In the Linux kernel, the following vulnerability has been resolved: riscv: probes: save original sp in rethook trampoline Reading a word from the stack in a kretprobe crashes a risc-v kernel. $ cd /sys/kernel/tracing/ $ echo 'r n_tty_write $stack0' > dynamic_events $ echo 1 > events/kprobes/enable Unable to handle kernel paging request at virtual address 0000000200000128 ... [<ffffffff80016d16>] regs_get_kernel_stack_nth+0x26/0x38 [<ffffffff80177196>] process_fetch_insn+0x3ee/0x760 [<ffffffff80177836>] kretprobe_trace_func+0x116/0x1f0 [<ffffffff8017795a>] kretprobe_dispatcher+0x4a/0x58 [<ffffffff8013572e>] kretprobe_rethook_handler+0x5e/0x90 [<ffffffff80180838>] rethook_trampoline_handler+0x70/0x108 [<ffffffff8001ba32>] arch_rethook_trampoline_callback+0x12/0x1c [<ffffffff8001ba84>] arch_rethook_trampoline+0x48/0x94 [<ffffffff8067872a>] tty_write+0x1a/0x30 In regs_get_kernel_stack_nth, regs->sp contains an arbitrary value. arch_rethook_trampoline saves the registers from the probed function in a struct pt_regs. sp is not saved. Instead, sp is decremented for arch_rethook_trampoline's local stack. Fix this crash and save the original sp along with the other registers. Use a0 as a temporary register, it is overwritten anyway. [pjw@kernel.org: added Fixes tag; cc'ed stable]

In the Linux kernel, the following vulnerability has been resolved: audit: fix potential use-after-free in audit_del_rule() `audit_del_rule()` destroys `e->rule.exe` via `audit_remove_mark_rule()` before unlinking the rule from RCU-visible filter lists and waiting for a grace period. Concurrent readers in `audit_filter()` and `audit_filter_rules()` still dereference `e->rule.exe`, while the fsnotify mark can be freed on an independent lifetime path. This creates a use-after-free window during rule deletion. Fix this by unlinking the rule from the RCU-visible lists and invoking `synchronize_rcu()` before calling `audit_remove_mark_rule()` (and other rule removal helpers). This ensures that all existing RCU readers have exited the critical section before any underlying resources are destroyed.

In the Linux kernel, the following vulnerability has been resolved: ipv4: igmp: Fix potential UAF in igmp_gq_start_timer() A race condition exists between device teardown (inetdev_destroy) and incoming IGMP query processing (igmp_rcv), leading to a Use-After-Free in the IGMP timer callback. During device destruction, inetdev_destroy() drops the primary reference to in_device, which can drop its refcount to 0. The actual freeing of in_device memory is deferred via RCU (using call_rcu()). Concurrently, igmp_rcv() runs under RCU read lock and obtains the in_device pointer. Because the memory is RCU-protected, CPU-0 can safely dereference in_device even if its refcount has hit 0. However, if CPU-0 calls igmp_gq_start_timer() and re-arms the timer, it attempts to acquire a reference using in_dev_hold(). This increments the refcount from 0 to 1, triggering a "refcount_t: addition on 0" warning. Since the in_device memory is still scheduled to be freed after the RCU grace period (as the free callback does not check the refcount again), the device is freed while the timer is still armed. When the timer expires, it accesses the freed memory, causing a kernel panic. Fix this by using refcount_inc_not_zero() (via a new helper in_dev_hold_safe()) to prevent acquiring a reference if the device is already being destroyed. If the refcount is 0, we do not arm the timer. A similar issue in IPv6 MLD is fixed in a subsequent patch.

In the Linux kernel, the following vulnerability has been resolved: SUNRPC: pin upper rpc_clnt across the TLS connect_worker The TLS connect path has a use-after-free: nothing pins the upper rpc_clnt across the delayed connect_worker. xs_connect() stores task->tk_client in sock_xprt::clnt as a raw pointer and queues the worker; for TLS-secured transports that worker is xs_tcp_tls_setup_socket(), which reads several fields out of the saved pointer (cl_timeout, cl_program, cl_prog, cl_vers, cl_cred, cl_stats) to construct the args for the inner handshake rpc_clnt. The xprt does not reference the rpc_clnt; the rpc_clnt references the xprt. xs_destroy() does cancel the connect_worker, but it runs only when the xprt's refcount drops to zero, which cannot happen until the rpc_clnt releases its cl_xprt reference in rpc_free_client_work(). When a TLS handshake fails fatally (for example, an mTLS mount whose client cert does not match the server), the connecting task is woken with -EACCES and exits, the mount caller invokes rpc_shutdown_client(), and the upper rpc_clnt is freed before the queued connect_worker fires. xs_tcp_tls_setup_socket() then dereferences the freed clnt, producing the refcount_t underflow Michael Nemanov reported. Take a reference on the upper rpc_clnt in xs_connect() for TLS transports via a new rpc_hold_client() helper, and drop it in the connect_worker's exit path with rpc_release_client(). The xprt_lock_connect() / xprt_unlock_connect() pairing already serialises xs_connect() with xs_tcp_tls_setup_socket(), so the take and release are balanced one-for-one. The non-TLS connect worker (xs_tcp_setup_socket) never reads sock_xprt::clnt, so leave that path alone and avoid the clnt-holds-xprt-holds-clnt cycle that would otherwise prevent xprt destruction.

