| CVE |
Vendors |
Products |
Updated |
CVSS v3.1 |
| In the Linux kernel, the following vulnerability has been resolved:
fsverity: Fix bpf_get_fsverity_digest() dynptr assumptions
The BPF verifier and the dynptr abstraction ensure that the memory space
referenced by a dynptr remains valid. They do not, however, provide any
guarantee that the contents of the memory are stable. kfuncs are
expected to remain memory-safe even if concurrent modifications occur.
bpf_get_fsverity_digest() didn't follow that: it could crash if
arg->digest_size was concurrently modified.
Fix that by using the known-good value hash_alg->digest_size instead.
Also widen 'dynptr_sz' and 'out_digest_sz' to u64 to match the return
type of __bpf_dynptr_size(). It doesn't appear that it can actually be
more than INT_MAX currently (since __bpf_dynptr_data_rw() excludes
file-based pointers), but the correct type might as well be used. |
| In the Linux kernel, the following vulnerability has been resolved:
bpf, sockmap: Fix sk_redir use-after-free in send verdict
sk_psock_msg_verdict() takes a socket reference for psock->sk_redir.
tcp_bpf_send_verdict() copies that pointer while holding the source socket
lock, but does not take a reference for the local copy before dropping the
lock around tcp_bpf_sendmsg_redir().
When apply_bytes keeps the cached verdict active, another sendmsg() on the
same source socket can consume the remaining bytes and release the cached
reference while the first thread still holds only the raw local pointer:
CPU 0 CPU 1
sk_redir = psock->sk_redir
apply_bytes remains nonzero
release_sock(sk)
lock_sock(sk)
apply_bytes reaches zero
psock->sk_redir = NULL
release_sock(sk)
tcp_bpf_sendmsg_redir(sk_redir)
sock_put(sk_redir)
tcp_bpf_sendmsg_redir(sk_redir)
The final sock_put() can free sk_redir before CPU 0 dereferences it.
KASAN reported:
BUG: KASAN: slab-use-after-free in tcp_bpf_sendmsg_redir+0xf39/0x1020
Read of size 8 at addr ffff888108537090 by task poc/87
Call Trace:
tcp_bpf_sendmsg_redir+0xf39/0x1020
tcp_bpf_sendmsg+0x977/0x1a50
__sys_sendto+0x32c/0x3a0
__x64_sys_sendto+0xdb/0x1b0
Allocated by task 85:
sk_prot_alloc+0x56/0x210
sk_clone+0x6f/0x14b0
inet_csk_clone_lock+0x24/0x740
tcp_create_openreq_child+0x25/0x2710
tcp_v4_syn_recv_sock+0x10a/0xe00
Freed by task 0:
__kasan_slab_free+0x43/0x70
slab_free_after_rcu_debug+0xa6/0x1e0
rcu_core+0x50a/0x1850
Last potentially related work creation:
__sk_destruct+0x3da/0x540
sk_psock_destroy+0x81e/0xab0
process_one_work+0x63a/0x1070
Take a temporary socket reference while the source socket lock still
protects psock->sk_redir, and drop it after tcp_bpf_sendmsg_redir()
returns. This keeps each unlocked use independent of cached-verdict
ownership. |
| In the Linux kernel, the following vulnerability has been resolved:
RDMA/bnxt_re: zero shared page before exposing to userspace
bnxt_re_alloc_ucontext() allocates uctx->shpg via
__get_free_page(GFP_KERNEL). The buddy allocator does not zero pages
without __GFP_ZERO, so the page contains stale kernel data from
whatever object most recently freed it.
The page is then mapped into userspace via vm_insert_page() under
BNXT_RE_MMAP_SH_PAGE in bnxt_re_mmap(). The driver only ever writes
4 bytes (a u32 AVID) at offset BNXT_RE_AVID_OFFT (0x10) inside
bnxt_re_create_ah(); the remaining 4092 bytes of the page are exposed
to userspace unsanitised, leaking kernel memory contents.
Any user with access to /dev/infiniband/uverbsX on a host with a
bnxt_re device (typically rdma group membership) can read this data
via a single mmap() at pgoff 0 after IB_USER_VERBS_CMD_GET_CONTEXT.
