| CVE |
Vendors |
Products |
Updated |
CVSS v3.1 |
| In the Linux kernel, the following vulnerability has been resolved:
wifi: iwlwifi: mvm: fix sched scan IE sizing
Scheduled scan built the probe request before iwl_mvm_scan_fits(),
so oversized IEs could be copied into the fixed preq buffer before
length validation. Move iwl_mvm_build_scan_probe() after the fits
check.
Also advertise max_sched_scan_ie_len using iwl_mvm_max_scan_ie_len()
so userspace limits account for driver-inserted DS/TPC bytes. |
| In the Linux kernel, the following vulnerability has been resolved:
KVM: arm64: nv: Fix life cycle of the nested_mmus array
The nested_mmus array holds the shadow page tables that are used when
a guest is running a nested context. These structures are allocated on
VCPU_INIT for whole guest, which implies that they may have to be
relocated as the array grows.
Should a VCPU_INIT occur whilst a vcpu is actively running an L2 and
that the allocation requires relocation, that vcpu will still be
running with a pointer to the previous structure, which will have been
freed.
Fix this by turning the array of structures to an array of pointers,
which is now allocated at VM creation, sized to the absolute maximum
that KVM can handle.
In turn, each VCPU_INIT contributes S2_MMU_PER_VCPU to the pool. No
reallocation is ever performed, and the life cycle of each object is
much clearer:
- the nested_mmus array is allocated in kvm_init_nested(), and freed
in kvm_arch_destroy_vm()
- s2_mmu structures are allocated in kvm_vcpu_init_nested(), and freed
on kvm_arch_flush_shadow_all()
Finally, the freeing of vcpu->arch.vncr_array is made consistent
rather than being done on some failure paths, but not others. |
| In the Linux kernel, the following vulnerability has been resolved:
nvmet: use the local P2P device on metadata allocation failure
nvmet_req_alloc_p2pmem_sgls() assigns req->p2p_dev only after the data
and metadata SGL allocations succeed. If the data allocation succeeds
but the metadata allocation fails, out_free_sg passes req->p2p_dev to
pci_p2pmem_free_sgl() before that assignment has taken place.
Pass the local p2p_dev argument instead, so cleanup uses the same PCI
device as the successful data allocation. |
| In the Linux kernel, the following vulnerability has been resolved:
ice: Restore Ordered MMIO Writes for Tx Doorbells
The DQL accounting state which tracks the number of bytes queued for the
NIC to transmit, namely dql->num_queued, is updated by the ICE driver
when it invokes __netdev_tx_sent_queue(). Subsequently the driver
updates the hardware queue tail allowing the NIC to begin processing the
work queue. The queue accounting update should be ordered before the NIC
begins transmitting descriptors.
The transmit path currently updates the hardware doorbell using
writel_relaxed(), which (on arm64) does not provide the same ordering
guarantees between writes to normal memory and writes to MMIO registers
that writel() does. This introduces a potential race where the NIC
begins transmitting descriptors before the dql->num_queued update is
globally visible. If the NIC finishes before the update is observed by
dql_completed(), it detects an invalid state where more bytes have been
completed than have been queued. When this happens the following BUG_ON
is triggered.
BUG_ON(count > num_queued - dql->num_completed);
This has been observed and manifests as the following crash (note that
the trace has been trimmed) in an environment with sustained network
load that uses an Intel Corporation Ethernet Controller E810-XXV for SFP
(rev 02) on an arm64 machine. Replacing writel_relaxed() with writel()
in a test kernel eliminated the crash in the user's workload, which
previously reproduced the issue reliably.
