linux-azure-4.15 vulnerabilities · Page 194

KVM: VMX: Do _all_ initialization before exposing /dev/kvm to userspace

In the Linux kernel, the following vulnerability has been resolved: KVM: VMX: Do _all_ initialization before exposing /dev/kvm to userspace Call kvm_init() only after _all_ setup is complete, as kvm_init() exposes /dev/kvm to userspace and thus allows userspace to create VMs (and call other ioctls). E.g. KVM will encounter a NULL pointer when attempting to add a vCPU to the per-CPU loaded_vmcss_on_cpu list if userspace is able to create a VM before vmx_init() configures said list. BUG: kernel NULL pointer dereference, address: 0000000000000008 #PF: supervisor write access in kernel mode #PF: error_code(0x0002) - not-present page PGD 0

codel: remove sch->q.qlen check before qdisc_tree_reduce_backlog()

In the Linux kernel, the following vulnerability has been resolved: codel: remove sch->q.qlen check before qdisc_tree_reduce_backlog() After making all ->qlen_notify() callbacks idempotent, now it is safe to remove the check of qlen!=0 from both fq_codel_dequeue() and codel_qdisc_dequeue().

• Update to 4.15.0-1190.205

net_sched: hfsc: Fix a UAF vulnerability in class handling

In the Linux kernel, the following vulnerability has been resolved: net_sched: hfsc: Fix a UAF vulnerability in class handling This patch fixes a Use-After-Free vulnerability in the HFSC qdisc class handling. The issue occurs due to a time-of-check/time-of-use condition in hfsc_change_class() when working with certain child qdiscs like netem or codel. The vulnerability works as follows: 1. hfsc_change_class() checks if a class has packets (q.qlen != 0) 2. It then calls qdisc_peek_len(), which for certain qdiscs (e.g., codel, netem) might drop packets and empty the queue 3. The code continues assuming the queue is still non-empty, adding

• Update to 4.15.0-1191.206

UBUNTU-CVE-2022-49856

Rejected reason: This CVE ID has been rejected or withdrawn by its CVE Numbering Authority.

UBUNTU-CVE-2025-37795

Rejected reason: This CVE ID has been rejected or withdrawn by its CVE Numbering Authority.

UBUNTU-CVE-2025-37782

Rejected reason: This CVE ID has been rejected or withdrawn by its CVE Numbering Authority.

RDMA/core: Fix null-ptr-deref in ib_core_cleanup()

In the Linux kernel, the following vulnerability has been resolved: RDMA/core: Fix null-ptr-deref in ib_core_cleanup() KASAN reported a null-ptr-deref error: KASAN: null-ptr-deref in range [0x0000000000000118-0x000000000000011f] CPU: 1 PID: 379 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996) RIP: 0010:destroy_workqueue+0x2f/0x740 RSP: 0018:ffff888016137df8 EFLAGS: 00000202 ... Call Trace: ib_core_cleanup+0xa/0xa1 [ib_core] __do_sys_delete_module.constprop.0+0x34f/0x5b0 do_syscall_64+0x3a/0x90 entry_SYSCALL_64_after_hwframe+0x63/0xcd RIP: 0033:0x7fa1a0d221b7 ... It is because the fail of roce_gid_mgmt_in

nfc: fdp: Fix potential memory leak in fdp_nci_send()

In the Linux kernel, the following vulnerability has been resolved: nfc: fdp: Fix potential memory leak in fdp_nci_send() fdp_nci_send() will call fdp_nci_i2c_write that will not free skb in the function. As a result, when fdp_nci_i2c_write() finished, the skb will memleak. fdp_nci_send() should free skb after fdp_nci_i2c_write() finished.

nfc: nxp-nci: Fix potential memory leak in nxp_nci_send()

In the Linux kernel, the following vulnerability has been resolved: nfc: nxp-nci: Fix potential memory leak in nxp_nci_send() nxp_nci_send() will call nxp_nci_i2c_write(), and only free skb when nxp_nci_i2c_write() failed. However, even if the nxp_nci_i2c_write() run succeeds, the skb will not be freed in nxp_nci_i2c_write(). As the result, the skb will memleak. nxp_nci_send() should also free the skb when nxp_nci_i2c_write() succeeds.

