{"id":"CVE-2026-89780","summary":"net: qualcomm: rmnet: restore skb-\u003edev on deaggregated frames","details":"In the Linux kernel, the following vulnerability has been resolved:\n\nnet: qualcomm: rmnet: restore skb-\u003edev on deaggregated frames\n\nrmnet_map_deaggregate() allocates each sub-frame with alloc_skb() and\nleaves skb-\u003edev NULL. __rmnet_map_ingress_handler() assigns\nskb-\u003edev = ep-\u003eegress_dev only on the data path, but a MAP command frame\nis dispatched to rmnet_map_command() before that, so rmnet_map_send_ack()\nruns netif_tx_lock(skb-\u003edev) on a NULL device. An unprivileged user\nreaches this by unsharing a user+net namespace, creating an rmnet link\nover a tap device with INGRESS_DEAGGREGATION and INGRESS_MAP_COMMANDS,\nand writing an aggregated frame carrying a flow-control command to the\ntap fd.\n\nRestore the assignment dropped by 378e25357ac7, so every skb leaving\nrmnet_map_deaggregate() has a valid device.\n\n  BUG: KASAN: null-ptr-deref in _raw_spin_lock (kernel/locking/spinlock.c:158)\n  Write of size 4 at addr 00000000000004b4 by task exploit/144\n  Call Trace:\n   _raw_spin_lock (kernel/locking/spinlock.c:158)\n   netif_tx_lock (net/sched/sch_generic.c:497)\n   rmnet_map_command (drivers/net/ethernet/qualcomm/rmnet/rmnet_map_command.c:67)\n   rmnet_rx_handler (drivers/net/ethernet/qualcomm/rmnet/rmnet_handlers.c:125)\n   __netif_receive_skb_core.constprop.0 (net/core/dev.c:6103)\n   ...\n   __netif_receive_skb_one_core (net/core/dev.c:6214)\n   netif_receive_skb (net/core/dev.c:6474)\n   tun_get_user (drivers/net/tun.c:1966)\n   tun_chr_write_iter (drivers/net/tun.c:2012)\n   vfs_write (fs/read_write.c:687)\n   ksys_write (fs/read_write.c:739)\n   do_syscall_64 (arch/x86/entry/syscall_64.c:94)\n   entry_SYSCALL_64_after_hwframe (arch/x86/entry/entry_64.S:121)\n  Kernel panic - not syncing: Fatal exception in interrupt","modified":"2026-09-17T03:47:08.080562293Z","published":"2026-09-16T08:48:19.760Z","database_specific":{"cna_assigner":"Linux","osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/89xxx/CVE-2026-89780.json"},"references":[{"type":"PACKAGE","url":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git"},{"type":"WEB","url":"https://git.kernel.org/stable/c/200460a0793dc6af97d3b36d92ac245350ac26fc"},{"type":"WEB","url":"https://git.kernel.org/stable/c/4bcef54e4a3355a62d9ad90729fe563435ec76c3"},{"type":"WEB","url":"https://git.kernel.org/stable/c/5aaa7409c1b4ca4c60d66e2afa99703bf4eb7ddd"},{"type":"WEB","url":"https://git.kernel.org/stable/c/7abe769e72c792e5f9eb273813eb3ecd8389854c"},{"type":"WEB","url":"https://git.kernel.org/stable/c/9b78ab84ddf97c06a8567edb62b6c0fd582f9a62"},{"type":"WEB","url":"https://git.kernel.org/stable/c/9d18c6c6cd1666b2cb7915cad052e22abf520997"},{"type":"WEB","url":"https://git.kernel.org/stable/c/a66734a1c5e36525ea07e9f4547fddc51e916de3"},{"type":"WEB","url":"https://git.kernel.org/stable/c/b14c22c31d9e30f38ea1693ac06d318f32258f5d"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/89xxx/CVE-2026-89780.json"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-89780"}],"affected":[{"ranges":[{"type":"GIT","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","events":[{"introduced":"378e25357ac78ad02fbc98bec9b4e3baaa916c5c"},{"fixed":"5aaa7409c1b4ca4c60d66e2afa99703bf4eb7ddd"},{"fixed":"9b78ab84ddf97c06a8567edb62b6c0fd582f9a62"},{"fixed":"9d18c6c6cd1666b2cb7915cad052e22abf520997"},{"fixed":"4bcef54e4a3355a62d9ad90729fe563435ec76c3"},{"fixed":"b14c22c31d9e30f38ea1693ac06d318f32258f5d"},{"fixed":"7abe769e72c792e5f9eb273813eb3ecd8389854c"},{"fixed":"200460a0793dc6af97d3b36d92ac245350ac26fc"},{"fixed":"a66734a1c5e36525ea07e9f4547fddc51e916de3"}]}],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-89780.json"}},{"package":{"name":"Kernel","ecosystem":"Linux"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"4.17.0"},{"fixed":"5.10.270"}]},{"type":"ECOSYSTEM","events":[{"introduced":"5.11.0"},{"fixed":"5.15.221"}]},{"type":"ECOSYSTEM","events":[{"introduced":"5.16.0"},{"fixed":"6.1.188"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.2.0"},{"fixed":"6.6.157"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.7.0"},{"fixed":"6.12.110"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.13.0"},{"fixed":"6.18.52"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.19.0"},{"fixed":"7.2.6"}]}],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-89780.json"}}],"schema_version":"1.9.0"}