kernel BUG at lib/dynamic_queue_limits.c:99
Internal error: Oops - BUG: 00000000f2000800 [#1] SMP
pc : dql_completed+0x268/0x2a0
lr : ice_clean_tx_irq+0x1d4/0x620 [ice]
Call trace:
dql_completed+0x268/0x2a0 (P)
ice_napi_poll+0x94/0x520 [ice]
__napi_poll+0x48/0x3f0
net_rx_action+0x194/0x420
This restores the behaviour prior to commit ccde82e90946 ("ice: add E830
Earliest TxTime First Offload support"), which changed the notification
mechanism from writel() to writel_relaxed(). |
| In the Linux kernel, the following vulnerability has been resolved:
xfs: stop exchanging reflink flags when exchanging mappings
When an exchange covers both files from offset 0 to i_disk_size,
xmi_can_exchange_reflink_flags() assumes every mapping moved and hands
the reflink flag over to the other file.
That assumption is wrong. A file can still own shared blocks past
i_disk_size, e.g. after EXCHANGE_RANGE_TO_EOF sets a smaller size
without unmapping anything. The flag is cleared anyway, and the next
write to such a block happens in place instead of CoW, corrupting the
other file that shares it.
Commit a23eca88448e ("xfs: fix exchange-range reflink flag clearing
issue with INO1_WRITTEN") fixed one instance of this. Rather than add
another special case, stop moving the flags.
xfs_exchmaps_ensure_reflink() already sets the flag on both inodes
before the exchange, so both just keep it.
Nothing sets CLEAR_INO{1,2}_REFLINK anymore. Intents logged by older
kernels may still carry them; recovery already masks them off, so they
stay in the log format mask and are ignored.
XFS_IOC_SWAPEXT has the same problem: it moves the reflink flag from
one inode to the other along with the extents. Just removing that is
not enough here: the exchange path flags both inodes up front in
xfs_exchmaps_ensure_reflink(), but swapext has no such step, so the
inode receiving the shared extents would be left without the flag.
Set it on both inodes instead, and make sure both have a CoW fork,
since an inode with the reflink flag is expected to have one.
The flag now stays until FALLOC_FL_UNSHARE_RANGE, xfs_scrub, or a
truncate to zero removes it. |
| In the Linux kernel, the following vulnerability has been resolved:
namespace: keep the lock on a mount that a propagated copy is moved beneath
attach_recursive_mnt() transfers MNT_LOCKED from the top mount to the
mount that is moved beneath it with MOVE_MOUNT_BENEATH. This allows the
owner of a user namespace to replace its locked /proc or its root. The
mount beneath takes on the job of covering the underlying mountpoint
allowing the top mount to be unmounted.
Consider two mount namespaces:
(H) The host H has a shared mount P with a secret in P/d
(Z) Z is a user namespace made from M. Its copy of P receives
propagation from the host's P and its copy of M's cover on P/d is
locked Z's owner must not get to see P/d.
Now (H) mounts X on P/d. This propagates into (Z). The copy of X lands
beneath (Z)'s locked cover. The locked property is transfered from (Z)'s
cover to the copy of X propagated beneath it. The cover is now unlocked.
Now (H) unmounts X again. The copy of X in (Z) gets unmounted and the
covering mount is left unlocked on top of P/d. (Z) can now unmount it:
Z: umount2(P/d) = EINVAL /* the cover is locked */
H: mount X on P/d, umount X /* both propagate into Z /*
Z: umount2(P/d) = 0 /* the cover is now unlocked */
Z: read P/d/secret = "covered-by-root" /* secret revealed */
So only transfer the locked property to the mount beneath for mounts the
caller has placed. A propagated copy that lands beneath a locked mount
is locked as well so that the mount at the bottom of the stack carries a
lock the way every check expects. The mount on top of it remains locked
to ensure that it keeps covering even if the propagated mount is
unmounted again. |
| In the Linux kernel, the following vulnerability has been resolved:
namei: don't reveal overmounted entries in refwalk
In rcuwalk the dentry is validated before it is accepted. step_into()
step_into() rechecks d_seq and __follow_mount_rcu() rechecks mount_lock.
An entry that gets unlinked in between causes the lookup to retry and
miss.
