| CVE |
Vendors |
Products |
Updated |
CVSS v3.1 |
| In the Linux kernel, the following vulnerability has been resolved:
tipc: clear sock->sk on the failed-insert path in tipc_sk_create()
When tipc_sk_create() fails to insert the new socket (tipc_sk_insert()
returns non-zero), its error path frees the sk with sk_free() but leaves
sock->sk pointing at the freed object:
if (tipc_sk_insert(tsk)) {
sk_free(sk);
pr_warn("Socket create failed; port number exhausted\n");
return -EINVAL;
}
This is harmless for plain socket(): the syscall layer clears sock->ops
before releasing, so tipc_release() is never called. It is not harmless
on the accept() path. tipc_accept() creates the pre-allocated child
socket with tipc_sk_create(net, new_sock, 0, kern); on failure it leaves
new_sock->sk dangling and new_sock->ops non-NULL, and do_accept() then
fput()s the new file, so __sock_release() -> tipc_release() runs
lock_sock(new_sock->sk) on the freed sk -- a use-after-free write of the
sk_lock spinlock.
tipc_release() already guards this exact "failed accept() releases a
pre-allocated child" case with "if (sk == NULL) return 0;", but the
guard is bypassed because tipc_sk_create() left sock->sk non-NULL
(dangling) rather than NULL.
Clear sock->sk on the failed-insert path so the existing tipc_release()
NULL check fires and the use-after-free is avoided.
The tipc_sk_insert() failure is reached when the per-netns socket
rhashtable hits its max_size (tsk_rht_params.max_size = 1048576, ~2M
elements) -- i.e. once a netns holds ~2M TIPC sockets every insert
returns -E2BIG.
BUG: KASAN: slab-use-after-free in lock_sock_nested (net/core/sock.c:3839)
Write of size 8 at addr ffff8880047cdc38 by task init/1
lock_sock_nested (net/core/sock.c:3839)
tipc_release (net/tipc/socket.c:638)
__sock_release (net/socket.c:710)
sock_close (net/socket.c:1501)
__fput (fs/file_table.c:512)
Allocated by task 1:
sk_alloc (net/core/sock.c:2308)
tipc_sk_create (net/tipc/socket.c:487)
tipc_accept (net/tipc/socket.c:2744)
do_accept (net/socket.c:2034)
Freed by task 1:
__sk_destruct (net/core/sock.c:2391)
tipc_sk_create (net/tipc/socket.c:504)
tipc_accept (net/tipc/socket.c:2744)
do_accept (net/socket.c:2034) |
| In the Linux kernel, the following vulnerability has been resolved:
drm/amdgpu: invoke pm_genpd_remove() before freeing genpd
Call pm_genpd_remove() to unregister from global list prior to releasing
acp_genpd memory, and clear the pointer after free.
(cherry picked from commit cd8650d7a91ee8b768e202354672553faa5cc1f2) |
| In the Linux kernel, the following vulnerability has been resolved:
RDMA/rxe: Fix a use-after-free problem in rxe_mmap
rxe_mmap() removes a rxe_mmap_info struct from the pending_mmaps list
and releases pending_lock while the struct's kref is still at 1:
list_del_init(&ip->pending_mmaps);
spin_unlock_bh(&rxe->pending_lock); /* ref == 1, no lock held */
ret = remap_vmalloc_range(vma, ip->obj, 0); /* walks PTEs */
[...]
rxe_vma_open(vma); /* kref_get, ref → 2 */
remap_vmalloc_range_partial() walks PTEs without any lock.
A concurrent DESTROY_CQ ioctl on another CPU calls:
kref_put(&q->ip->ref, rxe_mmap_release) /* ref 1→0 */
vfree(ip->obj) /* clears vmalloc PTEs mid-walk */
kfree(ip) /* frees rxe_mmap_info */
This yields:
1. Kernel crash, vmalloc_to_page() returns NULL when vfree wins the
per-PTE race -> vm_insert_page(NULL) → GPF in validate_page_before_insert
2. Page UAF, vmalloc_to_page() reads a stale PTE before vfree clears
it. User VMA holds a PTE to a free'd page which might eventually get
reallocated later by vmalloc which allows the attacker to get a clean
page-level UAF.
It is worth noting that even though a page-level UAF is possible given
the strong primitive, it is statistically very difficult to achieve
given the very short time window (after the last insert_page and before
the kref_get).
