CVE-2021-47296

The Linux Kernel, the operating system core itself.

Security Fix(es):

In the Linux kernel, the following vulnerability has been resolved:

KVM: PPC: Fix kvm_arch_vcpu_ioctl vcpu_load leak

vcpu_put is not called if the user copy fails. This can result in preempt notifier corruption and crashes, among other issues.(CVE-2021-47296)

In the Linux kernel, the following vulnerability has been resolved:

net: qcom/emac: fix UAF in emac_remove

adpt is netdev private data and it cannot be used after free_netdev() call. Using adpt after free_netdev() can cause UAF bug. Fix it by moving free_netdev() at the end of the function.(CVE-2021-47311)

In the Linux kernel, the following vulnerability has been resolved:

RDMA/cma: Ensure rdma_addr_cancel() happens before issuing more requests

The FSM can run in a circle allowing rdma_resolve_ip() to be called twice on the same id_priv. While this cannot happen without going through the work, it violates the invariant that the same address resolution background request cannot be active twice.

   CPU 1                                  CPU 2

rdma_resolve_addr(): RDMA_CM_IDLE -> RDMA_CM_ADDR_QUERY rdma_resolve_ip(addr_handler) #1

		 process_one_req(): for #1
                      addr_handler():
                        RDMA_CM_ADDR_QUERY -> RDMA_CM_ADDR_BOUND
                        mutex_unlock(&id_priv->handler_mutex);
                        [.. handler still running ..]

rdma_resolve_addr(): RDMA_CM_ADDR_BOUND -> RDMA_CM_ADDR_QUERY rdma_resolve_ip(addr_handler) !! two requests are now on the req_list

rdma_destroy_id(): destroy_id_handler_unlock(): _destroy_id(): cma_cancel_operation(): rdma_addr_cancel()

                      // process_one_req() self removes it
	          spin_lock_bh(&lock);
                       cancel_delayed_work(&req->work);
                   if (!list_empty(&req->list)) == true

  ! rdma_addr_cancel() returns after process_on_req #1 is done

kfree(id_priv)

		 process_one_req(): for #2
                      addr_handler():
                    mutex_lock(&id_priv->handler_mutex);
                        !! Use after free on id_priv

rdma_addr_cancel() expects there to be one req on the list and only cancels the first one. The self-removal behavior of the work only happens after the handler has returned. This yields a situations where the req_list can have two reqs for the same "handle" but rdma_addr_cancel() only cancels the first one.

The second req remains active beyond rdma_destroy_id() and will use-after-free id_priv once it inevitably triggers.

Fix this by remembering if the id_priv has called rdma_resolve_ip() and always cancel before calling it again. This ensures the req_list never gets more than one item in it and doesn't cost anything in the normal flow that never uses this strange error path.(CVE-2021-47391)

In the Linux kernel, the following vulnerability has been resolved:

sch_cake: do not call cake_destroy() from cake_init()

qdiscs are not supposed to call their own destroy() method from init(), because core stack already does that.

syzbot was able to trigger use after free:

DEBUG_LOCKS_WARN_ON(lock->magic != lock) WARNING: CPU: 0 PID: 21902 at kernel/locking/mutex.c:586 __mutex_lock_common kernel/locking/mutex.c:586 [inline] WARNING: CPU: 0 PID: 21902 at kernel/locking/mutex.c:586 __mutex_lock+0x9ec/0x12f0 kernel/locking/mutex.c:740 Modules linked in: CPU: 0 PID: 21902 Comm: syz-executor189 Not tainted 5.16.0-rc4-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:__mutex_lock_common kernel/locking/mutex.c:586 [inline] RIP: 0010:__mutex_lock+0x9ec/0x12f0 kernel/locking/mutex.c:740 Code: 08 84 d2 0f 85 19 08 00 00 8b 05 97 38 4b 04 85 c0 0f 85 27 f7 ff ff 48 c7 c6 20 00 ac 89 48 c7 c7 a0 fe ab 89 e8…

In the Linux kernel, the following vulnerability has been resolved: KVM: PPC: Fix kvm_arch_vcpu_ioctl vcpu_load leak vcpu_put is not called if the user copy fails. This can result in preempt notifier corruption and crashes, among other issues.

