{"id":"CVE-2021-47590","state":"PUBLISHED","title":"mptcp: fix deadlock in __mptcp_push_pending()","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nmptcp: fix deadlock in __mptcp_push_pending()\n\n__mptcp_push_pending() may call mptcp_flush_join_list() with subflow\nsocket lock held. If such call hits mptcp_sockopt_sync_all() then\nsubsequently __mptcp_sockopt_sync() could try to lock the subflow\nsocket for itself, causing a deadlock.\n\nsysrq: Show Blocked State\ntask:ss-server       state:D stack:    0 pid:  938 ppid:     1 flags:0x00000000\nCall Trace:\n <TASK>\n __schedule+0x2d6/0x10c0\n ? __mod_memcg_state+0x4d/0x70\n ? csum_partial+0xd/0x20\n ? _raw_spin_lock_irqsave+0x26/0x50\n schedule+0x4e/0xc0\n __lock_sock+0x69/0x90\n ? do_wait_intr_irq+0xa0/0xa0\n __lock_sock_fast+0x35/0x50\n mptcp_sockopt_sync_all+0x38/0xc0\n __mptcp_push_pending+0x105/0x200\n mptcp_sendmsg+0x466/0x490\n sock_sendmsg+0x57/0x60\n __sys_sendto+0xf0/0x160\n ? do_wait_intr_irq+0xa0/0xa0\n ? fpregs_restore_userregs+0x12/0xd0\n __x64_sys_sendto+0x20/0x30\n do_syscall_64+0x38/0x90\n entry_SYSCALL_64_after_hwframe+0x44/0xae\nRIP: 0033:0x7f9ba546c2d0\nRSP: 002b:00007ffdc3b762d8 EFLAGS: 00000246 ORIG_RAX: 000000000000002c\nRAX: ffffffffffffffda RBX: 00007f9ba56c8060 RCX: 00007f9ba546c2d0\nRDX: 000000000000077a RSI: 0000000000e5e180 RDI: 0000000000000234\nRBP: 0000000000cc57f0 R08: 0000000000000000 R09: 0000000000000000\nR10: 0000000000000000 R11: 0000000000000246 R12: 00007f9ba56c8060\nR13: 0000000000b6ba60 R14: 0000000000cc7840 R15: 41d8685b1d7901b8\n </TASK>\n\nFix the issue by using __mptcp_flush_join_list() instead of plain\nmptcp_flush_join_list() inside __mptcp_push_pending(), as suggested by\nFlorian. The sockopt sync will be deferred to the workqueue.","publishedAt":"2024-06-19T14:53:54.244Z","updatedAt":"2026-05-11T13:57:29.079Z","severity":null,"assigner":"Linux","products":["Linux Linux"],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"1b3e7ede1365a24db1b4fd837e58a595f52fa4ad","status":"affected","lessThan":"23311b92755ffa9087332d1bb8c71c0f6a10cc08","versionType":"git"},{"version":"1b3e7ede1365a24db1b4fd837e58a595f52fa4ad","status":"affected","lessThan":"3d79e3756ca90f7a6087b77b62c1d9c0801e0820","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["net/mptcp/protocol.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"5.13","status":"affected"},{"version":"0","status":"unaffected","lessThan":"5.13","versionType":"semver"},{"version":"5.15.11","status":"unaffected","lessThanOrEqual":"5.15.*","versionType":"semver"},{"version":"5.16","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["net/mptcp/protocol.c"]}],"references":["https://git.kernel.org/stable/c/23311b92755ffa9087332d1bb8c71c0f6a10cc08","https://git.kernel.org/stable/c/3d79e3756ca90f7a6087b77b62c1d9c0801e0820"],"weaknesses":[],"ingestedAt":"2026-10-29T19:49:19.404Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2021/47xxx/CVE-2021-47590.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2021-47590","state":"PUBLISHED","datePublished":"2024-06-19T14:53:54.244Z","dateUpdated":"2026-05-11T13:57:29.079Z","assignerShortName":"Linux","assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateReserved":"2024-05-24T15:11:00.733Z"},"containers":{"cna":{"title":"mptcp: fix deadlock in __mptcp_push_pending()","descriptions":[{"lang":"en","value":"In the Linux kernel, the following vulnerability has been resolved:\n\nmptcp: fix deadlock in __mptcp_push_pending()\n\n__mptcp_push_pending() may call mptcp_flush_join_list() with subflow\nsocket lock held. If such call hits mptcp_sockopt_sync_all() then\nsubsequently __mptcp_sockopt_sync() could try to lock the subflow\nsocket for itself, causing a deadlock.