The call trace are as below:
Oops: general protection fault, probably for non-canonical address 0xdffffc0000000001: 0000 [#1] SMP KASAN NOPTI
KASAN: null-ptr-deref in range [0x0000000000000008-0x000000000000000f]
CPU: 0 UID: 1000 PID: 413 Comm: poc Not tainted 7.0.0-rc5-dirty #28 PREEMPT(lazy)
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.15.0-1 04/01/2014
RIP: 0010:validate_page_before_insert+0x32/0x300
Code: e5 41 57 41 56 49 89 fe 41 55 41 54 53 48 89 f3 e8 93 b5 a3 ff 48 8d 7b 08 48 b8 00 00 00 00 00 fc ff df 48 89 fa 48 c1 ea 03 <80> 3c 02 00 0f 85 7b 02 00 00 4c 8b 63 08 31 ff 4d 89 e5 41 83 e5
RSP: 0018:ffff88811b15f2f0 EFLAGS: 00000202
RAX: dffffc0000000000 RBX: 0000000000000000 RCX: 0000000000000000
RDX: 0000000000000001 RSI: 0000000000000000 RDI: 0000000000000008
RBP: ffff88811b15f318 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000000 R12: ffff8881181eee00
R13: 0000000000000000 R14: ffff8881181eee00 R15: ffff8881181eee20
FS: 00007b1e000f76c0(0000) GS:ffff8884268e0000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007b1e00a24ac0 CR3: 0000000116eb3000 CR4: 00000000000006f0
Call Trace:
<TASK>
insert_page+0x8f/0x190
? __pfx_insert_page+0x10/0x10
? kasan_save_alloc_info+0x38/0x60
vm_insert_page+0x2e7/0x400
remap_vmalloc_range_partial+0x212/0x3e0
remap_vmalloc_range+0x6e/0xb0
? __kasan_check_write+0x14/0x30
rxe_mmap+0x2e9/0x5d0
ib_uverbs_mmap+0x1ad/0x2c0
__mmap_region+0x12c2/0x2ad0
? __pfx___mmap_region+0x10/0x10
? __sanitizer_cov_trace_switch+0x58/0xb0
? mas_prev_slot+0x360/0x39c0
? __sanitizer_cov_trace_switch+0x58/0xb0
? mas_next_slot+0x1e5b/0x2f40
? __sanitizer_cov_trace_cmp8+0x18/0x30
? unmapped_area_topdown+0x4dd/0x610
? kfree+0x1b1/0x440
? free_cpumask_var+0x16/0x30
? __kasan_slab_free+0x7d/0xa0
? __sanitizer_cov_trace_cmp8+0x18/0x30
mmap_region+0x2e6/0x3c0
do_mmap+0xa3e/0x12a0
? __pfx_do_mmap+0x10/0x10
? __kasan_check_write+0x14/0x30
? down_write_killable+0xba/0x160
? __pfx_down_write_killable+0x10/0x10
? __sanitizer_cov_trace_cmp4+0x16/0x30
vm_mmap_pgoff+0x2d4/0x4a0
? __pfx_vm_mmap_pgoff+0x10/0x10
? fget+0x1bf/0x270
ksys_mmap_pgoff+0x40c/0x690
? __sanitizer_cov_trace_const_cmp4+0x16/0x30
? __pfx_ksys_mmap_pgoff+0x10/0x10
? __kasan_check_write+0x14/0x30
? _raw_spin_trylock+0xbb/0x130
? __pfx__raw_spin_trylock+0x10/0x10
__x64_sys_mmap+0x135/0x1e0
x64_sys_c
---truncated--- |
| In the Linux kernel, the following vulnerability has been resolved:
xfrm: policy: preallocate inexact bins before xfrm_hash_rebuild reinsert
xfrm_hash_rebuild()'s first loop preallocates the bins/chains the reinsert
loop needs, so the reinsert (after hlist_del_rcu()) cannot allocate or
fail. But its guard is inverted: it skips policies with prefixlen <
threshold and preallocates for the rest.
prefixlen < threshold is exactly when policy_hash_bysel() returns NULL and
the reinsert takes the allocating xfrm_policy_inexact_insert() path. So the
loop preallocates for the exact policies (which never allocate) and skips
the inexact ones, whose bin/node is then allocated GFP_ATOMIC during
reinsert. On failure the error path only WARN_ONCE()s and continues,
leaving a poisoned bydst node; the next rebuild's hlist_del_rcu()
dereferences LIST_POISON2 and takes a GPF. Reachable under memory pressure,
deterministic via failslab.
