A flaw that allowed an attacker to corrupt memory and possibly escalate privileges was found in the mwifiex kernel module while connecting to a malicious wireless network.

rtl_p2p_noa_ie in drivers/net/wireless/realtek/rtlwifi/ps.c in the Linux kernel through 5.3.6 lacks a certain upper-bound check, leading to a buffer overflow.

Integer overflow in api.cc in Google V8, as used in Google Chrome before 34.0.1847.131 on Windows and OS X and before 34.0.1847.132 on Linux, allows remote attackers to cause a denial of service or possibly have unspecified other impact via a large length value.

NVIDIA GPU Display Driver for Linux contains a vulnerability in the kernel mode layer (nvidia.ko), where an integer overflow may lead to denial of service.

Integer overflow in ANGLE in Google Chrome prior to 148.0.7778.216 allowed a remote attacker to leak cross-origin data via a crafted HTML page. (Chromium security severity: Critical)

NVIDIA Triton Inference Server for Windows and Linux contains a vulnerability where a user could cause an integer overflow or wraparound, leading to a segmentation fault, by providing an invalid request. A successful exploit of this vulnerability might lead to denial of service.

NVIDIA Triton Inference Server for Windows and Linux contains a vulnerability where an attacker could cause an integer overflow through specially crafted inputs. A successful exploit of this vulnerability might lead to denial of service and data tampering.

NVIDIA Triton Inference Server for Windows and Linux contains a vulnerability where a user could cause an integer overflow or wraparound, leading to a segmentation fault, by providing an invalid request. A successful exploit of this vulnerability might lead to denial of service.

In the Linux kernel, the following vulnerability has been resolved: KVM: Reject wrapped offset in kvm_reset_dirty_gfn() kvm_reset_dirty_gfn() guards the gfn range with if (!memslot || (offset + __fls(mask)) >= memslot->npages) return; but offset is u64 and the addition is unchecked. The check can be silently bypassed by a u64 wrap. The dirty ring backing those entries is MAP_SHARED at KVM_DIRTY_LOG_PAGE_OFFSET of the vcpu fd, so the VMM can rewrite the slot and offset fields of any entry between when the kernel pushes them and when KVM_RESET_DIRTY_RINGS consumes them. On reset, kvm_dirty_ring_reset() re-reads the values via READ_ONCE() and feeds them straight back into this check; only the flags handshake is treated as the handover, the slot/offset payload is taken on trust. Crafting two entries entry[i].offset = 0xffffffffffffffc1 entry[i+1].offset = 0 makes the coalescing loop in kvm_dirty_ring_reset() compute delta = (s64)(0 - 0xffffffffffffffc1) = 63 which falls in [0, BITS_PER_LONG), so it folds entry[i+1] into the existing mask by setting bit 63. The trailing kvm_reset_dirty_gfn() call then sees offset = 0xffffffffffffffc1 and __fls(mask) = 63; the sum is 0 in u64 and the bounds check passes. That offset propagates into kvm_arch_mmu_enable_log_dirty_pt_masked() unchanged. On the legacy MMU path -- kvm_memslots_have_rmaps() == true, i.e. shadow paging, any VM that has allocated shadow roots, or a write-tracked slot -- it reaches gfn_to_rmap(), which indexes slot->arch.rmap[0][] with a near-U64_MAX gfn. That is an out-of-bounds load of a kvm_rmap_head, followed by a conditional clear of PT_WRITABLE_MASK in whatever the loaded pointer points at. The path is reachable from any process holding /dev/kvm. Range-check offset on its own first, so the addition cannot wrap. memslot->npages is bounded well below U64_MAX, so once offset < npages holds, offset + __fls(mask) (with __fls(mask) < BITS_PER_LONG) stays in range.

Integer overflow in Adobe Flash Player before 13.0.0.250 and 14.x and 15.x before 15.0.0.189 on Windows and OS X and before 11.2.202.411 on Linux, Adobe AIR before 15.0.0.293, Adobe AIR SDK before 15.0.0.302, and Adobe AIR SDK & Compiler before 15.0.0.302 allows attackers to execute arbitrary code via unspecified vectors.