The SUSE Linux Enterprise 15 SP3 RT kernel was updated to receive various security bugfixes.

The following security bugs were fixed:

• CVE-2024-26921: Preserve kabi for sk_buff (bsc#1223138).
• CVE-2021-47378: Destroy cm id before destroy qp to avoid use after free (bsc#1225201).
• CVE-2021-47496: Fix flipped sign in tls_err_abort() calls (bsc#1225354)
• CVE-2021-47402: Protect fl_walk() with rcu (bsc#1225301)
• CVE-2022-48673: kABI workarounds for struct smc_link (bsc#1223934).
• CVE-2023-52871: Handle a second device without data corruption (bsc#1225534)
• CVE-2024-26828: Fixed underflow in parse_server_interfaces() (bsc#1223084).
• CVE-2021-47497: Fixed shift-out-of-bound (UBSAN) with byte size cells (bsc#1225355).
• CVE-2021-47500: Fixed trigger reference couting (bsc#1225360).
• CVE-2024-27413: Fixed incorrect allocation size (bsc#1224438).
• CVE-2021-47383: Fiedx out-of-bound vmalloc access in imageblit (bsc#1225208).
• CVE-2021-47511: Fixed negative period/buffer sizes (bsc#1225411).
• CVE-2023-52840: Fix use after free in rmi_unregister_function() (bsc#1224928).
• CVE-2021-47261: Fix initializing CQ fragments buffer (bsc#1224954)
• CVE-2021-47254: Fix use-after-free in gfs2_glock_shrink_scan (bsc#1224888).
• CVE-2024-27398: Fixed use-after-free bugs caused by sco_sock_timeout (bsc#1224174).
• CVE-2024-26929: Fixed double free of fcport (bsc#1223715).
• CVE-2024-26930: Fixed double free of the ha->vp_map pointer (bsc#1223626).
• CVE-2023-52655: Check packet for fixup for true limit (bsc#1217169).
• CVE-2023-4244: Fixed a use-after-free in the nf_tables component, which could be exploited to achieve local privilege escalation (bsc#1215420).
• CVE-2023-1829: Fixed a use-after-free vulnerability in the control index filter (tcindex) (bsc#1210335).
• CVE-2023-52686: Fix a null pointer in opal_event_init() (bsc#1065729).

The following non-security bugs were fixed:

• af_unix: annote lockless accesses to unix_tot_inflight & gc_in_progress (bsc#1223384).
• af_unix: Do not use atomic ops for unix_sk(sk)->inflight (bsc#1223384).
• af_unix: Replace BUG_ON() with WARN_ON_ONCE() (bsc#1223384).
• btrfs: do not start relocation until in progress drops are done (bsc#1222251).
• btrfs: do not start relocation until in progress drops are done (bsc#1222251).
• cifs: add missing spinlock around tcon refcount (bsc#1213476).
• cifs: avoid dup prefix path in dfs_get_automount_devname() (bsc#1213476).
• cifs: avoid race conditions with parallel reconnects (bsc#1213476).
• cifs: avoid re-lookups in dfs_cache_find() (bsc#1213476).
• cifs: avoid use of global locks for high contention data (bsc#1213476).
• cifs: check only tcon status on tcon related functions (bsc#1213476).
• cifs: do all necessary checks for credits within or before locking (bsc#1213476).
• cifs: do not block in dfs_cache_noreq_update_tgthint() (bsc#1213476).
• cifs: do not refresh cached referrals from unactive mounts (bsc#1213476).
• cifs: do not take exclusive lock for updating target hints (bsc#1213476).
• cifs: fix confusing debug message (bsc#1213476).
• cifs: fix missing unload_nls() in smb2_reconnect() (bsc#1213476).
• cifs: fix potential deadlock in cache_refresh_path() (bsc#1213476).
• cifs: fix refresh of cached referrals (bsc#1213476).
• cifs: fix return of uninitialized rc in dfs_cache_update_tgthint() (bsc#1213476).
• cifs: fix source pathname comparison of dfs supers (bsc#1213476).
• cifs: fix status checks in cifs_tree_connect (bsc#1213476).
• cifs: fix use-after-free bug in refresh_cache_worker() (bsc#1213476).
• cifs: get rid of dns resolve worker (bsc#1213476).
• cifs: get rid of mount options string parsing (bsc#1213476).
• cifs: handle cache lookup errors different than -ENOENT (bsc#1213476).
• cifs: ignore ipc reconnect failures during dfs failover (bsc#1213476).
• cifs: match even the scope id for ipv6 addresses (bsc#1213476).
• cifs: optimize reconnect of nested links (bsc#1213476).
• cifs: prevent data race in smb2_reconnect() (bsc#1213476). -…