Invert the guard so preallocation covers exactly the reinserted policies;
the reinsert then allocates nothing and cannot fail.
Crash:
Oops: general protection fault, probably for non-canonical address
0xfbd59c0000000024: 0000 [#1] SMP KASAN NOPTI
KASAN: maybe wild-memory-access in range [0xdead...]
...
Workqueue: events xfrm_hash_rebuild
RIP: 0010:xfrm_hash_rebuild+0x5b3/0x1190
RAX: dead000000000122 (LIST_POISON2 + offset)
...
Call Trace:
hlist_del_rcu (include/linux/rculist.h:599)
xfrm_hash_rebuild (net/xfrm/xfrm_policy.c:1365)
process_one_work (kernel/workqueue.c:3322)
worker_thread (kernel/workqueue.c:3486)
kthread (kernel/kthread.c:436)
ret_from_fork (arch/x86/kernel/process.c:158)
ret_from_fork_asm (arch/x86/entry/entry_64.S:245)
...
Kernel panic - not syncing: Fatal exception in interrupt |
| In the Linux kernel, the following vulnerability has been resolved:
bpf: tcp: fix double sock release on batch realloc
bpf_iter_tcp_batch() releases the current batch via
bpf_iter_tcp_put_batch(), which drops the socket refs and rewrites
each slot with the socket cookie, then grows the batch. cur_sk/end_sk
are kept for bpf_iter_tcp_resume(), but on realloc failure the function
returns ERR_PTR() before resume runs, leaving cur_sk < end_sk over
slots that now hold cookies rather than sock pointers.
bpf_iter_tcp_seq_stop() then calls bpf_iter_tcp_put_batch() again and
dereferences a cookie as a struct sock.
Empty the batch on the failure path so stop() does not release it
again. The sockets were already freed by the first
bpf_iter_tcp_put_batch(), so nothing leaks, and a later read() rescans
the bucket from the start instead of skipping it. The sibling
GFP_NOWAIT failure path still holds real socket references and is left
for stop() to release.
BUG: KASAN: null-ptr-deref in __sock_gen_cookie
Read of size 8 at addr 0000000000000059 by task exploit
...
__sock_gen_cookie (net/core/sock_diag.c:28)
bpf_iter_tcp_put_batch (net/ipv4/tcp_ipv4.c:2918)
bpf_iter_tcp_seq_stop (net/ipv4/tcp_ipv4.c:3270)
bpf_seq_read (kernel/bpf/bpf_iter.c:205)
vfs_read (fs/read_write.c:572)
ksys_read (fs/read_write.c:716)
do_syscall_64
entry_SYSCALL_64_after_hwframe
Kernel panic - not syncing: Fatal exception |
| In the Linux kernel, the following vulnerability has been resolved:
ipv4: fib: free fib_alias with kfree_rcu() on insert error path
fib_table_insert() publishes new_fa into the leaf's fa_list with
fib_insert_alias() before calling the fib entry notifiers. When a
notifier fails, the error path removes new_fa with fib_remove_alias()
(hlist_del_rcu) and frees it right away with kmem_cache_free().
fib_table_lookup() walks that list under rcu_read_lock() only, so a
concurrent lookup that already reached new_fa keeps reading it after the
free:
BUG: KASAN: slab-use-after-free in fib_table_lookup (net/ipv4/fib_trie.c:1601)
Read of size 1 at addr ffff88810676d4eb by task exploit/297
Call Trace:
fib_table_lookup (net/ipv4/fib_trie.c:1601)
ip_route_output_key_hash_rcu (net/ipv4/route.c:2814)
ip_route_output_key_hash (net/ipv4/route.c:2705)
__ip4_datagram_connect (net/ipv4/datagram.c:49)
udp_connect (net/ipv4/udp.c:2144)
__sys_connect (net/socket.c:2167)
__x64_sys_connect (net/socket.c:2173)
do_syscall_64
entry_SYSCALL_64_after_hwframe
which belongs to the cache ip_fib_alias of size 56
Triggering the error path needs CAP_NET_ADMIN and a registered fib
notifier that can reject a route; a netdevsim device whose IPv4 FIB
resource is exhausted is enough.
