{"id":"CVE-2026-31507","revision":"0482be52cb6f486ab2d8765a60a94ab1","records":[{"revision":"0482be52cb6f486ab2d8765a60a94ab1","observedAt":"2026-10-23T15:48:27.903+00:00","statement":{"source":"cve-program","id":"CVE-2026-31507","aliases":[],"title":"net/smc: fix double-free of smc_spd_priv when tee() duplicates splice pipe buffer","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nnet/smc: fix double-free of smc_spd_priv when tee() duplicates splice pipe buffer\n\nsmc_rx_splice() allocates one smc_spd_priv per pipe_buffer and stores\nthe pointer in pipe_buffer.private.  The pipe_buf_operations for these\nbuffers used .get = generic_pipe_buf_get, which only increments the page\nreference count when tee(2) duplicates a pipe buffer.  The smc_spd_priv\npointer itself was not handled, so after tee() both the original and the\ncloned pipe_buffer share the same smc_spd_priv *.\n\nWhen both pipes are subsequently released, smc_rx_pipe_buf_release() is\ncalled twice against the same object:\n\n  1st call: kfree(priv)  sock_put(sk)  smc_rx_update_cons()  [correct]\n  2nd call: kfree(priv)  sock_put(sk)  smc_rx_update_cons()  [UAF]\n\nKASAN reports a slab-use-after-free in smc_rx_pipe_buf_release(), which\nthen escalates to a NULL-pointer dereference and kernel panic via\nsmc_rx_update_consumer() when it chases the freed priv->smc pointer:\n\n  BUG: KASAN: slab-use-after-free in smc_rx_pipe_buf_release+0x78/0x2a0\n  Read of size 8 at addr ffff888004a45740 by task smc_splice_tee_/74\n  Call Trace:\n   <TASK>\n   dump_stack_lvl+0x53/0x70\n   print_report+0xce/0x650\n   kasan_report+0xc6/0x100\n   smc_rx_pipe_buf_release+0x78/0x2a0\n   free_pipe_info+0xd4/0x130\n   pipe_release+0x142/0x160\n   __fput+0x1c6/0x490\n   __x64_sys_close+0x4f/0x90\n   do_syscall_64+0xa6/0x1a0\n   entry_SYSCALL_64_after_hwframe+0x77/0x7f\n   </TASK>\n\n  BUG: kernel NULL pointer dereference, address: 0000000000000020\n  RIP: 0010:smc_rx_update_consumer+0x8d/0x350\n  Call Trace:\n   <TASK>\n   smc_rx_pipe_buf_release+0x121/0x2a0\n   free_pipe_info+0xd4/0x130\n   pipe_release+0x142/0x160\n   __fput+0x1c6/0x490\n   __x64_sys_close+0x4f/0x90\n   do_syscall_64+0xa6/0x1a0\n   entry_SYSCALL_64_after_hwframe+0x77/0x7f\n   </TASK>\n  Kernel panic - not syncing: Fatal exception\n\nBeyond the memory-safety problem, duplicating an SMC splice buffer is\nsemantically questionable: smc_rx_update_cons() would advance the\nconsumer cursor twice for the same data, corrupting receive-window\naccounting.  A refcount on smc_spd_priv could fix the double-free, but\nthe cursor-accounting issue would still need to be addressed separately.\n\nThe .get callback is invoked by both tee(2) and splice_pipe_to_pipe()\nfor partial transfers; both will now return -EFAULT.  Users who need\nto duplicate SMC socket data must use a copy-based read path.","state":0,"publishedAt":"2026-04-22T13:54:25.91+00:00","modifiedAt":"2026-10-19T18:45:54.233+00:00","affected":[{"ecosystem":"Vendor product","name":"Linux","ranges":[],"versions":[],"rawVersionEvidence":"{\n                    \"product\": \"Linux\",\n                    \"vendor\": \"Linux\",\n                    \"defaultStatus\": \"unaffected\",\n                    \"repo\": \"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git\",\n                    \"programFiles\": [\n                        \"net/smc/smc_rx.c\"\n                    ],\n                    \"versions\": [\n                        {\n                            \"version\": \"9014db202cb764b8e14c53e7bacc81f9a1a2ba7f\",\n                            \"lessThan\": \"7e8916f46c2f48607f907fd401590093753a6bc5\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"9014db202cb764b8e14c53e7bacc81f9a1a2ba7f\",\n                            \"lessThan\": \"ae5575e660410c8d2c5d38fb28a0f37aea945676\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"9014db202cb764b8e14c53e7bacc81f9a1a2ba7f\",\n                            \"lessThan\": \"98ba5cb274768146e25ffbfde47753652c1c20d3\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"9014db202cb764b8e14c53e7bacc81f9a1a2ba7f\",\n                            \"lessThan\": \"81acbd345d405994875d419d43b319fee0b9ad62\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"9014db202cb764b8e14c53e7bacc81f9a1a2ba7f\",\n                            \"lessThan\": \"7bcb974c771c863e8588cea0012ac204443a7126\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"9014db202cb764b8e14c53e7bacc81f9a1a2ba7f\",\n                            \"lessThan\": \"54c87a730157868543ebdfa0ecb21b4590ed23a5\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"9014db202cb764b8e14c53e7bacc81f9a1a2ba7f\",\n                            \"lessThan\": \"3cc76380fea749280c026f410af56a28aaac388a\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"9014db202cb764b8e14c53e7bacc81f9a1a2ba7f\",\n                            \"lessThan\": \"24dd586bb4cbba1889a50abe74143817a095c1c9\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        }\n                    ]\n                }"},{"ecosystem":"Vendor product","name":"Linux","ranges":[],"versions":[],"rawVersionEvidence":"{\n                    \"product\": \"Linux\",\n                    \"vendor\": \"Linux\",\n                    \"defaultStatus\": \"affected\",\n                    \"repo\": \"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git\",\n                    \"programFiles\": [\n                        \"net/smc/smc_rx.c\"\n                    ],\n                    \"versions\": [\n                        {\n                            \"version\": \"4.18\",\n                            \"status\": \"affected\"\n                        },\n                        {\n                            \"version\": \"0\",\n                            \"lessThan\": \"4.18\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"5.10.253\",\n                            \"lessThanOrEqual\": \"5.10.*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"5.15.203\",\n                            \"lessThanOrEqual\": \"5.15.*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"6.1.168\",\n                            \"lessThanOrEqual\": \"6.1.*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"6.6.131\",\n                            \"lessThanOrEqual\": \"6.6.*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"6.12.80\",\n                            \"lessThanOrEqual\": \"6.12.*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"6.18.21\",\n                            \"lessThanOrEqual\": \"6.18.*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"6.19.11\",\n                            \"lessThanOrEqual\": \"6.19.*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"7.0\",\n                            \"lessThanOrEqual\": \"*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"original_commit_for_fix\"\n                        }\n                    ]\n                }"}],"metrics":[{"system":"CVSS 3.1","vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","score":7.8,"severity":"HIGH"}],"references":["https://git.kernel.org/stable/c/7e8916f46c2f48607f907fd401590093753a6bc5","https://git.kernel.org/stable/c/ae5575e660410c8d2c5d38fb28a0f37aea945676","https://git.kernel.org/stable/c/98ba5cb274768146e25ffbfde47753652c1c20d3","https://git.kernel.org/stable/c/81acbd345d405994875d419d43b319fee0b9ad62","https://git.kernel.org/stable/c/7bcb974c771c863e8588cea0012ac204443a7126","https://git.kernel.org/stable/c/54c87a730157868543ebdfa0ecb21b4590ed23a5","https://git.kernel.org/stable/c/3cc76380fea749280c026f410af56a28aaac388a","https://git.kernel.org/stable/c/24dd586bb4cbba1889a50abe74143817a095c1c9"],"sourceUrl":"https://www.cve.org/CVERecord?id=CVE-2026-31507","license":"CVE Program Terms of Use","key":"cve-program:CVE-2026-31507","identifiers":["CVE-2026-31507"]},"retained":false,"historicalAffected":[]}],"coverage":[]}