A refwalk doesn't do this. lookup_fast() takes a reference on the hashed
dentry and simply accepts it. So an unlink that happens after the
reference was taken isn't seen by refwalk. That's fine for a simple
file. We just happened to open it before it was unlinked, no problem.
For a mountpoint and specifically a locked mountpoint it very much
isn't. The unlink detaches all mounts and then removes the name. Any
refwalk that hasn't traversed the mounts yet simply reveals the
underlying entry. It's a very narrow window but it can be hit:
reads of a covered file in 60 s, 3 walkers, ~15000 unlinks
no widening 27
that step + 200 us 3741
See the appended patch for a more reliable reproducer.
So check the entry after step_into(). unlink(), rmdir() and rename()
mark the dentry with dont_mount() before they detach the mounts and
remove the dentry.
So a dentry that is marked with DCACHE_CANT_MOUNT and is unhashed by the
time its mounts were looked at is a name that was unlinked under the
refwalk. DCACHE_CANT_MOUNT is read after the mounts were looked up and
it is set before they are detached by detach_mounts(). A refwalk that
missed the mounts will see DCACHE_CANT_MOUNT.
Plain d_unlinked() is fine. A rename takes the dentry off its hash chain
but ___d_drop() leaves d_hash.pprev set. So only __d_drop() and a rename
over the dentry unhash it. The only move that flips IS_ROOT splices in a
disconnected alias. That doesn't have DCACHE_CANT_MOUNT set.
Add the to step_into_slowpath(). ".." and LOOKUP_DOWN may legitimately
land on an unhashed directory. A refwalk that crossed onto a mount has
path.mnt different from nd->path.mnt. A dentry that a filesystem dropped
on its own (d_invalidate(), d_drop()) doesn't have the flag set and is
treated as before.
// SPDX-License-Identifier: GPL-2.0
/*
* unlink_covered: unlink a file that is a mountpoint in a detached copy of
* its mount, against walkers that open it through that copy.
*
* A is a tmpfs with the file f1 (content SECRET_F) and the plain file
* MARK_A. A' is an open_tree(OPEN_TREE_CLONE) copy of A with MARK_A bound
* on A'/f1, held through an O_PATH fd on its root once the tree fd is
* closed. Walkers open f1 through that fd while the driver unlinks A/f1,
* where nothing is mounted on it. A walker may read MARK_A or get ENOENT.
* A read of SECRET_F is a hit: the name was found after its mount was
* gone. The lockless walks use openat2(RESOLVE_CACHED).
*
* usage: unlink_covered [-t seconds] [-w walkers]
*/
#ifndef _GNU_SOURCE
#define _GNU_SOURCE
#endif
#include <errno.h>
#include <fcntl.h>
#include <pthread.h>
#include <stdatomic.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <sys/mount.h>
#include <sys/stat.h>
#include <sys/syscall.h>
#include <linux/openat2.h>
#ifndef __NR_open_tree
#define __NR_open_tree 428
#endif
#ifndef __NR_move_mount
#define __NR_move_mount 429
#endif
#ifndef __NR_openat2
#define __NR_openat2 437
#endif
#ifndef OPEN_TREE_CLONE
#define OPEN_TREE_CLONE 1
#endif
#ifndef OPEN_TREE_CLOEXEC
#define OPEN_TREE_CLOEXEC O_CLOEXEC
#endif
#ifndef MOVE_MOUNT_F_EMPTY_PATH
#define MOVE_MOUNT_F_EMPTY_PATH 0x00000004
#endif
#define WORK "/tmp/uc"
#define ADIR WORK "/A"
static int duration = 60, nwalkers = 3;
static atomic_int stop, writer_waiting;
static pthread_rwlock_t cur_lock = PTHREAD_RWLOCK_INITIALIZER;
static int cur_fd = -1; /* the root of A', -1 while there is none */
static atomic_long n_unlink, n_walk, n_mark, n_enoent, n_othe
---truncated--- |
| In the Linux kernel, the following vulnerability has been resolved:
namespace: unhash a dentry before detaching the mounts on it
unlink(), rmdir() and rename() remove the entry from the filesystem,
call detach_mounts() on the entry with the inode locked and then call
d_delete() once the inode is unlocked.
