In the Linux kernel, the following vulnerability has been resolved: comedi: Fix initialization of data for instructions that write to subdevice Some Comedi subdevice instruction handlers are known to access instruction data elements beyond the first `insn->n` elements in some cases. The `do_insn_ioctl()` and `do_insnlist_ioctl()` functions allocate at least `MIN_SAMPLES` (16) data elements to deal with this, but they do not initialize all of that. For Comedi instruction codes that write to the subdevice, the first `insn->n` data elements are copied from user-space, but the remaining elements are left uninitialized. That could be a problem if the subdevice instruction handler reads the uninitialized data. Ensure that the first `MIN_SAMPLES` elements are initialized before calling these instruction handlers, filling the uncopied elements with 0. For `do_insnlist_ioctl()`, the same data buffer elements are used for handling a list of instructions, so ensure the first `MIN_SAMPLES`...

In the Linux kernel, the following vulnerability has been resolved: net/sched: sch_qfq: Fix race condition on qfq_aggregate A race condition can occur when 'agg' is modified in qfq_change_agg (called during qfq_enqueue) while other threads access it concurrently. For example, qfq_dump_class may trigger a NULL dereference, and qfq_delete_class may cause a use-after-free. This patch addresses the issue by: 1. Moved qfq_destroy_class into the critical section. 2. Added sch_tree_lock protection to qfq_dump_class and qfq_dump_class_stats.

In the Linux kernel, the following vulnerability has been resolved: rpl: Fix use-after-free in rpl_do_srh_inline(). Running lwt_dst_cache_ref_loop.sh in selftest with KASAN triggers the splat below [0]. rpl_do_srh_inline() fetches ipv6_hdr(skb) and accesses it after skb_cow_head(), which is illegal as the header could be freed then. Let's fix it by making oldhdr to a local struct instead of a pointer. [0]: [root@fedora net]# ./lwt_dst_cache_ref_loop.sh ... TEST: rpl (input) [ 57.631529] ================================================================== BUG: KASAN: slab-use-after-free in rpl_do_srh_inline.isra.0 (net/ipv6/rpl_iptunnel.c:174) Read of size 40 at addr ffff888122bf96d8 by task ping6/1543 CPU: 50 UID: 0 PID: 1543 Comm: ping6 Not tainted 6.16.0-rc5-01302-gfadd1e6231b1 #23 PREEMPT(voluntary) Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.16.3-debian-1.16.3-2 04/01/2014 Call Trace: <IRQ> dump_stack_lvl (lib/dump_stack.c:122) print_report (mm/kasan/report.c:4...

In the Linux kernel, the following vulnerability has been resolved: smc: Fix various oops due to inet_sock type confusion. syzbot reported weird splats [0][1] in cipso_v4_sock_setattr() while freeing inet_sk(sk)->inet_opt. The address was freed multiple times even though it was read-only memory. cipso_v4_sock_setattr() did nothing wrong, and the root cause was type confusion. The cited commit made it possible to create smc_sock as an INET socket. The issue is that struct smc_sock does not have struct inet_sock as the first member but hijacks AF_INET and AF_INET6 sk_family, which confuses various places. In this case, inet_sock.inet_opt was actually smc_sock.clcsk_data_ready(), which is an address of a function in the text segment. $ pahole -C inet_sock vmlinux struct inet_sock { ... struct ip_options_rcu * inet_opt; /* 784 8 */ $ pahole -C smc_sock vmlinux struct smc_sock { ... void (*clcsk_data_ready)(struct sock *); /* 784 8 */ The ...

In the Linux kernel, the following vulnerability has been resolved: usb: net: sierra: check for no status endpoint The driver checks for having three endpoints and having bulk in and out endpoints, but not that the third endpoint is interrupt input. Rectify the omission.

