In the Linux kernel, the following vulnerability has been resolved:
net: caif: clear client service pointer on teardown
`caif_connect()` can tear down an existing client after remote shutdown by
calling `caif_disconnect_client()` followed by `caif_free_client()`.
`caif_free_client()` releases the service layer referenced by
`adap_layer->dn`, but leaves that pointer stale.
When the socket is later destroyed, `caif_sock_destructor()` calls
`caif_free_client()` again and dereferences the freed service pointer.
Clear the client/service links before releasing the service object so
repeated teardown becomes harmless.
In the Linux kernel, the following vulnerability has been resolved:
ALSA: control: Validate buf_len before strnlen() in snd_ctl_elem_init_enum_names()
snd_ctl_elem_init_enum_names() advances pointer p through the names
buffer while decrementing buf_len. If buf_len reaches zero but items
remain, the next iteration calls strnlen(p, 0).
While strnlen(p, 0) returns 0 and would hit the existing name_len == 0
error path, CONFIG_FORTIFY_SOURCE's fortified strnlen() first checks
maxlen against __builtin_dynamic_object_size(). When Clang loses track
of p's object size inside the loop, this triggers a BRK exception panic
before the return value is examined.
Add a buf_len == 0 guard at the loop entry to prevent calling fortified
strnlen() on an exhausted buffer.
Found by kernel fuzz testing through Xiaomi Smartphone.
In the Linux kernel, the following vulnerability has been resolved:
ALSA: aloop: Fix peer runtime UAF during format-change stop
loopback_check_format() may stop the capture side when playback starts
with parameters that no longer match a running capture stream. Commit
826af7fa62e3 ("ALSA: aloop: Fix racy access at PCM trigger") moved
the peer lookup under cable->lock, but the actual snd_pcm_stop() still
runs after dropping that lock.
A concurrent close can clear the capture entry from cable->streams[] and
detach or free its runtime while the playback trigger path still holds a
stale peer substream pointer.
Keep a per-cable count of in-flight peer stops before dropping
cable->lock, and make free_cable() wait for those stops before
detaching the runtime. This preserves the existing behavior while
making the peer runtime lifetime explicit.
In the Linux kernel, the following vulnerability has been resolved:
crypto: atmel-tdes - fix DMA sync direction
Before DMA output is consumed by the CPU, ->dma_addr_out must be synced
with dma_sync_single_for_cpu() instead of dma_sync_single_for_device().
Using the wrong direction can return stale cache data on non-coherent
platforms.
In the Linux kernel, the following vulnerability has been resolved:
KVM: SVM: Inject #UD for INVLPGA if EFER.SVME=0
INVLPGA should cause a #UD when EFER.SVME is not set. Add a check to
properly inject #UD when EFER.SVME=0.
[sean: tag for stable@]
In the Linux kernel, the following vulnerability has been resolved:
fbdev: defio: Disconnect deferred I/O from the lifetime of struct fb_info
Hold state of deferred I/O in struct fb_deferred_io_state. Allocate an
instance as part of initializing deferred I/O and remove it only after
the final mapping has been closed. If the fb_info and the contained
deferred I/O meanwhile goes away, clear struct fb_deferred_io_state.info
to invalidate the mapping. Any access will then result in a SIGBUS
signal.
Fixes a long-standing problem, where a device hot-unplug happens while
user space still has an active mapping of the graphics memory. The hot-
unplug frees the instance of struct fb_info. Accessing the memory will
operate on undefined state.
In the Linux kernel, the following vulnerability has been resolved:
ibmasm: fix heap over-read in ibmasm_send_i2o_message()
The ibmasm_send_i2o_message() function uses get_dot_command_size() to
compute the byte count for memcpy_toio(), but this value is derived from
user-controlled fields in the dot_command_header (command_size: u8,
data_size: u16) and is never validated against the actual allocation size.
A root user can write a small buffer with inflated header fields, causing
memcpy_toio() to read up to ~65 KB past the end of the allocation into
adjacent kernel heap, which is then forwarded to the service processor
over MMIO.
Silently clamping the copy size is not sufficient: if the header fields
claim a larger size than the buffer, the SP receives a dot command whose
own header is inconsistent with the I2O message length, which can cause
the SP to desynchronize. Reject such commands outright by returning
failure.
Validate command_size before calling get_mfa_inbound() to avoid leaking
an I2O message frame: reading INBOUND_QUEUE_PORT dequeues a hardware
frame from the controller's free pool, and returning without a
corresponding set_mfa_inbound() call would permanently exhaust it.
Additionally, clamp command_size to I2O_COMMAND_SIZE before the
memcpy_toio() so the MMIO write stays within the I2O message frame,
consistent with the clamping already performed by outgoing_message_size()
for the header field.
In the Linux kernel, the following vulnerability has been resolved:
Bluetooth: hci_event: fix potential UAF in SSP passkey handlers
hci_conn lookup and field access must be covered by hdev lock in
hci_user_passkey_notify_evt() and hci_keypress_notify_evt(), otherwise
the connection can be freed concurrently.