The SUSE Linux Enterprise 15 SP2 kernel was updated to receive various security bugfixes.

The following security bugs were fixed:

• CVE-2021-47497: Fixed shift-out-of-bound (UBSAN) with byte size cells (bsc#1225355).
• CVE-2021-47500: Fixed trigger reference couting (bsc#1225360).
• CVE-2021-47383: Fiedx out-of-bound vmalloc access in imageblit (bsc#1225208).
• CVE-2021-47511: Fixed negative period/buffer sizes (bsc#1225411).
• CVE-2024-27398: Fixed use-after-free bugs caused by sco_sock_timeout (bsc#1224174).
• CVE-2023-4244: Fixed a use-after-free in the nf_tables component, which could be exploited to achieve local privilege escalation (bsc#1215420).
• CVE-2023-4244: Fixed a use-after-free in the nf_tables component, which could be exploited to achieve local privilege escalation (bsc#1215420).
• CVE-2023-1829: Fixed a use-after-free vulnerability in the control index filter (tcindex) (bsc#1210335).
• CVE-2021-47378: Destroy cm id before destroy qp to avoid use after free (bsc#1225201).
• CVE-2021-47496: Fix flipped sign in tls_err_abort() calls (bsc#1225354)
• CVE-2021-47402: Protect fl_walk() with rcu (bsc#1225301)
• CVE-2022-48673: kABI workarounds for struct smc_link (bsc#1223934).
• CVE-2023-52871: Handle a second device without data corruption (bsc#1225534)
• CVE-2024-26828: Fix underflow in parse_server_interfaces() (bsc#1223084).
• CVE-2024-27413: Fix incorrect allocation size (bsc#1224438).
• CVE-2023-52840: Fix use after free in rmi_unregister_function() (bsc#1224928).
• CVE-2021-47261: Fix initializing CQ fragments buffer (bsc#1224954)
• CVE-2021-47254: Fix use-after-free in gfs2_glock_shrink_scan (bsc#1224888).
• CVE-2023-52655: Check packet for fixup for true limit (bsc#1217169).
• CVE-2023-52686: Fix a null pointer in opal_event_init() (bsc#1065729).

The following non-security bugs were fixed:

