{
   "containers": {
      "cna": {
         "providerMetadata": {
            "orgId": "f4215fc3-5b6b-47ff-a258-f7189bd81038"
         },
         "descriptions": [
            {
               "lang": "en",
               "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nRevert \"tty: n_gsm: fix UAF in gsm_cleanup_mux\"\n\nThis reverts commit 9b9c8195f3f0d74a826077fc1c01b9ee74907239.\n\nThe commit above is reverted as it did not solve the original issue.\n\ngsm_cleanup_mux() tries to free up the virtual ttys by calling\ngsm_dlci_release() for each available DLCI. There, dlci_put() is called to\ndecrease the reference counter for the DLCI via tty_port_put() which\nfinally calls gsm_dlci_free(). This already clears the pointer which is\nbeing checked in gsm_cleanup_mux() before calling gsm_dlci_release().\nTherefore, it is not necessary to clear this pointer in gsm_cleanup_mux()\nas done in the reverted commit. The commit introduces a null pointer\ndereference:\n <TASK>\n ? __die+0x1f/0x70\n ? page_fault_oops+0x156/0x420\n ? search_exception_tables+0x37/0x50\n ? fixup_exception+0x21/0x310\n ? exc_page_fault+0x69/0x150\n ? asm_exc_page_fault+0x26/0x30\n ? tty_port_put+0x19/0xa0\n gsmtty_cleanup+0x29/0x80 [n_gsm]\n release_one_tty+0x37/0xe0\n process_one_work+0x1e6/0x3e0\n worker_thread+0x4c/0x3d0\n ? __pfx_worker_thread+0x10/0x10\n kthread+0xe1/0x110\n ? __pfx_kthread+0x10/0x10\n ret_from_fork+0x2f/0x50\n ? __pfx_kthread+0x10/0x10\n ret_from_fork_asm+0x1b/0x30\n </TASK>\n\nThe actual issue is that nothing guards dlci_put() from being called\nmultiple times while the tty driver was triggered but did not yet finished\ncalling gsm_dlci_free()."
            }
         ],
         "affected": [
            {
               "product": "Linux",
               "vendor": "Linux",
               "defaultStatus": "unaffected",
               "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
               "programFiles": [
                  "drivers/tty/n_gsm.c"
               ],
               "versions": [
                  {
                     "version": "8fc0eabaa73b",
                     "lessThan": "6d5c8862932d",
                     "status": "affected",
                     "versionType": "git"
                  },
                  {
                     "version": "5138c228311a",
                     "lessThan": "a48d2bcd23f2",
                     "status": "affected",
                     "versionType": "git"
                  },
                  {
                     "version": "9615ca54bc13",
                     "lessThan": "c61d0b87a702",
                     "status": "affected",
                     "versionType": "git"
                  },
                  {
                     "version": "9b9c8195f3f0",
                     "lessThan": "2bff660e0ff3",
                     "status": "affected",
                     "versionType": "git"
                  },
                  {
                     "version": "9b9c8195f3f0",
                     "lessThan": "29346e217b8a",
                     "status": "affected",
                     "versionType": "git"
                  }
               ]
            },
            {
               "product": "Linux",
               "vendor": "Linux",
               "defaultStatus": "affected",
               "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
               "programFiles": [
                  "drivers/tty/n_gsm.c"
               ],
               "versions": [
                  {
                     "version": "6.5",
                     "status": "affected"
                  },
                  {
                     "version": "0",
                     "lessThan": "6.5",
                     "status": "unaffected",
                     "versionType": "custom"
                  },
                  {
                     "version": "5.10.198",
                     "lessThanOrEqual": "5.10.*",
                     "status": "unaffected",
                     "versionType": "custom"
                  },
                  {
                     "version": "5.15.134",
                     "lessThanOrEqual": "5.15.*",
                     "status": "unaffected",
                     "versionType": "custom"
                  },
                  {
                     "version": "6.1.56",
                     "lessThanOrEqual": "6.1.*",
                     "status": "unaffected",
                     "versionType": "custom"
                  },
                  {
                     "version": "6.5.6",
                     "lessThanOrEqual": "6.5.*",
                     "status": "unaffected",
                     "versionType": "custom"
                  },
                  {
                     "version": "6.6",
                     "lessThanOrEqual": "*",
                     "status": "unaffected",
                     "versionType": "original_commit_for_fix"
                  }
               ]
            }
         ],
         "references": [
            {
               "url": "https://git.kernel.org/stable/c/6d5c8862932d31a810b6545f7d69ecc124402c6e"
            },
            {
               "url": "https://git.kernel.org/stable/c/a48d2bcd23f2c98d575bc2f9b7a3fbd16aeea9eb"
            },
            {
               "url": "https://git.kernel.org/stable/c/c61d0b87a7028c2c10faffc524d748334c7b9827"
            },
            {
               "url": "https://git.kernel.org/stable/c/2bff660e0ff349dee84dc4f6f6d10da4497f5b28"
            },
            {
               "url": "https://git.kernel.org/stable/c/29346e217b8ab8a52889b88f00b268278d6b7668"
            }
         ],
         "title": "Revert \"tty: n_gsm: fix UAF in gsm_cleanup_mux\"",
         "x_generator": {
            "engine": "bippy-a5840b7849dd"
         }
      }
   },
   "cveMetadata": {
      "assignerOrgId": "f4215fc3-5b6b-47ff-a258-f7189bd81038",
      "cveID": "CVE-2023-52564",
      "requesterUserId": "gregkh@kernel.org",
      "serial": "1",
      "state": "PUBLISHED"
   },
   "dataType": "CVE_RECORD",
   "dataVersion": "5.0"
}