btrfs: fix inode list leak during backref walking at find_parent_nodes()

In the Linux kernel, the following vulnerability has been resolved: btrfs: fix inode list leak during backref walking at find_parent_nodes() During backref walking, at find_parent_nodes(), if we are dealing with a data extent and we get an error while resolving the indirect backrefs, at resolve_indirect_refs(), or in the while loop that iterates over the refs in the direct refs rbtree, we end up leaking the inode lists attached to the direct refs we have in the direct refs rbtree that were not yet added to the refs ulist passed as argument to find_parent_nodes(). Since they were not yet added to the refs ulist and prelim_release() does not

Bluetooth: L2CAP: Fix use-after-free caused by l2cap_reassemble_sdu

In the Linux kernel, the following vulnerability has been resolved: Bluetooth: L2CAP: Fix use-after-free caused by l2cap_reassemble_sdu Fix the race condition between the following two flows that run in parallel: 1. l2cap_reassemble_sdu -> chan->ops->recv (l2cap_sock_recv_cb) -> __sock_queue_rcv_skb. 2. bt_sock_recvmsg -> skb_recv_datagram, skb_free_datagram. An SKB can be queued by the first flow and immediately dequeued and freed by the second flow, therefore the callers of l2cap_reassemble_sdu can't use the SKB after that function returns. However, some places continue accessing struct l2cap_ctrl that resides in the SKB's CB for a

btrfs: fix tree mod log mishandling of reallocated nodes

In the Linux kernel, the following vulnerability has been resolved: btrfs: fix tree mod log mishandling of reallocated nodes We have been seeing the following panic in production kernel BUG at fs/btrfs/tree-mod-log.c:677! invalid opcode: 0000 [#1] SMP RIP: 0010:tree_mod_log_rewind+0x1b4/0x200 RSP: 0000:ffffc9002c02f890 EFLAGS: 00010293 RAX: 0000000000000003 RBX: ffff8882b448c700 RCX: 0000000000000000 RDX: 0000000000008000 RSI: 00000000000000a7 RDI: ffff88877d831c00 RBP: 0000000000000002 R08: 000000000000009f R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000100c40 R12: 0000000000000001 R13: ffff8886c26d6a00 R14:

ftrace: Fix use-after-free for dynamic ftrace_ops

In the Linux kernel, the following vulnerability has been resolved: ftrace: Fix use-after-free for dynamic ftrace_ops KASAN reported a use-after-free with ftrace ops [1]. It was found from vmcore that perf had registered two ops with the same content successively, both dynamic. After unregistering the second ops, a use-after-free occurred. In ftrace_shutdown(), when the second ops is unregistered, the FTRACE_UPDATE_CALLS command is not set because there is another enabled ops with the same content. Also, both ops are dynamic and the ftrace callback function is ftrace_ops_list_func, so the FTRACE_UPDATE_TRACE_FUNC command will not be set.

ext4: fix BUG_ON() when directory entry has invalid rec_len

In the Linux kernel, the following vulnerability has been resolved: ext4: fix BUG_ON() when directory entry has invalid rec_len The rec_len field in the directory entry has to be a multiple of 4. A corrupted filesystem image can be used to hit a BUG() in ext4_rec_len_to_disk(), called from make_indexed_dir(). ------------[ cut here ]------------ kernel BUG at fs/ext4/ext4.h:2413! ... RIP: 0010:make_indexed_dir+0x53f/0x5f0 ... Call Trace: <TASK> ? add_dirent_to_buf+0x1b2/0x200 ext4_add_entry+0x36e/0x480 ext4_add_nondir+0x2b/0xc0 ext4_create+0x163/0x200 path_openat+0x635/0xe90 do_filp_open+0xb4/0x160 ? __create_object.

scsi: scsi_transport_sas: Fix error handling in sas_phy_add()

