net/sched: bound qdisc_pkt_len to prevent qdisc soft lockup
In the Linux kernel, the following vulnerability has been resolved:
net/sched: bound qdisc_pkt_len to prevent qdisc soft lockup
qdisc_get_stab() accepts a user-supplied size table, and
__qdisc_calculate_pkt_len() amplifies qdisc_pkt_len() through the
overhead, the size-table data (u16), and size_log (up to
STAB_SIZE_LOG_MAX). A crafted stab can therefore set qdisc_pkt_len()
to ~1 GiB for an ordinary skb. Per-flow deficit schedulers such as
DRR and ETS replenish one quantum per loop iteration; with a tiny
quantum (1) they spin billions of times under the qdisc lock,
producing a soft lockup / RCU stall as illustrated by [email protected].
Cap
slip: remove slip_hangup() to fix use-after-free in slip_receive_buf()
In the Linux kernel, the following vulnerability has been resolved:
slip: remove slip_hangup() to fix use-after-free in slip_receive_buf()
Jaeyoung Chung and Eulgyu Kim reported a slab-use-after-free read
in slip_receive_buf() when racing against tty hangup.
tty_ldisc_hangup() calls ld->ops->hangup() while holding only
a read lock on tty->ldisc_sem (via tty_ldisc_ref()).
Because slip_hangup() simply called slip_close(), it ran concurrently
with reader functions such as slip_receive_buf().
slip_close() unregisters and frees the net device and its private
struct slip, causing concurrent reader threads in slip_receive_buf()
to dereference fr
In the Linux kernel, the following vulnerability has been resolved:
net: fec: only stop PTP if it was initialized
fec_ptp_init() is only called when fep->bufdesc_ex is available.
However, fec_probe() unconditionally calls fec_ptp_stop() on the
failed_init path, and fec_drv_remove() unconditionally calls
fec_ptp_stop() during device removal.
Check fep->bufdesc_ex before calling fec_ptp_stop() in both paths
to avoid stopping PTP when it was not initialized.
In the Linux kernel, the following vulnerability has been resolved:
usb: atm: usbatm: fix invalid ci_range initialization
syzbot reported a shift-out-of-bounds in __vcc_connect():
UBSAN: shift-out-of-bounds in net/atm/common.c:382:32
shift exponent -1 is negative
CPU: 0 UID: 0 PID: 5987 Comm: syz.0.18 Not tainted syzkaller #0 PREEMPT(full)
Hardware name: Google Compute Engine/Google Compute Engine, BIOS Google 08/05/2026
Call Trace:
<TASK>
dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120
ubsan_epilogue+0xa/0x30 lib/ubsan.c:233
__ubsan_handle_shift_out_of_bounds+0x36d/0x400 lib/ubsan.c:494
__vcc_connect+0x14b4/0x19c0
tcp: fix corruption of urgent data on multi-segment retransmit
In the Linux kernel, the following vulnerability has been resolved:
tcp: fix corruption of urgent data on multi-segment retransmit
On the normal xmit path, while in urgent mode we refuse to build a
multi-segment TSO packet, so every segment gets its own urg_ptr:
/* tcp_write_xmit() */
limit = mss_now;
if (tso_segs > 1 && !tcp_urg_mode(tp))
limit = tcp_mss_split_point(...);
The retransmit path has no such guard. __tcp_retransmit_skb() builds a
segs > 1 skb and hands it to the GSO layer, which only advances th->seq
per segment and copies urg_ptr verbatim:
/* __tcp_retransmit_skb() */
len = cur_mss * segs; /* segs > 1, no urg_mode c
In the Linux kernel, the following vulnerability has been resolved:
net/sched: sch_htb: limit htb_classify inner-class filter hops
htb_classify() follows each filter-selected inner class by switching
to cl->filter_list, but never bounds the number of hops. A filter on
an inner class can point back to itself or to another inner class that
points back, creating an infinite loop in the packet classification
path with the qdisc lock held and BH disabled — a soft lockup / panic
from a single packet.
