Sicherheitslücken in linux-kvm · Seite 157

net/sched: sch_qfq: Fix null-deref in agg_dequeue

In the Linux kernel, the following vulnerability has been resolved: net/sched: sch_qfq: Fix null-deref in agg_dequeue To prevent a potential crash in agg_dequeue (net/sched/sch_qfq.c) when cl->qdisc->ops->peek(cl->qdisc) returns NULL, we check the return value before using it, similar to the existing approach in sch_hfsc.c. To avoid code duplication, the following changes are made: 1. Changed qdisc_warn_nonwc(include/net/pkt_sched.h) into a static inline function. 2. Moved qdisc_peek_len from net/sched/sch_hfsc.c to include/net/pkt_sched.h so that sch_qfq can reuse it. 3. Applied qdisc_peek_len in agg_dequeue to avoid crashing.

perf: arm_spe: Prevent overflow in PERF_IDX2OFF()

In the Linux kernel, the following vulnerability has been resolved: perf: arm_spe: Prevent overflow in PERF_IDX2OFF() Cast nr_pages to unsigned long to avoid overflow when handling large AUX buffer sizes (>= 2 GiB).

nbd: restrict sockets to TCP and UDP

In the Linux kernel, the following vulnerability has been resolved: nbd: restrict sockets to TCP and UDP Recently, syzbot started to abuse NBD with all kinds of sockets. Commit cf1b2326b734 ("nbd: verify socket is supported during setup") made sure the socket supported a shutdown() method. Explicitely accept TCP and UNIX stream sockets.

tcp_metrics: use dst_dev_net_rcu()

In the Linux kernel, the following vulnerability has been resolved: tcp_metrics: use dst_dev_net_rcu() Replace three dst_dev() with a lockdep enabled helper.

ipv4: start using dst_dev_rcu()

In the Linux kernel, the following vulnerability has been resolved: ipv4: start using dst_dev_rcu() Change icmpv4_xrlim_allow(), ip_defrag() to prevent possible UAF. Change ipmr_prepare_xmit(), ipmr_queue_fwd_xmit(), ip_mr_output(), ipv4_neigh_lookup() to use lockdep enabled dst_dev_rcu().

ocfs2: fix double free in user_cluster_connect()

In the Linux kernel, the following vulnerability has been resolved: ocfs2: fix double free in user_cluster_connect() user_cluster_disconnect() frees "conn->cc_private" which is "lc" but then the error handling frees "lc" a second time. Set "lc" to NULL on this path to avoid a double free.

net: dlink: handle copy_thresh allocation failure

In the Linux kernel, the following vulnerability has been resolved: net: dlink: handle copy_thresh allocation failure The driver did not handle failure of `netdev_alloc_skb_ip_align()`. If the allocation failed, dereferencing `skb->protocol` could lead to a NULL pointer dereference. This patch tries to allocate `skb`. If the allocation fails, it falls back to the normal path. Tested-on: D-Link DGE-550T Rev-A3

Squashfs: fix uninit-value in squashfs_get_parent

In the Linux kernel, the following vulnerability has been resolved: Squashfs: fix uninit-value in squashfs_get_parent Syzkaller reports a "KMSAN: uninit-value in squashfs_get_parent" bug. This is caused by open_by_handle_at() being called with a file handle containing an invalid parent inode number. In particular the inode number is that of a symbolic link, rather than a directory. Squashfs_get_parent() gets called with that symbolic link inode, and accesses the parent member field. unsigned int parent_ino = squashfs_i(inode)->parent; Because non-directory inodes in Squashfs do not have a parent value, this is uninitialised, and this

uio_hv_generic: Let userspace take care of interrupt mask

In the Linux kernel, the following vulnerability has been resolved: uio_hv_generic: Let userspace take care of interrupt mask Remove the logic to set interrupt mask by default in uio_hv_generic driver as the interrupt mask value is supposed to be controlled completely by the user space. If the mask bit gets changed by the driver, concurrently with user mode operating on the ring, the mask bit may be set when it is supposed to be clear, and the user-mode driver will miss an interrupt which will cause a hang. For eg- when the driver sets inbound ring buffer interrupt mask to 1, the host does not interrupt the guest on the UIO VMBus channel.

