| CVE |
Vendors |
Products |
Updated |
CVSS v3.1 |
| In the Linux kernel, the following vulnerability has been resolved:
locking/rt: Fix the incorrect RCU protection in rt_spin_unlock()
rt_spin_unlock() releases the RCU protection before unlocking the
lock. That opens the door for the following UAF scenario:
T1 T2
spin_lock(&p->lock); rcu_read_lock();
invalidate(p); p = rcu_dereference(ptr);
rcu_assign_pointer(ptr, NULL); if (!p) return;
spin_unlock(&p->lock); spin_lock(&p->lock)
lock(&lock->lock);
rcu_read_lock();
kfree_rcu(p); rcu_read_unlock();
....
spin_unlock(&p->lock)
rcu_read_unlock(); // Ends grace period
rcu_do_batch()
kfree(p);
UAF -> rt_mutex_cmpxchg_release(&lock->lock...)
Regular spinlocks keep preemption disabled accross the unlock operation,
which provides full RCU protection, but the RT substitution fails to
resemble that. Same applies for the rwlock substitution.
Move the rcu_read_unlock() invocation past the unlock operations to match
the non-RT semantics. This makes it asymmetric vs. rt_xxx_lock(), but
that's harmless as the caller needs to hold RCU read lock across the lock
operation. The migrate_enable() call stays before the unlock operation
because there is no per CPU operation in the unlock path which would
require migration to be kept disabled. |
| In the Linux kernel, the following vulnerability has been resolved:
tracing/osnoise: Call synchronize_rcu() when unregistering
This ensures that any RCU readers traversing the instance list
have finished, before releasing the reference on the tracer that
the instance points to. |
| In the Linux kernel, the following vulnerability has been resolved:
ALSA: seq: close a re-opened queue timer in the destructor
queue_delete() closes the queue timer, then frees it. snd_seq_timer_close()
clears q->timer->timeri. snd_use_lock_sync() then drains borrowers, and
snd_seq_timer_delete() frees q->timer.
A borrower can re-open the timer inside that window. A SET_QUEUE_CLIENT
that took a queueptr() use_lock reference before the queue was unlinked
runs snd_seq_timer_open() after the close. Open refuses re-open only while
timeri is set, and the close just cleared it, so it re-opens timeri.
snd_seq_timer_delete() does not close that instance. Its snd_seq_timer_stop()
is a no-op, because running was cleared first. So it frees q->timer with the
instance still live. The queue is freed next.
The instance stays on the global timer with callback_data pointing at the
freed queue. A non-owner START on the unlocked queue arms it. The next tick
derefs the freed queue in snd_seq_timer_interrupt().
Reachable by an unprivileged user with access to /dev/snd/seq. No CAP and
no queue ownership required.
Close any lingering instance in the destructor. There, ->timeri can no
longer change: the queue is unlinked and all use_lock borrowers have
drained, so no snd_seq_queue_use() can re-open it. Close it before clearing
q->timer. snd_timer_close() waits for any in-flight snd_seq_timer_interrupt()
to finish, and that callback still reads q->timer (via snd_seq_check_queue()),
so q->timer must stay valid until it drains. |
| In the Linux kernel, the following vulnerability has been resolved:
wifi: ath6kl: fix use-after-free in aggr_reset_state()
The aggr_reset_state() function uses timer_delete() (non-synchronous)
for the aggregation timer before proceeding to delete TID state and
before the structure is freed by callers like aggr_module_destroy().
If the timer callback (aggr_timeout) is executing when aggr_reset_state()
is called, the callback will continue to access aggr_conn fields like
rx_tid[] and stat[] which may be freed immediately after by
kfree(aggr_info->aggr_conn) in aggr_module_destroy().
Additionally, the timer callback can re-arm itself via mod_timer() while
aggr_reset_state() is running, creating a more complex race condition.
Use timer_delete_sync() instead to ensure any running timer callback
has completed before returning. |
| In the Linux kernel, the following vulnerability has been resolved:
sctp: avoid auth_enable sysctl UAF during netns teardown
proc_sctp_do_auth() updates the SCTP control socket after changing
net.sctp.auth_enable. The handler gets the per-net SCTP state from
ctl->data, so an already opened sysctl file can still target a network
namespace while that namespace is being torn down.
