kernel/linux.git/drivers/net/usb/cdc_ncm.c, branch linux-7.0.y

net: usb: cdc_ncm: add ndpoffset to NDP32 nframes bounds check

2026-03-17T03:14:48+00:00

The same bounds-check bug fixed for NDP16 in the previous patch also exists in cdc_ncm_rx_verify_ndp32(). The DPE array size is validated against the total skb length without accounting for ndpoffset, allowing out-of-bounds reads when the NDP32 is placed near the end of the NTB. Add ndpoffset to the nframes bounds check and use struct_size_t() to express the NDP-plus-DPE-array size more clearly. Compile-tested only. Fixes: 0fa81b304a79 ("cdc_ncm: Implement the 32-bit version of NCM Transfer Block") Signed-off-by: Tobi Gaertner Link: https://patch.msgid.link/20260314054640.2895026-3-tob.gaertner@me.com Signed-off-by: Jakub Kicinski

net: usb: cdc_ncm: add ndpoffset to NDP16 nframes bounds check

2026-03-17T03:14:48+00:00

cdc_ncm_rx_verify_ndp16() validates that the NDP header and its DPE entries fit within the skb. The first check correctly accounts for ndpoffset: if ((ndpoffset + sizeof(struct usb_cdc_ncm_ndp16)) > skb_in->len) but the second check omits it: if ((sizeof(struct usb_cdc_ncm_ndp16) + ret * (sizeof(struct usb_cdc_ncm_dpe16))) > skb_in->len) This validates the DPE array size against the total skb length as if the NDP were at offset 0, rather than at ndpoffset. When the NDP is placed near the end of the NTB (large wNdpIndex), the DPE entries can extend past the skb data buffer even though the check passes. cdc_ncm_rx_fixup() then reads out-of-bounds memory when iterating the DPE array. Add ndpoffset to the nframes bounds check and use struct_size_t() to express the NDP-plus-DPE-array size more clearly. Fixes: ff06ab13a4cc ("net: cdc_ncm: splitting rx_fixup for code reuse") Signed-off-by: Tobi Gaertner Link: https://patch.msgid.link/20260314054640.2895026-2-tob.gaertner@me.com Signed-off-by: Jakub Kicinski

Convert 'alloc_obj' family to use the new default GFP_KERNEL argument

2026-02-22T01:09:51+00:00

This was done entirely with mindless brute force, using git grep -l '\

treewide: Replace kmalloc with kmalloc_obj for non-scalar types

2026-02-21T09:02:28+00:00

This is the result of running the Coccinelle script from scripts/coccinelle/api/kmalloc_objs.cocci. The script is designed to avoid scalar types (which need careful case-by-case checking), and instead replace kmalloc-family calls that allocate struct or union object instances: Single allocations: kmalloc(sizeof(TYPE), ...) are replaced with: kmalloc_obj(TYPE, ...) Array allocations: kmalloc_array(COUNT, sizeof(TYPE), ...) are replaced with: kmalloc_objs(TYPE, COUNT, ...) Flex array allocations: kmalloc(struct_size(PTR, FAM, COUNT), ...) are replaced with: kmalloc_flex(*PTR, FAM, COUNT, ...) (where TYPE may also be *VAR) The resulting allocations no longer return "void *", instead returning "TYPE *". Signed-off-by: Kees Cook

cdc_ncm: Flag Intel OEM version of Fibocom L850-GL as WWAN

2025-08-20T00:16:37+00:00

This lets NetworkManager/ModemManager know that this is a modem and needs to be connected first. Signed-off-by: Lubomir Rintel Link: https://patch.msgid.link/20250814154214.250103-1-lkundrak@v3.sk Signed-off-by: Jakub Kicinski

net: usb: cdc-ncm: check for filtering capability

2025-07-21T23:59:26+00:00

If the decice does not support filtering, filtering must not be used and all packets delivered for the upper layers to sort. Signed-off-by: Oliver Neukum Link: https://patch.msgid.link/20250717120649.2090929-1-oneukum@suse.com Signed-off-by: Jakub Kicinski

net/cdc_ncm: Switch to use hrtimer_setup()

2025-02-18T09:35:46+00:00

hrtimer_setup() takes the callback function pointer as argument and initializes the timer completely. Replace hrtimer_init() and the open coded initialization of hrtimer::function with the new setup mechanism. Patch was created by using Coccinelle. Signed-off-by: Nam Cao Signed-off-by: Thomas Gleixner Link: https://lore.kernel.org/all/219735f98754fb30dcfd892fbaa5766f9d78c1f1.1738746872.git.namcao@linutronix.de