The thing is that between detach_mounts() and d_delete() the dentry is
still hashed and positive. But after detach_mounts() nothing covers the
dentry anymore. A lookup that finds this dentry in the dcache can
uncover what the mounts hid.
That's a problem when unlinking files or directories that are
mountpoints in other mount namespaces. Everybody who had the underlying
entry covered can race the detach_mount() call until d_delete() has run.
The race window isn't all that small. It encompasses namespace_unlock()
with a full synchronize_rcu_expedited() grace period and the
inode_unlock() of the entry.
In my experiments three walkers that kept trying read an overmounted
file in 11938 of the 16140 unlinks that removed its mountpoint from a
bind mount of the filesystem within a minute.
Fun fact, d_invalidate() has the same ordering problem but gets it
right. It unhashes the dentry first and detaches the mounts afterwards.
Let's do the same in __detach_mounts():
- A lookup that hasn't found the dentry yet misses it in the dcache and
waits for the directory lock that the caller holds until the name is
gone for good.
- A lockless lookup that found it already fails the mount_lock check
while the dentry still counts as a mountpoint and the d_seq check once
it doesn't, and retries.
This fixes the lockless path. We still need to fix the reference count
lookup in a follow-up patch.
So d_drop() the dentry. The dentry stays positive and held but can't be
found anymore. Then proceed with the detach and unlink.
Reproducer:
The reads were counted with the program below, three walkers for 60 s
in a VM with 4 CPUs. The race window is stretched with the debug patch
pasted here. fs.detach_race_walk_us sleeps in lookup_fast() once it
found a mountpoint dentry and before its mounts are crossed.
fs.detach_race_unlink_us sleeps in vfs_unlink() between detach_mounts()
and d_delete().
// SPDX-License-Identifier: GPL-2.0
/*
* unlink_covered: unlink a file that is a mountpoint in a detached copy of
* its mount, against lookups that open it through that copy.
*
* A is a tmpfs with the file f1 (content SECRET_F) and the plain file
* MARK_A. A' is an open_tree(OPEN_TREE_CLONE) copy of A with MARK_A bound
* on A'/f1, held through an O_PATH fd on its root once the tree fd is
* closed. Walkers open f1 through that fd while the driver unlinks A/f1,
* where nothing is mounted on it. A walker may read MARK_A or get ENOENT.
* A read of SECRET_F is a hit: the name was found after its mount was
* gone. The lockless walks use openat2(RESOLVE_CACHED).
*
* usage: unlink_covered [-t seconds] [-w walkers]
*/
#ifndef _GNU_SOURCE
#define _GNU_SOURCE
#endif
#include <errno.h>
#include <fcntl.h>
#include <pthread.h>
#include <stdatomic.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <sys/mount.h>
#include <sys/stat.h>
#include <sys/syscall.h>
#include <linux/openat2.h>
#ifndef __NR_open_tree
#define __NR_open_tree 428
#endif
#ifndef __NR_move_mount
#define __NR_move_mount 429
#endif
#ifndef __NR_openat2
#define __NR_openat2 437
#endif
#ifndef OPEN_TREE_CLONE
#define OPEN_TREE_CLONE 1
#endif
#ifndef OPEN_TREE_CLOEXEC
#define OPEN_TREE_CLOEXEC O_CLOEXEC
#endif
#ifndef MOVE_MOUNT_F_EMPTY_PATH
#define MOVE_MOUNT_F_EMPTY_PATH 0x00000004
#endif
#define WORK "/tmp/uc"
#define ADIR WORK "/A"
static int duration = 60, nwalkers = 3;
static atomic_int stop, writer_waiting;
static pthread_rwlock_t cur_lock = PTHREAD_RWLOCK_INITIALIZER;
static int cur_fd = -1; /* the root of A', -1 wh
---truncated--- |
| In the Linux kernel, the following vulnerability has been resolved:
namespace: don't let a pseudo dentry become the root of a mount
d_alloc_pseudo() hands out dentries for pipes, sockets and other files
that are never anyone's child or parent. They carry DCACHE_NORCU and
dentry_free() frees them right away because no lockless path walk can
ever reach them. That holds as long as such a dentry isn't the root of
a mount. But bind mounting /proc/self/fd/<fd> of such a file does
exactly that.