Free new_fa with alias_free_mem_rcu(), as fib_table_delete() already
does for a fib_alias removed from the trie. |
| In the Linux kernel, the following vulnerability has been resolved:
sctp: don't free the ASCONF's own transport in DEL-IP processing
sctp_process_asconf() caches the transport the ASCONF chunk is processed
against in asconf->transport (== chunk->transport, set once in sctp_rcv()).
For an ASCONF located through its Address Parameter by
__sctp_rcv_asconf_lookup(), that cached transport corresponds to the
Address Parameter, which need not be the packet's source address.
sctp_process_asconf_param() rejects a DEL-IP for the packet source address
(ADDIP D8, SCTP_ERROR_DEL_SRC_IP), but nothing protects asconf->transport.
A single ASCONF can therefore carry, in order:
[Address Parameter L] [DEL-IP L] [DEL-IP 0.0.0.0]
where L differs from the source. The DEL-IP for L passes the D8 check and
calls sctp_assoc_rm_peer() on the transport that asconf->transport still
points at, freeing it (RCU-deferred). The following wildcard DEL-IP then
reuses the now-dangling asconf->transport in sctp_assoc_set_primary() and
sctp_assoc_del_nonprimary_peers(): set_primary() dereferences the freed
transport (->ipaddr, ->state) and plants the dangling pointer into
asoc->peer.primary_path / active_path, and del_nonprimary_peers(), keeping
only the pointer that is no longer on the list, removes every real
transport, leaving the association with a transport_count of 0 and
primary_path/active_path pointing at freed memory.
Reject a DEL-IP that targets the transport the ASCONF is being processed
against, mirroring the existing source-address guard, so the wildcard
branch can never reuse a freed transport. |
| In the Linux kernel, the following vulnerability has been resolved:
KVM: x86: Check for invalid/obsolete root *after* making MMU pages available
Check for a "stale" page fault, i.e. for an invalid and/or obsolete root,
after making MMU pages available for the shadow MMU. If reclaiming shadow
pages zaps an in-use root, i.e. marks it invalid, then KVM will attempt to
map memory into an invalid root. On its own, populating an invalid root is
"fine", but because child shadow pages inherit their parent's role, any
children created during the map/fetch will be created as invalid pages,
thus violating KVM's invariant that invalid pages are never on the list of
active MMU pages.
Note, the underlying flaw has existed since KVM first started tracking
invalid roots in 2008 (commit 2e53d63acba7, "KVM: MMU: ignore zapped root
pagetables"), but the true badness only came along in 2020 (Linux 5.9)
with the invariant that invalid shadow pages can't be on the list of
active pages.
Note #2, inheriting role.invalid when creating child shadow pages is also
far from ideal; that flaw will be addressed separately. |
| In the Linux kernel, the following vulnerability has been resolved:
tipc: fix use-after-free of the discoverer in tipc_disc_rcv()
bearer_disable() frees b->disc with tipc_disc_delete()'s plain kfree(),
but tipc_disc_rcv() still dereferences b->disc in RX softirq under
rcu_read_lock() (tipc_udp_recv -> tipc_rcv -> tipc_disc_rcv).
L2 bearers are safe thanks to the synchronize_net() in
tipc_disable_l2_media(), but the UDP bearer defers that call to the
cleanup_bearer() workqueue, so the discoverer is freed with no grace
period:
BUG: KASAN: slab-use-after-free in tipc_disc_rcv (net/tipc/discover.c:149)
Read of size 8 at addr ffff88802348b728 by task poc_tipc/184
<IRQ>
tipc_disc_rcv (net/tipc/discover.c:149)
tipc_rcv (net/tipc/node.c:2126)
tipc_udp_recv (net/tipc/udp_media.c:391)
udp_rcv (net/ipv4/udp.c:2643)
ip_local_deliver_finish (net/ipv4/ip_input.c:241)
</IRQ>
Freed by task 181:
kfree (mm/slub.c:6565)
bearer_disable (net/tipc/bearer.c:418)
tipc_nl_bearer_disable (net/tipc/bearer.c:1001)
The bearer is freed with kfree_rcu(); free the discoverer the same way.
Add an rcu_head to struct tipc_discoverer and free it and its skb from an
RCU callback.