In the Linux kernel, the following vulnerability has been resolved: net/rose: prevent integer overflows in rose_setsockopt() In case of possible unpredictably large arguments passed to rose_setsockopt() and multiplied by extra values on top of that, integer overflows may occur. Do the safest minimum and fix these issues by checking the contents of 'opt' and returning -EINVAL if they are too large. Also, switch to unsigned int and remove useless check for negative 'opt' in ROSE_IDLE case.

In the Linux kernel, the following vulnerability has been resolved: fs/ntfs3: Fix a couple integer overflows on 32bit systems On 32bit systems the "off + sizeof(struct NTFS_DE)" addition can have an integer wrapping issue. Fix it by using size_add().

In the Linux kernel, the following vulnerability has been resolved: cifs: Fix integer overflow while processing acregmax mount option User-provided mount parameter acregmax of type u32 is intended to have an upper limit, but before it is validated, the value is converted from seconds to jiffies which can lead to an integer overflow. Found by Linux Verification Center (linuxtesting.org) with SVACE.

In the Linux kernel, the following vulnerability has been resolved: ksmbd: fix integer overflows on 32 bit systems On 32bit systems the addition operations in ipc_msg_alloc() can potentially overflow leading to memory corruption. Add bounds checking using KSMBD_IPC_MAX_PAYLOAD to avoid overflow.

In the Linux kernel, the following vulnerability has been resolved: ksmbd: fix overflow in dacloffset bounds check The dacloffset field was originally typed as int and used in an unchecked addition, which could overflow and bypass the existing bounds check in both smb_check_perm_dacl() and smb_inherit_dacl(). This could result in out-of-bounds memory access and a kernel crash when dereferencing the DACL pointer. This patch converts dacloffset to unsigned int and uses check_add_overflow() to validate access to the DACL.

In the Linux kernel, the following vulnerability has been resolved: cifs: Fix integer overflow while processing closetimeo mount option User-provided mount parameter closetimeo of type u32 is intended to have an upper limit, but before it is validated, the value is converted from seconds to jiffies which can lead to an integer overflow. Found by Linux Verification Center (linuxtesting.org) with SVACE.

In the Linux kernel, the following vulnerability has been resolved: xsk: fix an integer overflow in xp_create_and_assign_umem() Since the i and pool->chunk_size variables are of type 'u32', their product can wrap around and then be cast to 'u64'. This can lead to two different XDP buffers pointing to the same memory area. Found by InfoTeCS on behalf of Linux Verification Center (linuxtesting.org) with SVACE.

In the Linux kernel, the following vulnerability has been resolved: fs/ntfs3: Prevent integer overflow in hdr_first_de() The "de_off" and "used" variables come from the disk so they both need to check. The problem is that on 32bit systems if they're both greater than UINT_MAX - 16 then the check does work as intended because of an integer overflow.

In the Linux kernel, the following vulnerability has been resolved: cifs: Fix integer overflow while processing acdirmax mount option User-provided mount parameter acdirmax of type u32 is intended to have an upper limit, but before it is validated, the value is converted from seconds to jiffies which can lead to an integer overflow. Found by Linux Verification Center (linuxtesting.org) with SVACE.

In the Linux kernel, the following vulnerability has been resolved: nilfs2: fix possible int overflows in nilfs_fiemap() Since nilfs_bmap_lookup_contig() in nilfs_fiemap() calculates its result by being prepared to go through potentially maxblocks == INT_MAX blocks, the value in n may experience an overflow caused by left shift of blkbits. While it is extremely unlikely to occur, play it safe and cast right hand expression to wider type to mitigate the issue. Found by Linux Verification Center (linuxtesting.org) with static analysis tool SVACE.

NVIDIA GPU Display Driver for Linux contains a vulnerability in the kernel mode layer (nvidia.ko), where an integer overflow may lead to information disclosure, data tampering or denial of service.

Integer overflow in the fb_mmap function in drivers/video/fbmem.c in the Linux kernel before 3.8.9, as used in a certain Motorola build of Android 4.1.2 and other products, allows local users to create a read-write memory mapping for the entirety of kernel memory, and consequently gain privileges, via crafted /dev/graphics/fb0 mmap2 system calls, as demonstrated by the Motochopper pwn program.