CDC-NCM: add support for Apple's private interface

2024-06-13T01:57:03+00:00

Available on iOS/iPadOS >= 17, where this new interface is used by developer tools using the new RemoteXPC protocol. This private interface lacks a status endpoint, presumably because there isn't a physical cable that can be unplugged, nor any speed changes to be notified about. Note that NCM interfaces are not exposed until a mode switch is requested, which macOS does automatically. The mode switch can be performed like this: uint8_t status; libusb_control_transfer(device_handle, LIBUSB_RECIPIENT_DEVICE | LIBUSB_REQUEST_TYPE_VENDOR | LIBUSB_ENDPOINT_IN, 82, /* bRequest */ 0, /* wValue */ 3, /* wIndex */ &status, sizeof(status), 0); Newer versions of usbmuxd do this automatically. Co-developed-by: Håvard Sørbø Signed-off-by: Håvard Sørbø Signed-off-by: Ole André Vadla Ravnås Link: https://lore.kernel.org/r/20240607074117.31322-1-oleavr@frida.re Signed-off-by: Jakub Kicinski

net: annotate writes on dev->mtu from ndo_change_mtu()

2024-05-07T23:19:14+00:00

Simon reported that ndo_change_mtu() methods were never updated to use WRITE_ONCE(dev->mtu, new_mtu) as hinted in commit 501a90c94510 ("inet: protect against too small mtu values.") We read dev->mtu without holding RTNL in many places, with READ_ONCE() annotations. It is time to take care of ndo_change_mtu() methods to use corresponding WRITE_ONCE() Signed-off-by: Eric Dumazet Reported-by: Simon Horman Closes: https://lore.kernel.org/netdev/20240505144608.GB67882@kernel.org/ Reviewed-by: Jacob Keller Reviewed-by: Sabrina Dubroca Reviewed-by: Simon Horman Acked-by: Shannon Nelson Link: https://lore.kernel.org/r/20240506102812.3025432-1-edumazet@google.com Signed-off-by: Jakub Kicinski

net: cdc_ncm: Deal with too low values of dwNtbOutMaxSize

2023-05-19T02:56:17+00:00

Currently in cdc_ncm_check_tx_max(), if dwNtbOutMaxSize is lower than the calculated "min" value, but greater than zero, the logic sets tx_max to dwNtbOutMaxSize. This is then used to allocate a new SKB in cdc_ncm_fill_tx_frame() where all the data is handled. For small values of dwNtbOutMaxSize the memory allocated during alloc_skb(dwNtbOutMaxSize, GFP_ATOMIC) will have the same size, due to how size is aligned at alloc time: size = SKB_DATA_ALIGN(size); size += SKB_DATA_ALIGN(sizeof(struct skb_shared_info)); Thus we hit the same bug that we tried to squash with commit 2be6d4d16a084 ("net: cdc_ncm: Allow for dwNtbOutMaxSize to be unset or zero") Low values of dwNtbOutMaxSize do not cause an issue presently because at alloc_skb() time more memory (512b) is allocated than required for the SKB headers alone (320b), leaving some space (512b - 320b = 192b) for CDC data (172b). However, if more elements (for example 3 x u64 = [24b]) were added to one of the SKB header structs, say 'struct skb_shared_info', increasing its original size (320b [320b aligned]) to something larger (344b [384b aligned]), then suddenly the CDC data (172b) no longer fits in the spare SKB data area (512b - 384b = 128b). Consequently the SKB bounds checking semantics fails and panics: skbuff: skb_over_panic: text:ffffffff831f755b len:184 put:172 head:ffff88811f1c6c00 data:ffff88811f1c6c00 tail:0xb8 end:0x80 dev: ------------[ cut here ]------------ kernel BUG at net/core/skbuff.c:113! invalid opcode: 0000 [#1] PREEMPT SMP KASAN CPU: 0 PID: 57 Comm: kworker/0:2 Not tainted 5.15.106-syzkaller-00249-g19c0ed55a470 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/14/2023 Workqueue: mld mld_ifc_work RIP: 0010:skb_panic net/core/skbuff.c:113 [inline] RIP: 0010:skb_over_panic+0x14c/0x150 net/core/skbuff.c:118 [snip] Call Trace: skb_put+0x151/0x210 net/core/skbuff.c:2047 skb_put_zero include/linux/skbuff.h:2422 [inline] cdc_ncm_ndp16 drivers/net/usb/cdc_ncm.c:1131 [inline] cdc_ncm_fill_tx_frame+0x11ab/0x3da0 drivers/net/usb/cdc_ncm.c:1308 cdc_ncm_tx_fixup+0xa3/0x100 Deal with too low values of dwNtbOutMaxSize, clamp it in the range [USB_CDC_NCM_NTB_MIN_OUT_SIZE, CDC_NCM_NTB_MAX_SIZE_TX]. We ensure enough data space is allocated to handle CDC data by making sure dwNtbOutMaxSize is not smaller than USB_CDC_NCM_NTB_MIN_OUT_SIZE. Fixes: 289507d3364f ("net: cdc_ncm: use sysfs for rx/tx aggregation tuning") Cc: stable@vger.kernel.org Reported-by: syzbot+9f575a1f15fc0c01ed69@syzkaller.appspotmail.com Link: https://syzkaller.appspot.com/bug?extid=b982f1059506db48409d Link: https://lore.kernel.org/all/20211202143437.1411410-1-lee.jones@linaro.org/ Signed-off-by: Tudor Ambarus Reviewed-by: Simon Horman Link: https://lore.kernel.org/r/20230517133808.1873695-2-tudor.ambarus@linaro.org Signed-off-by: Jakub Kicinski