Because the RCU callback (tipc_disc_free_rcu) lives in module text, a
call_rcu() that is still pending when the tipc module is unloaded would
invoke a freed function. Add an rcu_barrier() to tipc_exit() after the
bearer subsystem has been torn down, so all pending discoverer callbacks
have run before the module text goes away.
Reachable from an unprivileged user namespace: the TIPCv2 genl family is
netnsok and its bearer commands have no GENL_ADMIN_PERM. Needs CONFIG_TIPC
and CONFIG_TIPC_MEDIA_UDP. |
| In the Linux kernel, the following vulnerability has been resolved:
blk-mq: pop cached request if it is usable
When submitting a bio to blk-mq, if the task should sleep after peeking
a cached request, but before it pops it, the plug flushes and calls
blk_mq_free_plug_rqs, freeing the cached_rqs. This creates a
use-after-free bug. Fix this by popping the cached request before any
possible blocking calls if it is suitable for use.
Popping this request first holds a queue reference, so avoid any
serialization races with queue freezes and can safely proceed with
dispatching that request to the driver. This potentially increases a
timing window from when a driver wants to freeze its queue to when
requests stop being dispatched. That scenario is off the fast path
though, and drivers need to appropriately handle requests during a
freeze request anyway.
The downside is the popped element needs to be individually freed when
we performed a bio plug merge. The cached request would have had to be
freed later anyway, but this patch does it inline with building the plug
list instead of after flushing it. |
| In the Linux kernel, the following vulnerability has been resolved:
Bluetooth: hci_conn: fix potential UAF in create_big_sync
Add hci_conn_valid() check in create_big_sync() to detect stale
connections before proceeding with BIG creation. Handle the
resulting -ECANCELED in create_big_complete() and re-validate the
connection under hci_dev_lock() before dereferencing, matching the
pattern used by create_le_conn_complete() and create_pa_complete().
Keep the hci_conn object alive across the async boundary by taking
a reference via hci_conn_get() when queueing create_big_sync(), and
dropping it in the completion callback. The refcount and the lock
are complementary: the refcount keeps the object allocated, while
hci_dev_lock() serializes hci_conn_hash_del()'s list_del_rcu() on
hdev->conn_hash, as required by hci_conn_del().
hci_conn_put() is called outside hci_dev_unlock() so the final put
(which resolves to kfree() via bt_link_release) does not run under
hdev->lock, though the release path would be safe either way.
Without this, create_big_complete() would unconditionally
dereference the conn pointer on error, causing a use-after-free
via hci_connect_cfm() and hci_conn_del(). |
| Valkey is a distributed key-value database. Prior to 7.2.14, 8.0.10, 8.1.9, 9.0.5, and 9.1.1, Valkey's tlsProcessPendingData function iterates pending_list while an authenticated client can trigger CLIENT KILL, causing connTLSClose to delete the iterator's cached next node and producing a use-after-free that can crash the server or potentially allow remote code execution when TLS is enabled. This issue is fixed in versions 7.2.14, 8.0.10, 8.1.9, 9.0.5, and 9.1.1. |
| Privilege escalation due to invalid pointer in the Graphics component. This vulnerability was fixed in Firefox 154, Firefox ESR 153.1, Thunderbird 154, and Thunderbird 153.1. |
| Use-after-free in the JavaScript: GC component. This vulnerability was fixed in Firefox 154, Firefox ESR 153.1, Thunderbird 154, and Thunderbird 153.1. |
| In the Linux kernel, the following vulnerability has been resolved:
ksmbd: fix use-after-free of fp->owner.name in durable handle owner check
Two concurrent SMB2 durable reconnects (DH2C/DHnC) on the same
persistent_id race the fp->owner.name compare-read in
ksmbd_vfs_compare_durable_owner() against the kfree() in
ksmbd_reopen_durable_fd()'s reopen-success path. fp->owner.name is a
standalone kstrdup() buffer whose lifetime is independent of the fp
refcount, and the two sites share no lock: the compare reads the buffer
while the reopen frees it, so the strcmp() can dereference freed memory.
Commit 7ce4fc40018d ("ksmbd: fix durable reconnect double-bind race in
ksmbd_reopen_durable_fd") made the fp->conn claim atomic under
global_ft.lock (closing the owner.name double-free and the ksmbd_file
write-UAF), but the compare-read versus reopen-free pair was left
unserialized.