.NET and Visual Studio Remote Code Execution Vulnerability

Integer overflow in Skia in Google Chrome prior to 147.0.7727.55 allowed a remote attacker to execute arbitrary code inside a sandbox via a crafted HTML page. (Chromium security severity: High)

NVIDIA GPU Display Driver for Linux contains a vulnerability in the kernel mode layer (nvidia.ko), where an integer overflow may lead to denial of service, data tampering, or information disclosure.

Integer overflow in Adobe Flash Player before 10.3.183.75 and 11.x before 11.7.700.169 on Windows and Mac OS X, before 10.3.183.75 and 11.x before 11.2.202.280 on Linux, before 11.1.111.50 on Android 2.x and 3.x, and before 11.1.115.54 on Android 4.x; Adobe AIR before 3.7.0.1530; and Adobe AIR SDK & Compiler before 3.7.0.1530 allows remote attackers to execute arbitrary code via unspecified vectors, as demonstrated by VUPEN during a Pwn2Own competition at CanSecWest 2013.

Integer overflow in the padding implementation in the opus_packet_parse_impl function in src/opus_decoder.c in Opus before 1.0.2, as used in Google Chrome before 25.0.1364.97 on Windows and Linux and before 25.0.1364.99 on Mac OS X and other products, allows remote attackers to cause a denial of service (out-of-bounds read) via a long packet.

NVIDIA GPU Display Driver for Linux contains a vulnerability in the kernel mode layer (nvidia.ko), where an integer overflow in index validation may lead to denial of service, information disclosure, or data tampering.

NVIDIA GPU Display Driver for Linux contains a vulnerability in the kernel mode layer handler, where an Integer overflow may lead to denial of service or information disclosure.

In the Linux kernel, the following vulnerability has been resolved: net/sched: fix pedit partial COW leading to page cache corruption tcf_pedit_act() computes the COW range for skb_ensure_writable() once before the key loop using tcfp_off_max_hint, but the hint does not account for the runtime header offset added by typed keys. This can leave part of the write region un-COW'd. Fix by moving skb_ensure_writable() inside the per-key loop where the actual write offset is known, and add overflow checking on the offset arithmetic. For negative offsets (e.g. Ethernet header edits at ingress), use skb_cow() to COW the headroom instead. Guard offset_valid() against INT_MIN, where negation is undefined.

Integer overflow in the snd_compr_allocate_buffer function in sound/core/compress_offload.c in the ALSA subsystem in the Linux kernel before 3.6-rc6-next-20120917 allows local users to cause a denial of service (insufficient memory allocation) or possibly have unspecified other impact via a crafted SNDRV_COMPRESS_SET_PARAMS ioctl call.

Integer overflow in fs/aio.c in the Linux kernel before 3.4.1 allows local users to cause a denial of service or possibly have unspecified other impact via a large AIO iovec.