In the Linux kernel, the following vulnerability has been resolved: Bluetooth: Fix null-ptr-deref in l2cap_sock_resume_cb() syzbot reported null-ptr-deref in l2cap_sock_resume_cb(). [0] l2cap_sock_resume_cb() has a similar problem that was fixed by commit 1bff51ea59a9 ("Bluetooth: fix use-after-free error in lock_sock_nested()"). Since both l2cap_sock_kill() and l2cap_sock_resume_cb() are executed under l2cap_sock_resume_cb(), we can avoid the issue simply by checking if chan->data is NULL. Let's not access to the killed socket in l2cap_sock_resume_cb(). [0]: BUG: KASAN: null-ptr-deref in instrument_atomic_write include/linux/instrumented.h:82 [inline] BUG: KASAN: null-ptr-deref in clear_bit include/asm-generic/bitops/instrumented-atomic.h:41 [inline] BUG: KASAN: null-ptr-deref in l2cap_sock_resume_cb+0xb4/0x17c net/bluetooth/l2cap_sock.c:1711 Write of size 8 at addr 0000000000000570 by task kworker/u9:0/52 CPU: 1 UID: 0 PID: 52 Comm: kworker/u9:0 Not tainted 6.16.0-rc4-syzkaller-g7...

In the Linux kernel, the following vulnerability has been resolved: netfilter: nf_conntrack: fix crash due to removal of uninitialised entry A crash in conntrack was reported while trying to unlink the conntrack entry from the hash bucket list: [exception RIP: __nf_ct_delete_from_lists+172] [..] #7 [ff539b5a2b043aa0] nf_ct_delete at ffffffffc124d421 [nf_conntrack] #8 [ff539b5a2b043ad0] nf_ct_gc_expired at ffffffffc124d999 [nf_conntrack] #9 [ff539b5a2b043ae0] __nf_conntrack_find_get at ffffffffc124efbc [nf_conntrack] [..] The nf_conn struct is marked as allocated from slab but appears to be in a partially initialised state: ct hlist pointer is garbage; looks like the ct hash value (hence crash). ct->status is equal to IPS_CONFIRMED|IPS_DYING, which is expected ct->timeout is 30000 (=30s), which is unexpected. Everything else looks like normal udp conntrack entry. If we ignore ct->status and pretend its 0, the entry matches those that are newly allocated but not yet inserted into the...

In the Linux kernel, the following vulnerability has been resolved: tls: always refresh the queue when reading sock After recent changes in net-next TCP compacts skbs much more aggressively. This unearthed a bug in TLS where we may try to operate on an old skb when checking if all skbs in the queue have matching decrypt state and geometry. BUG: KASAN: slab-use-after-free in tls_strp_check_rcv+0x898/0x9a0 [tls] (net/tls/tls_strp.c:436 net/tls/tls_strp.c:530 net/tls/tls_strp.c:544) Read of size 4 at addr ffff888013085750 by task tls/13529 CPU: 2 UID: 0 PID: 13529 Comm: tls Not tainted 6.16.0-rc5-virtme Call Trace: kasan_report+0xca/0x100 tls_strp_check_rcv+0x898/0x9a0 [tls] tls_rx_rec_wait+0x2c9/0x8d0 [tls] tls_sw_recvmsg+0x40f/0x1aa0 [tls] inet_recvmsg+0x1c3/0x1f0 Always reload the queue, fast path is to have the record in the queue when we wake, anyway (IOW the path going down "if !strp->stm.full_len").

In the Linux kernel, the following vulnerability has been resolved: net: vlan: fix VLAN 0 refcount imbalance of toggling filtering during runtime Assuming the "rx-vlan-filter" feature is enabled on a net device, the 8021q module will automatically add or remove VLAN 0 when the net device is put administratively up or down, respectively. There are a couple of problems with the above scheme. The first problem is a memory leak that can happen if the "rx-vlan-filter" feature is disabled while the device is running: # ip link add bond1 up type bond mode 0 # ethtool -K bond1 rx-vlan-filter off # ip link del dev bond1 When the device is put administratively down the "rx-vlan-filter" feature is disabled, so the 8021q module will not remove VLAN 0 and the memory will be leaked [1]. Another problem that can happen is that the kernel can automatically delete VLAN 0 when the device is put administratively down despite not adding it when the device was put administratively up since during that t...

