devm-managed, so it stays armed until the devm
cleanup that runs after remove() returns. remove() cancels
bq->iilimit_setup_work while the threaded handler can still fire; that
handler reschedules the work and dereferences bq, so the work runs
against freed memory once devm frees bq.
Make the delayed work device-managed with devm_delayed_work_autocancel(),
registered before the interrupt request. The devm cleanup then releases
the interrupt first, so the handler can no longer reschedule the work,
and cancels the work before bq is freed. The explicit
cancel_delayed_work_sync() in remove() is no longer needed and is dropped.
Found by static analysis. |
| In the Linux kernel, the following vulnerability has been resolved:
power: supply: bq256xx: drain usb_work before freeing the charger
The USB-PHY notifier queues usb_work, whose handler calls
power_supply_changed(bq->charger). The reset devm action only unregisters
the notifier and was registered before the power supplies, so devm frees
bq->charger on unwind before the action runs; a usb_work still queued can
then dereference it.
Register the reset action after the power supplies, so it unregisters
the notifiers and drains usb_work before the supplies are released.
Initialize usb_work and obtain the PHY references before registering
the notifiers, so the worker cannot run before the supplies exist.
Found by static analysis. |
| In the Linux kernel, the following vulnerability has been resolved:
power: supply: lp8727: fix use-after-free in lp8727_release_irq()
lp8727_isr_func(), the threaded IRQ handler, is the only caller that arms
pchg->work via schedule_delayed_work(). lp8727_release_irq() currently
cancels the work before freeing the IRQ, so an IRQ delivered in between
can re-arm the work through the threaded handler. After .remove returns
the devm layer frees pchg while lp8727_delayed_func() may still run and
dereference it.
Free the IRQ first so the threaded handler is quiesced and can no longer
queue work, then cancel the delayed work to drain the final generation.
This issue was found by an in-house static analysis tool. |
| In the Linux kernel, the following vulnerability has been resolved:
power: supply: rt9455: quiesce delayed work before teardown
The threaded IRQ handler can queue pwr_rdy_work,
max_charging_time_work and batt_presence_work. pwr_rdy_work and
batt_presence_work can also queue max_charging_time_work, while
batt_presence_work can requeue itself.
rt9455_remove() cancels max_charging_time_work before
batt_presence_work. The latter can therefore queue
max_charging_time_work after it has already been cancelled:
rt9455_remove() workqueue
cancel pwr_rdy_work
cancel max_charging_time_work
batt_presence_work queues
max_charging_time_work
cancel batt_presence_work
return
devres frees rt9455_info
max_charging_time_work dereferences
rt9455_info
The IRQ also remains registered until devres cleanup and can queue more
work after any of the cancellation calls. If rt9455_hw_init() fails
after the IRQ has been requested, probe returns without cancelling work
that may already have been queued. A pending callback can then access
rt9455_info after it has been freed.
Register rt9455_cancel_all_delayed_works() through
devm_add_action_or_reset() right after devm_power_supply_register().
devres invokes the action in reverse registration order, after the
managed IRQ has been freed and before rt9455_info is released, so the
delayed works are drained in both rt9455_remove() and the probe error
path. Cancel pwr_rdy_work and batt_presence_work before
max_charging_time_work because both can queue the latter.
This issue was found by an in-house static analysis tool. |
| In the Linux kernel, the following vulnerability has been resolved:
power: supply: twl4030_charger: cancel workers via devm
bci is devm-allocated. Two workers (bci->work and bci->current_worker)
dereference it. twl4030_bci_remove() disables charging and masks
interrupts. It cancels neither worker. A worker pending at remove() can
run after devm frees bci.
The USB transceiver comes from devm_usb_get_phy_by_node(). devm
unregisters its notifier only after remove() returns. A cancel_work_sync()
in remove() can then race a notifier reschedule. devm_work_autocancel()
and devm_delayed_work_autocancel() avoid that. They cancel the workers
during devm release, before bci is freed.
The current_worker is registered first, since devm will cancel in
reverse order and bci->work can reschedule current_worker.
[Move comment about order into the commit message] |
| In the Linux kernel, the following vulnerability has been resolved:
power: supply: max17040: synchronize work cancellation on suspend
max17040_work() requeues itself after every poll. cancel_delayed_work()
only cancels a pending instance and does not wait for a callback that is
already running.
If system suspend races with the polling callback, the callback can
continue accessing the fuel gauge and requeue itself after the suspend
callback returns.
Use cancel_delayed_work_sync() to ensure polling is quiesced before
suspend completes. |
| In the Linux kernel, the following vulnerability has been resolved:
s390/dasd: Do not complete a failed ESE read as successful
dasd_int_handler() completes an NRF read of an unallocated ESE track by
calling ese_read() and unconditionally marking the request
DASD_CQR_SUCCESS. dasd_eckd_ese_read() can return an error before it has
zeroed the destination buffer: a failed sense-data parse or a current
track outside the requested range both return early, leaving the
destination pages untouched. The request is still completed successfully,
so the block layer is handed stale / uninitialized memory instead of
zeros.