Other shared pages in the same file already use get_zeroed_page()
correctly:
drivers/infiniband/hw/bnxt_re/ib_verbs.c
srq->uctx_srq_page = (void *)get_zeroed_page(GFP_KERNEL);
cq->uctx_cq_page = (void *)get_zeroed_page(GFP_KERNEL);
uctx->shpg is the only outlier. Bring it in line with the existing
convention by switching to get_zeroed_page(). |
| In the Linux kernel, the following vulnerability has been resolved:
net/sched: cls_route: fix fastmap use-after-free on filter
The route4 classifier maintains a 16-slot fastmap cache that stores raw
struct route4_filter pointers indexed by (id, iif). The reader
(route4_classify) populates this cache via route4_set_fastmap() for every
classified packet that hits a filter. The writer (route4_delete,
route4_change) clears the cache via route4_reset_fastmap() before
RCU-deferred kfree of the filter.
This creates a UAF race:
1. Reader walks the RCU-protected bucket chain, finds filter f
2. Writer unlinks f, calls route4_reset_fastmap(), then tcf_queue_work()
3. Reader calls route4_set_fastmap() and writes f into the cache
*after* the writer's reset, caching a pointer about to be freed
4. After the RCU grace period, kfree(f) executes
5. Next classified packet on the same (id, iif) tuple hits the stale
fastmap entry and reads f->res from freed memory
Reproduced with an mdelay(100) accelerator in route4_set_fastmap() and a
concurrent add/delete stress test (provided by both zdi and Santosh).
Both triggered KASAN slab-use-after-free reports in the route4 fastmap
paths.
Fix:
Introduce a per-filter boolean dying flag to suppress stale fastmap
republishing by in-flight readers. |
| In the Linux kernel, the following vulnerability has been resolved:
packet: use consistent hard_header_len in non-ring send paths
packet_snd() reads dev->hard_header_len multiple times while allocating
and constructing an skb. Device reconfiguration can change this value
concurrently, for example through bonding device type changes.
For SOCK_RAW, packet_snd() can save a larger value in reserve and later
allocate headroom using a smaller value. Moving skb->data back by reserve
then places it before skb->head, and the following copy from userspace can
attempt an out-of-bounds write.
packet_sendmsg_spkt() has the same issue because it calculates its
reservation and header offset from separate reads before dropping the RCU
read lock to allocate the skb.
Add LL_RESERVED_SPACE_EX() for callers that already saved a header length.
Read hard_header_len once in packet_snd() and use it for allocation and
construction. In packet_sendmsg_spkt(), preserve the allocation-time value
through the device lookup retry.
The separate SOCK_DGRAM consistency problem between hard_header_len and
header_ops->create is not addressed here. |
| In the Linux kernel, the following vulnerability has been resolved:
netfilter: nft_payload: fix mask build for partial field offload
nft_payload_offload_mask() builds the offload match mask for a payload
expression that covers only part of a header field. For a partial IPv6
address match (field_len = 16, priv_len = 1) that shift is 1 << 120, which
is undefined on the 32-bit int operand. It also trims only one word, so
the remaining words stay 0xffffffff (and when priv_len is a multiple of 4
the trim is skipped entirely), leaving the mask covering more bytes than
the rule matches.
UBSAN: shift-out-of-bounds in net/netfilter/nft_payload.c:278:20
shift exponent 120 is too large for 32-bit type 'int'
...
The match is byte-granular and struct nft_data is zero-initialised, so the
correct mask is simply the first priv_len bytes set to 0xff. Set those
bytes directly and drop the word/shift trimming; this removes the undefined
shift and no longer over-masks the trailing bytes. |
| In the Linux kernel, the following vulnerability has been resolved:
crypto: algif_skcipher - force synchronous processing on trees without ctx->state
The AIO/async path in skcipher_recvmsg() passes the socket-wide ctx->iv
directly into the skcipher request. After io_submit() the socket lock is
dropped and the request is processed asynchronously, so a concurrent
sendmsg(ALG_SET_IV) can overwrite ctx->iv and make the in-flight request
run under an attacker-controlled IV. For CTR/stream modes this is
IV/keystream reuse and lets an unprivileged user recover the plaintext of
a concurrent operation.
Snapshotting ctx->iv into per-request storage for the async path is not
sufficient. For ciphers with statesize == 0 - which includes cbc and ctr -
the MSG_MORE inter-chunk IV chaining is carried solely by the in-place
req->iv writeback, which a snapshot redirects into per-request memory that
af_alg_free_resources() releases on completion, silently producing wrong
output. Writing the IV back from the completion callback instead is not
possible either: that would require lock_sock() there, but the callback can
run in softirq/atomic context, so it must not sleep.