In the Linux kernel, the following vulnerability has been resolved: KVM: x86/xen: Fix cleanup logic in emulation of Xen schedop poll hypercalls kvm_xen_schedop_poll does a kmalloc_array() when a VM polls the host for more than one event channel potr (nr_ports > 1). After the kmalloc_array(), the error paths need to go through the "out" label, but the call to kvm_read_guest_virt() does not. [Adjusted commit message. - Paolo]

In the Linux kernel, the following vulnerability has been resolved: net/sched: Return NULL when htb_lookup_leaf encounters an empty rbtree htb_lookup_leaf has a BUG_ON that can trigger with the following: tc qdisc del dev lo root tc qdisc add dev lo root handle 1: htb default 1 tc class add dev lo parent 1: classid 1:1 htb rate 64bit tc qdisc add dev lo parent 1:1 handle 2: netem tc qdisc add dev lo parent 2:1 handle 3: blackhole ping -I lo -c1 -W0.001 127.0.0.1 The root cause is the following: 1. htb_dequeue calls htb_dequeue_tree which calls the dequeue handler on the selected leaf qdisc 2. netem_dequeue calls enqueue on the child qdisc 3. blackhole_enqueue drops the packet and returns a value that is not just NET_XMIT_SUCCESS 4. Because of this, netem_dequeue calls qdisc_tree_reduce_backlog, and since qlen is now 0, it calls htb_qlen_notify -> htb_deactivate -> htb_deactiviate_prios -> htb_remove_class_from_row -> htb_safe_rb_erase 5. As this is the only class in the selected hpr...

In the Linux kernel, the following vulnerability has been resolved: drm/exynos: exynos7_drm_decon: add vblank check in IRQ handling If there's support for another console device (such as a TTY serial), the kernel occasionally panics during boot. The panic message and a relevant snippet of the call stack is as follows: Unable to handle kernel NULL pointer dereference at virtual address 000000000000000 Call trace: drm_crtc_handle_vblank+0x10/0x30 (P) decon_irq_handler+0x88/0xb4 [...] Otherwise, the panics don't happen. This indicates that it's some sort of race condition. Add a check to validate if the drm device can handle vblanks before calling drm_crtc_handle_vblank() to avoid this.

In the Linux kernel, the following vulnerability has been resolved: perf: Revert to requiring CAP_SYS_ADMIN for uprobes Jann reports that uprobes can be used destructively when used in the middle of an instruction. The kernel only verifies there is a valid instruction at the requested offset, but due to variable instruction length cannot determine if this is an instruction as seen by the intended execution stream. Additionally, Mark Rutland notes that on architectures that mix data in the text segment (like arm64), a similar things can be done if the data word is 'mistaken' for an instruction. As such, require CAP_SYS_ADMIN for uprobes.

In the Linux kernel, the following vulnerability has been resolved: netlink: Fix wraparounds of sk->sk_rmem_alloc. Netlink has this pattern in some places if (atomic_read(&sk->sk_rmem_alloc) > sk->sk_rcvbuf) atomic_add(skb->truesize, &sk->sk_rmem_alloc); , which has the same problem fixed by commit 5a465a0da13e ("udp: Fix multiple wraparounds of sk->sk_rmem_alloc."). For example, if we set INT_MAX to SO_RCVBUFFORCE, the condition is always false as the two operands are of int. Then, a single socket can eat as many skb as possible until OOM happens, and we can see multiple wraparounds of sk->sk_rmem_alloc. Let's fix it by using atomic_add_return() and comparing the two variables as unsigned int. Before: [root@fedora ~]# ss -f netlink Recv-Q Send-Q Local Address:Port Peer Address:Port -1668710080 0 rtnl:nl_wraparound/293 * After: [root@fedora ~]# ss -f netlink Recv-Q Send-Q Local Address:Port Peer Address:Port 21474830...

In the Linux kernel, the following vulnerability has been resolved: tipc: Fix use-after-free in tipc_conn_close(). syzbot reported a null-ptr-deref in tipc_conn_close() during netns dismantle. [0] tipc_topsrv_stop() iterates tipc_net(net)->topsrv->conn_idr and calls tipc_conn_close() for each tipc_conn. The problem is that tipc_conn_close() is called after releasing the IDR lock. At the same time, there might be tipc_conn_recv_work() running and it could call tipc_conn_close() for the same tipc_conn and release its last ->kref. Once we release the IDR lock in tipc_topsrv_stop(), there is no guarantee that the tipc_conn is alive. Let's hold the ref before releasing the lock and put the ref after tipc_conn_close() in tipc_topsrv_stop(). [0]: BUG: KASAN: use-after-free in tipc_conn_close+0x122/0x140 net/tipc/topsrv.c:165 Read of size 8 at addr ffff888099305a08 by task kworker/u4:3/435 CPU: 0 PID: 435 Comm: kworker/u4:3 Not tainted 4.19.204-syzkaller #0 Hardware name: Google Google Comp...