SCTP previously registered its per-net sysctls from sctp_defaults_init(),
while the control socket is created later from sctp_ctrlsock_init(). This
exposed a window during initialization where auth_enable was writable
before net->sctp.ctl_sock existed, and a teardown window where auth_enable
stayed writable after inet_ctl_sock_destroy() had released the control
socket.
Move the per-net SCTP sysctl registration into sctp_ctrlsock_init() after
sctp_ctl_sock_init() succeeds, and unregister the sysctl table before
destroying the control socket in sctp_ctrlsock_exit(). If sysctl
registration fails after the control socket was created, destroy the
control socket in the same init path.
Make sctp_sysctl_net_unregister() tolerate a missing header and clear the
saved pointer so init-error and exit paths can safely share the unregister
helper. |
| In the Linux kernel, the following vulnerability has been resolved:
ALSA: us144mkii: re-anchor capture URBs on resubmission
capture_urb_complete() resubmits each capture URB without anchoring it:
usb_get_urb(urb);
ret = usb_submit_urb(urb, GFP_ATOMIC);
Anchoring is a property of a submission, not of the URB. The giveback
path calls usb_unanchor_urb() before urb->complete(), so an URB
resubmitted from its own completion handler is off the anchor. The
capture URBs are anchored once, at stream start, so from the first
completion onward tascam->capture_anchor is empty.
tascam_free_urbs(), tascam_disconnect(), tascam_suspend() and the
stop-work path all call usb_kill_anchored_urbs(&tascam->capture_anchor)
to reap the capture URBs before anything is freed. With the anchor empty
those calls return immediately and the URBs stay queued on the host
controller.
tascam_free_urbs() then returns the capture transfer buffers with
usb_free_coherent(), and snd_card_free() releases the snd_card
allocation that embeds tascam (card->private_data). The controller
completes the queued URBs afterwards, writing device-supplied data into
the freed transfer buffer, and capture_urb_complete() dereferences the
freed driver object.
KASAN on 7.2.0-rc5 (arm64):
BUG: KASAN: slab-use-after-free in dummy_timer
Write of size 512 at addr ffff000015b62000
__asan_memcpy
dummy_timer
hrtimer_run_softirq
Allocated by task 64:
usb_alloc_coherent
tascam_alloc_urbs
tascam_probe
Freed by task 170:
usb_free_coherent
tascam_free_urbs
tascam_disconnect
usb_unbind_interface
BUG: KASAN: slab-use-after-free in capture_urb_complete
Read of size 4 at addr ffff0000170ee878
Freed by task 170:
release_card_device
snd_card_free
tascam_disconnect
Restore the usb_anchor_urb() between the reference count bump and the
resubmission. That also makes the handler's usb_unanchor_urb() failure
arm meaningful again and restores usb_kill_anchored_urbs() as a barrier
on the disconnect, suspend and stop-work paths.
The anchoring was removed on the premise that the URB is already anchored
from the initial submission, which does not hold once the first giveback
has run.
Discovered by XBOW, triaged by Baul Lee <baul.lee@xbow.com> |
| In the Linux kernel, the following vulnerability has been resolved:
tcp: defer md5sig_info kfree past RCU grace period in tcp_connect
The md5+ao reconciliation in tcp_connect() (net/ipv4/tcp_output.c)
has two symmetric branches:
if (needs_md5) {
tcp_ao_destroy_sock(sk, false);
} else if (needs_ao) {
tcp_clear_md5_list(sk);
kfree(rcu_replace_pointer(tp->md5sig_info, NULL, ...));
}
Both branches free a per-socket auth-info object while the socket is
in TCP_SYN_SENT and is already on the inet ehash (inserted by
inet_hash_connect() in tcp_v4_connect()). Both branches are reachable
by softirq RX-path readers that load the corresponding info pointer
via implicit RCU before bh_lock_sock_nested() is taken.
The needs_md5 branch is fixed in the prior patch by re-introducing
the call_rcu() free in tcp_ao_destroy_sock(): the equivalent per-key
loop runs inside tcp_ao_info_free_rcu(), the RCU callback, so by the
time it frees each tcp_ao_key all softirq readers that captured the
container have already completed rcu_read_unlock().