Make the operation synchronous instead, which removes both the IV race and
any writeback race. This is equivalent to the upstream resolution, commit
fcc77d33a34c ("net: Remove support for AIO on sockets"), which removed the
AIO socket path across net/ entirely and so produces the same end state for
this file. This patch deviates from that commit deliberately: rather than
removing AIO socket support tree-wide, which would be far too invasive for
stable, it removes only the AIO branch in crypto/algif_skcipher.c.
io_submit() now completes synchronously; AF_ALG async is rarely used in
practice.
The -EIOCBQUEUED check in skcipher_recvmsg() is now dead but harmless,
and is left alone to keep the fix minimal.
Tested on 6.6.y: attacker IV injection dropped from 2296/200000 to 0/200000
after the change; MSG_MORE chunked CTR output bit-identical to single-shot. |
| In the Linux kernel, the following vulnerability has been resolved:
mm/slab: prevent unbounded recursion in free path with new kmalloc type
Commit 280ea9c3154b ("mm/slab: avoid allocating slabobj_ext array from
its own slab") avoided recursive allocation of obj_exts from kmalloc
caches of the same size, by bumping the obj_exts array's allocation
size whenever the array size equals the size of the object being
allocated.
However, as reported by Danielle Costantino and Shakeel Butt,
even slabs from kmalloc caches of different sizes can form a cycle
by allocating obj_exts arrays from each other [1]:
What happened: a KMALLOC_NORMAL slab's obj_exts array (used by
allocation profiling / memcg accounting) is itself kmalloc()'d from a
KMALLOC_NORMAL cache, so the "slab holds another slab's obj_exts array"
relation can form cycles. With sizeof(struct slabobj_ext) == 16 and
the host's geometry:
- kmalloc-512 has 64 objects/slab -> array is 64*16 == 1024 bytes,
served from kmalloc-1k;
- kmalloc-1k has 32 objects/slab -> array is 32*16 == 512 bytes,
served from kmalloc-512.
A kmalloc-512 slab and a kmalloc-1k slab therefore hold each other's
obj_exts array. Discarding one frees the other's array, which empties
and discards that slab, which frees the first's array, and so on:
__free_slab() -> free_slab_obj_exts() -> kfree() -> discard_slab() ->
__free_slab() recurses along the cycle until the stack is exhausted.
With memory allocation profiling, this allows unbounded recursion
in the free path and led to a stack overflow on a production host in
the Meta fleet [1]:
BUG: TASK stack guard page was hit
Oops: stack guard page
RIP: 0010:kfree+0x8/0x5d0
Call Trace:
__free_slab+0x66/0xc0
kfree+0x3f0/0x5d0
... ( ~125x __free_slab <-> kfree ) ...
<kernel driver freeing a resource>
do_syscall_64
It is proposed [1] to resolve this issue by always serving the obj_exts
array allocation from kmalloc caches (or large kmalloc) of sizes larger
than the object size. However, as pointed out by Vlastimil Babka [2],
this can waste an excessive amount of memory as slabs from large
kmalloc sizes (e.g. kmalloc-8k) generally need obj_exts arrays much
smaller than the object size.
Therefore, rather than bumping the size, let us take a different
approach; disallow formation of cycles between kmalloc types when
allocating obj_exts arrays. Currently, all obj_exts arrays are served
from normal kmalloc caches. Cycles cannot be created if obj_exts arrays
of normal kmalloc caches are served from a special kmalloc type that can
never have obj_exts arrays.
To achieve this, create a new kmalloc type called KMALLOC_NO_OBJ_EXT.
KMALLOC_NO_OBJ_EXT caches are created with SLAB_NO_OBJ_EXT flag when
either 1) memory allocation profiling is not permanently disabled,
or 2) kmalloc types with a priority higher than KMALLOC_CGROUP are
aliased with KMALLOC_NORMAL.
Sheaf bootstrapping for KMALLOC_NO_OBJ_EXT caches now must be deferred
because allocation of a barn can trigger obj_exts array allocation of
normal kmalloc caches when the KMALLOC_NO_OBJ_EXT cache for that size
is not ready yet. For simplicity, perform bootstrapping of sheaves for
all kmalloc caches later.