In the Linux kernel, the following vulnerability has been resolved: RDMA/mlx5: Fix page_size variable overflow Change all variables storing mlx5_umem_mkc_find_best_pgsz() result to unsigned long to support values larger than 31 and avoid overflow. For example: If we try to register 4GB of memory that is contiguous in physical memory, the driver will optimize the page_size and try to use an mkey with 4GB entity size. The 'unsigned int' page_size variable will overflow to '0' and we'll hit the WARN_ON() in alloc_cacheable_mr(). WARNING: CPU: 2 PID: 1203 at drivers/infiniband/hw/mlx5/mr.c:1124 alloc_cacheable_mr+0x22/0x580 [mlx5_ib] Modules linked in: mlx5_ib mlx5_core bonding ip6_gre ip6_tunnel tunnel6 ip_gre gre rdma_rxe rdma_ucm ib_uverbs ib_ipoib ib_umad rpcrdma ib_iser libiscsi scsi_transport_iscsi rdma_cm iw_cm ib_cm fuse ib_core [last unloaded: mlx5_core] CPU: 2 UID: 70878 PID: 1203 Comm: rdma_resource_l Tainted: G W 6.14.0-rc4-dirty #43 Tainted: [W]=WARN Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS rel-1.13.0-0-gf21b5a4aeb02-prebuilt.qemu.org 04/01/2014 RIP: 0010:alloc_cacheable_mr+0x22/0x580 [mlx5_ib] Code: 90 90 90 90 90 90 90 90 0f 1f 44 00 00 55 48 89 e5 41 57 41 56 41 55 41 54 41 52 53 48 83 ec 30 f6 46 28 04 4c 8b 77 08 75 21 <0f> 0b 49 c7 c2 ea ff ff ff 48 8d 65 d0 4c 89 d0 5b 41 5a 41 5c 41 RSP: 0018:ffffc900006ffac8 EFLAGS: 00010246 RAX: 0000000004c0d0d0 RBX: ffff888217a22000 RCX: 0000000000100001 RDX: 00007fb7ac480000 RSI: ffff8882037b1240 RDI: ffff8882046f0600 RBP: ffffc900006ffb28 R08: 0000000000000001 R09: 0000000000000000 R10: 00000000000007e0 R11: ffffea0008011d40 R12: ffff8882037b1240 R13: ffff8882046f0600 R14: ffff888217a22000 R15: ffffc900006ffe00 FS: 00007fb7ed013340(0000) GS:ffff88885fd00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fb7ed1d8000 CR3: 00000001fd8f6006 CR4: 0000000000772eb0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 PKRU: 55555554 Call Trace: <TASK> ? __warn+0x81/0x130 ? alloc_cacheable_mr+0x22/0x580 [mlx5_ib] ? report_bug+0xfc/0x1e0 ? handle_bug+0x55/0x90 ? exc_invalid_op+0x17/0x70 ? asm_exc_invalid_op+0x1a/0x20 ? alloc_cacheable_mr+0x22/0x580 [mlx5_ib] create_real_mr+0x54/0x150 [mlx5_ib] ib_uverbs_reg_mr+0x17f/0x2a0 [ib_uverbs] ib_uverbs_handler_UVERBS_METHOD_INVOKE_WRITE+0xca/0x140 [ib_uverbs] ib_uverbs_run_method+0x6d0/0x780 [ib_uverbs] ? __pfx_ib_uverbs_handler_UVERBS_METHOD_INVOKE_WRITE+0x10/0x10 [ib_uverbs] ib_uverbs_cmd_verbs+0x19b/0x360 [ib_uverbs] ? walk_system_ram_range+0x79/0xd0 ? ___pte_offset_map+0x1b/0x110 ? __pte_offset_map_lock+0x80/0x100 ib_uverbs_ioctl+0xac/0x110 [ib_uverbs] __x64_sys_ioctl+0x94/0xb0 do_syscall_64+0x50/0x110 entry_SYSCALL_64_after_hwframe+0x76/0x7e RIP: 0033:0x7fb7ecf0737b Code: ff ff ff 85 c0 79 9b 49 c7 c4 ff ff ff ff 5b 5d 4c 89 e0 41 5c c3 66 0f 1f 84 00 00 00 00 00 f3 0f 1e fa b8 10 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 8b 0d 7d 2a 0f 00 f7 d8 64 89 01 48 RSP: 002b:00007ffdbe03ecc8 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00007ffdbe03edb8 RCX: 00007fb7ecf0737b RDX: 00007ffdbe03eda0 RSI: 00000000c0181b01 RDI: 0000000000000003 RBP: 00007ffdbe03ed80 R08: 00007fb7ecc84010 R09: 00007ffdbe03eed4 R10: 0000000000000009 R11: 0000000000000246 R12: 00007ffdbe03eed4 R13: 000000000000000c R14: 000000000000000c R15: 00007fb7ecc84150 </TASK>

The perf_cpu_time_max_percent_handler function in kernel/events/core.c in the Linux kernel before 4.11 allows local users to cause a denial of service (integer overflow) or possibly have unspecified other impact via a large value, as demonstrated by an incorrect sample-rate calculation.

Integer overflow in the xfs_acl_from_disk function in fs/xfs/xfs_acl.c in the Linux kernel before 3.1.9 allows local users to cause a denial of service (panic) via a filesystem with a malformed ACL, leading to a heap-based buffer overflow.

Integer overflow in the drm_mode_dirtyfb_ioctl function in drivers/gpu/drm/drm_crtc.c in the Direct Rendering Manager (DRM) subsystem in the Linux kernel before 3.1.5 allows local users to gain privileges or cause a denial of service (memory corruption) via a crafted ioctl call.