The needs_ao branch is not symmetric in the same way. The container
free can be deferred via kfree_rcu(md5sig, rcu) -- struct
tcp_md5sig_info already has the required rcu member
(include/net/tcp.h:1999-2002), and the rest of the tree already does
this in the tcp_md5sig_info_add() rollback paths
(net/ipv4/tcp_ipv4.c:1410, 1436). But the per-key teardown is done
by tcp_clear_md5_list() in process context BEFORE the container's
RCU grace period: it walks &md5sig->head and frees each
tcp_md5sig_key with bare hlist_del + kfree. A concurrent softirq
reader in __tcp_md5_do_lookup() / __tcp_md5_do_lookup_exact()
(tcp_ipv4.c:1253, 1298) walks the same list via
hlist_for_each_entry_rcu() and races with that bare kfree on the
keys themselves -- a per-key slab use-after-free of the same class
as the TCP-AO bug, on the same race window.
Fix this in two halves:
1. Convert the bare kfree() in tcp_connect() to kfree_rcu() so the
md5sig_info container joins the rest of the md5sig lifecycle.
The local-variable lift is mechanical and required because
kfree_rcu() is a macro that expects an lvalue.
2. Make tcp_clear_md5_list() RCU-safe by replacing hlist_del +
kfree(key) with hlist_del_rcu + kfree_rcu(key, rcu). struct
tcp_md5sig_key already carries the rcu member
(include/net/tcp.h:1995) and tcp_md5_do_del()
(net/ipv4/tcp_ipv4.c:1456) already uses kfree_rcu, so this
restores the lifecycle invariant the rest of the file follows
rather than introducing a one-off.
The other caller of tcp_clear_md5_list() is tcp_md5_destruct_sock()
(net/ipv4/tcp.c:412), which runs from the sock destructor when the
socket is already unhashed and unreachable; the extra grace period
there is unnecessary but harmless. Making the helper unconditionally
RCU-safe is the cleaner contract.
The needs_ao branch is not reachable by the userns reproducer used
to demonstrate the AO-side splat (the repro installs both keys but
ends up in the needs_md5 branch because the connect peer matches
the MD5 key, not the AO key); however the symmetric race exists
and a maintainer touching this code should not have to think about
which branch escapes RCU and which one does not.
[also credits to Qihang, who found that this races with tcp-diag] |
| In the Linux kernel, the following vulnerability has been resolved:
mm/memory_hotplug: fix incorrect altmap passing in error path
In create_altmaps_and_memory_blocks(), when arch_add_memory() succeeds
with memmap_on_memory enabled, the vmemmap pages are allocated from
params.altmap. If create_memory_block_devices() subsequently fails, the
error path calls arch_remove_memory() with a NULL altmap instead of
params.altmap.
This is a bug that could lead to memory corruption. Since altmap is NULL,
vmemmap_free() falls back to freeing the vmemmap pages into the system
buddy allocator via free_pages() instead of the altmap.
arch_remove_memory() then immediately destroys the physical linear mapping
for this memory. This injects unowned pages into the buddy allocator,
causing machine checks or memory corruption if the system later attempts
to allocate and use those freed pages.
Fix this by passing params.altmap to arch_remove_memory() in the error
path. |
| In the Linux kernel, the following vulnerability has been resolved:
batman-adv: bla: reacquire gw address after skb realloc
The pskb_may_pull() called by batadv_bla_is_backbone_gw() could reallocate
the buffer behind the skb. Variables which were pointing to the old buffer
need to be reassigned to avoid an use-after-free. |
| In the Linux kernel, the following vulnerability has been resolved:
netfilter: nf_nat_sip: reload possible stale data pointer
quoting sashiko:
------------------------------------------------------------------------
[..] noticed a potential memory bug and header corruption involving the
SIP NAT helper.
