{ "dataType": "CVE_RECORD", "dataVersion": "5.1", "cveMetadata": { "cveId": "CVE-2021-46936", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2024-02-25T13:45:52.720Z", "datePublished": "2024-02-27T09:44:02.758Z", "dateUpdated": "2024-09-11T17:33:18.637Z" }, "containers": { "cna": { "providerMetadata": { "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2024-05-29T04:59:08.745Z" }, "descriptions": [ { "lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nnet: fix use-after-free in tw_timer_handler\n\nA real world panic issue was found as follow in Linux 5.4.\n\n BUG: unable to handle page fault for address: ffffde49a863de28\n PGD 7e6fe62067 P4D 7e6fe62067 PUD 7e6fe63067 PMD f51e064067 PTE 0\n RIP: 0010:tw_timer_handler+0x20/0x40\n Call Trace:\n \n call_timer_fn+0x2b/0x120\n run_timer_softirq+0x1ef/0x450\n __do_softirq+0x10d/0x2b8\n irq_exit+0xc7/0xd0\n smp_apic_timer_interrupt+0x68/0x120\n apic_timer_interrupt+0xf/0x20\n\nThis issue was also reported since 2017 in the thread [1],\nunfortunately, the issue was still can be reproduced after fixing\nDCCP.\n\nThe ipv4_mib_exit_net is called before tcp_sk_exit_batch when a net\nnamespace is destroyed since tcp_sk_ops is registered befrore\nipv4_mib_ops, which means tcp_sk_ops is in the front of ipv4_mib_ops\nin the list of pernet_list. There will be a use-after-free on\nnet->mib.net_statistics in tw_timer_handler after ipv4_mib_exit_net\nif there are some inflight time-wait timers.\n\nThis bug is not introduced by commit f2bf415cfed7 (\"mib: add net to\nNET_ADD_STATS_BH\") since the net_statistics is a global variable\ninstead of dynamic allocation and freeing. Actually, commit\n61a7e26028b9 (\"mib: put net statistics on struct net\") introduces\nthe bug since it put net statistics on struct net and free it when\nnet namespace is destroyed.\n\nMoving init_ipv4_mibs() to the front of tcp_init() to fix this bug\nand replace pr_crit() with panic() since continuing is meaningless\nwhen init_ipv4_mibs() fails.\n\n[1] https://groups.google.com/g/syzkaller/c/p1tn-_Kc6l4/m/smuL_FMAAgAJ?pli=1" } ], "affected": [ { "product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "net/ipv4/af_inet.c" ], "versions": [ { "version": "61a7e26028b9", "lessThan": "15579e1301f8", "status": "affected", "versionType": "git" }, { "version": "61a7e26028b9", "lessThan": "e73164e89d1b", "status": "affected", "versionType": "git" }, { "version": "61a7e26028b9", "lessThan": "5c2fe20ad37f", "status": "affected", "versionType": "git" }, { "version": "61a7e26028b9", "lessThan": "a8e1944b44f9", "status": "affected", "versionType": "git" }, { "version": "61a7e26028b9", "lessThan": "fe5838c22b98", "status": "affected", "versionType": "git" }, { "version": "61a7e26028b9", "lessThan": "2386e81a1d27", "status": "affected", "versionType": "git" }, { "version": "61a7e26028b9", "lessThan": "08eacbd141e2", "status": "affected", "versionType": "git" }, { "version": "61a7e26028b9", "lessThan": "e22e45fc9e41", "status": "affected", "versionType": "git" } ] }, { "product": "Linux", "vendor": "Linux", "defaultStatus": "affected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "net/ipv4/af_inet.c" ], "versions": [ { "version": "2.6.27", "status": "affected" }, { "version": "0", "lessThan": "2.6.27", "status": "unaffected", "versionType": "custom" }, { "version": "4.4.298", "lessThanOrEqual": "4.4.*", "status": "unaffected", "versionType": "custom" }, { "version": "4.9.296", "lessThanOrEqual": "4.9.*", "status": "unaffected", "versionType": "custom" }, { "version": "4.14.261", "lessThanOrEqual": "4.14.*", "status": "unaffected", "versionType": "custom" }, { "version": "4.19.224", "lessThanOrEqual": "4.19.*", "status": "unaffected", "versionType": "custom" }, { "version": "5.4.170", "lessThanOrEqual": "5.4.*", "status": "unaffected", "versionType": "custom" }, { "version": "5.10.90", "lessThanOrEqual": "5.10.*", "status": "unaffected", "versionType": "custom" }, { "version": "5.15.13", "lessThanOrEqual": "5.15.*", "status": "unaffected", "versionType": "custom" }, { "version": "5.16", "lessThanOrEqual": "*", "status": "unaffected", "versionType": "original_commit_for_fix" } ] } ], "references": [ { "url": "https://git.kernel.org/stable/c/15579e1301f856ad9385d720c9267c11032a5022" }, { "url": "https://git.kernel.org/stable/c/e73164e89d1be561228a4534e1091369ee4ba41a" }, { "url": "https://git.kernel.org/stable/c/5c2fe20ad37ff56070ae0acb34152333976929b4" }, { "url": "https://git.kernel.org/stable/c/a8e1944b44f94f5c5f530e434c5eaee787254566" }, { "url": "https://git.kernel.org/stable/c/fe5838c22b986c1190f1dce9aa09bf6a491c1a69" }, { "url": "https://git.kernel.org/stable/c/2386e81a1d277f540e1285565c9d41d531bb69d4" }, { "url": "https://git.kernel.org/stable/c/08eacbd141e2495d2fcdde84358a06c4f95cbb13" }, { "url": "https://git.kernel.org/stable/c/e22e45fc9e41bf9fcc1e92cfb78eb92786728ef0" } ], "title": "net: fix use-after-free in tw_timer_handler", "x_generator": { "engine": "bippy-a5840b7849dd" } }, "adp": [ { "providerMetadata": { "orgId": "af854a3a-2127-422b-91ae-364da2661108", "shortName": "CVE", "dateUpdated": "2024-08-04T05:17:42.878Z" }, "title": "CVE Program Container", "references": [ { "url": "https://git.kernel.org/stable/c/15579e1301f856ad9385d720c9267c11032a5022", "tags": [ "x_transferred" ] }, { "url": "https://git.kernel.org/stable/c/e73164e89d1be561228a4534e1091369ee4ba41a", "tags": [ "x_transferred" ] }, { "url": 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