• NFC: nxp: add NXP1002 (bsc#1185589).
• PCI: rpaphp: Add MODULE_DESCRIPTION (bsc#1176869 ltc#188243).
• af_unix: Do not use atomic ops for unix_sk(sk)->inflight (bsc#1223384).
• af_unix: Replace BUG_ON() with WARN_ON_ONCE() (bsc#1223384).
• af_unix: annote lockless accesses to unix_tot_inflight & gc_in_progress (bsc#1223384).
• btrfs: do not start relocation until in progress drops are done (bsc#1222251).
• md: Replace snprintf with scnprintf (git-fixes).
• netfilter: nf_tables: GC transaction race with abort path (git-fixes).
• netfilter: nf_tables: GC transaction race with netns dismantle (git-fixes).
• netfilter: nf_tables: defer gc run if previous batch is still pending (git-fixes).
• netfilter: nf_tables: fix GC transaction races with netns and netlink event exit path (git-fixes).
• netfilter: nf_tables: fix kdoc warnings after gc rework (git-fixes).
• netfilter: nf_tables: fix memleak when more than 255 elements expired (git-fixes).
• netfilter: nf_tables: mark newset as dead on transaction abort (git-fixes).
• netfilter: nf_tables: mark set as dead when unbinding anonymous set with timeout (git-fixes).
• netfilter: nf_tables: nft_set_rbtree: fix spurious insertion failure (git-fixes).
• netfilter: nf_tables: release mutex after nft_gc_seq_end from abort path (git-fixes).
• netfilter: nf_tables: skip dead set elements in netlink dump (git-fixes).
• netfilter: nf_tables: use correct lock to protect gc_list (git-fixes).
• netfilter: nft_set_hash: try later when GC hits EAGAIN on iteration (git-fixes).
• netfilter: nft_set_rbtree: Add missing expired checks (git-fixes).
• netfilter: nft_set_rbtree: Detect partial overlap with start endpoint match (git-fixes).
• netfilter: nft_set_rbtree: Detect partial overlaps on insertion (git-fixes).
• netfilter: nft_set_rbtree: Do not account for expired elements on insertion (git-fixes).
• netfilter: nft_set_rbtree: Drop spurious condition for overlap detection on insertion (git-fixes).
• netfilter: nft_set_rbtree: Handle outcomes of tree rotations in overlap detection (git-fixes).
• netfilter: nft_set_rbtree: Introduce and use nft_rbtree_interval_start() (git-fixes). -…

The SUSE Linux Enterprise 15 SP3 kernel was updated to receive various security bugfixes.

The following security bugs were fixed:

• CVE-2021-47378: Destroy cm id before destroy qp to avoid use after free (bsc#1225201).
• CVE-2021-47496: Fix flipped sign in tls_err_abort() calls (bsc#1225354)
• CVE-2021-47402: Protect fl_walk() with rcu (bsc#1225301)
• CVE-2022-48673: kABI workarounds for struct smc_link (bsc#1223934).
• CVE-2023-52871: Handle a second device without data corruption (bsc#1225534)
• CVE-2024-26828: Fix underflow in parse_server_interfaces() (bsc#1223084).
• CVE-2021-47497: Fixed shift-out-of-bound (UBSAN) with byte size cells (bsc#1225355).
• CVE-2021-47500: Fixed trigger reference couting (bsc#1225360).
• CVE-2024-27413: Fix incorrect allocation size (bsc#1224438).
• CVE-2021-47383: Fiedx out-of-bound vmalloc access in imageblit (bsc#1225208).
• CVE-2021-47511: Fixed negative period/buffer sizes (bsc#1225411).
• CVE-2023-52840: Fix use after free in rmi_unregister_function() (bsc#1224928).
• CVE-2021-47261: Fix initializing CQ fragments buffer (bsc#1224954)
• CVE-2021-47254: Fix use-after-free in gfs2_glock_shrink_scan (bsc#1224888).
• CVE-2024-27398: Fixed use-after-free bugs caused by sco_sock_timeout (bsc#1224174).
• CVE-2024-26921: Preserve kabi for sk_buff (bsc#1223138).
• CVE-2023-52655: Check packet for fixup for true limit (bsc#1217169).
• CVE-2023-4244: Fixed a use-after-free in the nf_tables component, which could be exploited to achieve local privilege escalation (bsc#1215420).
• CVE-2023-4244: Fixed a use-after-free in the nf_tables component, which could be exploited to achieve local privilege escalation (bsc#1215420).
• CVE-2023-1829: Fixed a use-after-free vulnerability in the control index filter (tcindex) (bsc#1210335).
• CVE-2023-52686: Fix a null pointer in opal_event_init() (bsc#1065729).