In net/netfilter/nf_nat_sip.c:nf_nat_sip():
if (skb_ensure_writable(skb, skb->len)) {
nf_ct_helper_log(skb, ct, "cannot mangle packet");
return NF_DROP;
}
uh = (void *)skb->data + protoff;
uh->dest = ct_sip_info->forced_dport;
if (!nf_nat_mangle_udp_packet(skb, ct, ctinfo, protoff,
0, 0, NULL, 0)) {
If a cloned or fragmented SKB is reallocated by skb_ensure_writable(), the
old data buffer is freed. However, nf_nat_sip() fails to update *dptr to
point to the new buffer.
It also appears to use nf_nat_mangle_udp_packet() on what could be a TCP
packet, which would overwrite the sequence number with a checksum update.
------------------------------------------------------------------------
nf_conntrack_sip linerizes skbs, hence no fragmented skb can be seen.
But clones are possible, so rebuild dptr.
Disable nf_nat_mangle_udp_packet() branch for TCP streams.
It doesn't look like this can ever happen, else we should have received
bug reports about this, so just check the conntrack is UDP and drop
otherwise.
The calling conntrack_sip set ->forced_dport for SIP_HDR_VIA_UDP messages,
so I don't think this is ever expected to be true for a TCP stream. |
| In the Linux kernel, the following vulnerability has been resolved:
batman-adv: access unicast_ttvn skb->data only after skb realloc
The pskb_may_pull() called by batadv_get_vid() could reallocate the buffer
behind the skb. Variables which were pointing to the old buffer need to be
reassigned to avoid an use-after-free.
This was done correctly for the ethernet header but missed for the
unicast_packet pointer. |
| In the Linux kernel, the following vulnerability has been resolved:
batman-adv: retrieve ethhdr after potential skb realloc on RX
pskb_may_pull() in batadv_interface_rx() could reallocate the buffer behind
the skb. Variables which were pointing to the old buffer need to be
reassigned to avoid an use-after-free.
This was done correctly for the VLAN header but missed for the ethernet
header which is later used for the TT and AP isolation handling. |
| In the Linux kernel, the following vulnerability has been resolved:
accel/amdxdna: Fix potential amdxdna_umap lifetime race
amdxdna_umap_release() calls the blocking mmu_interval_notifier_remove()
before removing the object from abo->mem.umap_list. If
aie2_populate_range() runs concurrently, it may obtain a reference to an
amdxdna_umap that is being released, leading to a potential use-after-free.
Use kref_get_unless_zero() in aie2_populate_range() when acquiring a
reference. If the reference count has already dropped to zero, release
is in progress and the entry is skipped. |
| In the Linux kernel, the following vulnerability has been resolved:
KVM: x86: Nullify irqfd->producer if updating IRTE for bypass fails
Nullify irqfd->producer if updating the IRTE for bypass fails, as leaving a
dangling pointer will result in a use-after-free if the irqfd is reachable
through KVM's routing, but the producer is freed separately. E.g. for VFIO
PCI, the producer is embedded in struct "vfio_pci_irq_ctx" and freed when
the vector is disabled, which can happen independent of routing updates.
[sean: drop PPC change, massage changelog] |
| In the Linux kernel, the following vulnerability has been resolved:
SUNRPC: pin upper rpc_clnt across the TLS connect_worker
The TLS connect path has a use-after-free: nothing pins the
upper rpc_clnt across the delayed connect_worker. xs_connect()
stores task->tk_client in sock_xprt::clnt as a raw pointer
and queues the worker; for TLS-secured transports that worker
is xs_tcp_tls_setup_socket(), which reads several fields out
of the saved pointer (cl_timeout, cl_program, cl_prog,
cl_vers, cl_cred, cl_stats) to construct the args for the
inner handshake rpc_clnt.
The xprt does not reference the rpc_clnt; the rpc_clnt
references the xprt. xs_destroy() does cancel the
connect_worker, but it runs only when the xprt's refcount
drops to zero, which cannot happen until the rpc_clnt
releases its cl_xprt reference in rpc_free_client_work().
When a TLS handshake fails fatally (for example, an mTLS
mount whose client cert does not match the server), the
connecting task is woken with -EACCES and exits, the mount
caller invokes rpc_shutdown_client(), and the upper rpc_clnt
is freed before the queued connect_worker fires.
xs_tcp_tls_setup_socket() then dereferences the freed clnt,
producing the refcount_t underflow Michael Nemanov reported.