Most callers of alloc_file_pseudo() put their files on kernel-internal
mounts and may_copy_tree() refuses those. bpf_token_create() doesn't. It
places the token file on the bpffs mount the caller handed it and that
mount is in the caller's mount namespace so the clone goes through:
mount --bind /proc/self/fd/<token> <file>
open_tree(tokfd, "", AT_EMPTY_PATH | OPEN_TREE_CLONE) + move_mount()
__follow_mount_rcu() then loads ->mnt_root of that mount, reads d_seq
and d_flags of the dentry and only then checks mount_lock. The dentry
can be gone by then. The final mntput() of an unmounted parent unhooks
a child that stayed attached to it under mount_lock alone. When the
child's holder does the final put right after that the root is dput()
and freed immediately while a walker that found the mount hashed still
looks at it.
Refuse to clone a mount with a DCACHE_NORCU dentry as its root. Nothing
sensible can be done with a bind mount of a bpf token anyway. |
| In the Linux kernel, the following vulnerability has been resolved:
net/mlx5e: Prevent stale XSK buffer release on refill retry
When an XDP redirect to an AF_XDP socket fails because its RX ring is
full, the XSK core frees the buffer. During the subsequent batched refill
of a legacy cyclic RQ, mlx5e also releases the WQE's XSK buffer before
allocating a replacement. If that refill succeeds only partially, a WQE
left without a replacement retains its old buffer pointer.
The buffer can meanwhile be allocated to another WQE. A later refill
retry can then free the live buffer through the stale pointer and publish
the same UMEM frame twice.
Mark the WQE as released immediately after the driver-side free. The flag
is already cleared when a replacement buffer is assigned, so refill
retries no longer release stale pointers.
The failure is silent and produces no kernel warning or splat. A
standalone legacy cyclic-RQ zero-copy libxsk reproducer, using 64-byte UDP
traffic offered at 12 Mpps, detected it: stock stopped after 2,854,914
packets in 4.094 seconds, with 4,542 xdp_rx_ring_full events and 64
ownership/double-publication errors. With this change it processed
356,904,225 packets in 30 seconds despite 571,405 xdp_rx_ring_full events,
with no ownership or data errors. |
| In the Linux kernel, the following vulnerability has been resolved:
bnxt_en: fix DMA mapping length for padded small packets
Stefan Fleischmann reported Intel IOMMU DMA Read faults on BCM57412
NetXtreme-E NICs when transmitting packets on VLAN/macvlan interfaces:
DMAR: [DMA Read NO_PASID] Request device [18:00.0] fault addr 0xfc499000
[fault reason 0x06] PTE Read access is not set
bnxt_en 0000:18:00.0 eno1np0: Abandoning msg {0xb4 0x41a} len: 0 due to firmware status: 0x2000001
...
NETDEV WATCHDOG: eno1np0 (bnxt_en): transmit queue 0 timed out
The fault address (0xfc499000) is on an exact 4KB page boundary,
pointing to a DMA read buffer overrun.