The following non-security bugs were fixed:

• af_unix: annote lockless accesses to unix_tot_inflight & gc_in_progress (bsc#1223384).
• af_unix: Do not use atomic ops for unix_sk(sk)->inflight (bsc#1223384).
• af_unix: Replace BUG_ON() with WARN_ON_ONCE() (bsc#1223384).
• btrfs: do not start relocation until in progress drops are done (bsc#1222251).
• btrfs: do not start relocation until in progress drops are done (bsc#1222251).
• cifs: add missing spinlock around tcon refcount (bsc#1213476).
• cifs: avoid dup prefix path in dfs_get_automount_devname() (bsc#1213476).
• cifs: avoid race conditions with parallel reconnects (bsc#1213476).
• cifs: avoid re-lookups in dfs_cache_find() (bsc#1213476).
• cifs: avoid use of global locks for high contention data (bsc#1213476).
• cifs: check only tcon status on tcon related functions (bsc#1213476).
• cifs: do all necessary checks for credits within or before locking (bsc#1213476).
• cifs: do not block in dfs_cache_noreq_update_tgthint() (bsc#1213476).
• cifs: do not refresh cached referrals from unactive mounts (bsc#1213476).
• cifs: do not take exclusive lock for updating target hints (bsc#1213476).
• cifs: fix confusing debug message (bsc#1213476).
• cifs: fix missing unload_nls() in smb2_reconnect() (bsc#1213476).
• cifs: fix potential deadlock in cache_refresh_path() (bsc#1213476).
• cifs: fix refresh of cached referrals (bsc#1213476).
• cifs: fix return of uninitialized rc in dfs_cache_update_tgthint() (bsc#1213476).
• cifs: fix source pathname comparison of dfs supers (bsc#1213476).
• cifs: fix status checks in cifs_tree_connect (bsc#1213476).
• cifs: fix use-after-free bug in refresh_cache_worker() (bsc#1213476).
• cifs: get rid of dns resolve worker (bsc#1213476).
• cifs: get rid of mount options string parsing (bsc#1213476).
• cifs: handle cache lookup errors different than -ENOENT (bsc#1213476).
• cifs: ignore ipc reconnect failures during dfs failover (bsc#1213476).
• cifs: match even the scope id for ipv6 addresses (bsc#1213476).
• cifs: optimize reconnect of nested links (bsc#1213476).
• cifs: prevent data race in smb2_reconnect() (bsc#1213476). -…

The SUSE Linux Enterprise 15 SP3 RT kernel was updated to receive various security bugfixes.

The following security bugs were fixed:

• CVE-2022-49110: netfilter: conntrack: revisit gc autotuning (bsc#1237981).
• CVE-2022-49139: Bluetooth: fix null ptr deref on hci_sync_conn_complete_evt (bsc#1238032).
• CVE-2022-49767: 9p/trans_fd: always use O_NONBLOCK read/write (bsc#1242493).
• CVE-2022-49769: gfs2: Check sb_bsize_shift after reading superblock (bsc#1242440).
• CVE-2022-49770: ceph: avoid putting the realm twice when decoding snaps fails (bsc#1242597).
• CVE-2022-49775: tcp: cdg: allow tcp_cdg_release() to be called multiple times (bsc#1242245).
• CVE-2022-49789: scsi: zfcp: Fix double free of FSF request when qdio send fails (bsc#1242366).
• CVE-2023-53039: HID: intel-ish-hid: ipc: Fix potential use-after-free in work function (bsc#1242745).
• CVE-2024-53168: sunrpc: fix one UAF issue caused by sunrpc kernel tcp socket (bsc#1234887).
• CVE-2024-56558: nfsd: make sure exp active before svc_export_show (bsc#1235100).
• CVE-2025-21812: ax25: rcu protect dev->ax25_ptr (bsc#1238471).
• CVE-2025-21999: proc: fix UAF in proc_get_inode() (bsc#1240802).
• CVE-2025-37789: net: openvswitch: fix nested key length validation in the set() action (bsc#1242762).

The following non-security bugs were fixed:

• HID: intel-ish-hid: ipc: Fix dev_err usage with uninitialized dev->devc (bsc#1242745).
• devm-helpers: Add resource managed version of work init (bsc#1242745).
• mtd: phram: Add the kernel lock down check (bsc#1232649).
• ocfs2: fix the issue with discontiguous allocation in the global_bitmap (git-fixes).
• workqueue: Add resource managed version of delayed work init (bsc#1242745).
• Remove debug flavor (bsc#1243919).