In the Linux kernel, the following vulnerability has been resolved: power: supply: cpcap-battery: Fix missing nvmem_device_put() causing reference leak In cpcap_battery_detect_battery_type(), the reference to an nvmem device obtained via nvmem_device_find() is not released with nvmem_device_put() on the success or read-failure paths, causing a permanent reference leak. The driver’s retry logic on subsequent battery property reads can compound this leak, preventing the nvmem device from ever being freed. Found by code review.

In the Linux kernel, the following vulnerability has been resolved: gpio: mvebu: free generic chips on unbind irq_alloc_domain_generic_chips() allocates generic chip data that must be freed via irq_domain_remove_generic_chips(). The devres action mvebu_gpio_remove_irq_domain() only called irq_domain_remove(), which only frees the generic chips if IRQ_DOMAIN_FLAG_DESTROY_GC is set. Call irq_domain_remove_generic_chips() explicitly before irq_domain_remove() instead.

In the Linux kernel, the following vulnerability has been resolved: netdev-genl: report NAPI thread PID in the caller's pid namespace netdev_nl_napi_fill_one() reports the NAPI kthread PID in NETDEV_A_NAPI_PID using task_pid_nr(), which returns the PID in the initial pid namespace. NETDEV_CMD_NAPI_GET does not have GENL_ADMIN_PERM and the netdev genl family is netnsok, so a caller in a child pid namespace can issue it. That caller then sees the kthread's global PID, even though the kthread is not visible in its pid namespace, where the value should be 0. Translate the PID through the caller's pid namespace, the same way commit 3799c2570982 ("io_uring/fdinfo: translate SqThread PID through caller's pid_ns") did for the io_uring SQPOLL thread. The doit and dumpit paths both run synchronously in the caller's context, so task_active_pid_ns(current) is the caller's pid namespace.

In the Linux kernel, the following vulnerability has been resolved: accel/amdxdna: Fix VMA access race aie2_populate_range() and amdxdna_umap_release() access a saved VMA pointer that may have already been freed, leading to a potential use-after-free. Remove the VMA accesses from these functions to avoid the race.

DBI versions before 1.652 for Perl allow a heap out-of-bounds write on 32-bit perl via an integer wraparound in the output buffer size computed by preparse. preparse reserves its output buffer with `newSV(strlen(statement) * 7 + 16)`, budgeting seven output bytes per input byte for the longest ':p99999' expansion. The product is computed in STRLEN, which is 32 bits wide on a 32-bit perl build, so a statement of 613,566,757 bytes multiplies to 4,294,967,299, wraps modulo 2^32 to 3, and reserves 19 bytes. The parser then copies the statement out through a raw pointer with no capacity check, writing the whole 585 MB input past the end of the allocation. The 99,999 placeholder limit does not bound this path, which is reached by ordinary non-placeholder content. Any caller that passes an untrusted statement of that length to preparse on a 32-bit perl gets a heap out-of-bounds write of attacker controlled bytes. Builds with a 64-bit STRLEN are not affected, since the wrap there needs a statement of about 2.3 exabytes.

In the Linux kernel, the following vulnerability has been resolved: bpf: fix crash in bpf_[set|remove]_dentry_xattr for negative dentries bpf_set_dentry_xattr and bpf_remove_dentry_xattr BPF kfuncs attempt to lock the inode of the supplied dentry without checking if it is NULL. If a negative dentry is passed (e.g. from security_inode_create), d_inode(dentry) returns NULL, and inode_lock(inode) will cause a NULL pointer dereference. Trivially fix this by adding a NULL check for inode before attempting to lock it, returning -EINVAL if it is NULL. Additionally, drop WARN_ON(!inode) in bpf_xattr_read_permission() and bpf_xattr_write_permission(). These warnings could be triggered by passing a negative dentry to bpf_get_dentry_xattr() or the _locked variants of the xattr kfuncs, potentially causing a Denial of Service on systems with panic_on_warn enabled. Instead, simply return -EINVAL.