Extend the hci_dev_lock critical section to cover all conn usage in both
handlers.
Keep the existing keypress notification behavior unchanged by routing
the early exits through a common unlock path.
In the Linux kernel, the following vulnerability has been resolved:
ALSA: ctxfi: Add fallback to default RSR for S/PDIF
spdif_passthru_playback_get_resources() uses atc->pll_rate as the RSR
for the MSR calculation loop. However, pll_rate is only updated in
atc_pll_init() and not in hw_pll_init(), so it remains 0 after the
card init.
When spdif_passthru_playback_setup() skips atc_pll_init() for
32000 Hz, (rsr * desc.msr) always becomes 0, causing the loop to spin
indefinitely.
Add fallback to use atc->rsr when atc->pll_rate is 0. This reflects
the hardware state, since hw_card_init() already configures the PLL
to the default RSR.
In the Linux kernel, the following vulnerability has been resolved:
ceph: only d_add() negative dentries when they are unhashed
Ceph can call d_add(dentry, NULL) on a negative dentry that is already
present in the primary dcache hash.
In the current VFS that is not safe. d_add() goes through __d_add()
to __d_rehash(), which unconditionally reinserts dentry->d_hash into
the hlist_bl bucket. If the dentry is already hashed, reinserting the
same node can corrupt the bucket, including creating a self-loop.
Once that happens, __d_lookup() can spin forever in the hlist_bl walk,
typically looping only on the d_name.hash mismatch check and
eventually triggering RCU stall reports like this one:
rcu: INFO: rcu_sched self-detected stall on CPU
rcu: 87-....: (2100 ticks this GP) idle=3a4c/1/0x4000000000000000 softirq=25003319/25003319 fqs=829
rcu: (t=2101 jiffies g=79058445 q=698988 ncpus=192)
CPU: 87 UID: 2952868916 PID: 3933303 Comm: php-cgi8.3 Not tainted 6.18.17-i1-amd #950 NONE
Hardware name: Dell Inc. PowerEdge R7615/0G9DHV, BIOS 1.6.6 09/22/2023
RIP: 0010:__d_lookup+0x46/0xb0
Code: c1 e8 07 48 8d 04 c2 48 8b 00 49 89 fc 49 89 f5 48 89 c3 48 83 e3 fe 48 83 f8 01 77 0f eb 2d 0f 1f 44 00 00 48 8b 1b 48 85 db <74> 20 39 6b 18 75 f3 48 8d 7b 78 e8 ba 85 d0 00 4c 39 63 10 74 1f
RSP: 0018:ff745a70c8253898 EFLAGS: 00000282
RAX: ff26e470054cb208 RBX: ff26e470054cb208 RCX: 000000006e958966
RDX: ff26e48267340000 RSI: ff745a70c82539b0 RDI: ff26e458f74655c0
RBP: 000000006e958966 R08: 0000000000000180 R09: 9cd08d909b919a89
R10: ff26e458f74655c0 R11: 0000000000000000 R12: ff26e458f74655c0
R13: ff745a70c82539b0 R14: d0d0d0d0d0d0d0d0 R15: 2f2f2f2f2f2f2f2f
FS: 00007f5770896980(0000) GS:ff26e482c5d88000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f5764de50c0 CR3: 000000a72abb5001 CR4: 0000000000771ef0
PKRU: 55555554
Call Trace:
<TASK>
lookup_fast+0x9f/0x100
walk_component+0x1f/0x150
link_path_walk+0x20e/0x3d0
path_lookupat+0x68/0x180
filename_lookup+0xdc/0x1e0
vfs_statx+0x6c/0x140
vfs_fstatat+0x67/0xa0
__do_sys_newfstatat+0x24/0x60
do_syscall_64+0x6a/0x230
entry_SYSCALL_64_after_hwframe+0x76/0x7e
This is reachable with reused cached negative dentries. A Ceph lookup
or atomic_open can be handed a negative dentry that is already hashed,
and fs/ceph/dir.c then hits one of two paths that incorrectly assume
"negative" also means "unhashed":
- ceph_finish_lookup():
MDS reply is -ENOENT with no trace
-> d_add(dentry, NULL)
- ceph_lookup():
local ENOENT fast path for a complete directory with shared caps
-> d_add(dentry, NULL)
Both paths can therefore re-add an already-hashed negative dentry.
Ceph already uses the correct pattern elsewhere: ceph_fill_trace() only
calls d_add(dn, NULL) for a negative null-dentry reply when d_unhashed(dn)
is true.
Fix both fs/ceph/dir.c sites the same way: only call d_add() for a
negative dentry when it is actually unhashed. If the negative dentry
is already hashed, leave it in place and reuse it as-is.
This preserves the existing behavior for unhashed dentries while
avoiding d_hash list corruption for reused hashed negatives.