BUG: KASAN: slab-use-after-free in strcmp+0x2c/0x80
Read of size 1 by task kworker
strcmp
ksmbd_vfs_compare_durable_owner
smb2_check_durable_oplock
smb2_open
Freed by task kworker:
kfree
ksmbd_reopen_durable_fd
smb2_open
Allocated by task kworker:
kstrdup
session_fd_check
smb2_session_logoff
The buggy address belongs to the cache kmalloc-8
Serialize both sides of the race with fp->f_lock. The global durable
file-table lock still protects the durable reconnect claim, but
fp->owner.name is per-open state and does not need to block unrelated
durable table lookups or reconnects. The teardown is left at its
existing location after the reopen-success point so that an __open_id()
rollback still retains owner.name for a later legitimate reconnect to
verify. |
| In the Linux kernel, the following vulnerability has been resolved:
wifi: mac80211: capture fast-RX rate before mesh reuses skb->cb
ieee80211_invoke_fast_rx() reads RX status through
IEEE80211_SKB_RXCB(skb), which aliases the same skb->cb storage
that ieee80211_rx_mesh_data() reuses as IEEE80211_TX_INFO. In the
unicast forward path, mesh_data does:
info = IEEE80211_SKB_CB(fwd_skb);
memset(info, 0, sizeof(*info));
on the same skb the caller still names via rx->skb, then either
queues the skb for TX (success) or kfree_skb()'s it (no-route)
before returning RX_QUEUED. The caller's RX_QUEUED arm then
calls sta_stats_encode_rate(status) on memory that is either
zeroed (success path) or freed (no-route path). The latter is
KASAN slab-use-after-free in ieee80211_prepare_and_rx_handle.
Fix by encoding the rate from status before invoking
ieee80211_rx_mesh_data(), so the RX_QUEUED arm consumes a value
captured while status was still backed by valid memory. |
| In the Linux kernel, the following vulnerability has been resolved:
net/mlx5e: macsec: fix use-after-free of metadata_dst on RX SC delete
When an offloaded MACsec RX SC is deleted, macsec_del_rxsc_ctx() freed
the per-SC metadata_dst with metadata_dst_free(), which kfree()s the
object unconditionally and ignores the dst reference count. The RX
datapath in mlx5e_macsec_offload_handle_rx_skb() looks up the SC under
rcu_read_lock() via xa_load(), takes a reference with dst_hold() and
attaches the dst to the skb with skb_dst_set(). A reader that already
obtained the rx_sc pointer can race with the delete path and operate on
freed memory.
Fix the owner side by dropping the reference with dst_release() instead
of freeing unconditionally, and convert the RX datapath to
dst_hold_safe() so a reader racing the SC delete cannot attach a dst
whose last reference was just dropped; only attach it when a reference
was actually taken.
mlx5e_macsec_add_rxsc() also published sc_xarray_element via xa_alloc()
before rx_sc->md_dst was allocated and initialised, so a datapath reader
that looked the SC up by fs_id could observe rx_sc with md_dst still
NULL or, on weakly-ordered architectures, a non-NULL md_dst pointer
whose contents were not yet visible. NULL-check the xa_load() result and
md_dst on the datapath, and reorder add_rxsc() so the xa_alloc() publish
happens only after md_dst is fully initialised; the xarray RCU publish
then pairs with the rcu_read_lock()/xa_load() in the datapath.
Note: macsec_del_rxsc_ctx() also kfree()s rx_sc->sc_xarray_element
without an RCU grace period while the same datapath reads it under
rcu_read_lock(); that is a separate pre-existing issue left to a
follow-up patch.
Found by 0sec automated security-research tooling (https://0sec.ai). |
| In the Linux kernel, the following vulnerability has been resolved:
mmc: vub300: fix use-after-free on probe failure
The vub300 driver lifetime-manages its controller state using
vub300->kref, with vub300_delete() freeing the mmc host when the last
reference is dropped. The probe error path after the inactivity timer has
been armed still bypasses that lifetime rule, however, and falls through
to mmc_free_host() directly if mmc_add_host() fails.