Check the ese_read() return value and fail the request through the normal
error path instead of forcing DASD_CQR_SUCCESS. |
| In the Linux kernel, the following vulnerability has been resolved:
mmc: via-sdmmc: stop card-detect handling on probe failure
request_irq() registers the SD card-detect interrupt and the probe enables
it before mmc_add_host() runs. If mmc_add_host() fails, the error path only
unmaps the registers and returns: the interrupt stays registered, so the
handler keeps running against the host once it is freed. via_sdc_isr()
dereferences sdhost and its MMIO base and schedules carddet_work, which
via_sdc_card_detect() also runs against freed memory through its
container_of() dereference.
Add a probe-error path that disables and frees the interrupt and cancels
carddet_work before unmapping. carddet_work can re-enable the device
interrupt via via_reset_pcictrl(), which restores PCIINTCTRL, so mask it
again after cancelling the work.
This issue was found by an in-house static analysis tool and confirmed by
manual code review. |
| In the Linux kernel, the following vulnerability has been resolved:
interconnect: Fix use after free in icc_get() and of_icc_get_by_index()
In of_icc_get_by_index() and icc_get(), if the dynamic allocation for
path->name fails via kasprintf(), the error handling path directly
calls kfree(path) to free the path object and returns an error.
However, prior to this point, path_find() calls path_init(), which
already links the path's requests into the req_list of the respective
interconnect nodes via hlist_add_head(). Directly invoking kfree(path)
leaves dangling pointers in the hlist. A subsequent call to icc_get()
or icc_set_bw() will traverse or modify these corrupted lists, triggering
a slab use afterfree.
KASAN report showing the vulnerability when reproducing via debugfs:
BUG: KASAN: slab-use-after-free in path_find+0x6f8/0xcfc
Write of size 8 at addr fff000000d43f748 by task sh/1
...
Call trace:
kasan_report+0xac/0xfc
path_find+0x6f8/0xcfc
icc_get+0x148/0x380
icc_get_set+0xf8/0x2d0
...
Freed by task 1:
kfree+0x1a0/0x4a4
icc_get+0x2cc/0x380
icc_get_set+0xf8/0x2d0
Fix this by replacing kfree(path) with the proper teardown function,
icc_put(path), which safely removes the requests from the req_list using
hlist_del() and drops the provider usage references before freeing the
memory.
Additionally, in icc_get(), ensure that the icc_lock mutex is released
prior to calling icc_put(path) to avoid a deadlock, as icc_put()
internally acquires the same lock. |
| In the Linux kernel, the following vulnerability has been resolved:
slip: fix use-after-free in sl_sync()
slip_devs[] stores bare net_device pointers and takes no reference on
them. sl_sync() and sl_alloc() walk that table from slip_open() under
rtnl_lock(), while an entry is dropped by sl_free_netdev(), which
sl_setup() installs as dev->priv_destructor.
priv_destructor is called from netdev_run_todo(), which deliberately
runs with the RTNL semaphore released so that it can sleep while waiting
for the device refcount to drop:
/* Snapshot list, allow later requests */
list_replace_init(&net_todo_list, &list);
__rtnl_unlock();
...
if (dev->priv_destructor)
dev->priv_destructor(dev); /* slip_devs[i] = NULL */
if (dev->needs_free_netdev)
free_netdev(dev);
...
/* Free network device */
kobject_put(&dev->dev.kobj);
So rtnl_lock() does not serialise slip_open() against the teardown at
all. sl_sync() can load slip_devs[i] while the entry is still published
and dereference it after netdev_run_todo() has run the destructor and
released the device:
CPU0 (slip_open) CPU1 (slip_close)
unregister_netdev()
rtnl_unlock()
netdev_run_todo()
__rtnl_unlock()
rtnl_lock()
sl_sync()
dev = slip_devs[i]
priv_destructor(dev)
slip_devs[i] = NULL
kobject_put(&dev->dev.kobj)
/* dev is freed */
sl = netdev_priv(dev)
if (sl->tty || sl->leased) /* use-after-free */
BUG: KASAN: use-after-free in sl_sync drivers/net/slip/slip.c:730 [inline]
BUG: KASAN: use-after-free in slip_open+0xef4/0x1210 drivers/net/slip/slip.c:806
Read of size 1 at addr ffff8880712dac71 by task syz-executor.2/6506
CPU: 2 PID: 6506 Comm: syz-executor.2 Not tainted 6.1.134-syzkaller-00260-g0c8fc3469765 #0
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.12.0-1 04/01/2014
Call Trace:
sl_sync drivers/net/slip/slip.c:730 [inline]
slip_open+0xef4/0x1210 drivers/net/slip/slip.c:806
tty_ldisc_open+0xa2/0x120 drivers/tty/tty_ldisc.c:433
tty_set_ldisc+0x324/0x720 drivers/tty/tty_ldisc.c:564
tiocsetd drivers/tty/tty_io.c:2428 [inline]
tty_ioctl+0x5f0/0x1530 drivers/tty/tty_io.c:2712
Allocated by task 6502:
alloc_netdev_mqs+0x98/0xfe0 net/core/dev.c:10719
sl_alloc drivers/net/slip/slip.c:756 [inline]
slip_open+0x36d/0x1210 drivers/net/slip/slip.c:817
tty_ldisc_open+0xa2/0x120 drivers/tty/tty_ldisc.c:433
tty_set_ldisc+0x324/0x720 drivers/tty/tty_ldisc.c:564
Freed by task 6497:
device_release+0xa2/0x240 drivers/base/core.c:2507
kobject_put+0x179/0x280 lib/kobject.c:729
netdev_run_todo+0x6c8/0xef0 net/core/dev.c:10509
slip_close+0x166/0x1c0 drivers/net/slip/slip.c:906
tty_ldisc_close+0x113/0x1a0 drivers/tty/tty_ldisc.c:456
tty_ldisc_kill+0x94/0x160 drivers/tty/tty_ldisc.c:614
tty_ldisc_release+0xe3/0x2b0 drivers/tty/tty_ldisc.c:782
tty_release+0xbcc/0xe70 drivers/tty/tty_io.c:1860
Commit e58c19124189 ("slip: Fix use-after-free Read in slip_open") fixed
a different source of stale entries - a device left in slip_devs[] after
slip_open() freed it on the registration error path - and does not
address this race, which is why the report survives it.