fs: udf: fix OOB read in lengthAllocDescs handling

In the Linux kernel, the following vulnerability has been resolved: fs: udf: fix OOB read in lengthAllocDescs handling When parsing Allocation Extent Descriptor, lengthAllocDescs comes from on-disk data and must be validated against the block size. Crafted or corrupted images may set lengthAllocDescs so that the total descriptor length (sizeof(allocExtDesc) + lengthAllocDescs) exceeds the buffer, leading udf_update_tag() to call crc_itu_t() on out-of-bounds memory and trigger a KASAN use-after-free read. BUG: KASAN: use-after-free in crc_itu_t+0x1d5/0x2b0 lib/crc-itu-t.c:60 Read of size 1 at addr ffff888041e7d000 by task syz-executor317/53

net: nfc: nci: Add parameter validation for packet data

In the Linux kernel, the following vulnerability has been resolved: net: nfc: nci: Add parameter validation for packet data Syzbot reported an uninitialized value bug in nci_init_req, which was introduced by commit 5aca7966d2a7 ("Merge tag 'perf-tools-fixes-for-v6.17-2025-09-16' of git://git.kernel.org/pub/scm/linux/kernel/git/perf/perf-tools"). This bug arises due to very limited and poor input validation that was done at nic_valid_size(). This validation only validates the skb->len (directly reflects size provided at the userspace interface) with the length provided in the buffer itself (interpreted as NCI_HEADER). This leads to the proc

tracing: Fix race condition in kprobe initialization causing NULL pointer dereference

In the Linux kernel, the following vulnerability has been resolved: tracing: Fix race condition in kprobe initialization causing NULL pointer dereference There is a critical race condition in kprobe initialization that can lead to NULL pointer dereference and kernel crash. [1135630.084782] Unable to handle kernel paging request at virtual address 0000710a04630000 ... [1135630.260314] pstate: 404003c9 (nZcv DAIF +PAN -UAO) [1135630.269239] pc : kprobe_perf_func+0x30/0x260 [1135630.277643] lr : kprobe_dispatcher+0x44/0x60 [1135630.286041] sp : ffffaeff4977fa40 [1135630.293441] x29: ffffaeff4977fa40 x28: ffffaf015340e400 [1135630.302837] x27:

Input: uinput - zero-initialize uinput_ff_upload_compat to avoid info leak

In the Linux kernel, the following vulnerability has been resolved: Input: uinput - zero-initialize uinput_ff_upload_compat to avoid info leak Struct ff_effect_compat is embedded twice inside uinput_ff_upload_compat, contains internal padding. In particular, there is a hole after struct ff_replay to satisfy alignment requirements for the following union member. Without clearing the structure, copy_to_user() may leak stack data to userspace. Initialize ff_up_compat to zero before filling valid fields.

net/9p: fix double req put in p9_fd_cancelled

In the Linux kernel, the following vulnerability has been resolved: net/9p: fix double req put in p9_fd_cancelled Syzkaller reports a KASAN issue as below: general protection fault, probably for non-canonical address 0xfbd59c0000000021: 0000 [#1] PREEMPT SMP KASAN NOPTI KASAN: maybe wild-memory-access in range [0xdead000000000108-0xdead00000000010f] CPU: 0 PID: 5083 Comm: syz-executor.2 Not tainted 6.1.134-syzkaller-00037-g855bd1d7d838 #0 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.12.0-1 04/01/2014 RIP: 0010:__list_del include/linux/list.h:114 [inline] RIP: 0010:__list_del_entry include/linux/list.h:137 [inline] RIP: 001