In bnxt_start_xmit(), packets smaller than BNXT_MIN_PKT_SIZE (52 bytes),
such as 42-byte untagged ARP frames, are padded:
if (length < BNXT_MIN_PKT_SIZE) {
pad = BNXT_MIN_PKT_SIZE - length;
if (skb_pad(skb, pad))
goto tx_kick_pending;
length = BNXT_MIN_PKT_SIZE;
}
mapping = dma_map_single(&pdev->dev, skb->data, len, DMA_TO_DEVICE);
...
dma_unmap_len_set(tx_buf, len, len);
However, 'len' was initialized earlier to skb_headlen(skb) (e.g. 42 bytes)
and is left unadjusted after padding. Consequently, dma_map_single() and
dma_unmap_len_set() map and track only 42 bytes.
Later, the hardware TX buffer descriptor is programmed with the padded length:
txbd->tx_bd_len_flags_type =
cpu_to_le32(((len + pad) << TX_BD_LEN_SHIFT) | flags |
TX_BD_FLAGS_PACKET_END);
The NIC DMA engine is thus instructed to read 52 bytes from a region where
only 42 bytes were DMA-mapped. If skb->data ends near the boundary of a 4KB
page (within 'pad' bytes of the next page), the hardware DMA read overruns
into the unmapped adjacent page, triggering an IOMMU fault.
This issue was exposed after commit 447cbe95ebb9 ("vlan: fix skb_under_panic
and races when toggling HW VLAN offload") because reserving extra VLAN
headroom rounded LL_RESERVED_SPACE from 48 up to 64 bytes, shifting skb->data
offsets and potentially causing small frames to land right against page
boundaries.
Fix this by using skb_put_padto(skb, BNXT_MIN_PKT_SIZE) in
bnxt_start_xmit(), before skb_shinfo(skb)->nr_frags is sampled,
because padding might linearize the skb.
This ensures skb->len and skb_headlen(skb) reflect the padded size so
that dma_map_single() maps the full buffer and the descriptor length is
consistent. This also removes the temporary 'pad' variable and masking logic.
The padding is done after the SW USO branch, otherwise
bnxt_sw_udp_gso_xmit() would account the padding as UDP payload
and send it in extra segments.
Note that SW USO segments are still not padded: with IPv4, a segment
carrying less than 10 bytes of UDP payload (small gso_size, or a short
last segment) is sent as a frame shorter than BNXT_MIN_PKT_SIZE.
This is a separate issue, left for a followup patch. |
| The GeoDirectory WordPress plugin before 2.8.194 does not correctly verify ownership of listings submitted by logged-out users before allowing them to be edited, allowing unauthenticated attackers to modify, unpublish, attach images to, or reassign any guest-submitted listing when guest posting is enabled. |
| Use after free in Windows Kernel allows an authorized attacker to elevate privileges locally. |
| Out-of-bounds read in Microsoft Office Excel allows an unauthorized attacker to disclose information over a network. |
| Use after free in Microsoft Windows Search Component allows an authorized attacker to elevate privileges locally. |
| A flaw was found in Nautilus. When a removable drive or disk image is unmounted or ejected, Nautilus prompts the user to empty the trash without verifying whether the trash directory paths are symbolic links. An attacker can exploit this flaw by tricking a user into mounting a crafted storage volume and confirming the prompt to empty the trash, leading to the arbitrary deletion of files accessible to that user. |
| In the Linux kernel, the following vulnerability has been resolved:
scsi: libiscsi_tcp: Check the data direction of a Data-In PDU
The Data-In branch of iscsi_tcp_hdr_dissect() resolves the ITT to a task
and copies the PDU's data segment into that command's scatterlist without
asking whether the command was reading. iscsi_tcp_r2t_rsp() in the same
file does ask, and rejects an R2T for a command that is not DMA_TO_DEVICE.
A target that answers a WRITE command's ITT with a Data-In therefore has
the initiator write target-supplied bytes into the pages that write was
about to send. Those are the caller's own pinned pages for an O_DIRECT
write, and page cache pages for a buffered one.