Drop the entry from ndo_uninit instead. unregister_netdevice() calls
ndo_uninit under RTNL, before the device is queued to netdev_run_todo(),
so an entry that sl_sync() can still see while holding RTNL belongs to a
device that cannot be freed until RTNL is dropped. sl_free_netdev()
stays only for the slip_open() error path, where register_netdevice()
may have failed before ndo_init and ndo_uninit is then not called
either. Both running for the same device is harmless: the
---truncated--- |
| In the Linux kernel, the following vulnerability has been resolved:
net: openvswitch: fix flow mask use-after-free on flow deletion
The commit in the Fixes tag below made so flow->mask free is scheduled
via RCU right after it is removed from the flow table. The pointer
stays in the flow structure and it can be accessible while in the same
RCU critical section. This is done to avoid requiring ovs_mutex for
the ovs_flow_free().
However, while removing the flow during processing of CMD_DEL, we do
not take RCU read lock before the removal, and ovs_flow_cmd_fill_info()
uses the flow->mask pointer afterwards. The RCU read lock is taken,
but it's already late at that point. The comment on that line
acknowledges that the lock is cosmetic and doesn't serve a real purpose.
This leads to use-after-free if the RCU grace period passes between
removal and the filling. It is a short race window, but it is there
and can lead to a real crash in case memory allocation for the info
takes a bit longer:
BUG: KASAN: slab-use-after-free in __ovs_nla_put_key
net/openvswitch/flow_netlink.c:1996
BUG: KASAN: slab-use-after-free in ovs_nla_put_key+0x2463/0x2e30
net/openvswitch/flow_netlink.c:2250
Read of size 4 at addr ffff88801ee89970 by task ovs_flow_del_ec/9487
Call Trace:
<TASK>
__ovs_nla_put_key net/openvswitch/flow_netlink.c:1996
ovs_nla_put_key+0x2463/0x2e30 net/openvswitch/flow_netlink.c:2250
ovs_flow_cmd_fill_info+0x420/0x9c0 net/openvswitch/datapath.c:930
ovs_flow_cmd_del+0x53a/0x970 net/openvswitch/datapath.c:1467
...
netlink_rcv_skb+0x156/0x420 net/netlink/af_netlink.c:2556
</TASK>
Allocated by task 9487:
mask_alloc net/openvswitch/flow_table.c:967
flow_mask_insert net/openvswitch/flow_table.c:1012
ovs_flow_tbl_insert+0xea2/0x1a90 net/openvswitch/flow_table.c:1084
ovs_flow_cmd_new+0x7e3/0xd90 net/openvswitch/datapath.c:1086
...
netlink_rcv_skb+0x156/0x420 net/netlink/af_netlink.c:2556
Freed by task 9485:
rcu_free_sheaf+0x1e/0x100 mm/slub.c:5978
rcu_do_batch kernel/rcu/tree.c:2645
rcu_core+0x59c/0x10c0 kernel/rcu/tree.c:2897
handle_softirqs+0x1e4/0x9a0 kernel/softirq.c:622
...
instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1062
ovs_flow_tbl_remove() must be called after the ovs_flow_cmd_fill_info()
to avoid this race. This also helps with cleaning up the forced cast
and the cosmetic RCU read lock. Before the commit in the Fixes tag the
order did not matter as long as the flow object itself was not freed.
A wider RCU critical section could be another option, but we have a
GFP_KERNEL allocation in the way.
Reported by Trend Micro's Zero Day Initiative as ZDI-CAN-32042. |