An integer overflow vulnerability was found in vmwgfx driver in drivers/gpu/vmxgfx/vmxgfx_execbuf.c in GPU component of Linux kernel with device file '/dev/dri/renderD128 (or Dxxx)'. This flaw allows a local attacker with a user account on the system to gain privilege, causing a denial of service(DoS).

In the Linux kernel, the following vulnerability has been resolved: net/sctp: Prevent autoclose integer overflow in sctp_association_init() While by default max_autoclose equals to INT_MAX / HZ, one may set net.sctp.max_autoclose to UINT_MAX. There is code in sctp_association_init() that can consequently trigger overflow.

In the Linux kernel, the following vulnerability has been resolved: rdma/cxgb4: Prevent potential integer overflow on 32bit The "gl->tot_len" variable is controlled by the user. It comes from process_responses(). On 32bit systems, the "gl->tot_len + sizeof(struct cpl_pass_accept_req) + sizeof(struct rss_header)" addition could have an integer wrapping bug. Use size_add() to prevent this.

In the Linux kernel, the following vulnerability has been resolved: binfmt_flat: Fix integer overflow bug on 32 bit systems Most of these sizes and counts are capped at 256MB so the math doesn't result in an integer overflow. The "relocs" count needs to be checked as well. Otherwise on 32bit systems the calculation of "full_data" could be wrong. full_data = data_len + relocs * sizeof(unsigned long);

In the Linux kernel, the following vulnerability has been resolved: printk: Fix signed integer overflow when defining LOG_BUF_LEN_MAX Shifting 1 << 31 on a 32-bit int causes signed integer overflow, which leads to undefined behavior. To prevent this, cast 1 to u32 before performing the shift, ensuring well-defined behavior. This change explicitly avoids any potential overflow by ensuring that the shift occurs on an unsigned 32-bit integer.

In the Linux kernel, the following vulnerability has been resolved: rtc: tps6594: Fix integer overflow on 32bit systems The problem is this multiply in tps6594_rtc_set_offset() tmp = offset * TICKS_PER_HOUR; The "tmp" variable is an s64 but "offset" is a long in the (-277774)-277774 range. On 32bit systems a long can hold numbers up to approximately two billion. The number of TICKS_PER_HOUR is really large, (32768 * 3600) or roughly a hundred million. When you start multiplying by a hundred million it doesn't take long to overflow the two billion mark. Probably the safest way to fix this is to change the type of TICKS_PER_HOUR to long long because it's such a large number.

In the Linux kernel, the following vulnerability has been resolved: ring-buffer: Fix overflow in __rb_map_vma An overflow occurred when performing the following calculation: nr_pages = ((nr_subbufs + 1) << subbuf_order) - pgoff; Add a check before the calculation to avoid this problem. syzbot reported this as a slab-out-of-bounds in __rb_map_vma: BUG: KASAN: slab-out-of-bounds in __rb_map_vma+0x9ab/0xae0 kernel/trace/ring_buffer.c:7058 Read of size 8 at addr ffff8880767dd2b8 by task syz-executor187/5836 CPU: 0 UID: 0 PID: 5836 Comm: syz-executor187 Not tainted 6.13.0-rc2-syzkaller-00159-gf932fb9b4074 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 11/25/2024 Call Trace: <TASK> __dump_stack lib/dump_stack.c:94 [inline] dump_stack_lvl+0x116/0x1f0 lib/dump_stack.c:120 print_address_description mm/kasan/report.c:378 [inline] print_report+0xc3/0x620 mm/kasan/report.c:489 kasan_report+0xd9/0x110 mm/kasan/report.c:602 __rb_map_vma+0x9ab/0xae0 kernel/trace/ring_buffer.c:7058 ring_buffer_map+0x56e/0x9b0 kernel/trace/ring_buffer.c:7138 tracing_buffers_mmap+0xa6/0x120 kernel/trace/trace.c:8482 call_mmap include/linux/fs.h:2183 [inline] mmap_file mm/internal.h:124 [inline] __mmap_new_file_vma mm/vma.c:2291 [inline] __mmap_new_vma mm/vma.c:2355 [inline] __mmap_region+0x1786/0x2670 mm/vma.c:2456 mmap_region+0x127/0x320 mm/mmap.c:1348 do_mmap+0xc00/0xfc0 mm/mmap.c:496 vm_mmap_pgoff+0x1ba/0x360 mm/util.c:580 ksys_mmap_pgoff+0x32c/0x5c0 mm/mmap.c:542 __do_sys_mmap arch/x86/kernel/sys_x86_64.c:89 [inline] __se_sys_mmap arch/x86/kernel/sys_x86_64.c:82 [inline] __x64_sys_mmap+0x125/0x190 arch/x86/kernel/sys_x86_64.c:82 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xcd/0x250 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f The reproducer for this bug is: ------------------------8<------------------------- #include <fcntl.h> #include <stdlib.h> #include <unistd.h> #include <asm/types.h> #include <sys/mman.h> int main(int argc, char **argv) { int page_size = getpagesize(); int fd; void *meta; system("echo 1 > /sys/kernel/tracing/buffer_size_kb"); fd = open("/sys/kernel/tracing/per_cpu/cpu0/trace_pipe_raw", O_RDONLY); meta = mmap(NULL, page_size, PROT_READ, MAP_SHARED, fd, page_size * 5); } ------------------------>8-------------------------