KVM: x86: Don't (re)check L1 intercepts when completing userspace I/O

In the Linux kernel, the following vulnerability has been resolved: KVM: x86: Don't (re)check L1 intercepts when completing userspace I/O When completing emulation of instruction that generated a userspace exit for I/O, don't recheck L1 intercepts as KVM has already finished that phase of instruction execution, i.e. has already committed to allowing L2 to perform I/O. If L1 (or host userspace) modifies the I/O permission bitmaps during the exit to userspace, KVM will treat the access as being intercepted despite already having emulated the I/O access. Pivot on EMULTYPE_NO_DECODE to detect that KVM is completing emulation. Of the three us

f2fs: fix to do sanity check on node footer for non inode dnode

In the Linux kernel, the following vulnerability has been resolved: f2fs: fix to do sanity check on node footer for non inode dnode As syzbot reported below: ------------[ cut here ]------------ kernel BUG at fs/f2fs/file.c:1243! Oops: invalid opcode: 0000 [#1] SMP KASAN NOPTI CPU: 0 UID: 0 PID: 5354 Comm: syz.0.0 Not tainted 6.17.0-rc1-syzkaller-00211-g90d970cade8e #0 PREEMPT(full) RIP: 0010:f2fs_truncate_hole+0x69e/0x6c0 fs/f2fs/file.c:1243 Call Trace: <TASK> f2fs_punch_hole+0x2db/0x330 fs/f2fs/file.c:1306 f2fs_fallocate+0x546/0x990 fs/f2fs/file.c:2018 vfs_fallocate+0x666/0x7e0 fs/open.c:342 ksys_fallocate fs/open.c:366 [inline] __

can: peak_usb: fix shift-out-of-bounds issue

In the Linux kernel, the following vulnerability has been resolved: can: peak_usb: fix shift-out-of-bounds issue Explicitly uses a 64-bit constant when the number of bits used for its shifting is 32 (which is the case for PC CAN FD interfaces supported by this driver). [mkl: update subject, apply manually]

ipvs: Defer ip_vs_ftp unregister during netns cleanup

In the Linux kernel, the following vulnerability has been resolved: ipvs: Defer ip_vs_ftp unregister during netns cleanup On the netns cleanup path, __ip_vs_ftp_exit() may unregister ip_vs_ftp before connections with valid cp->app pointers are flushed, leading to a use-after-free. Fix this by introducing a global `exiting_module` flag, set to true in ip_vs_ftp_exit() before unregistering the pernet subsystem. In __ip_vs_ftp_exit(), skip ip_vs_ftp unregister if called during netns cleanup (when exiting_module is false) and defer it to __ip_vs_cleanup_batch(), which unregisters all apps after all connections are flushed. If called during mod

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net: sched: cls_u32: Undo tcf_bind_filter if u32_replace_hw_knode

In the Linux kernel, the following vulnerability has been resolved: net: sched: cls_u32: Undo tcf_bind_filter if u32_replace_hw_knode When u32_replace_hw_knode fails, we need to undo the tcf_bind_filter operation done at u32_set_parms.

netlink: fix potential deadlock in netlink_set_err()

In the Linux kernel, the following vulnerability has been resolved: netlink: fix potential deadlock in netlink_set_err() syzbot reported a possible deadlock in netlink_set_err() [1] A similar issue was fixed in commit 1d482e666b8e ("netlink: disable IRQs for netlink_lock_table()") in netlink_lock_table() This patch adds IRQ safety to netlink_set_err() and __netlink_diag_dump() which were not covered by cited commit. [1] WARNING: possible irq lock inversion dependency detected 6.4.0-rc6-syzkaller-00240-g4e9f0ec38852 #0 Not tainted syz-executor.2/23011 just changed the state of lock: ffffffff8e1a7a58 (nl_table_lock){.+.?}-{2:2}, at: netl