In the Linux kernel, the following vulnerability has been resolved: tcp: Correct signedness in skb remaining space calculation Syzkaller reported a bug [1] where sk->sk_forward_alloc can overflow. When we send data, if an skb exists at the tail of the write queue, the kernel will attempt to append the new data to that skb. However, the code that checks for available space in the skb is flawed: ''' copy = size_goal - skb->len ''' The types of the variables involved are: ''' copy: ssize_t (s64 on 64-bit systems) size_goal: int skb->len: unsigned int ''' Due to C's type promotion rules, the signed size_goal is converted to an unsigned int to match skb->len before the subtraction. The result is an unsigned int. When this unsigned int result is then assigned to the s64 copy variable, it is zero-extended, preserving its non-negative value. Consequently, copy is always >= 0. Assume we are sending 2GB of data and size_goal has been adjusted to a value smaller than skb->len. The subtraction ...

In the Linux kernel, the following vulnerability has been resolved: vsock: Fix transport_{g2h,h2g} TOCTOU vsock_find_cid() and vsock_dev_do_ioctl() may race with module unload. transport_{g2h,h2g} may become NULL after the NULL check. Introduce vsock_transport_local_cid() to protect from a potential null-ptr-deref. KASAN: null-ptr-deref in range [0x0000000000000118-0x000000000000011f] RIP: 0010:vsock_find_cid+0x47/0x90 Call Trace: __vsock_bind+0x4b2/0x720 vsock_bind+0x90/0xe0 __sys_bind+0x14d/0x1e0 __x64_sys_bind+0x6e/0xc0 do_syscall_64+0x92/0x1c0 entry_SYSCALL_64_after_hwframe+0x4b/0x53 KASAN: null-ptr-deref in range [0x0000000000000118-0x000000000000011f] RIP: 0010:vsock_dev_do_ioctl.isra.0+0x58/0xf0 Call Trace: __x64_sys_ioctl+0x12d/0x190 do_syscall_64+0x92/0x1c0 entry_SYSCALL_64_after_hwframe+0x4b/0x53

In the Linux kernel, the following vulnerability has been resolved: vsock: Fix transport_* TOCTOU Transport assignment may race with module unload. Protect new_transport from becoming a stale pointer. This also takes care of an insecure call in vsock_use_local_transport(); add a lockdep assert. BUG: unable to handle page fault for address: fffffbfff8056000 Oops: Oops: 0000 [#1] SMP KASAN RIP: 0010:vsock_assign_transport+0x366/0x600 Call Trace: vsock_connect+0x59c/0xc40 __sys_connect+0xe8/0x100 __x64_sys_connect+0x6e/0xc0 do_syscall_64+0x92/0x1c0 entry_SYSCALL_64_after_hwframe+0x4b/0x53

In the Linux kernel, the following vulnerability has been resolved: atm: clip: Fix potential null-ptr-deref in to_atmarpd(). atmarpd is protected by RTNL since commit f3a0592b37b8 ("[ATM]: clip causes unregister hang"). However, it is not enough because to_atmarpd() is called without RTNL, especially clip_neigh_solicit() / neigh_ops->solicit() is unsleepable. Also, there is no RTNL dependency around atmarpd. Let's use a private mutex and RCU to protect access to atmarpd in to_atmarpd().

In the Linux kernel, the following vulnerability has been resolved: atm: clip: Fix infinite recursive call of clip_push(). syzbot reported the splat below. [0] This happens if we call ioctl(ATMARP_MKIP) more than once. During the first call, clip_mkip() sets clip_push() to vcc->push(), and the second call copies it to clip_vcc->old_push(). Later, when the socket is close()d, vcc_destroy_socket() passes NULL skb to clip_push(), which calls clip_vcc->old_push(), triggering the infinite recursion. Let's prevent the second ioctl(ATMARP_MKIP) by checking vcc->user_back, which is allocated by the first call as clip_vcc. Note also that we use lock_sock() to prevent racy calls. [0]: BUG: TASK stack guard page was hit at ffffc9000d66fff8 (stack is ffffc9000d670000..ffffc9000d678000) Oops: stack guard page: 0000 [#1] SMP KASAN NOPTI CPU: 0 UID: 0 PID: 5322 Comm: syz.0.0 Not tainted 6.16.0-rc4-syzkaller #0 PREEMPT(full) Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.1...