\n\nsysrq: Show Blocked State\ntask:ss-server       state:D stack:    0 pid:  938 ppid:     1 flags:0x00000000\nCall Trace:\n <TASK>\n __schedule+0x2d6/0x10c0\n ? __mod_memcg_state+0x4d/0x70\n ? csum_partial+0xd/0x20\n ? _raw_spin_lock_irqsave+0x26/0x50\n schedule+0x4e/0xc0\n __lock_sock+0x69/0x90\n ? do_wait_intr_irq+0xa0/0xa0\n __lock_sock_fast+0x35/0x50\n mptcp_sockopt_sync_all+0x38/0xc0\n __mptcp_push_pending+0x105/0x200\n mptcp_sendmsg+0x466/0x490\n sock_sendmsg+0x57/0x60\n __sys_sendto+0xf0/0x160\n ? do_wait_intr_irq+0xa0/0xa0\n ? fpregs_restore_userregs+0x12/0xd0\n __x64_sys_sendto+0x20/0x30\n do_syscall_64+0x38/0x90\n entry_SYSCALL_64_after_hwframe+0x44/0xae\nRIP: 0033:0x7f9ba546c2d0\nRSP: 002b:00007ffdc3b762d8 EFLAGS: 00000246 ORIG_RAX: 000000000000002c\nRAX: ffffffffffffffda RBX: 00007f9ba56c8060 RCX: 00007f9ba546c2d0\nRDX: 000000000000077a RSI: 0000000000e5e180 RDI: 0000000000000234\nRBP: 0000000000cc57f0 R08: 0000000000000000 R09: 0000000000000000\nR10: 0000000000000000 R11: 0000000000000246 R12: 00007f9ba56c8060\nR13: 0000000000b6ba60 R14: 0000000000cc7840 R15: 41d8685b1d7901b8\n </TASK>\n\nFix the issue by using __mptcp_flush_join_list() instead of plain\nmptcp_flush_join_list() inside __mptcp_push_pending(), as suggested by\nFlorian. The sockopt sync will be deferred to the workqueue."}],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"1b3e7ede1365a24db1b4fd837e58a595f52fa4ad","status":"affected","lessThan":"23311b92755ffa9087332d1bb8c71c0f6a10cc08","versionType":"git"},{"version":"1b3e7ede1365a24db1b4fd837e58a595f52fa4ad","status":"affected","lessThan":"3d79e3756ca90f7a6087b77b62c1d9c0801e0820","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["net/mptcp/protocol.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"5.13","status":"affected"},{"version":"0","status":"unaffected","lessThan":"5.13","versionType":"semver"},{"version":"5.15.11","status":"unaffected","lessThanOrEqual":"5.15.*","versionType":"semver"},{"version":"5.16","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["net/mptcp/protocol.c"]}],"references":[{"url":"https://git.kernel.org/stable/c/23311b92755ffa9087332d1bb8c71c0f6a10cc08"},{"url":"https://git.kernel.org/stable/c/3d79e3756ca90f7a6087b77b62c1d9c0801e0820"}],"providerMetadata":{"shortName":"Linux","orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateUpdated":"2026-05-11T13:57:29.079Z"},"cpeApplicability":[{"nodes":[{"operator":"OR","negate":false,"cpeMatch":[{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.13","versionEndExcluding":"5.15.11"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.13","versionEndExcluding":"5.16"}]}]}],"x_generator":{"engine":"bippy-1.2.0"}},"adp":[{"title":"CVE Program Container","references":[{"url":"https://git.kernel.org/stable/c/23311b92755ffa9087332d1bb8c71c0f6a10cc08","tags":["x_transferred"]},{"url":"https://git.kernel.org/stable/c/3d79e3756ca90f7a6087b77b62c1d9c0801e0820","tags":["x_transferred"]}],"providerMetadata":{"shortName":"CVE","orgId":"af854a3a-2127-422b-91ae-364da2661108","dateUpdated":"2024-08-04T05:39:59.776Z"}},{"title":"CISA ADP Vulnrichment","metrics":[{"other":{"type":"ssvc","content":{"id":"CVE-2021-47590","role":"CISA Coordinator","options":[{"Exploitation":"none"},{"Automatable":"no"},{"Technical Impact":"partial"}],"version":"2.0.3","timestamp":"2024-09-10T17:12:36.639321Z"}}}],"providerMetadata":{"shortName":"CISA-ADP","orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","dateUpdated":"2024-09-11T17:34:52.467Z"}}]}}}