Observed against a test target that emits one 512-byte Data-In naming a 128
KB write's ITT, after the R2T for that write. With O_DIRECT the caller's
buffer ends up holding 512 bytes of the target's data while pwrite()
returns 131072. Buffered is quieter: pwrite() and fsync() both succeed,
nothing is logged, and reading those blocks back returns the target's bytes
out of the page cache without a command going on the wire.
Check the direction before using the scatterlist, the way the R2T path
already does. |
| In the Linux kernel, the following vulnerability has been resolved:
drm/vmwgfx: validate pitch coming from userspace
Validate the pitch, alongside the box dimensions before trying
to copy data from the underlying surface. Fixes possible
out of bounds reads with cursor snooping. |
| In the Linux kernel, the following vulnerability has been resolved:
drm/i915/gem: Prevent overstepping exec array boundary
It is possible for eb_relocate_parse_slow() to call kvfree() on
entries outside the original exec array during following
scenario inside eb_relocate_parse_slow():
1) eb_copy_relocations() allocates as many as eb->buffer_count
copies for exec entries;
2) eb_parse() appends up to two VMAs, right after incrementing
eb->buffer_count;
3) cleanup under "out" label uses this incremented buffer_count
to release relocation pointers from exec array via kvfree(),
not from VMA array.
To amend this problem, ensure that relocation cleanup uses the
original exec object count, excluding the VMAs appended by the
command parser.
(cherry picked from commit 2a0158925fb943c7ba8f3216e2734952128defc9) |
| In the Linux kernel, the following vulnerability has been resolved:
Bluetooth: SCO: serialise sco_conn lifetime against sco_recv_scodata()
sco_recv_scodata() upgrades the weak hcon->sco_data back-pointer to a
strong reference under hdev->lock:
hci_dev_lock(hdev);
hcon = hci_conn_hash_lookup_handle(hdev, handle);
...
conn = sco_conn_hold_unless_zero(hcon->sco_data);
hci_dev_unlock(hdev);
but the pointer is cleared from the other side without that lock. When
the last sco_conn reference is dropped, sco_conn_free() ran
conn->hcon->sco_data = NULL;
with no hdev->lock held, so the RX path could read hcon->sco_data and
call kref_get_unless_zero() on an sco_conn that was concurrently freed:
BUG: KASAN: slab-use-after-free in sco_conn_hold_unless_zero+0xbe/0x160
Write of size 4 by task kworker/u17:0
Workqueue: hci0 hci_rx_work
Call Trace:
sco_conn_hold_unless_zero+0xbe/0x160
sco_recv_scodata+0x13f/0x490
hci_rx_work+0x3af/0x730
kref_get_unless_zero() only guards against a zero refcount, not against
the backing memory already being freed.
Give hcon->sco_data an actual reference on the sco_conn it points to, so
the object cannot be freed while the pointer is still installed, and only
clear and drop it from sco_conn_del(), which runs under hdev->lock (its
callers, sco_connect_cfm() and sco_disconn_cfm(), hold it). The reader in
sco_recv_scodata() also takes hdev->lock, so the store and the read are
now serialised: the RX path either observes NULL or a reference that is
guaranteed to stay valid until it drops its own.
sco_conn_add() no longer hands its kref_init() reference to the caller as
the connection's only reference; that initial reference is the one owned
by hcon->sco_data, and callers get their own via sco_conn_hold().
Because the sco_conn can now outlive the socket (the association keeps it
alive until the link goes down), the hci_conn can no longer be dropped
from sco_conn_free() without regressing socket close: closing a connected
SCO socket must still tear the link down. Move hci_conn ownership to the
socket instead: __sco_chan_add() takes an hci_conn reference and it is
released from sco_chan_del() and sco_sock_destruct(), exactly once. The
sco_conn no longer owns an hci_conn reference, so sco_conn_add() stops
consuming one and sco_connect() drops the hci_connect_sco() reference on
every path; sco_connect_cfm() no longer needs its hci_conn_hold() dance. |