Integer overflow in the agp_generic_insert_memory function in drivers/char/agp/generic.c in the Linux kernel before 2.6.38.5 allows local users to gain privileges or cause a denial of service (system crash) via a crafted AGPIOC_BIND agp_ioctl ioctl call.

An integer overflow in FFmpeg in Google Chrome prior to 57.0.2987.98 for Mac, Windows, and Linux and 57.0.2987.108 for Android allowed a remote attacker to perform an out of bounds memory write via a crafted video file, related to ChunkDemuxer.

In the Linux kernel, the following vulnerability has been resolved: RDMA/uverbs: Prevent integer overflow issue In the expression "cmd.wqe_size * cmd.wr_count", both variables are u32 values that come from the user so the multiplication can lead to integer wrapping. Then we pass the result to uverbs_request_next_ptr() which also could potentially wrap. The "cmd.sge_count * sizeof(struct ib_uverbs_sge)" multiplication can also overflow on 32bit systems although it's fine on 64bit systems. This patch does two things. First, I've re-arranged the condition in uverbs_request_next_ptr() so that the use controlled variable "len" is on one side of the comparison by itself without any math. Then I've modified all the callers to use size_mul() for the multiplications.

Multiple integer overflows in the next_pidmap function in kernel/pid.c in the Linux kernel before 2.6.38.4 allow local users to cause a denial of service (system crash) via a crafted (1) getdents or (2) readdir system call.

In the Linux kernel, the following vulnerability has been resolved: io_uring: check for overflows in io_pin_pages WARNING: CPU: 0 PID: 5834 at io_uring/memmap.c:144 io_pin_pages+0x149/0x180 io_uring/memmap.c:144 CPU: 0 UID: 0 PID: 5834 Comm: syz-executor825 Not tainted 6.12.0-next-20241118-syzkaller #0 Call Trace: <TASK> __io_uaddr_map+0xfb/0x2d0 io_uring/memmap.c:183 io_rings_map io_uring/io_uring.c:2611 [inline] io_allocate_scq_urings+0x1c0/0x650 io_uring/io_uring.c:3470 io_uring_create+0x5b5/0xc00 io_uring/io_uring.c:3692 io_uring_setup io_uring/io_uring.c:3781 [inline] ... </TASK> io_pin_pages()'s uaddr parameter came directly from the user and can be garbage. Don't just add size to it as it can overflow.

In the Linux kernel, the following vulnerability has been resolved: EDAC/bluefield: Fix potential integer overflow The 64-bit argument for the "get DIMM info" SMC call consists of mem_ctrl_idx left-shifted 16 bits and OR-ed with DIMM index. With mem_ctrl_idx defined as 32-bits wide the left-shift operation truncates the upper 16 bits of information during the calculation of the SMC argument. The mem_ctrl_idx stack variable must be defined as 64-bits wide to prevent any potential integer overflow, i.e. loss of data from upper 16 bits.