Bound the traversal with a hop counter and drop the packet with a
rate-limited warning once the bound is exceeded. The counter is
incremented at th
In the Linux kernel, the following vulnerability has been resolved:
tcp: reject non zerocopy devmem tx
Devmem tcp tx doesn't work without zero-copy, however it's not currently
enforced if NETIF_F_SG isn't present. In this case, tcp_sendmsg_locked()
will try the copy path and try to copy data from an iovec which consists
of offsets into the dma-buf and would normally fail. Moreover,
d9c56501c72fd ("net: tcp: block mixing readable and unreadable frags")
relies on that and assumes that the devmem binding is present IFF we're
using the zero-copy path, which can be used to mix net-iov and pages in
a single skb, and break invariants. Let's reject
net: skbuff: don't skb_tx_error() the source skb in skb_zerocopy()
In the Linux kernel, the following vulnerability has been resolved:
net: skbuff: don't skb_tx_error() the source skb in skb_zerocopy()
skb_zerocopy() copies frags from @from into @to. On an
skb_orphan_frags() failure it calls skb_tx_error(@from), a destructive
operation on the source skb the copy helper does not own. That completes
@from's zerocopy uarg and clears SKBFL_ALL_ZEROCOPY, including the
SKBFL_SHARED_FRAG page-ownership marker.
Both callers already report the failure on their own drop path.
nfnetlink_queue does it at nla_put_failure, and Open vSwitch does it in
the flow-miss drop arm of ovs_dp_process_packet(), so nothing is lost
fs/ntfs3: fix slab-out-of-bounds write in ni_create_attr_list()
In the Linux kernel, the following vulnerability has been resolved:
fs/ntfs3: fix slab-out-of-bounds write in ni_create_attr_list()
ni_create_attr_list() allocates a fixed buffer of al_aligned(record_size)
(== record_size) bytes and then walks every attribute of the primary MFT
record, writing one ATTR_LIST_ENTRY per attribute and advancing the cursor
by le_size(name_len), with no check against the end of the buffer; the
total size is only computed after the loop.
A minimum-size resident attribute occupies SIZEOF_RESIDENT (0x18 = 24)
bytes on disk, but an unnamed attribute expands to le_size(0) (0x20 = 32)
bytes in the list. Because the n
drm/xe: Don't hand out the flat CCS storage as usable VRAM
In the Linux kernel, the following vulnerability has been resolved:
drm/xe: Don't hand out the flat CCS storage as usable VRAM
get_flat_ccs_offset() reads the base of the flat CCS storage from the
hardware, scales it by the number of enabled L3 nodes, and rounds the
result up to 128K. Everything below that offset is then handed to the
VRAM allocator as usable memory.
Rounding a limit that means "usable memory ends here" upwards publishes
whatever lies between the real base and the rounded one as free memory,
and that memory belongs to the compression hardware. The scaled value
has no reason to be 128K aligned, and on a Battlemage G21 wit
In the Linux kernel, the following vulnerability has been resolved:
mm/page_alloc: don't spin_trylock() in NMI on UP
Patch series "mm/page_alloc: fixes for free_pages_nolock() on RT/UP".
Pre-existing bugs found by Sashiko during review of this other series:
https://lore.kernel.org/all/[email protected]/
I have not reproduced these bugs, and I suspect there is no real-world
user that is affected by them.
This patch (of 2):
As noted in can_spin_trylock(), using this is unsafe in this context.
commit 620b46ed6ae17 ("mm/page_alloc: return NULL early from
alloc_frozen_pages_nolock() in NMI on UP") fixed th
In the Linux kernel, the following vulnerability has been resolved:
USB: gadget: ffs: fix mm lifetime handling
io_data stores a pointer to the submitting task's mm_struct,
but does not currently hold a reference to it while async
requests are pending.
This can result in a use-after-free if the task exits before
completion handling finishes.
Take a reference with mmgrab() when queuing the read request
and release it with mmdrop() on request completion.
usb: gadget: f_fs: Fix Use-After-Free in AIO error path
In the Linux kernel, the following vulnerability has been resolved:
usb: gadget: f_fs: Fix Use-After-Free in AIO error path
In ffs_epfile_write_iter() and ffs_epfile_read_iter(), when ffs_epfile_io()
fails with an error other than -EIOCBQUEUED, the io_data structure (`p`) is
freed. However, for AIO operations, the kiocb cancel function was already
armed and kiocb->private was set to `p`.
If a concurrent cancel operation (such as sys_io_cancel()) executes after
ffs_epfile_io() fails but before the function frees `p`, a Use-After-Free
can occur when the cancellation handler accesses the freed pointer.