Take a reference on the upper rpc_clnt in xs_connect() for
TLS transports via a new rpc_hold_client() helper, and drop
it in the connect_worker's exit path with rpc_release_client().
The xprt_lock_connect() / xprt_unlock_connect() pairing
already serialises xs_connect() with xs_tcp_tls_setup_socket(),
so the take and release are balanced one-for-one.
The non-TLS connect worker (xs_tcp_setup_socket) never reads
sock_xprt::clnt, so leave that path alone and avoid the
clnt-holds-xprt-holds-clnt cycle that would otherwise prevent
xprt destruction. |
| In the Linux kernel, the following vulnerability has been resolved:
net/liquidio: drop cached VF pci_dev LUT
The PF SR-IOV enable path caches VF pci_dev pointers in
dpiring_to_vfpcidev_lut[] by iterating with pci_get_device(). Those
entries do not own a reference, because the iterator drops the previous
device reference on each step. The cached pointer is then dereferenced
later when handling OCTEON_VF_FLR_REQUEST.
Replace the cached VF mapping with runtime lookup on the mailbox DPI
ring: derive the VF index from q_no, resolve the VF via exported PCI
IOV helpers, validate it with the PF pointer and VF ID, then issue
pcie_flr() and drop the reference with pci_dev_put(). Remove the
unused VF lookup table initialization and cleanup. |
| In the Linux kernel, the following vulnerability has been resolved:
accel/amdxdna: Fix VMA access race
aie2_populate_range() and amdxdna_umap_release() access a saved VMA
pointer that may have already been freed, leading to a potential
use-after-free.
Remove the VMA accesses from these functions to avoid the race. |
| In the Linux kernel, the following vulnerability has been resolved:
Bluetooth: MGMT: Fix adv monitor add failure cleanup
hci_add_adv_monitor() publishes a new adv_monitor in
hdev->adv_monitors_idr before the powered MSFT setup step. The MSFT
offload add path can then fail either locally before the controller add
command completes, or in the MSFT add callback. In the current queued
management add flow, hci_cmd_sync_work() still invokes
mgmt_add_adv_patterns_monitor_complete() with the original pending command
after msft_add_monitor_pattern() returns.
The buggy scenario involves two paths, with each column showing the order
within that path:
MSFT add handling MGMT completion
1. insert monitor and handle 1. receive sync error
2. send MSFT add command 2. call add-monitor completion
3. callback sees bad response 3. load cmd->user_data
4. callback frees monitor 4. read monitor->handle
Local MSFT setup failures have the other half of the same ownership bug:
they return an error after the IDR insertion, but no later code removes the
failed monitor from the IDR.
Keep ownership with the pending management command until its completion.
For normal management adds, the MSFT add callback now records successful
controller state and returns errors to its caller. The management
completion frees the monitor on non-success after copying the response
handle, while resume/reregister callback-error cleanup remains in the
MSFT callback. The success path keeps the existing bookkeeping.
Validation reproduced this kernel report:
BUG: KASAN: slab-use-after-free in mgmt_add_adv_patterns_monitor_complete+0xfb/0x260 [bluetooth]
Call Trace:
<TASK>
dump_stack_lvl+0x66/0xa0
print_report+0xce/0x5f0
? mgmt_add_adv_patterns_monitor_complete+0xfb/0x260 [bluetooth]
? srso_alias_return_thunk+0x5/0xfbef5
? __virt_addr_valid+0x19f/0x330
? mgmt_add_adv_patterns_monitor_complete+0xfb/0x260 [bluetooth]
kasan_report+0xe0/0x110
? mgmt_add_adv_patterns_monitor_complete+0xfb/0x260 [bluetooth]
mgmt_add_adv_patterns_monitor_complete+0xfb/0x260 [bluetooth]
? srso_alias_return_thunk+0x5/0xfbef5
? 0xffffffffc00d00da