Introduce a new slab alloc flag, SLAB_ALLOC_NO_OBJ_EXT, to prevent
allocation of obj_exts arrays, and let kmalloc_slab() override the type
to KMALLOC_NO_OBJ_EXT when specified. Note that kmalloc_type() remains
unchanged because kmalloc_flags() bypasses the kmalloc fastpath.
Do not pass SLAB_ALLOC_NO_RECURSE to kmalloc_flags() in
alloc_slab_obj_exts() and instead use SLAB_ALLOC_NO_OBJ_EXT only when
the objects are allocated from normal kmalloc caches. While this
prevents unbounded recursive allocation of obj_exts, it allows
KMALLOC_NO_OBJ_EXT caches to have sheaves.
Since sheaf allocations specify SLAB_ALLOC_NO_RECURSE that prevents
allocation of both sheaves and obj_exts arrays, the recursion depth
is bounded.
obj_exts arrays for non-
---truncated--- |
| In the Linux kernel, the following vulnerability has been resolved:
thunderbolt: Prevent XDomain delayed work use-after-free on disconnect
tb_xdp_handle_request() runs on system_wq and queues
xd->state_work via queue_delayed_work() in three request handlers:
PROPERTIES_CHANGED_REQUEST, UUID_REQUEST (via start_handshake),
and LINK_STATE_CHANGE_REQUEST. Similarly, update_xdomain() queues
xd->properties_changed_work when local properties change.
Concurrently, tb_xdomain_remove() calls stop_handshake() which does
cancel_delayed_work_sync() on both delayed works. Later,
tb_xdomain_unregister() calls device_unregister() which eventually
frees the xdomain. Since commit 559c1e1e0134 ("thunderbolt: Run
tb_xdp_handle_request() in system workqueue") moved the request
handler off tb->wq, the handler and the remove path are no longer
serialized. If queue_delayed_work() executes after
cancel_delayed_work_sync() but before the xdomain is freed, the
delayed work fires on a freed object.
Add xd->removing that tb_xdomain_remove() sets under xd->lock
before calling stop_handshake(). Each external queue site holds
the same lock and checks removing before calling
queue_delayed_work(). This provides the mutual exclusion needed:
either the queue site acquires the lock first and queues work that
the subsequent cancel will see, or the remove path acquires the
lock first and the queue site observes removing == true and skips
the queue. |
| In the Linux kernel, the following vulnerability has been resolved:
dmaengine: idxd: fix fdev setup failure cleanup in idxd_cdev_open()
The failed_dev_add and failed_dev_name paths drop the file-device
reference while wq->wq_lock is still held. If put_device(fdev) drops the
last reference, idxd_file_dev_release() runs synchronously and tries to
take wq->wq_lock again, deadlocking.
Those paths also fall through into the later ctx cleanup labels even
though idxd_file_dev_release() owns that cleanup and frees ctx. This can
make idxd_xa_pasid_remove(ctx) and kfree(ctx) operate on a freed context.
Move idxd_wq_get() before file-device setup can fail, since the release
callback always calls idxd_wq_put(). Then unlock wq->wq_lock before
put_device(fdev) and return directly from the file-device setup failure
path, leaving ctx cleanup to the release callback. |
| In the Linux kernel, the following vulnerability has been resolved:
btrfs: zoned: fix deadlock between metadata writeback and transaction commit
When writing out metadata extent buffers in a zoned filesystem,
btree_writepages() holds fs_info->zoned_meta_io_lock across the whole
writeback loop, including the call to btrfs_check_meta_write_pointer() ->
check_bg_is_active().
For the tree-log block group, check_bg_is_active() may fail to activate
the zone and fall back to btrfs_zone_finish_one_bg() to free an active
zone. That path waits for the running transaction to commit while still
holding zoned_meta_io_lock, but the committer needs that same lock to
write out the tree extents, so the two tasks deadlock:
Task A (kworker, metadata writeback) Task B (fsstress, transaction commit)
------------------------------------ -------------------------------------
wb_workfn() btrfs_commit_transaction(T)
btree_writepages() btrfs_write_and_wait_transaction()
btrfs_zoned_meta_io_lock() btrfs_write_marked_extents()
btrfs_check_meta_write_pointer() btree_writepages()
check_bg_is_active() [treelog_bg] btrfs_zoned_meta_io_lock()
btrfs_zone_finish_one_bg() <blocks on zoned_meta_io_lock,
btrfs_zone_finish() held by Task A>
do_zone_finish()
btrfs_inc_block_group_ro()
btrfs_wait_for_commit()
<blocks waiting for commit
of transaction T, done by
Task B>
The sibling branch in check_bg_is_active() already drops zoned_meta_io_lock
around do_zone_finish() for this exact reason. Do the same in the tree-log
branch: release the lock around btrfs_zone_finish_one_bg() and re-acquire
it afterwards. The lock only protects fs_info->active_{meta,system}_bg,
which this branch does not touch, and ctx->zoned_bg keeps a reference to
the block group across the unlock, so nothing is lost while the lock
is dropped.