To securely fix this race condition, we
zram: fix slot lock bit position on big-endian 64-bit
In the Linux kernel, the following vulnerability has been resolved:
zram: fix slot lock bit position on big-endian 64-bit
The slot lock is a bit operation on the whole __lock word, which flags and
ac_time alias as two u32s. On little-endian the lock bit lands in the
position ZRAM_ENTRY_LOCK reserves in flags, so the aliasing works out. On
64-bit big-endian it lands in ac_time instead: with
ZRAM_TRACK_ENTRY_ACTIME enabled, storing the access time from
mark_slot_accessed() or slot_free() wipes out the held lock bit, letting
another CPU take the same slot lock; an access time value with that bit
set makes the slot look locked forever.
Shift
ceph: properly decrypt filenames in vmalloc() buffers
In the Linux kernel, the following vulnerability has been resolved:
ceph: properly decrypt filenames in vmalloc() buffers
The fscrypt subsystem uses the scatterlist crypto API, inheriting its
requirement that any buffers are in the linear mapping region. However,
the messenger client uses kvmalloc() to create buffers for messages,
which will occasionally place those buffers in the vmalloc() region when
physical memory fragmentation doesn't permit a large enough kmalloc().
The various callers of ceph_fname_to_usr() directly pass (slices of) raw
messages from the MDS without considering that the messages may be in
vmalloc() buffers, resulting
In the Linux kernel, the following vulnerability has been resolved:
HID: sony: clean up device list on probe failure
sony_input_configured() adds some controllers to sony_device_list before
HID core registers their input devices. input_register_device() can fail
after the callback returns successfully. sony_probe() then observes that
HID_CLAIMED_INPUT is clear and unwinds, but only stops the HID hardware.
The devres-managed sony_sc is freed while its list node remains linked, so
the next matching controller traverses freed memory.
Initialize the list node and device ID to inactive states. Make list
removal idempotent and run the driver-pri
KVM: SEV: Forcefully invalidate SNP VMSA if its backing gmem page is zapped
In the Linux kernel, the following vulnerability has been resolved:
KVM: SEV: Forcefully invalidate SNP VMSA if its backing gmem page is zapped
Wire up a gmem_invalidate_range() call for SNP VMs, and use it to force
vCPUs to reload/recheck their guest-provided VMSA if the backing gmem
page is being invalidated, e.g. is being PUNCH_HOLE'd. Use the same core
logic to handle invalidations as VMX does for the APIC-access page, as the
two concepts are nearly identical: shove the physical address of a page
into the vCPU's control structure:
1. Snapshot the invalidation sequence counter
2. Grab the pfn (from guest_memfd in this case)
3. Acqui
NFSD: Guard admin state-revocation walks with NFSD_NET_UP
In the Linux kernel, the following vulnerability has been resolved:
NFSD: Guard admin state-revocation walks with NFSD_NET_UP
Writing to /proc/fs/nfsd/unlock_filesystem, or sending the
NFSD_CMD_UNLOCK_FILESYSTEM or NFSD_CMD_UNLOCK_EXPORT netlink command,
walks the NFSv4 client hash tables to revoke open state and cancel
async COPY operations. All three handlers gate that walk on
nn->nfsd_serv, but a listener added via portlist or netlink
listener_set sets nn->nfsd_serv before any nfsd thread starts.
nfsd_startup_net() has not yet allocated nn->conf_id_hashtbl, so the
walkers dereference a NULL table. A local administrator with
CAP_SYS_ADM
NFSD: Prevent client use-after-free during close_lru reaping
In the Linux kernel, the following vulnerability has been resolved:
NFSD: Prevent client use-after-free during close_lru reaping
An nfs4_openowner left on nn->close_lru after its final CLOSE keeps
its last closed stateid in oo_last_closed_stid, holding only a raw
pointer to its nfs4_client. The laundromat reaps timed-out entries,
drops nn->client_lock, and calls nfs4_put_stid(), which dereferences
the client through cl_lock. Nothing pins the client across that
window, so a concurrent force_expire_client() can free it and
nfs4_put_stid() reads freed memory. __destroy_client() hits the same
race, walking clp->cl_openowners without cl_lock.
P
NFSD: Prevent client use-after-free during blocked-lock reaping
In the Linux kernel, the following vulnerability has been resolved:
NFSD: Prevent client use-after-free during blocked-lock reaping
A bare lock owner -- its only remaining reference a blocked lock on
nn->blocked_locks_lru -- holds a raw pointer to its nfs4_client but
no reference keeping the client alive. When the per-net laundromat
reaps such a lock, freeing the nbl drops the owner reference
held through flc_owner, and the final nfs4_put_stateowner()
takes the client's cl_lock. Because the laundromat detaches the
nbl first, __destroy_client() no longer finds it, so a concurrent
force_expire_client() can free the client before nfs4_put_stat