? __pfx_mgmt_add_adv_patterns_monitor_complete+0x10/0x10 [bluetooth]
? __pfx_mgmt_add_adv_patterns_monitor_complete+0x10/0x10 [bluetooth]
? hci_cmd_sync_work+0x1ab/0x210 [bluetooth]
hci_cmd_sync_work+0x1c0/0x210 [bluetooth]
? __pfx_mgmt_add_adv_patterns_monitor_complete+0x10/0x10 [bluetooth]
process_one_work+0x4fd/0xbc0
? __pfx_process_one_work+0x10/0x10
? srso_alias_return_thunk+0x5/0xfbef5
? srso_alias_return_thunk+0x5/0xfbef5
? __list_add_valid_or_report+0x37/0xf0
? __pfx_hci_cmd_sync_work+0x10/0x10 [bluetooth]
? srso_alias_return_thunk+0x5/0xfbef5
worker_thread+0x2d8/0x570
? __pfx_worker_thread+0x10/0x10
kthread+0x1ad/0x1f0
? __pfx_kthread+0x10/0x10
ret_from_fork+0x3c9/0x540
? __pfx_ret_from_fork+0x10/0x10
? srso_alias_return_thunk+0x5/0xfbef5
? __switch_to+0x2e9/0x730
? __pfx_kthread+0x10/0x10
ret_from_fork_asm+0x1a/0x30
</TASK>
Allocated by task 471 on cpu 3 at 285.205389s:
kasan_save_stack+0x33/0x60
kasan_save_track+0x17/0x60
__kasan_kmalloc+0xaa/0xb0
add_adv_patterns_monitor_rssi+0xd5/0x230 [bluetooth]
hci_sock_sendmsg+0x96b/0xf80 [bluetooth]
__sys_sendto+0x2bc/0x2d0
__x64_sys_sendto+0x76/0x90
do_syscall_64+0x115/0x6a0
entry_SYSCALL_64_after_hwframe+0x77/0x7f
Freed by task 454 on cpu 2 at 285.217112s:
kasan_save_stack+0x33/0x60
kasan_save_track+0x17/0x60
kasan_save_free_info+0x3b/0x60
__kasan_slab_free+0x5f/0x80
kfree+0x313/0x590
msft_add_monitor_sync+0x54a/0x570 [bluetooth]
hci_add_adv_monitor+0x133/0x180 [bluetooth]
hci_cmd_sync_work+0x187/0x210 [bluetooth]
process_one_work+0x4fd/0xbc0
worker_thread+0x2d8/0x570
kthread+0x1ad/0x1f0
ret_from_fork+0x3c9/0x540
ret_from_fork_asm+0x1a/0x30 |
| In the Linux kernel, the following vulnerability has been resolved:
Bluetooth: 6lowpan: avoid untracked enable work
lowpan_enable_set() allocates a temporary work item and schedules
do_enable_set() on system_wq, then returns to debugfs. The debugfs active
operation has ended at that point, but the worker still executes module
text and manipulates enable_6lowpan and listen_chan.
bt_6lowpan_exit() removes the debugfs files and immediately closes and
puts listen_chan. It has no pointer to the queued work item, so it cannot
cancel or flush it before tearing down the state that the worker uses.
The buggy scenario involves two paths, with each column showing the order
within that path:
debugfs enable write module exit
1. lowpan_enable_set() allocates 1. bt_6lowpan_exit() removes
set_enable work the debugfs file
2. schedule_work() queues 2. bt_6lowpan_exit() closes
do_enable_set() and puts listen_chan
3. the write operation returns 3. module teardown can continue
4. do_enable_set() later runs
against stale state
Run the enable state transition synchronously in lowpan_enable_set()
instead. The simple debugfs setter can sleep, and this file already handles
the 6LoWPAN control write synchronously under the same set_lock. Once the
setter returns, debugfs removal covers the whole operation and exit can no
longer race with an untracked work item.
Validation reproduced this kernel report:
BUG: KASAN: slab-use-after-free in do_enable_set+0x113/0x2e0
Workqueue: events do_enable_set [bluetooth_6lowpan]
The buggy address belongs to the object at ffff888109cb8000 |
| In the Linux kernel, the following vulnerability has been resolved:
ntfs: avoid stale runlist element dereference in fallocate
ntfs_attr_fallocate() allocates holes and delayed allocations inside
initialized size by looking up the current runlist element under
ni->runlist.lock. The returned struct runlist_element is only a borrowed
pointer into ni->runlist.rl. A writer can replace and free that array
after the read lock is dropped, so later reads of rl->lcn, rl->length and
rl->vcn can touch freed memory.