This hang occasionally reproduces with fstests generic/475 on a zoned
btrfs filesystem. |
| In the Linux kernel, the following vulnerability has been resolved:
keys: fix out-of-bounds read in keyring_get_key_chunk()
For description-level chunks keyring_get_key_chunk() advances the read
pointer by level * sizeof(long) past the inline prefix but only
bounds-checks the prefix, so a long enough key description is read past
its kmemdup(desc, desc_len + 1) allocation. Compute the full byte
offset and bounds-check the description against it before reading.
The walk only reaches a description-level chunk when two keys collide
through the hash, x, type and domain_tag chunks, so this is reached from
an unprivileged add_key(2) with a crafted pair of same-type keys whose
index hashes collide; KASAN reports a slab-out-of-bounds read. |
| In the Linux kernel, the following vulnerability has been resolved:
netfilter: xt_hashlimit: validate hashtable supports XT_HASHLIMIT_RATE_MATCH
The XT_HASHLIMIT_RATE_MATCH flag mode changes the semantics of the
dsthash_ent structure which represents an entry in the hashtable. There
is a union area which uses a different layout to express the rate match
mode.
Update .checkentry path to validate the XT_HASHLIMIT_RATE_MATCH mode
flag is requested by two or more different rules that refer to the same
hashtable. Otherwise, uninitialized access to the burst field in the
union is possible.
Reject the use of the XT_HASHLIMIT_RATE_MATCH mode flag if set on by
revision less than 3 too. |
| In the Linux kernel, the following vulnerability has been resolved:
rds: tcp: hold the RCU lock across ipv6_chk_addr() in rds_tcp_laddr_check()
rds_tcp_laddr_check() looks up a scoped IPv6 interface with
dev_get_by_index_rcu(), drops the RCU read-side lock, and only then
passes the bare struct net_device * into ipv6_chk_addr().
dev_get_by_index_rcu() only keeps the device alive within the same RCU
read-side section. After rcu_read_unlock(), a concurrent RTM_DELLINK can
free the net_device; ipv6_chk_addr() then dereferences the stale pointer
in __ipv6_chk_addr_and_flags() (e.g. l3mdev_master_dev_rcu(dev)), reading
freed memory.
Keep the RCU read-side lock held across the ipv6_chk_addr() call instead
of dropping it right after the lookup, so the device cannot be freed
while it is in use.
BUG: KASAN: slab-use-after-free in __ipv6_chk_addr_and_flags (... net/ipv6/addrconf.c:1998)
Read of size 8 at addr ffff8880106ec000 by task exploit/153
Call Trace:
...
kasan_report (mm/kasan/report.c:595)
__ipv6_chk_addr_and_flags (... net/ipv6/addrconf.c:1998)
ipv6_chk_addr (net/ipv6/addrconf.c:2031 net/ipv6/addrconf.c:1972)
rds_tcp_laddr_check (net/rds/tcp.c:370)
rds_bind (net/rds/bind.c:248)
__sys_bind (net/socket.c:1920)
__x64_sys_bind (net/socket.c:1956)
do_syscall_64 (arch/x86/entry/syscall_64.c:63)
entry_SYSCALL_64_after_hwframe (arch/x86/entry/entry_64.S:121) |
| In the Linux kernel, the following vulnerability has been resolved:
scsi: libiscsi: Fix stale-data leak into the SCSI sense buffer
iscsi_scsi_cmd_rsp() copies the sense data of a SCSI Response from the
target-supplied data segment. The segment carries a 2-byte sense length
followed by the sense bytes, so it must hold 2 + senselen bytes, but the
bounds check only requires datalen >= senselen:
senselen = get_unaligned_be16(data);
if (datalen < senselen)
goto invalid_datalen;
memcpy(sc->sense_buffer, data + 2,
min_t(uint16_t, senselen, SCSI_SENSE_BUFFERSIZE));
A target that returns a SCSI Response whose datalen equals senselen
(with senselen <= SCSI_SENSE_BUFFERSIZE) makes the memcpy() from data +
2 read up to two bytes past the received data. Those bytes are stale
conn->data contents and end up in the command's sense buffer, which is
returned to userspace.