The race window is between arming the inactivity timer and reaching the
probe error unwind after mmc_add_host() fails:
probe thread timer/workqueue
------------ ---------------
kref_init(&vub300->kref) ref = 1
kref_get(&vub300->kref) ref = 2, timer ref
add_timer(inactivity_timer) fires after one second
|
| race window
|<---------------------------------------------------->
|
mmc_add_host(mmc)
inactivity timer fires
vub300_queue_dead_work()
kref_get() ref = 3
queue_work(deadwork)
mmc_add_host() fails
timer_delete_sync()
mmc_free_host(mmc)
frees vub300
deadwork runs
use-after-free
The inactivity timeout is one second, so this would require
mmc_add_host() to both fail and take more than one second to do so. This
is unlikely to happen in practice, but the error path is still wrong.
timer_delete_sync() only waits for the timer callback itself. It does
not flush deadwork that the callback may already have queued. As a
result, queued deadwork can still hold a kref while the probe error path
directly frees the backing mmc host, including the vub300 storage.
Fix this by using the same lifetime mechanism as disconnect. Clear
vub300->interface so that the timer callback and any queued deadwork
return early and drop their references, then drop the initial probe
reference and return without falling through to err_free_host. |
| In the Linux kernel, the following vulnerability has been resolved:
fs/resctrl: Fix use-after-free during unmount
During unmount or failure teardown all mon_data structures that contain
monitoring event file private data are freed after which kernfs nodes are
removed. However, the RDT_DELETED flag is never set for the statically
allocated default resource group.
A concurrent reader of an event file associated with the default resource
group may, after dropping kernfs active protection, block on rdtgroup_mutex
while unmount proceeds to free the file private data and destroy the kernfs
node without waiting for the reader.
When the mutex is released, the reader wakes up, observes that RDT_DELETED
is not set for the default group, and dereferences the already-freed
file private data.
The scenario can be depicted as follows:
CPU0 CPU1
/*
* Default resource group's
* monitoring data accessible via
* kernfs file with kernfs_node::priv
* pointing to a struct mon_data.
* User opens the file for reading.
*/
rdtgroup_mondata_show() /* arch encounters fatal error */
rdtgroup_kn_lock_live() resctrl_exit()
atomic_inc(&rdtgroup_default.waitcount) cpus_read_lock()
kernfs_break_active_protection(kn) mutex_lock(&rdtgroup_mutex)
cpus_read_lock() resctrl_fs_teardown()
mutex_lock(&rdtgroup_mutex) rmdir_all_sub()
mon_put_kn_priv()
/* Delete all mon_data structures */
rdtgroup_destroy_root()
kernfs_destroy_root()
rdtgroup_default.kn = NULL
mutex_unlock(&rdtgroup_mutex)
/*
* rdtgroup_default.flags is empty so
* rdtgroup_kn_lock_live() returns
* &rdtgroup_default
*/
md = of->kn->priv;
/* md points to freed mon_data */
Set RDT_DELETED for the default group unconditionally since the flag does
not lead to the freeing of this statically allocated group.
Do not allow a new resctrl mount if there are any waiters on default group
of previous mount. A new mount will re-initialize the default group that
would appear to waiters from previous mount as though the default group is
accessible causing them to access the mon_data structures from the previous
mount that have been removed. |
| In the Linux kernel, the following vulnerability has been resolved:
net: dsa: mxl862xx: fix use-after-free of DSA ports in crc_err_work
Upon an MDIO CRC error mxl862xx_crc_err_work_fn() walks the DSA ports
and closes the CPU port conduits:
dsa_switch_for_each_cpu_port(dp, priv->ds)
dev_close(dp->conduit);
mxl862xx_remove() unregisters the switch before cancelling this work:
set_bit(MXL862XX_FLAG_WORK_STOPPED, &priv->flags);
cancel_delayed_work_sync(&priv->stats_work);
dsa_unregister_switch(ds);
mxl862xx_host_shutdown(priv);
dsa_unregister_switch() frees the dsa_port objects. If a CRC error
schedules the work during teardown it can run after the ports have been
freed and dereference freed memory.
Guard the port walk with MXL862XX_FLAG_WORK_STOPPED, which is already set
before dsa_unregister_switch(). DSA tears the ports down under
rtnl_lock(), so checking the flag under rtnl_lock() means the work either
runs before teardown and sees valid ports, or runs afterwards, observes
the flag and skips the walk. This mirrors the host_flood_work handler,
which skips torn-down ports under rtnl_lock(). |