In the Linux kernel, the following vulnerability has been resolved: scsi: scsi_transport_sas: Fix error handling in sas_phy_add() If transport_add_device() fails in sas_phy_add(), the kernel will crash trying to delete the device in transport_remove_device() called from sas_remove_host(). Unable to handle kernel NULL pointer dereference at virtual address 0000000000000108 CPU: 61 PID: 42829 Comm: rmmod Kdump: loaded Tainted: G W 6.1.0-rc1+ #173 pstate: 60000005 (nZCv daif -PAN -UAO -TCO -DIT -SSBS BTYPE=--) pc : device_del+0x54/0x3d0 lr : device_del+0x37c/0x3d0 Call trace: device_del+0x54/0x3d0 attribute_container_class_d

sctp: clear out_curr if all frag chunks of current msg are pruned

In the Linux kernel, the following vulnerability has been resolved: sctp: clear out_curr if all frag chunks of current msg are pruned A crash was reported by Zhen Chen: list_del corruption, ffffa035ddf01c18->next is NULL WARNING: CPU: 1 PID: 250682 at lib/list_debug.c:49 __list_del_entry_valid+0x59/0xe0 RIP: 0010:__list_del_entry_valid+0x59/0xe0 Call Trace: sctp_sched_dequeue_common+0x17/0x70 [sctp] sctp_sched_fcfs_dequeue+0x37/0x50 [sctp] sctp_outq_flush_data+0x85/0x360 [sctp] sctp_outq_uncork+0x77/0xa0 [sctp] sctp_cmd_interpreter.constprop.0+0x164/0x1450 [sctp] sctp_side_effects+0x37/0xe0 [sctp] sctp_do_sm+0x

hugetlbfs: don't delete error page from pagecache

In the Linux kernel, the following vulnerability has been resolved: hugetlbfs: don't delete error page from pagecache This change is very similar to the change that was made for shmem [1], and it solves the same problem but for HugeTLBFS instead. Currently, when poison is found in a HugeTLB page, the page is removed from the page cache. That means that attempting to map or read that hugepage in the future will result in a new hugepage being allocated instead of notifying the user that the page was poisoned. As [1] states, this is effectively memory corruption. The fix is to leave the page in the page cache. If the user attempts to use

ata: libata-transport: fix error handling in ata_tport_add()

In the Linux kernel, the following vulnerability has been resolved: ata: libata-transport: fix error handling in ata_tport_add() In ata_tport_add(), the return value of transport_add_device() is not checked. As a result, it causes null-ptr-deref while removing the module, because transport_remove_device() is called to remove the device that was not added. Unable to handle kernel NULL pointer dereference at virtual address 00000000000000d0 CPU: 12 PID: 13605 Comm: rmmod Kdump: loaded Tainted: G W 6.1.0-rc3+ #8 pstate: 60400009 (nZCv daif +PAN -UAO -TCO -DIT -SSBS BTYPE=--) pc : device_del+0x48/0x39c lr : device_del+0x44/0x39

ata: libata-transport: fix error handling in ata_tlink_add()

In the Linux kernel, the following vulnerability has been resolved: ata: libata-transport: fix error handling in ata_tlink_add() In ata_tlink_add(), the return value of transport_add_device() is not checked. As a result, it causes null-ptr-deref while removing the module, because transport_remove_device() is called to remove the device that was not added. Unable to handle kernel NULL pointer dereference at virtual address 00000000000000d0 CPU: 33 PID: 13850 Comm: rmmod Kdump: loaded Tainted: G W 6.1.0-rc3+ #12 pstate: 60400009 (nZCv daif +PAN -UAO -TCO -DIT -SSBS BTYPE=--) pc : device_del+0x48/0x39c lr : device_del+0x44/0x3

ata: libata-transport: fix error handling in ata_tdev_add()

In the Linux kernel, the following vulnerability has been resolved: ata: libata-transport: fix error handling in ata_tdev_add() In ata_tdev_add(), the return value of transport_add_device() is not checked. As a result, it causes null-ptr-deref while removing the module, because transport_remove_device() is called to remove the device that was not added. Unable to handle kernel NULL pointer dereference at virtual address 00000000000000d0 CPU: 13 PID: 13603 Comm: rmmod Kdump: loaded Tainted: G W 6.1.0-rc3+ #36 pstate: 60400009 (nZCv daif +PAN -UAO -TCO -DIT -SSBS BTYPE=--) pc : device_del+0x48/0x3a0 lr : device_del+0x44/0x3a0