Account for the 2-byte sense length prefix in the check. |
| In the Linux kernel, the following vulnerability has been resolved:
wifi: ath12k: fix out-of-bounds clear_bit in ath12k_mac_dp_peer_cleanup()
ath12k_mac_dp_peer_cleanup() clears the ML peer ID slot on the
free_ml_peer_id_map bitmap by indexing it with dp_peer->peer_id. That is
wrong: dp_peer->peer_id for an MLO peer always carries the
ATH12K_PEER_ML_ID_VALID bit (BIT(13)), so clear_bit() is invoked with
index >= 0x2000, which is far outside the bitmap of ATH12K_MAX_MLO_PEERS
(256) bits and corrupts memory adjacent to ah->free_ml_peer_id_map. The
intended bitmap entry also never gets cleared, so subsequent
ath12k_peer_ml_alloc() calls eventually run out of IDs.
The ID without the VALID bit is what ath12k_peer_ml_alloc() returned and
is stored in ahsta->ml_peer_id. Use that instead.
While there, also reset ahsta->ml_peer_id to ATH12K_MLO_PEER_ID_INVALID so
the bitmap and ahsta->ml_peer_id stay in sync.
Tested-on: WCN7850 hw2.0 PCI WLAN.HMT.1.1.c5-00302-QCAHMTSWPL_V1.0_V2.0_SILICONZ-1.115823.3 |
| In the Linux kernel, the following vulnerability has been resolved:
net: do not send ICMP/NDISC Redirects when peer allocation fails
When inet_getpeer_v4() or inet_getpeer_v6() fails to allocate a peer entry
under memory pressure or tree size caps, redirect handlers previously fell
back to sending un-rate-limited ICMP/NDISC Redirect messages.
In IPv4, ip_rt_send_redirect() called icmp_send() directly when peer == NULL.
In IPv6, ip6_forward() and ndisc_send_redirect() passed a NULL peer into
inet_peer_xrlim_allow(), which returned true when peer == NULL.
Because ICMP/NDISC Redirects are not part of the default global rate limit
mask (sysctl_icmp_ratemask), sending redirects when peer == NULL creates
an un-rate-limited ICMP packet storm.
Fix this by failing closed in ip_rt_send_redirect(), ip6_forward(), and
ndisc_send_redirect() when peer is NULL. |
| In the Linux kernel, the following vulnerability has been resolved:
forcedeth: fix UAF of txrx_stats in nv_remove
nv_remove() frees the per-CPU txrx_stats before unregister_netdev().
Until unregister completes, ndo_get_stats64, the NAPI/xmit data path,
and nv_close()/drain may still access txrx_stats, leading to a
use-after-free.
Free the stats only after unregister_netdev(). |
| In the Linux kernel, the following vulnerability has been resolved:
Bluetooth: ISO: clear iso_data always when detaching conn from hcon
When setting conn->hcon = NULL, also conn->hcon->iso_data = NULL is
necessary, otherwise later iso_conn_free() will UAF.
Fix clearing of iso_data in iso_sock_disconn()
Fixes KASAN: slab-use-after-free in iso_conn_hold_unless_zero on
iso_sock_release() followed by hci_abort_conn_sync(). |
| In the Linux kernel, the following vulnerability has been resolved:
Bluetooth: L2CAP: fix UAF in l2cap_le_connect_rsp
l2cap_le_connect_rsp() obtains a channel via
__l2cap_get_chan_by_ident() but neither holds a reference nor uses
l2cap_chan_hold_unless_zero() before locking and operating on it.
A concurrent l2cap_chan_del() triggered by a remote disconnect can
free the channel between the lookup and l2cap_chan_lock(), causing
a use-after-free.
The BR/EDR counterpart l2cap_connect_rsp() and the sibling handler
l2cap_le_command_rej() already use l2cap_chan_hold_unless_zero()
to safely hold a reference, but l2cap_le_connect_rsp() was left
unprotected.
Fix by adding l2cap_chan_hold_unless_zero() after the ident lookup
and l2cap_chan_put() on the exit path, consistent with other L2CAP
response handlers. |
