CVE-2026-80795nfc: nci: fix out-of-bounds write in nci_target_auto_activated()

Official description

In the Linux kernel, the following vulnerability has been resolved: nfc: nci: fix out-of-bounds write in nci_target_auto_activated() nci_target_auto_activated() appends a target to the fixed-size array ndev->targets[NCI_MAX_DISCOVERED_TARGETS] and increments ndev->n_targets without first checking the array is full; unlike its sibling nci_add_new_target(), which bails out when n_targets already equals NCI_MAX_DISCOVERED_TARGETS. ndev->n_targets is only cleared by nci_clear_target_list(), so an NFCC that repeatedly re-runs discovery (RF_DISCOVER_RSP, which re-enters NCI_DISCOVERY without clearing the target list) and reports an auto-activated target (RF_INTF_ACTIVATED_NTF) drives n_targets past the limit. The append then writes a struct nfc_target past the end of the array (a slab out-of-bounds write), and nfc_targets_found() goes on to walk the array with the inflated count: BUG: KASAN: slab-out-of-bounds in nci_add_new_protocol+0x94/0x2ac [nci] Write of size 2 at addr ffff0000c7299a18 by task kworker/u8:0/12 Workqueue: nfc0_nci_rx_wq nci_rx_work [nci] Call trace: nci_add_new_protocol+0x94/0x2ac [nci] nci_ntf_packet+0xddc/0x11a0 [nci] nci_rx_work+0x15c/0x1e0 [nci] process_one_work+0x2dc/0x500 worker_thread+0x240/0x460 kthread+0x1c0/0x1d0 ret_from_fork+0x10/0x20 The buggy address belongs to the cache kmalloc-2k of size 2048 The buggy address is located 1024 bytes to the right of allocated 1560-byte region [ffff0000c7299000, ffff0000c7299618) Guard nci_target_auto_activated() with the same check used by nci_add_new_target().

Affected packages & fixed versions

Affected products (as reported)

References

• https://git.kernel.org/stable/c/0dc59de0075f88404a0f4a2b5233104ef459fbb2
• https://git.kernel.org/stable/c/94530ffabfca57e9bff1d207106010014cc84032
• https://git.kernel.org/stable/c/afd8605fb43becb892311102844955c3b127fc7e
• https://git.kernel.org/stable/c/24761d3a5f692df5f7d848caeabcb2afd10917aa
• https://git.kernel.org/stable/c/50e87e1c0e18d791dcd7dccf30f9a2f3e2cf3951
• https://git.kernel.org/stable/c/2f08dbce3b37624ec6b424d759336a99586170ec
• https://git.kernel.org/stable/c/d7083f41c21b30582e91b2e6de4d54dce74f6f9c
• https://git.kernel.org/stable/c/129032c0616d83a5e3e304f6ebf88f14ba01e5f7
• https://git.kernel.org/stable/c/ac200079db50af81e6b04d058b33ec92901d8edd