The buggy scenario involves two paths, with each column showing the order
within that path:
ntfs_attr_fallocate():
1. Take ni->runlist.lock for read.
2. Get rl from ntfs_attr_find_vcn_nolock().
3. Drop ni->runlist.lock.
4. Read rl->lcn, rl->length and rl->vcn.
mmap page_mkwrite:
1. Enter ntfs_filemap_page_mkwrite().
2. Reach __ntfs_write_iomap_begin() and ntfs_attr_map_cluster().
3. Merge allocation state with ntfs_runlists_merge().
4. Reallocate ni->runlist.rl in ntfs_rl_realloc(), freeing the old array.
Validation reproduced this kernel report:
BUG: KASAN: slab-use-after-free in ntfs_attr_fallocate+0xbb8/0xd00
Call Trace:
<TASK>
dump_stack_lvl+0x66/0xa0
print_report+0xce/0x630
? ntfs_attr_fallocate+0xbb8/0xd00
? srso_alias_return_thunk+0x5/0xfbef5
? __virt_addr_valid+0x20d/0x410
? ntfs_attr_fallocate+0xbb8/0xd00
kasan_report+0xe0/0x110
? ntfs_attr_fallocate+0xbb8/0xd00
ntfs_attr_fallocate+0xbb8/0xd00
? lock_acquire+0x2b8/0x2f0
? __pfx_ntfs_attr_fallocate+0x10/0x10
? 0xffffffffc0000095
? down_write+0x10d/0x1e0
ntfs_fallocate+0x5c9/0x1d00
? __pfx_ntfs_fallocate+0x10/0x10
? srso_alias_return_thunk+0x5/0xfbef5
? lock_acquire+0x2b8/0x2f0
? srso_alias_return_thunk+0x5/0xfbef5
? selinux_file_permission+0x3a7/0x510
vfs_fallocate+0x29d/0xd30
__x64_sys_fallocate+0xc7/0x150
? do_syscall_64+0x81/0x6a0
do_syscall_64+0x115/0x6a0
entry_SYSCALL_64_after_hwframe+0x77/0x7f
Allocated by task 410:
kasan_save_stack+0x33/0x60
kasan_save_track+0x14/0x30
__kasan_kmalloc+0xaa/0xb0
__kvmalloc_node_noprof+0x353/0x920
ntfs_rl_realloc+0x3f/0x110
ntfs_runlists_merge+0xaa3/0x3010
ntfs_attr_map_cluster+0x4e5/0xf80
ntfs_attr_fallocate+0x53f/0xd00
ntfs_fallocate+0x5c9/0x1d00
vfs_fallocate+0x29d/0xd30
__x64_sys_fallocate+0xc7/0x150
do_syscall_64+0x115/0x6a0
entry_SYSCALL_64_after_hwframe+0x77/0x7f
Freed by task 424:
kasan_save_stack+0x33/0x60
kasan_save_track+0x14/0x30
kasan_save_free_info+0x3b/0x60
__kasan_slab_free+0x5f/0x80
kfree+0x307/0x580
ntfs_rl_realloc+0x6f/0x110
ntfs_runlists_merge+0x7b1/0x3010
ntfs_attr_map_cluster+0x4e5/0xf80
__ntfs_write_iomap_begin+0x8cd/0x2280
iomap_iter+0x6de/0x11e0
iomap_page_mkwrite+0x391/0x650
ntfs_filemap_page_mkwrite+0x1ac/0x400
do_page_mkwrite+0x15c/0x280
__handle_mm_fault+0xd6d/0x1ca0
handle_mm_fault+0x19c/0x470
do_user_addr_fault+0x23b/0x9c0
exc_page_fault+0x5c/0xc0
asm_exc_page_fault+0x26/0x30
Fix this by copying the needed runlist fields while the read lock is still
held and using only those scalar snapshots after unlocking.
After the snapshot, ntfs_attr_map_cluster() can also find that the range
is already mapped and return balloc=false. Only call ntfs_dio_zero_range()
when new clusters were allocated, matching the write iomap path and
preserving the zero-newly-allocated-holes behavior. |
